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Chegg Guided Solutions for Fluid Mechanics for Chemical Engineers with Microfluidics and CFD 2nd Edition: Chapter 11
Chapter: Problem:
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• Step 1 of 4
For this problem, it is required to go through the derivation done in the mentioned example in the book and from there, develop the velocity profile of the Bingham plastic with yield stress , a pressure gradient of , and “viscosity” in a horizontal tub with radius a along with the assumption that the wall stress, , is greater in magnitude than the yield stress. Then it is necessary to then comment on what would occur if the wall stress is greater than the yield stress.
• Step 2 of 4
First, from the example in the book, apply a momentum balance in the direction of flow, producing the following equation to determine the applied stress,
• Step 3 of 4
Now, consider the stress and strain tensors under the case that = =0
Thus the Bingham model produces the following:
Because it is required to be under the assumption that , that case will only be considered. First, use the value of determined previously, like so
Isolate and integrate both side with respect to r to produce the general form of the velocity profile
To get the full velocity profile, boundary condition would need to be imposed. Because this was a first order differential equation, only one boundary condition would be needed to specify the profile. Based on the example in the book, it is known at the wall that the fluid’s velocity must be zero, therefore (a) must equal 0. This boundary condition is imposed in the following manner
Therefore the velocity profile is
• Step 4 of 4
In the case that , the fluid will remain stationary because the pressure gradient will not be strong enough to put the fluid in motion, due to the fact that the yield stress is greater than the maximum applied stress (which occurs at the wall)
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Climate Basics - Frequently Asked Questions
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What is climate?
Climate refers to the average meteorological conditions and patterns in a region over a long time period (classically 30 years according to the World Meteorological Organization). These meteorological conditions include measurements such as temperature, precipitation, and wind.
In other words, climate can be described as the 'average weather'. Although weather can change rapidly from day to day and can be difficult to predict, climate is much more predictable. For example, the weather where we live dictates what we wear each day, which can change dramatically from one day to the next. However, the climate influences the type of clothes we have in our closet, which is
generally consistent from year to year.
For more details, see the following resources (IPCC 2007):
What Factors Determine Earth's Climate?
What is the Relationship between Climate Change and Weather?
What has caused the climate to change in the past?
Climate and climate variability are determined by three main factors (Chapin et al. 2002):
1. The amount of incoming solar radiation. This is affected by changes in the Earth's orbit around the Sun and in the Sun's brightness.
2. The chemical composition of the atmosphere. For example, changes in the amount of carbon dioxide and other greenhouse gases in the atmosphere affect how much radiation (solar radiation that is re- emitted from the earth's surface as infrared radiation) passes from the earth into space and how much
stays behind to warm the planet.
3. The surface characteristics of the Earth. Certain Earth surface features, such as ice sheets, increase the amount of solar radiation that is reflected back into space.
These three factors and ways that they interact with one another have all contributed to the climate patterns and variability we see in earth's history.
Figure 1 - Changes in Carbon Dioxide and Temperature (U.S. EPA)
However, the fact that climate has changed without human influence in the past does not mean that current climate change is following 'natural' patterns. The factor that best explains the observed global warming over the last century is the increase of CO2 and other greenhouse gases in the atmosphere (IPCC 2007), largely caused by the burning of fossil fuels and other human activity.
For more details, see the following resources:
IPCC FAQs (2007):
What Factors Determine Earth's Climate?
Is the Current Climate Change Unusual Compared to Earlier Changes in Earth's History?
NASA Earth Observatory:
Is Current Warming Natural?
How do we know what climate was like in the past?
The factors that make up climate (such as temperature and precipitation) have been measured directly since the 1860's. However to understand what climate was like before this, scientists have to use 'proxies', or indirect measurements that have a well-defined relationship to temperature or other climatic variables. Some common proxies include:
1. Ice cores - The ratio of oxygen isotopes in the ice can indicate the temperature at the time the ice was formed. Air bubbles trapped in ice can show what the greenhouse gas concentration of the atmosphere was at the time of formation.
2. Ocean sediment cores - The remains of small hard-shelled creatures (foramnifera) are preserved in ocean sediments. The composition of their shells can reveal ocean temperatures at the time of their formation.
3. Pollen records - Fossilized pollen grains can indicate what types of plants were present at the time the fossils were formed.
4. Tree rings - The width of annual tree rings in temperate climates depend in part on soil moisture and temperature, and can therefore reveal information about these variables.
Past climate is often 'reconstructed' by looking at many of these measurements together. More
examples can be found at the following websites:
NOAA Paleoclimatology - proxy data
National Institute of Water and Atmospheric Research (NZ) - common questions
How do human activities affect climate?
Humans are affecting the climate by increasing the amount of greenhouse gases present in the atmosphere and by changing the surface characteristics of the land (see discussion about "albedo"). Activities such as fossil fuel burning, land-use change (e.g. deforestation), animal husbandry, and practicing fertilizer-dependent agriculture lead to increases in greenhouse gases including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). These contribute to the greenhouse effect and cause the surface temperature of the Earth to increase. Global atmospheric concentrations of CO2, CH4 and N2O have increased markedly since 1750 as a result of human activities, and now far exceed pre- industrial values (IPCC 2007, Chapter 2).
What is the greenhouse effect and what are the major greenhouse gases?
The greenhouse effect is the process by which certain gases in the atmosphere absorb and re-emit energy that would otherwise be lost into space (IPCC 2007, Chapter 1).
The Earth's transparent atmosphere lets sunlight through to warm the ground and the oceans (more when it is clear, less when it is cloudy). The Earth's warmed surface releases some of that heat in the form of infrared radiation, a form of light, but invisible to human eyes. Greenhouse gases in the atmosphere like carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor, absorb this infrared radiation and keep it from passing out into space. This energy is then reradiated in all directions, and the energy that is directed back toward the Earth's surface warms the planet.
The greenhouse effect is necessary for human survival, since without it the Earth's average temperature would be about 0 C (Swanston et al. 2011). However current concentrations of greenhouse gases are higher now than they have been for the past 800,000 years encompassing the history of human development, and are enhancing the greenhouse effect.
The 'greenhouse effect' gets its name from the fact that a fairly similar process takes place in a greenhouse. The glass panes on a greenhouse let incoming sunlight pass through them, but intercept some of the infrared light on its way back out, warming the interior (Climate Central 2009).
Figure 2 - The Greenhouse Effect (Pew Center on Global Climate Change)
What is the Greenhouse Effect?
If climate varied naturally in the past, how do we know that humans are disrupting climate now?
The factor that best explains the warming trend over the last century is the increase of greenhouse gases in the atmosphere, which are caused by human activity. Scientists have examined many other potential causes of recent warming, such the Sun's variations in brightness, however , the magnitude of these effects is not sufficient to explain actual temperature observations on Earth. Human disruption is simply the only current explanation we have that fits the data (Lean 2009).
Figure 3 - Global Surface Temperature vs. Sun's Energy (US Global Change Research Program)
Climate models are an important tool for studying all of the various influences on the Earth's climate. These models are constructed to include many different measurements that could affect temperature, including solar output, volcanic emissions, and the effects of greenhouse gas concentrations in the atmosphere. When the effects of increasing levels of greenhouse gases are included in the models, as well as natural external factors, the models produce good simulations of the warming that has occurred over the past century. The models fail to reproduce the observed warming when run using only natural factors (IPCC 2007).
For more details, see the following resources:
Is Current Warming Natural?
How is Today's Warming Different from the Past?
Is the rate of climate change greater now than the rate of natural climate change in the past?
Global average temperatures are currently increasing at greater rates than those that have occurred over the last million years of Earth's history. Global average temperatures started rapidly rising during the 1900's as the industrial revolution was accelerating and as humans started relying more heavily on burning fossil fuels for energy (see Figure 4).
Figure 4 - Annual Mean Temperature Change (NASA, Goddard Institute for Space Studies)
For the past 100 years, we have clear records of the increasing rate of global temperature change. The decade beginning January 2000 and ending December 2009 was the warmest decade in the modern record (since 1880), with 2010 tied with 2005 as the warmest year on record (NASA 2011). From the 1910s to the 1940s, global average temperatures increased by 0.35 °C, and for an equivalent time period from the 1970s to 2006, global average temperatures increased by 0.55 °C (IPCC 2007), reflecting an increasing rate of change.
The Earth's temperature has undergone some large changes in the past; according to proxy data, global average temperatures did change by as much as 4°C to 7°C between ice ages and warm interglacial periods. However, this change took approximately 5,000 years (IPCC 2007). Current rapid rates of global climate change are clearly very unusual in the context of past changes. More abrupt shifts may have occurred in the past at smaller, regional scales due to ocean heat transport, but did not likely affect the global mean temperature (IPCC 2007).
For more details, see the following resources:
How Are Temperatures on Earth Changing?
How is Today's Warming Different from the Past?
What are albedo and feedback, and how does the Earth's surface affect climate?
Albedo is the reflectance of a surface, such as the earth's surface. Different earth land covers have very different albedo; for example, ice and snow are highly reflective (high albedo) while darker surfaces like vegetation do not reflect as much radiation (low albedo). Albedo plays an important role in global temperature change, since absorbed solar radiation warms the Earth's surface, whereas reflected radiation does not.
Feedback is a general term that encompasses all of the different forms of energy exchange between the land surface and the atmosphere. In the context of global warming, positive feedbacks enhance land surface warming; negative feedbacks enhance land surface cooling.
Albedo is one component of this energy feedback. Since different land covers have varied albedo, land use change can influence albedo and whether a land surface has a warming or cooling effect. As mentioned, snow has a very high albedo because it reflects more sunlight, and thus has a cooling effect on global temperatures (negative feedback). However, if snow melts and is replaced by darker vegetation, more sunlight is absorbed, which will add to a warming effect (positive feedback - IPCC 2007).
An emerging topic of interest related to albedo and feedback is the deposition of black carbon. Black carbon is a component of air pollution and is produced by combustion. It absorbs solar radiation and can greatly lower surface albedo if deposited on snow or ice. Black carbon is now thought to have played a major role in warming in the arctic, mainly by changing albedo and causing a positive warming feedback (Shindell & Faluvegi, 2009).
For a more details, see the following resources
NASA Earth Observatory:
How Much More Will Earth Warm?
Pew Center on Global Climate Change:
What is Black Carbon?
What are examples of climate changes that have occurred over the past century?
Global average surface temperatures have increased by about 0.74°C (1.33°F) between 1906 and 2005 (IPCC 2007), although the rate and magnitude of change differs with location and the period examined. While 0.74°C may not seem like a large temperature change, on a global scale this has huge implications for many of the earth's processes that effect ecosystems and humans. Even with this relatively modest temperature change, clear effects have been observed.
For example, in concurrence with observed temperature changes, in the 20th century there has been a nearly worldwide reduction in glacial mass and extent, a decrease in snow cover in many Northern Hemisphere regions, a decrease in Arctic sea ice thickness and extent, a decrease in the length of river and lake ice seasons, warmer ocean temperatures, and rising sea levels (IPCC 2007).
From 1900 to 2005, long-term changes in precipitation trends have also been observed, leading to wetter conditions in some areas (eastern North and South America, northern Europe, northern and central Asia) and drier in others (the Sahel, southern Africa, the Mediterranean, southern Asia). Widespread increases in heavy precipitation events have been observed, even in places where total precipitation amounts have decreased (IPCC 2007).
See the 'Ecosystem Effects' section of the FAQ's to read more about the implications of these changes.
For more details, see the following resources:
IPCC FAQs (2007):
How are temperatures on earth changing?
How is precipitation changing?
Is the amount of snow and ice on earth decreasing?
Is sea level rising?
US Global Change Research Program:
National Climate ChangesRegional Factsheets
What do projections suggest for climate changes in the 21st century?
Average global surface temperatures are projected to increase by 1.1 to 6.4°C (2 to 11.5°F) by the end of the 21st century, relative to 1980-1990, with a best estimate of 1.8 to 4.0°C (3.2 to 7.2°F) (IPCC 2007). This large range in projections is due in part to the fact that we do not know whether greenhouse gas emissions will continue at their current levels, increase, or decrease. Temperature projections do vary regionally, with the highest projected warming taking place near the poles (USGCRP 2009). These temperature changes will continue to have effects on ice extent, snow cover, sea level, and many other factors. See the 'Ecosystem Effects' section of the FAQs for more detail.
Precipitation changes over the next century are more complex and uncertain, and differ within regions and subregions. Current models indicate that precipitation will generally increase in higher latitudes and in the tropical Pacific during the monsoon (rainy) seasons, and decrease in the subtropical dry belt. In the U.S. the Southwest is expected to become drier while northern regions may see an increase in precipitation (USGCRP 2009). Overall, the frequency and intensity of extreme weather events, such as heat waves, droughts, storms, heavy downpours, and heavy snowfall are projected to increase.
For more details, see the following resources:
IPCC FAQs (2007):
Do Projected Changes in Climate Vary from Region to Region?
US Global Change Research Program:
National Climate Changes
Regional Factsheets
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Most people who identify as Zionists will say that Zionism means basically two things. One, that there is a Jewish people, with its distinctive history and culture, and people who see themselves as Jews have the right to identify as part of that people. Two, that the Jewish people have a right to establish, and defend, their own independent national community within the area of their ancient homeland, in a society where they are a significant majority and have the possibility of developing their specific form of national culture in all its aspects (and the non-Jewish minority enjoys real, and not just formal, equality).
That is the meaning of saying that Zionism is the national movement of the Jewish people. Anti-Zionism essentially denies either or both of these premises, which of course leads to a denial of the existence of Israel – that, in turn, is a genocidal position, because a destruction of Israel can only be achieved by a genocide of its Jewish majority.
In contemporary Israel, a majority of Jews support the Right and its political parties. The Right argues, in a number of different ways, that there should be Jewish control of the West Bank; either through the expansion of settlements that will make the establishment of a Palestinian state impossible, or through Jewish supervision of an autonomous or quasi-independent Palestinian entity in parts of the territory. This entity, whatever its form, would be demilitarized and controlled by Israel. The Jordan Valley would be under Israeli control, and the borders of the Palestinian entity would be, in essence, dictated by the Jewish settlements, present and future.
The inhabitants, most rightists would argue, would of course have no political rights in the controlling power structure, i.e. within Israel. The reason adduced is that the area between the Mediterranean and the Jordan belongs to us and should be ruled by us. This, in turn, is based on a supposed divine decision, although the Bible includes very different statements regarding the borders of the Land of Israel. Palestinian Muslims will, of course, argue that God gave them the (same) land by legitimate conquest. Religious underpinning of political positions is a very dangerous, and always double-edged, exercise.
The Rightist stance means, in fact, the establishment of some kind of binational community, under Jewish-Israeli control. The Jews may make up a bare majority or a very large minority, but that hardly makes any difference; what matters is who is in charge. Sooner or later, however, some kind of political equality will inevitably be established between Palestinians and Israeli Jews, because the world of which Israel wants to be a part will not agree to the denial of political rights to the Palestinians.
Many on the Right try to paper this over by arguing that Palestinians can have a vote in Jordan, where there is, in any case, a Palestinian majority. But the West – never mind the Palestinians and the Jordanians – is hardly likely to accept a situation where the police chief of Tulkarm is appointed by the Jordanian Parliament and the sewage in Nablus is regulated from Amman, whereas real power rests with an Israeli force.
Some are willing to give Palestinians the vote in an enlarged Israel, but carefully, over time, and with limitations. This would, of course, lead to exactly the kind of a binational solution that will result in a bitter civil war. The argument that Israel must defend its position on the West Bank because of security reasons is self-defeating: there can never be security in a situation that invites constant conflict. Security can only be achieved if there is a peaceful solution based on an agreed mutual compromise.
Direct negotiations have been tried, and have failed. That invites, inevitably, outside pressure.
A tremendous amount of pressure is indeed building up, supporting the Palestinian position that demands a meaningful Palestinian state, contrary to the Israeli one, which only pays lip service to a Palestinian state, and now seems to be intent on suggesting various temporary solutions, none of which are likely to work. It may be possible to postpone that pressure temporarily, by various political maneuvers.
But it is quite clear that the vast majority of world nations are in favor of an Israel within the 1967 borders, with exchanges of territory. This has also essentially been the policy of US administrations, both Republican and Democratic, since George Bush, the father. Pressure directed toward both sides to achieve a solution by compromise stems from the simple fact that the major – and the minor – powers have no interest in perpetuating the Israeli-Palestinian conflict. The compromise demanded of the Palestinian appears to be, again by almost universal consensus, to give up the idea of a massive return of Palestinian refugees to Israeli areas
The Right in Israel opposes a Palestinian state, despite Prime Minister Binyamin Netanyahu’s pronouncements. Instead, it is looking for various paper decisions to perpetuate the present situation, all of which will inevitably lead to a binational state. The ideal of a state with a significant Jewish majority is being abandoned.
In other words, the Israeli Right is favoring what is, essentially, an anti-Zionist solution. The paradox is obvious. Radical Zionism metamorphoses into its opposite, radical anti-Zionism. Theodor Herzl, David Ben-Gurion, and Ze’ev Jabotinsky are turning in their graves.
The writer is a historian.
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Arts, Culture & Media
Slideshow: Slave Burial Ground in the Atlantic
Around 325 bodies in a combination of individual, multiple and mass graves were discovered. (Photo: University of Bristol)
For the Geo Quiz, we are looking for tiny island in the middle of the vast South Atlantic Ocean.
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It is an isolated spot 1,000 miles off the coast of west Africa.
That is why the British once used it as place of exile for Napoleon.
After Britain abolished slavery, the island became an important way-station for ships sailing across the Atlantic.
Specifically British Royal Navy ships that were intercepting slave ships.
Thousands of enslaved Africans were taken off slave ships and brought to this island by Royal Navy Patrols.
The island served as 19th century version of a refugee camp, a hospital and in many cases a graveyard.
St. Helena is the answer to the Geo Quiz.
It is here that archaeologists from the University of Bristol have been carrying out excavations to unearth slave burial sites. |
Digestive Health
Is a liver cleanse beneficial?
A Answers (2)
• ADiscovery Health answered
You get advice. You follow directions.
• ASarah LoBisco, Integrative Medicine, answered
The recent release of the CDC‘s Fourth National Report on Human Exposure to Environmental Chemicals study estimated that an average of 212 chemicals can be found in any individual’s blood or urine. What this translates to is a lot of extra burden placed on our body as the years go by, the main organ being affected is our detoxifying powerhouse- the liver. Therefore, assisting the liver with removal of toxins is important, as it provides many other functions for our body.
The liver is responsible for not only detoxifying harmful substances, but it also cleanses the body of old red blood cells, converts ammonia to urea for exertion, and breaks down hormones. The liver is also involved with protein formation, metabolism of nutrients, synthesizing of blood factors, angitotensinogen hormone, and the formation of bile. Furthermore, your liver stores glucose, vitamin A, vitamin D, vitamin B12, iron, and copper.
The health status and dietary intake of individuals affect the ability of one’s liver to clear out damaging environmental poisons. Specifically, deficiencies in certain nutrients can create a sluggish clearance or create excess free radical damage, harming various tissue structures. Furthermore, if one does a liver cleanse before the bowel is regular, more problems of toxic accumulation can result!
Other factors which influence detoxification include: genetics, medications, health history, immune status, and stress. The concerns I have over most detoxification protocols is that they typically don’t take into account one’s own unique biochemistry, health status, detoxification capability, and environmental exposure. Consulting with someone who is knowledgeable about detoxification, chelation, and pathology is important in when going through detoxification or cleansing support.
Some steps anyone can do to protect their liver include diet. Dark leafy greens and lean proteins provide good support for the two liver detoxification pathways. “Greening our home” using chemical-free products and natural personal care products also reduces toxic burden. A final way to help out our liver is to avoid things which harm it such as alcohol, drugs, and processed foods.
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Constellations known in Antiquity
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Can you pick the constellations known in Antiquity (as listed in Ptolemy's 'Almagest')?
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Diversity of fish
From Wikipedia, the free encyclopedia
Jump to: navigation, search
The deep sea Lasiognathus amphirhamphus is a rare ambush predator known only from a single female specimen (pictured).[4] It is an angler fish that "angles" for its prey with a lure attached to a line from its head.
Fish are very diverse animals and can be categorised in many ways. This article is an overview of some of ways in which fish are categorised. Although most fish species have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase, 32,800 species of fish had been described by June 2014.[5] That is more than the combined total of all other vertebrate species: mammals, amphibians, reptiles and birds.
By species[edit]
lampreys Boca de lamprea.1 - Aquarium Finisterrae.JPG
hagfish Pacific hagfish Myxine.jpg
sharks Tiger shark.png
rays Pastinachus sephen Day.jpg
chimaera Callorhinchus callorhynchus.JPG
lobe finned
lungfish Barramunda.jpg
coelacanths Coelacanth-bgiu.png
ray finned
chondrosteans Acipenser oxyrhynchus.jpg
holosteans Amia calva1.jpg
teleosts Bluefin-big.jpg
Basic taxonomy of fishes
The term "fish" describes any non-tetrapod chordate, (i.e., an animal with a backbone), that has gills throughout life and has limbs, if any, in the shape of fins.[8] Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including jawless, cartilaginous and skeletal types.[9][10]
Jawless fish[edit]
Jawless fish were the earliest fish to evolve. There is current debate over whether these are really fish at all. They have no jaw, no scales, no paired fins, and no bony skeleton. Their skin is smooth and soft to the touch, and they are very flexible. Instead of a jaw, they possess an oral sucker. They use this to fasten onto other fish, and then use their rasp-like teeth to grind through their host's skin into the viscera. Jawless fish inhabit both fresh and salt water environments. Some are anadromous, moving between both fresh and salt water habitats.
Extant jawless fish are either lamprey or hagfish. Juvenile lamprey feed by sucking up mud containing micro-organisms and organic debris. The lamprey has well-developed eyes, while the hagfish has only primitive eyespots. The hagfish coats itself and carcasses it finds with noxious slime to deter predators, and periodically ties itself into a knot to scrape the slime off. It is the only invertebrate fish and the only animal which has a skull but no vertebral column.[11] It has four hearts, two brains, and a paddle-like tail.[12]
Cartilaginous fish[edit]
Cartilaginous fish have a cartilaginous skeleton. However, their ancestors were bony animals, and were the first fish to develop paired fins. Cartilaginous fish don't have swim bladders. Their skin is covered in placoid scales (dermal denticles) that are as rough as sandpaper. Because cartilaginous fish do not have bone marrow, the spleen and special tissue around the gonads produces red blood cells. Their tails can be asymmetric, with the upper lobe longer than the lower lobe. Some cartilaginous fishes possess an organ called Leydig's Organ which also produces red blood cells.
Bony fish[edit]
There are three types of ray finned fishes: the chondrosteans, holosteans, and teleosts. The chondrosteans and holosteans are among the earlier fish to evolve, and share characteristics with both teleosts and sharks. In comparison with the other chondrosteans, the holosteans are closer to the teleosts and further from sharks.
Teleosts have a movable maxilla and premaxilla and corresponding modifications in the jaw musculature. These modifications make it possible for teleosts to protrude their jaws outwards from the mouth.[15][16] The caudal fin is homocercal, meaning the upper and lower lobes are about equal in size. The spine ends at the caudal peduncle, distinguishing this group from those in which the spine extends into the upper lobe of the caudal fin.[15]
By habitat[edit]
See also: Marine habitats
There is 10,000 times more saltwater in the oceans than there is freshwater in the lakes and rivers. However, only 58 percent of extant fish species are saltwater. A disproportionate 41 percent are freshwater fish (the remaining one percent are anadromous).[17] This diversity in freshwater species is, perhaps, not surprising, since the thousands of separate lake habitats promote speciation.[18]
Habitat Area Volume Depth Species Fish biomass
million km2 million cu km (mean) count percent million tonnes
Saltwater 361[19] 1370.8[20] 3.8 km 18,000 58[17] 800-2,000[21]
Freshwater 1.5[22] 0.13[23] 87 m 13,000 41[17]
Fish can also be demersal or pelagic. Demersal fish live on or near the bottom of oceans and lakes, while pelagic fish inhabit the water column away from the bottom. Habitats can also be vertically stratified. Epipelagic fish occupy sunlit waters down to 200 metres (110 fathoms), mesopelagic fish occupying deeper twilight waters down to 1,000 meters (3,300 ft), and bathypelagic fish inhabiting the cold and pitch black depths below.
Most oceanic species (78 percent, or 44 percent of all fish species), live near the shoreline. These coastal fish live on or above the relatively shallow continental shelf. Only 13 percent of all fish species live in the open ocean, off the shelf. Of these, 1 percent are epipelagic, 5 percent are pelagic, and 7 percent are deep water.[17]
Fish are found in nearly all natural aquatic environments.[24] Most fish, whether by species count or abundance, live in warmer environments with relatively stable temperatures.[18] However, some species survive temperatures up to 44.6 °C (112.3 °F), while others cope with colder waters; there are over 200 finfish species south of the Antarctic Convergence.[25] Some fish species tolerate salinities over 10 percent.[24]
Habitat Abyssobrotula galatheae The world's deepest living fish, Abyssobrotula galatheae, a species of cusk eel, lives in the Puerto Rico Trench at a depth of 8,372 meters (27,467 ft).[24][26] Due to the extreme pressure, this appears to be around the theoretical maximum depth possible for fish.[27][28]
Stone loach Barbatula barbatula.jpg At the other extreme, the Tibetan stone loach lives at altitudes over 5,200 meters (17,100 ft) in the Himalayas.[24][29]
Blue shark Prionace glauca.jpg Some marine pelagic fish range over vast areas, such as the blue shark that lives in all oceans.
Blind cave fish Mexican Tetra as Blind Cave Fish.jpg Other fish are confined to single, small living spaces, such as the blind cave fish in North America.[30]
Death Valley
Death Valley Pupfish.jpg Equally isolated desert pupfish, like the Death Valley pupfish (pictured), live in small desert spring systems in Mexico and the southwest United States.
Champagne vent white smokers.jpg The bythitid vent fish Thermichthys hollisi, lives around thermal vents 2,400 metres (1,300 fathoms) deep.[24][31]
Sargassum frogfish Histrio histrio by A. H. Baldwin.jpg The highly camouflaged sargassum frogfish lives in drifting sargassum seaweed. It has adapted fins which can grab strands of sargassum, enabling it to climb through the seaweed.[32] It avoids threats from larger predator fish by climbing out of water onto the surface of a seaweed mat, where it can survive for some time.[33]
By life span[edit]
Some of the shortest-lived species are gobies, which are small coral reef–dwelling fish. Some of the longest-lived are rockfish.
Seven-figure pygmy goby Gobidon okinawae1.jpg
External images
World's shortest lived fish
Among gobies, small coral reef-dwelling fish (pictured), are some of the shortest lived fishes. The seven-figure pygmy goby is the shortest lived of all fish species. It lives at most for 59 days, which is the shortest lifespan for any vertebrate.[34]
Ram cichlid Schmetterlingsbuntbarsch.jpg Short lived fish have particular value in genetic studies on aging. In particular, the ram cichlid is used in laboratory studies because of its ease of breeding and predictable aging pattern.[35][36]
Rougheye rockfish Red rockfish.jpg Some of the longest living fishes are rockfish. The longest lived fish is the 205 years reported for the rougheye rockfish, Sebastes aleutianus (pictured). This fish is found offshore in the North Pacific at 25–900 metres (14–492 fathoms) and exhibits negligible senescence.[37][38][39]
Orange roughy.png The orange roughy may be the longest lived commercial fish with a maximum reported age of 149 years.[40]
Koi Koi mit Zierfischfutter.JPG There are stories about Japanese koi goldfish passed from generation to generation for 300 years. Scientists are sceptical. Counting growth lines on the scales of fish confined to ponds or bowls is unreliable, since they lay down extra lines.[41][42] The maximum reliably reported age for a goldfish is 41 years[43]
Atlantic tarpon Tarpon.jpg One of the longest living sport fish is the Atlantic tarpon, with a reported age of 55 years.[44][45][46]
Green sturgeon Acipenser medirostris.jpg Some of the longest living fish are living fossils, such as the green sturgeon. This species is among the longest living species found in freshwater, with a reported age of 60 years. They are also among the largest fish species found in freshwater, with a maximum reported length of 2.5 meters (8.2 ft) and a maximum reported weight of 159 kg (351 lb).[47][48][49]
Australian lungfish Barramunda.jpg Another living fossil is the Australian lungfish. One individual has lived in an aquarium for at least 75 years, and is the oldest fish in captivity. According to fossil records, the Australian lungfish has hardly changed for 380 million years.[50][51][52]
By size[edit]
Size Paedocypris progenetica Paedocypris progenetica 001.jpg
External images
World's smallest fish
Paedocypris progenetica, a type of minnow, is the smallest of all fish species. It lives in the dark-colored peat swamps of the Indonesian island of Sumatra. The females of this species have a standard length of 7.9 mm (0.31 in) at maturity.[53][54][55] Until recently, this was the smallest of all known vertebrates. However, recently a minute Papua New Guinea frog, Paedophryne amauensis, with a standard length of 7.7 mm (0.30 in) was discovered.[56] The slender Indonesian fish may still be the smallest vertebrate by weight.
Photocorynus spiniceps Male individuals of the anglerfish species Photocorynus spiniceps are 6.2-7.3 mm long at maturity, and thus could be claimed as an even smaller species. However, these males do not survive on their own merits but only by sexual parasitism on the larger female.[57][58][59][60]
Stout infantfish The stout infantfish, a type of goby, is the second smallest known fish.[61] Females grow to a length of 8.4 millimetres (0.33 in) and males are mature at 7 millimetres (0.28 in).
Sinarapan Sinarapan, Mistichthys luzonensis Smith, 1902 by P. Bravo.jpg According to the Guinness Book of World Records, the sinarapan, also a goby, is the world's smallest commercially harvested fish.[62] Found in the Philippines, they have an average length of 12.5 mm (0.49 in), and are threatened by overfishing.[55]
Whale shark Whale shark Georgia aquarium.jpg The largest fish is the whale shark. It is a slow moving filter feeding shark with a maximum published length of 20 m (66 ft) and a maximum weight of 34 tonnes. Whale sharks can live up to 70 years.[63] The whale shark is a vulnerable fish.
Ocean sunfish Sunfish.jpg The ocean sunfish is the heaviest bony fish. It can weigh up to 2,300 kg (5,100 lb). It is found in all warm and temperate oceans.[64]
King of herrings King of herrings.png The king of herrings is the longest bony fish. Its total length can reach 11 m (36 ft), and it can weigh up to 272 kilograms (600 lb). It is a rarely seen oarfish found in all the world's oceans, at depths of between 20 m (66 ft) and 1,000 m (3,300 ft).[65]
Mekong giant catfish AquatottoGifu mekonoonamazu.jpg The largest recorded freshwater fish is a Mekong giant catfish caught in 2010, weighing 293 kg (646 lb).[66][67] The Mekong giant catfish is critically endangered.
By breeding behavior[edit]
In very deep waters, it is not easy for a fish to find a mate. There is no light, so some species depend on bioluminescence. Others are hermaphrodites, which doubles their chances of producing both eggs and sperm when an encounter does occur.[68]
Breeding Grouper Georgia Aquarium - Giant Grouper.jpg Female groupers change their sex to male if no male is available. Grouper are protogynous hermaphrodites, who school in harems of three to fifteen females. When no male is available, the most aggressive and largest females change their sex to male.
Toadfish Opsanus beta 1.jpg Male toadfish "sing" at up to 100 decibels with their swim bladders to attract mates.[69][70][71]
Anglerfish Haplophryne mollis (female, with atrophied male attached).gif Female Haplophryne mollis anglerfish trailing atrophied males she encountered.[72] The female anglerfish releases pheromones to attract tiny males. When a male finds her, he bites on to her and never lets go. When a male of the anglerfish species Haplophryne mollis bites into the skin of a female, he release an enzyme that digests the skin of his mouth and her body, fusing the pair to the point where the two circulatory systems join up. The male then atrophies into nothing more than a pair of gonads. This extreme sexual dimorphism ensures that, when the female is ready to spawn, she has a mate immediately available.[73]
Hammerheads Hammerhead shark.jpg Some sharks, such as hammerheads[74] are able to breed parthogenetically, that is asexually where the growth and development of embryos occur without fertilization.
By brooding behavior[edit]
See also: Spawning
Fish adopt a variety of strategies for nurturing their brood. Sharks, for example, variously follow three protocols with their brood. Most sharks, including lamniformes[75] are ovoviviparous, bearing their young after they nourish themselves after hatching and before birth, by consuming the remnants of the yolk and other available nutrients. Some such as hammerheads[74] are viviparous, bearing their young after nourishing hatchlings internally, analogously to mammalian gestation. Finally catsharks[76] and others are, oviparous, laying their eggs to hatch in the water.
Some animals, predominantly fish such as cardinalfish[77] practice mouthbrooding, caring for their offspring by holding them in the mouth of a parent for extended periods of time. Mouthbrooding has evolved independently in several different families of fish.
Brooding Chain catshark Chain catshark.png The chain catshark is oviparous, laying its eggs to hatch in the water.
Great white shark White shark.jpg The great white shark is ovoviviparous, gestating eggs in the uterus for 11 months before giving birth.
Scalloped hammerhead Hammerhead shark.jpg The scalloped hammerhead is viviparous, bearing its young after nourishing hatchlings internally
Cyphotilapia frontosa Cyphotilapia frontosa mouthbrooding.jpg A female Cyphotilapia frontosa mouthbrooding fry which can be seen looking out her mouth
Seahorses Longsnout Seahorse (Hippocampus reidi) (3149753448).jpg Seahorse males, practice pouch-brooding similar to Australia's kangaroos. When seahorses mate, the female deposits her eggs into a special pouch on the male’s belly. The pouch seals shut while he nurtures the developing eggs. Once the eggs hatch, the pouch opens and the male goes into labour.[78]
By feeding behaviour[edit]
External images
Video of a slingjaw wrasse catching prey by protruding its jaw
Video of a red bay snook catching prey by suction feeding
There are three basic methods by which food is gathered into the mouths of fish: by suction feeding, by ram feeding, and by manipulation or biting.[79] Nearly all fish species use one of these styles, and most use two.[80]
Early fish lineages had inflexible jaws limited to little more than opening and closing. Modern teleosts have evolved protusible jaws that can reach out to engulf prey.[81][82] An extreme example is the protusible jaw of the slingjaw wrasse. Its mouth extends into a tube half as long as its body, and with a strong suction it catches prey. The equipment tucks away under its body when it is not in use.[83][84]
In practice, feeding modes lie on a spectrum, with suction and ram feeding at the extremes. Many fish capture their prey using both suction pressure combined with a forward motion of the body or jaw.[85]
Most fish are food opportunists, or generalists. They eat whatever is most easily available.[86] For example, the blue shark feeds on dead whales and nearly everything else that wriggles: other fish, cephalopods, gastropods, ascidians, crustaceans.[87][88] Ocean sunfish prefer jellyfish.[64]
Feeding Anglerfish Bufoceratias.jpg Anglerfish are lie-in-wait ambush predators. The first spine of their dorsal fin has been modified so it can be used like a fishing line with a lure at the end. Most anglerfish, like the one pictured, live in the darkness of the deep sea and have a bioluminescent lure.[89]
Archerfish Archerfish (PSF).png Archerfish prey on land based insects and other small animals by literally shooting them down with water droplets from their specialized mouths. Archerfish are remarkably accurate; adults almost always hit the target on the first shot. They can bring down insects such as grasshoppers,[90] spiders and butterflies on a branch of an overhanging tree,[91] 3 m above the water's surface.[92] This is partially due to good eyesight, but also the ability to compensate for light refraction when aiming.[93]
Triggerfish Titan Triggerfish.jpg Triggerfish also use jets of water, to uncover sand dollars buried in sand or overturn sea urchins.[94]
Silver arowana Osteoglossum bicirrhosum.JPG Other fish have developed extreme specializations. Silver arowana, also called monkey fish, can leap two meters out of the water to capture prey. They usually swim near the surface of the water waiting for potential prey. Their main diet consist of crustaceans, insects, smaller fishes and other animals that float on the water surface, for which its draw-bridge-like mouth is exclusively adapted for feeding. The remains of small birds, bats, and snakes have also been found in their stomachs.[95]
Cookiecutter shark Cookiecutter damage.jpg The cookiecutter shark is a small dogfish which derives its name from the way it removes small circular plugs, looking as though cut with a cookie cutter, from the flesh and skin of cetaceans and larger fish, including other sharks. The cookiecutter attaches to its larger prey with its suctorial lips, and then protrudes its teeth to remove a symmetrical scoop of flesh.[96] Pictured is a pomfret with bite wounds from a cookiecutter shark.
Striped bass Striped bass FWS 1.jpg Striped bass eat smaller fish
Chinese algae eater Chinese algae eater.jpg Chinese algae eaters are kept in aquaria to control algae.
Emperor angelfish Pomocanthus imperator.jpg The Emperor angelfish feeds on coral sponges
Herring Herringramkils.jpg Schooling herrings ram feed on copepods
Mangrove jack Mangrovejack.jpg The mangrove jack eats crustaceans
Puffer fish Puffer Fish DSC01257.JPG Many puffer fish species crush the shells of molluscs
Bucktoothed tetra Bucktoothed Tetra.jpg The bucktoothed tetra eats scales off other fishes (lepidophagy)
Cleaner fish Mulloidichthys flavolineatus at cleaning station.jpg These two small wrasses are cleaner fish, and eat parasites off other fish.
Cleaning station Manta alfredi at a ‘cleaning station’ - journal.pone.0046170.g002B.png A reef manta ray at a cleaning station, maintaining a near stationary position atop a coral patch for several minutes while being cleaned by cleaner fishes [97]
Doctor fish Doctor fish2.jpg Doctor fish nibbling on the diseased skin of patients. Doctor fish (nibble fish) live and breed in the outdoor pools of some Turkish spas, where they feed on the skin of patients with psoriasis. The fish are like cleaner fish in that they only consume the affected and dead areas of the skin, leaving the healthy skin to recover.
By vision[edit]
Main article: Vision in fishes
Many species of fish can see the ultraviolet end of the spectrum, beyond the violet.[98]
Mesopelagic fishes live in deeper waters, in the twilight zone down to depths of 1000 metres, where the amount of sunlight available is not sufficient to support photosynthesis. These fish are adapted for an active life under low light conditions.
Vision Four-eyed fish Vierauge.jpg The four-eyed fish feeds at the surface of the water with eyes that allow it to see both above and below the surface at the same time. Four-eyed fish have eyes raised above the top of the head and divided in two different parts, so that they can see below and above the water surface at the same time. Four-eyed fish actually have only two eyes, but their eyes are specially adapted for their surface-dwelling lifestyle. The eyes are positioned on the top of the head, and the fish floats at the water surface with only the lower half of each eye underwater. The two halves are divided by a band of tissue and the eye has two pupils, connected by part of the iris. The upper half of the eye is adapted for vision in air, the lower half for vision in water.[99] The lens of the eye also changes in thickness top to bottom to account for the difference in the refractive indices of air versus water. These fish spend most of their time at the surface of the water. Their diet mostly consists of the terrestrial insects which are available at the surface.[100]
Two stripe damselfish Dascyllus reticulatus (Reticulated dascyllus).jpg The two stripe damselfish can signal secret alarms by reflecting ultraviolet to other fish of its species. The two stripe damselfish, Dascyllus reticulatus, has ultraviolet-reflecting colouration which they appear to use as an alarm signal to other fish of their species.[101] Predatory species cannot see this if their vision is not sensitive to ultraviolet. There is further evidence for this view that some fish use ultraviolet as a "high-fidelity secret communication channel hidden from predators", while yet other species use ultraviolet to make social or sexual signals.[102][103]
Barreleye Opisthoproctus soleatus.png The barreleye has barrel-shaped, telescopic eyes which are generally directed upwards, but can also be swivelled forward. Barreleyes are a family of small, unusual-looking mesopelagic fishes, named for their barrel-shaped, tubular eyes which are generally directed upwards to detect the silhouettes of available prey.[104][105] Barreleyes have large, telescoping eyes which dominate and protrude from the skull. These eyes generally gaze upwards, but can also be swivelled forwards in some species. Their eyes have a large lens and a retina with an exceptional number of rod cells and a high density of rhodopsin (the "visual purple" pigment); there are no cone cells.[104] The barreleye species, Macropinna microstoma, has a transparent protective dome over the top of its head, somewhat like the dome over an airplane cockpit, through which the lenses of its eyes can be seen. The dome is tough and flexible, and presumably protects the eyes from the nematocysts (stinging cells) of the siphonophores from which it is believed the barreleye steals food.[104][105][106]
Flashlight fish Flashlight fish use a retroreflector behind the retina with photophores to detect eyeshine in other fish. Another mesopelagic fish is the flashlight fish. For more sensitive vision in low light, this fish has a retroreflector behind the retina. They also have photophores, which they use in combination with their retroreflector to detect eyeshine in other fish.[107][108][109]
By shape[edit]
Boxfishes have heavily armoured plate-like scales fused into a solid, triangular, boxlike carapace, from which the fins, tail, eyes and mouth protrude. Because of this heavy armour, boxfish move slowly, but few other fish are able to eat the adults.[110]
By locomotion[edit]
See also: Fish locomotion
A number of species jump while swimming near the surface, skimming the water.
Dwarf seahorse Hippocampuszosterae.jpg The slowest-moving fishes are the sea horses. The slowest of these, the tiny dwarf seahorse, attains about five feet per hour.[111]
Atlantic bluefin tuna Bluefin-big.jpg The Atlantic bluefin tuna is capable of sustained high speed cruising, and maintains high muscle temperatures so it can cruise in relatively cold waters.
Indo-Pacific sailfish Istiophorus platypterus.jpg
Maind u0.gif
Among the fasted sprinters are the Indo-Pacific sailfish (left) and the black marlin (right). Both have been recorded in a burst at over 110 kilometres per hour (68 mph). For the sailfish, that is equivalent to 12 to 15 times their own length per second.
Shortfin mako Isurus oxyrinchus.jpg The shortfin mako shark is fast enough and agile enough to chase down and kill an adult swordfish, but they don't always win. Sometimes in the struggle with a shark a swordfish can kill it by ramming it in the gills or belly. The shortfin mako's speed has been recorded at 50 kilometres per hour (31 mph), and there are reports that it can achieve bursts of up to 74 kilometres per hour (46 mph).[112] It can jump up to 9 meters (30 ft) in the air. Due to its speed and agility, this high-leaping fish is sought as game worldwide. This shark is highly migratory. Its exothermic constitution partly accounts for its relatively great speed.[113]
Wahoo Acanthocybium solandri.png The wahoo is perhaps the fastest fish for its size, attaining a speed of 19 lengths per second, reaching 78 kilometres per hour (48 mph).
Flying fish Pink-wing flying fish.jpg
Sailfin flyingfish.jpg
Flying fish have unusually large pectoral fins, which enable the fish to take short gliding flights above the surface of the water, in order to escape from predators. Their glides are typically around 50 meters (160 ft), but they can use updrafts at the leading edge of waves to cover distances of at least 400 meters (1,300 ft).[114] In May 2008, a flying fish was filmed off the coast of Japan (see video). The fish spent 45 seconds aloft, and was able to stay aloft by occasionally beating the surface of the water with its caudal (tail) fin.[115] The previous record was 42 seconds.[115]
Climbing perches AnabasLyd.jpg Climbing perches are a family of fishes which have the ability to climb out of water and "walk" short distances. As labyrinth fishes, they possess a labyrinth organ, a structure in the fish's head which allows it to breathe atmospheric oxygen. Their method of terrestrial locomotion uses the gill plates as supports, and the fish pushes itself using its fins and tail.
Mudskipper Periophthalmus gracilis.jpg The mudskipper is another type of walking fish. Walking fish are often amphibious and can travel over land for extended periods of time. Able to spend longer times out of water, these fish may use a number of means of locomotion, including springing, snake-like lateral undulation, and tripod-like walking. The mudskipper is probably the best land-adapted of contemporary fish and is able to spend days moving about out of water and can even climb mangroves, although to only modest heights.[116] There are some species of fish that can "walk" along the sea floor but not on land. One such animal is the flying gurnard, which can walk on the sea floor.
By toxicity[edit]
Toxic fish produce strong poisons in their bodies. Both poisonous fish and venomous fish, contain toxins, but deliver them differently.
• Venomous fish bite, sting, or stab, causing an envenomation. Venomous fish don't necessarily cause poisoning if they are eaten, since the digestive system often destroys the venom.[117]
• By contrast, poisonous fish do not bite, sting, or stab to deliver their toxins, but they are poisonous to eat because they contain toxins in their body that the digestive system does not destroy.[117]
A 2006 study found that there are at least 1200 species of venomous fish.[118] There are more venomous fish than venomous snakes. In fact, there are more venomous fish than the combined total of all other venomous vertebrates.[118] Venomous fish are found in almost all habitats around the world, but mostly in tropical waters. They wound over 50,000 people every year.[119]
They carry their venom in venom glands and use various delivery systems, such as spines or sharp fins, barbs, spikes and fangs. Venomous fish tend to be either very visible, using flamboyant colors to warn enemies, or skilfully camouflaged and maybe buried in the sand. Apart from the defense or hunting value, venom help bottom dwelling fish by killing the bacteria that try to invade their skin. Few of these venoms have been studied. They are yet to be tapped resource for bioprospecting to find drugs with medical uses.[120]
Treatment for venom stings usually includes the application of heat, using water at temperatures of about 45 °C (113 °F), since heat breaks down most complex venom proteins.
Toxicity Puffer fish Tetraodon-hispidus.jpg The puffer fish is the most poisonous fish in the world. It is the second most poisonous vertebrate after the golden dart frog. It paralyzes the diaphragm muscles of human victims, who can die from suffocation. In Japan, skilled chefs use parts of a closely related species, the blowfish to create a delicacy called "fugu", including just enough toxin for that "special flavour".
Spotted trunkfish Lactophrys bicaudalis.jpg The spotted trunkfish secretes a ciguatera toxin from glands on its skin. The spotted trunkfish is a reef fish which secretes a colourless ciguatera toxin when touched. The toxin is only dangerous when ingested, so there's no immediate harm to divers. However, predators as large as nurse sharks can die as a result of eating a trunkfish.[121]
Giant moray G.Javanicus8.jpg The giant moray is a reef fish at the top of the food chain. Like many other apex reef fish, it is likely to cause ciguatera poisoning if eaten.[122][123] Outbreaks of ciguatera poisoning in the 11th to 15th centuries from large, carnivorous reef fish, caused by harmful algal blooms, could be a reason why Polynesians migrated to Easter Island, New Zealand, and possibly Hawaii.[124][125]
Reef stonefish Synanceia verrucosa.jpg The most venomous known fish is the reef stonefish.[126][127] It has a remarkable ability to camouflage itself amongst rocks. It is an ambush predator that sits on the bottom waiting for prey to approach. Instead of swimming away if disturbed, it erects 13 venomous spines along its back. For defense, it can shoot venom from each or all of these spines. Each spine is like a hypodermic needle, delivering the venom from two sacs attached to the spine. The stonefish has control over whether to shoot its venom, and does so when provoked or frightened.[120] The venom results in severe pain, paralysis and tissue death, and can be fatal if not treated. Despite its formidable defenses, stonefish have predators. Some bottom feeding rays and sharks with crushing teeth feed on them, as does the Stokes' seasnake[128]
Lionfish Pterois volitans Manado-e edit.jpg Head on view of the beautiful lionfish, a venomous coral reef fish[129] Unlike stonefish, a lionfish can only release venom if something strikes its spines. Although not native to the U.S. coast, lionfish have appeared around Florida and have spread up the coast to New York. They are attractive aquarium fish, sometimes used to stock ponds, and may have been washed into the sea during a hurricane. Lionfish can aggressively dart at scuba divers and attempt to puncture their facemask with their venomous spines.[120]
Stargazer Uranoscopus sulphureus.jpg The stargazer Uranoscopus sulphureus.[130] The stargazer buries itself and can deliver electric shocks as well as venom. It is a delicacy in some cultures (cooking destroys the venom), and can be found for sale in some fish markets with the electric organ removed. They have been called "the meanest things in creation"[120]
Stingray Stringray's sting.jpg Stingrays can sting with their stinger (pictured). Such envenomations can occur to people who wade in shallow water and tread on them. This can be avoided by shuffling through the sand or stamping on the bottom, as the rays detect this and swim away. The stinger usually breaks off in the wound. It is barbed, so it can easily penetrate but not so easily be removed. The stinger causes local trauma from the cut itself, pain and swelling from the venom, and possible later infection from bacteria. Occasionally severed arteries or death can result.[131]
By human use[edit]
Predator fish size up schooling forage fish
Fish are sought by humans for their value as commercial food fish, recreational sport fish, decorative aquarium fish and in tourism, attracting snorkelers and SCUBA divers .
Throughout human history, important fisheries have been based on forage fish.[132] Forage fish are small fish which are eaten by larger predators. They usually school together for protection. Typical ocean forage fish feed near the bottom of the food chain on plankton, often by filter feeding. They include the family Clupeidae (herrings, sardines, menhaden, hilsa, shad and sprats), as well as anchovies, capelin and halfbeaks. Important herring fisheries have existed for centuries in the North Atlantic and the North Sea. Likewise, important traditional for anchovy and sardine fisheries have operated in the Pacific, the Mediterranean, and the southeast Atlantic.[133] The world annual catch of forage fish in recent years has been around 25 million tonnes, or one quarter of the world's total catch.
Higher in the food chain, Gadidae (cod, pollock, haddock, saithe, hake and whiting also support important fisheries. Concentrated initially in the North Sea, Atlantic cod was one of Europe's oldest fisheries, later extending to the Grand Banks,[134] Declining numbers led to international "cod wars" and eventually the virtual abandonment of these fisheries. These days the Alaska pollock supports an important fishery in the Bering Sea and the north Pacific, yielding about 6 million tonnes, while cod amounts to about 9 million tonnes.[133]
Recreational and sport fishing is big business[135] U.S. saltwater fishers spend about $30 billion annually and support 350,000 jobs.[136] Some of the more popular recreational and sport fish include bass, marlin, porgie, shad, mahi-mahi, smelt whiting, swordfish, and walleye.
Fishkeeping is another popular pastime, and there is a large international trade for aquarium fish.
Snorkeling and SCUBA diving attract millions of people to beaches, coral reefs, lakes, and other water bodies to view fish and other marine life.
Yellowfin tuna Yellowfin tuna nurp.jpg Yellowfin tuna are now being fished as a replacement for the depleted southern bluefin tuna.
Anchovy Anchovy closeup.jpg These schooling anchovy are forage fish
Atlantic cod Atlantic cod.jpg Atlantic cod fisheries have collapsed
Alaska pollock Walleye pollock.jpg Alaska pollock
Koi Goldfish2.cropped.jpg Koi (and goldfish) have been kept in decorative ponds for centuries in China and Japan
By vulnerability[edit]
Other Bony-eared assfish Acanthonus armatus.jpg Fish hold the records for the relative brain weights of vertebrates. Most vertebrate species have similar brain-to-body weight ratios. The deep sea bathypelagic bony-eared assfish,[137] has the smallest ratio of all known vertebrates.[138]
Elephantnose fish Gnathonemus petersii.jpg At the other extreme, the elephantnose fish, an African freshwater fish, has the largest brain-to-body weight ratio of all known vertebrates.[139]
Hallucinogenic fish Sarpa salpa .jpg The hallucinogenic dream fish, Sarpa salpa, a species of bream recognizable by the golden stripes running the length of its body, can induce LSD-like hallucinations if it is eaten.[140] These widely distributed coastal fish[141] became a recreational drug during the Roman Empire, and are called "the fish that make dreams" in Arabic. Other hallucinogenic fish are Siganus spinus,[142] called "the fish that inebriates" in Reunion Island, and Mulloidichthys samoensis,[143] called "the chief of ghosts" in Hawaii.[144]
Nopoli rockclimbing goby Sicyopterus stimpsoni00.gif The Nopoli rockclimbing goby uses its mouth as a sucker to climb waterfalls. When the fish is young, it undergoes a radical transformation when it moves from saltwater to a freshwater stream. The mouth migrates over a period of two days from the front of its head to its chin. This allows the fish to feed by scraping algae from rocks. It also allows the fish to climb waterfalls by inching up rocks like a caterpillar, using its mouth as a sucker together with another sucker on its stomach. Pictured is the goby before and after the transformation.[145][146]
Vampire fish Candiru.png Smaller species of vampire fish, native to the Amazon River, have an alleged tendency to burrow into and parasitise the human urethra. However, despite ethnological reports dating back to the late 19th century, the first documented case of the removal of a vampire fish from a human urethra did not occur until 1997, and even that incident has remained a matter of controversy.[147]
See also[edit]
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External links[edit] |
Li Mu
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This is a Chinese name; the family name is Li.
Li Mu
Li Mu (Chinese: 李牧; died 229 BC) was a prominent military General of Zhao during the Warring States period of ancient China. He, together with Bai Qi, Wang Jian, and Lian Po were known as the Four Greatest Generals of the Warring States era.
Li Mu assumed command of Zhao's overall security situation after the death of Zhao She and the exile of Lian Po, both renowned former generals of Zhao. He began his career on the northern frontier fighting the Xiongnu. He adopted an extremely defensive strategy, was accused of cowardice and replaced by a more aggressive general who was defeated every time he attacked the Xiongnu. Li Mu was recalled and given a much larger army. He concealed his troops and played the coward. When a large force crossed the border, Li Mu surrounded it and smashed it. He then went on to defeat the Tan Lan, Lin Hu and Donghu. It was said that the Xiongnu did not dare approach the border for the next twenty years.
Later, as the threat from Qin increased with the ascension of Qin Shi Huang, he turned his focus more to the western parts of Zhao. The State of Zhao was merely a shadow of its former self. After suffering utter defeat from Qin during the Battle of Changping, which Zhao lost virtually its entire army, most of Zhao core territories had fallen to Qin. Furthermore, Zhao was diplomatically isolated as the Kingdoms of Wei, Yan and Han were too weak to offer any kind of support, while Qi and Chu were more willing to see the kingdom extinguished than face the powerful Qin.
However, Li Mu could still hold out against the much stronger Qin forces. So while Qin could raid Wei and Han at will, they had a much harder time pillaging in Zhao.
Getting rid of Li Mu became a necessity for Qin to conquer Zhao and unify China. Qin sent spies to the Zhao court, bribing key courtiers in order to persuade the King of Zhao that Li Mu was planning to revolt. The plan succeeded - Li Mu was arrested and soon executed on the king's orders. According the Sima Qian (chapter 102) this happened when King Qian, 'whose mother was a dancing girl', came to the throne.
With Li Mu's death, the fall of Zhao became inevitable. In about 10 years King Dai would fall and the State of Zhao would fade into history.
Li Mu, also known as Ri Boku, is the prime minister of the State of Zhao and a member of Three Great Heavens, in the manga series Kingdom.
• Di Cosmo, 'Ancient China and its Enemies', 2308. |
Document Sample
INVERSE-SQUARE LAW TESTS 1
INVERSE-SQUARE LAW
E.G.Adelberger, B.R. Heckel,and A.E. Nelson
KEYWORDS: gravitation, experimental tests of inverse-square law, quantum gravity, extra
ABSTRACT: We review recent experimental tests of the gravitational inverse-square law,
and the wide variety of theoretical considerations that suggest the law may break down in
experimentally accessible regions.
Unifying gravity with particle physics: 2 hierarchy problems . . . . . . . . . . . . . . . 6
Extra dimensions and TeV scale unification of gravity . . . . . . . . . . . . . . . . . . 12
Exchange forces from conjectured new bosons . . . . . . . . . . . . . . . . . . . . . . . 21
Attempts to solve the cosmological constant problem . . . . . . . . . . . . . . . . . . . 27
Annu. Rev. Nucl. Part. Physics. 2003 53 xxxxx
What if a violation of the 1/r2 law were observed? . . . . . . . . . . . . . . . . . . . . 59
1.1 Background
Gravitation was the first of the 4 known fundamental interactions to be under-
stood quantitatively and the first “grand unification” in physics; Isaac Newton’s
Theory of Universal Gravitation connected terrestrial phenomena (the“falling
apple”) with astronomical observations (the “falling Moon” and Kepler’s Laws).
This theory stood virtually unchallenged until Albert Einstein developed his rel-
INVERSE-SQUARE LAW TESTS 3
ativistic theory of gravitation in 1917. Since then General Relativity has success-
fully passed all experimental tests and is today the Standard Model of gravitation.
Yet some three centuries after Newton, gravitation remains one of the most puz-
zling topics in physics. Recently a completely unexpected and fundamentally
new gravitational property was discovered using distant Type Ia supernovae: the
apparent acceleration of the Hubble expansion(1, 2) that is as yet unexplained.
Furthermore, gravitation is not included, and in fact not includable, in the
imposing quantum field theory that constitutes the Standard Model of particle
physics. There is a broad consensus that the two Standard Models are incompat-
ible: the strong, weak and electromagnetic interactions are explained as results
of the quantum exchange of virtual bosons, while the gravitational interaction
is explained as a classical consequence of matter and energy curving space-time.
Because quantum field theories cannot describe gravitation and General Relativ-
ity predicts an infinite space-time curvature at the center of a black hole, neither
of these two standard models is likely to be truly fundamental.
Connecting gravity with the rest of physics is clearly the central challenge of
fundamental physics, and for the first time we have a candidate theory (string
or M-theory) that may unify gravitation with particle physics. But outstanding
theoretical problems remain that have focused attention on possible new phenom-
ena that could show up as deviations from familiar inverse-square law (ISL) of
gravity, generally at length scales less than a few millimeters, but sometimes also
at astronomical or even cosmological distances. We review these speculations in
Section 2.
While it is conventionally assumed that the ISL should be valid for separations
from infinity to roughly the Planck length (RP = G¯ /c3 = 1.6 × 10−35 m) it
4 ADELBERGER, HECKEL and NELSON
had, until a few years ago, only been precisely tested for separations ranging from
the scale of the solar system down to a few millimeters. The reasons for this are
obvious: on the one hand there are no independently known mass distributions on
length scales larger than the solar system, and on the other hand, it is difficult
to get enough matter in close enough proximity to obtain a background-free
gravitational signal at length scales smaller than 1 mm. This contrasts strongly
with Coulomb’s Law (and its electroweak generalization) which has been tested
for separations down to 10−18 m in e+ -e− leptonic interactions at high-energy
colliders(3). Although Coulomb’s Law has not been experimentally verified at
length scales large compared to laboratory dimensions, a null-type laboratory
measurement looking for effects of the galactic electromagnetic vector potential,
A, rules out deviations due a finite photon mass for length scales up to ∼ 2 × 1010
m (4).
1.1.1 Parameterizations
Historically, experimental tests of Coulomb’s and Newton’s inverse-square laws
were used to set limits on violations that, for gravity, took the form
m 1 m2
F (r) = G . (1)
r 2+
From the perspective of Gauss’s Law the exponent 2 is a purely geometrical
effect of 3 space dimensions, so that this parameterization was not well-motivated
theoretically. Instead, it is now customary to interpret tests of the ISL as setting
limits on an additional Yukawa contribution to the familiar 1/r 2 contribution,
which in the gravitational case creates a potential
m1 m2
V (r) = −G 1 + α e−r/λ , (2)
INVERSE-SQUARE LAW TESTS 5
where α is a dimensionless strength parameter and λ is a length scale or range.
The Yukawa contribution is the static limit of an interaction due the exchange
of virtual bosons of mass mb = ¯ /(λc), where mb is the boson mass; the Yukawa
form is also useful in other contexts (see Sec. 2.2.1 below).
Some investigators (see for example Ref. (5)) have considered the possibility
that a non-zero graviton mass could lead to a “pure Yukawa” gravitational poten-
tial V (r) = −Gm1 m2 e−r/λ /r, recognizing that this phenomenological form does
not have a well-defined theoretical foundation. Others have considered power law
modifications to the ISL(6):
N −1
m 1 m2 r0
V (r) = −G 1 + αN , (3)
r r
where αN is a dimensionless constant and r0 corresponds to a new length scale
associated with a non-Newtonian process.
Terms with N = 2 and N = 3 may be generated by the simultaneous exchange
of two massless scalar and two massless pseudoscalar particles, respectively(7, 8,
9), while N = 5 may be generated by the simultaneous exchange of two massless
axions(10) or a massless neutrino-antineutrino pair(11).
In this review, we focus on the parametrization of Eq. 2; any experiment that
detects a violation of the ISL will indicate a strength, α, and a length scale,
λ, that characterizes the violation. Once a violation is detected, it will become
necessary to determine the functional form of the violation. The parameterization
of Eq. 2 has strong implications for experimental tests of the ISL. Any one test of
the law necessarily covers a limited range of length scales. Suppose, for example,
one performs a Keplerian test, comparing the orbits of two planets orbiting a
common sun. Clearly, the test is insensitive to λ’s much less than the orbit
radius of the inner planet. It is also insensitive to λ’s much larger than the
6 ADELBERGER, HECKEL and NELSON
orbit radius of the outer planet because both planets simply feel a renormalized
Newtonian constant G = G(1 + α). Consequently a great variety of experiments
are needed to effectively explore a wide variety of length scales. This contrasts
with limits on Yukawa interactions from “Equivalence Principle” tests where a
single experimental result for a composition-dependent acceleration difference
typically provides a constraint on α for λ’s ranging from the length scale of the
attractor to infinity (see, for example, Ref. (12)).
1.2 Scope of this review
This review concentrates on experimental tests of the ISL at length scales of mil-
limeters or less, and on the wide range of theoretical developments suggesting
that new phenomena may occur in this regime. We also discuss speculations
about possible ISL violations at much larger length scales that could have im-
portant cosmological implications. A extensive review of experimental results at
longer length scales(13) appeared in 1999 which we update in Sec. 4.5 below. A
review of extra “gravitational” dimensions, with emphasis on collider signatures,
has recently appeared in this review series(14). Our review is focused on work
done since 1995, and should be current as of January 2003. An earlier review(12)
covered spin-dependent forces that we do not consider here.
2.1 Unifying gravity with particle physics: 2 hierarchy problems
The two greatest triumphs of 20th century physics are General Relativity (GR),
and Quantum Mechanics. However we do not currently know how to link these
two theories, or how to do calculations consistently in situations where both grav-
INVERSE-SQUARE LAW TESTS 7
ity and quantum effects are important such as for conditions near the Big Bang
and the cores of black holes. Clearly General Relativity must be contained in a
more fundamental quantum theory that would allow sensible calculations even
in extreme conditions. However attempts to quantize General Relativity have
been plagued with difficulties. Although one can construct an effective quantum
field theory of gravity and particle physics that is sufficiently accurate for many
applications, the theory is infamously “nonrenormalizable” or nonpredictive—
an infinite number of free parameters are needed to describe quantum effects at
arbitrarily short distances to arbitrary precision.
All known nongravitational physics is includable within The Standard Model of
particle physics— a quantum field theory in which the weak and electromagnetic
interactions are unified into a single framework known as the electroweak theory.
Symmetry between the weak and electromagnetic interactions is manifest above a
scale of roughly 100 GeV. This unification scale, where the electroweak symmetry
is spontaneously broken, is known as the electroweak scale. The electroweak scale
is set by a condensate of a scalar field known as the Higgs field that has negative
mass-squared term of order (100 GeV)2 in its potential. All three forces of the
Standard Model, the electromagnetic, weak and strong interactions, are similarly
unifiable into a simple group with a single coupling at the fantastically high
energy scale of 1016 GeV. This “grand” unified theory (GUT) successfully explains
the quantization of electric charge and, provided there exists a new symmetry
between fermions and bosons known as supersymmetry, predicts the observed
value for the relative strengths of the weak and electromagnetic couplings. But
supersymmetry has not yet been observed in nature and, if present, must be
spontaneously broken. Supersymmetry and grand unified theories have been
8 ADELBERGER, HECKEL and NELSON
Intriguingly, the Planck scale, MP = h
¯ c/G, at which quantum-gravity effects
must become important, MP c2 = 1.2 × 1019 GeV, is rather close to the apparent
unification scale of the other forces. This hints that all belong together in a unified
framework, containing a fundamental scale of order MP . Motivated by GUTs,
the conventional view is that the phenomenal weakness of gravity at accessible
energies—1032 times weaker than the other forces at the electroweak scale—is
due to the small masses of observed particles relative to MP .
In the Standard Model, particle masses derive from the Higgs condensate. The
tremendous discrepancy between the scale of this condensate and the presumed
fundamental scale of physics is known as the gauge hierarchy problem. In the
minimal Standard Model, the smallness of the Higgs mass-squared parameter rel-
ative to the GUT or Planck scales violates a principle known as “naturalness” —
renormalized values of parameters that receive large quantum corrections should
not be much smaller than the size of the corrections. The Higgs mass-squared
receives corrections proportional to the cutoff, or maximum scale of validity of
the theory. Naturalness would therefore demand that to describe physics at en-
ergies higher than about a TeV, the Standard Model should be contained within
a more fundamental theory, in which the quantum corrections to the Higgs mass
are suppressed. An example of such a theory is a supersymmetric extension
of the standard model. In theories with (spontaneously or softly broken) su-
persymmetry, the quantum corrections to scalar masses are proportional to the
supersymmetry-breaking scale. Provided the supersymmetry-breaking scale is of
order 100 GeV, the electroweak scale is natural, and the hierarchy question is
why the supersymmetry-breaking scale is so small compared to MP . This latter
INVERSE-SQUARE LAW TESTS 9
problem is theoretically tractable; in many supersymmetric models the scale of
supersymmetry breaking is proportional to exponentially small, nonperturbative
quantum effects (27, 28).
A second, and much bigger, hierarchy problem is known as the cosmological
constant problem. The strong observational evidence (1, 2) that the expansion
of the universe is accelerating can be explained by a nonvanishing cosmological
constant. The concordance of cosmological data indicates(29) that the universe
is filled with a vacuum-energy density ρvac ∼ 0.7ρc where ρc is the critical density
3H 2 c2 /(8πG) and H is the present value of the Hubble constant. This gives
ρvac ∼ 4 keV/cm3 which corresponds to an energy scale 4
(¯ c)3 ρvac ≈ 2 meV or
a length scale h
(¯ c)/ρvac ∼ 100 µm. Such a small energy density is particularly
puzzling because the quantum corrections to the vacuum energy density from
particle physics scale as the fourth power of the cutoff of the effective theory.
Such a cutoff might be provided by new physics in the gravitational sector. The
energy scale of new gravitational physics has been presumed to be around MP ,
which would imply a cosmological constant 10120 times larger than observed.
The success of the particle physics Standard Model at collider energy scales is
inconsistent with a cutoff lower than a TeV. Even a relatively low TeV cutoff gives
a theoretical contribution to the cosmological constant that is 1060 times larger
than experiment. Refs. (30, 31) conjecture that this monstrous discrepancy
could be eliminated with a much lower cutoff for the gravitational sector of the
effective theory, around an meV, corresponding to new gravitational physics at a
distance of about a hundred microns. The theoretical framework for such a low
gravity scale is necessarily very speculative. However, just as the gauge hierarchy
compels experimental exploration of the TeV scale, the cosmological-constant
10 ADELBERGER, HECKEL and NELSON
problem strongly motivates sub-millimeter scale tests of gravity.
General Relativity itself gives indications that the theory of quantum gravity
is radically different from a conventional quantum field theory. For instance, it
is known that in theories of gravity, the concept of entropy must be generalized
because entropy cannot be an extensive quantity scaling like volume. In fact
there is strong evidence in favor of an upper bound on the entropy of any region
that scales as the surface area of the boundary of the region (32, 33, 34). A
further conjecture, the “holographic principle”, suggests that this entropy bound
indicates that the fundamental degrees of freedom of a gravitational theory can
actually be formulated in a lower-dimensional theory. Ref. (35) gives a nice
review of these ideas and their subsequent development.
M-theory is a popular candidate for a theory of quantum gravity. This theory
was called string theory when it was believed that its fundamental degrees of
freedom were 1-dimensional objects propagating in a 10-dimensional space-time.
Six of these dimensions were assumed to be rolled up into a compact manifold
of size ∼ RP and unobservable. We now know that “string” theory necessarily
contains many types of objects, known as “branes” or “p-branes”, where p, the
number of spatial dimensions of the p-brane, can be anywhere from 0 to 9. This
realization has revolutionized our understanding of string theory. Furthermore,
string theory is “dual”, or physically equivalent as a quantum theory, to an
11-dimensional theory known as M-theory. There is much theoretical evidence
that all known consistent string theories, as well as 11-dimensional supergravity,
are just weakly-coupled limits in different vacua of a single theory of quantum
Extra dimensions might seem to be in conflict with the holographic assertion
INVERSE-SQUARE LAW TESTS 11
that the fundamental theory is actually lower dimensional. However, as compre-
hensively reviewed in (36), the discovery that string theory on certain space-times
with n non-compact dimensions is dual to a non-gravitational gauge theory with
n − 1 dimensions provides additional theoretical evidence for holography, as well
as for string theory. Strings, M-theory, p-branes, and duality have been reviewed
in Refs. (37, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53) and are the
subject of several excellent textbooks(38, 39).
Until recently, it was believed that experimental verification of a theory of
quantum gravity was out of the question, due to the impossibly short distance
scale at which quantum gravitational effects are known to be important. Fur-
thermore, string theory contains a stupendous number of vacua, with no known
principle for selecting the one we should live in, and so appears to have limited
predictive power. Its chief phenomenological success to date is that in many of
these vacua, the low-energy effective theory approximately resembles our world,
containing the fields of the Standard Model and gravity propagating in 4 large
dimensions. A major unsolved difficulty is that all known vacua are supersym-
metric, although there are a variety of conceivable ways for the supersymmetry
to be broken by a small amount.
As we discuss below, although string theory makes no unique prediction, all
known ways of rendering our observations compatible with string theory lead
to new, dramatic signals in feasible experiments. In particular, the discovery
of branes has led to new possibilities for explaining the gauge hierarchy and the
cosmological constant. Many of these can be tested in measurements of gravity at
submillimeter scales, or in searches for small deviations from General Relativity
at longer distances.
12 ADELBERGER, HECKEL and NELSON
2.2 Extra dimensions and TeV scale unification of gravity
2.2.1 “Large” extra dimensions
It is usually assumed that the Planck scale is an actual physical scale, as is the
weak scale, and that the gauge hierarchy problem is to explain the origin of two
vastly disparate scales. However Arkani-Hamed, Dimopoulos and Dvali (ADD)
(54) have proposed an alternative explanation for the weakness of gravity that has
stimulated much theoretical and experimental work; see reviews in Refs. (83, 84,
85, 86, 14, 87). ADD conjecture that gravity is weak, not because the fundamental
scale is high, but because gravity can propagate in new dimensions of size less
than a millimeter. Such “large” new dimensions are not seen by the Standard-
Model particles because these are confined to a 3-dimensional subspace of the
higher- dimensional theory. Such a framework can be accommodated in string
theory (55). A type of p-brane known as a Dp-brane does have gauge and other
degrees of freedom as light excitations that are confined to the brane. If the
Standard-Model particles are all confined to such a D3-brane, we will not sense
additional dimensions except via their modification of the gravitational force law.
The hierarchy problem can be reformulated in this framework. One can assume
that the fundamental scale M∗ is of order a TeV (56). There is then no hierarchy
between the weak scale and M∗ , and no gauge hierarchy problem. If there are n
new dimensions, the higher-dimensional Newton’s constant G(4+n) can be taken
to be
4π h
¯ c3
G(4+n) = (4)
S(2+n) M∗ c ¯
INVERSE-SQUARE LAW TESTS 13
where S(2+n) is the area of a unit (2 + n)-sphere,
2π (n+1)/2
S(2+n) = . (5)
Γ 2
At sufficiently short distances, the gravitational force at a separation r would be
proportional to G(4+n) /r 2+n . To reconcile this with the 1/r 2 force law observed
at long distances, ADD take the n new dimensions to be compact. At distances
long compared to the compactification scale the gravitational flux spreads out
evenly over the new dimensions, and is greatly diluted. Using Gauss’ law, one
finds that a for n new dimensions with radius R∗ , compactified on a torus, the
effective Newton’s constant at long distances is
¯c ¯
h 1
G= 2 M c
. (6)
M∗ ∗ Vn
where Vn is the volume of the n−torus, (2πR∗ )n . The relationship between
R∗ and M∗ for other geometries may be found simply by using the appropriate
formula for the volume.
The hierarchy problem then becomes transmuted into the problem of explaining
the size of the new dimensions, which are much larger than the fundamental scale.
There are several proposals for stable compactifications of new dimensions that
are naturally exponentially large (57, 58, 59, 60, 61).
To test the ADD proposal directly, one should probe the ISL at a distance scale
on the order of R∗ . Compact new dimensions will appear as new Yukawa-type
forces, of range R∗ , produced by the exchange of massive spin-2 particles called
Kaluza-Klein (KK) gravitons (62, 63, 64). To see this, note that the components
of the graviton momenta in the compact dimensions must be quantized. For
instance, compactification of a flat 5th dimension on a circle of radius R would
impose the condition on P5 , the 5th component of the graviton momentum, P5 =
14 ADELBERGER, HECKEL and NELSON
j¯ /R , where j is an integer. The dispersion relation for a massless particle in 5
Lorentz invariant dimensions is
E2 = 2
c2 Pi2 + c2 P5 . (7)
Comparing with the 4-dimensional massive dispersion relation
E2 = c2 Pi2 + c4 M 2 . (8)
we see that the 5th component of the momentum appears as a 4-dimensional
mass term. A 5-dimensional graviton thus appears as an infinite number of new
massive spin-2 particles. For a flat new dimension compactified on a circle of
radius R, the mass mj of the jth KK mode is mj = j¯ /(Rc) with j = 1, 2, ....
In factorizable geometries (whose spacetimes are simply products of a 4-dimensional
spacetime with an independent n-dimensional compact space) the squared wave
functions of the KK modes are uniform in the new dimensions. Low-energy
effective-field theory analyses of the KK modes and their couplings (65, 66, 67, 68)
show that higher-dimensional general coordinate invariance constrains this effec-
tive theory. Even at distances less than R, KK mode exchange will not violate
the Equivalence Principle. The leading terms in an expansion in 1/M∗ contain a
universal coupling of each graviton KK mode Gj to the stress tensor of form
− Gj T µν
µν (9)
MP j
that is, each KK mode simply couples to the stress tensor in the same manner as
the graviton. To compute the correction to the ISL for non-relativistic sources
at long distances it suffices to consider the correction to the potential from the
exchange of the lightest KK gravitons. The propagators for the KK states may
be found in Refs. (65, 66, 67, 68).
INVERSE-SQUARE LAW TESTS 15
For n new dimensions compactified on a flat torus, with the same radius R∗
for each dimension, the lowest lying KK mode has multiplicity 2n and Compton
wavelength R∗ . Direct searches for such new dimensions would observe such KK
gravitons via the contribution of their lowest-lying modes to the Yukawa potential
of Eq. 2, giving α = 8n/3 and λ = R∗ . A factor of 4/3 occurs in α because a
massive spin-2 particle has 5 polarization states, and the longitudinal mode does
not decouple from a non-relativistic source 1 Other compact geometries will give
similar effects, although the value of α is quite model-dependent.
Assuming all new dimensions are compactified on a torus of radius R∗ , and
M∗ = 1 TeV, Eq. 6 gives
1 −17+ 32
R∗ ≈ 10 n cm .
The case n = 1, R∗ = 3 × 1012 m, is clearly ruled out. The case n = 2, R∗ = 0.3
mm, is inconsistent with the results of Ref. (69). It has been shown that this case
is even more strongly constrained by the observation of the neutrinos from super-
nova 1987A (70, 71, 72, 73, 74). Gravitational radiation into the extra dimensions
would rapidly cool the supernova before the neutrinos could get emitted, plac-
ing a constraint R∗ < 0.7µm. The extra gravitational degrees of freedom also
necessarily spoil the successful calculations of big-bang nucleosynthesis unless
R∗ < 2µm, and the decay of the KK modes would add a diffuse background of
cosmological gamma rays whose non-observation implies R∗ < 0.05 µm (75). For
n ≥ 3, R∗ is less than about a nanometer, which is still allowed by astrophysics,
cosmology, and direct searches.
Note that Refs. (78, 79) included a contribution from a massless “radion” (gravitational
scalar) in their Newtonian potential, and the radion KK modes in the Yukawa potential, leading
to a different value for α. We discuss the radion and why it should be massive later in this
16 ADELBERGER, HECKEL and NELSON
It might, therefore, seem that direct observation of the new dimensions in ISL
tests is out of the question. However, this conclusion is false. Astrophysical and
cosmological bounds are still consistent with a single extra dimension of size 1
mm—in such a scenario the hierarchy problem might be solved via the existence of
several more much smaller new dimensions (76). Furthermore, as discussed in the
next section, it is easy to alter Eq. 6 and the predictions for higher-dimensional
graviton emission. Finally there is a strong argument that the ADD proposal
h 2
should modify the ISL at a scale of order ¯ MP /(cM∗ ).
In theories of gravity, the geometry of spacetime is dynamical, and can fluc-
tuate. In particular, the radius of new dimensions can fluctuate independently
at each point in our 4-dimensional spacetime. Thus low-energy effective theories
of compact extra dimensions inevitably contain spin-0 fields parameterizing the
radii of the new dimensions. If the size of the new dimensions is not determined
by dynamics, then the linear combination of these fields that determines the extra
dimensional volume is a massless Brans-Dicke scalar with gravitational strength
coupling, known as the “radion”. A massless radion is decisively ruled out by
tests of General Relativity(77). Stabilization of the volume of the extra dimen-
sions is equivalent to a massive radion. Since with a low fundamental scale, the
effective potential for the radion should not be much larger than O(M∗ ), and
its couplings are proportional to GN , the radion mass-squared should be lighter
than O(GN M∗ ). The radion will mediate a new, gravitational strength force,
with α = n/(n + 2) (Ref. (82), and G. Giudice, R. Rattazzi, N. Kaloper, private
communications). In many cases the radion is the lightest state associated with
new dimensions. For M∗ less than a few TeV, its range should be longer than of
order 100 microns. Even for relatively “small” new dimensions with size of or-
INVERSE-SQUARE LAW TESTS 17
der an inverse TeV, the radion will, under certain assumptions, have a Compton
wavelength in the vicinity of a hundred microns(80, 81).
2.2.2 Warped extra dimensions
The previous discussion assumed the metric for the new dimensions is factoriz-
able. However, the most general metric exhibiting 4-dimensional Poincare invari-
ance is a “warped product”,
ds2 = f (ξi )ηµν dxµ dxν + gij (ξi )ξi ξj (10)
where the ξi are the coordinates of the new dimensions, and f and g are general
functions of those coordinates. Solving the higher-dimensional Einstein equations
for a spacetime with an embedded brane with nonvanishing tension typically
requires warping. The “warp factor” f (ξi ) may be thought of as a ξ-dependent
gravitational redshift factor that leads to a potential term in the graviton wave
equation. This potential can have a dramatic effect on the ξ dependence of the
wavefunctions of the graviton, the graviton KK modes, and the radion.
Randall and Sundrum(88) (RSI) noted that a large hierarchy can be obtained
with a single small new dimension if the metric takes the form
ds2 = e−2krc ξ ηµν dxµ dxν + rc dξ 2 , (11)
where ξ is a coordinate living on the interval [0, π], k is a constant, and rc is the
compactification scale. This is just the metric for a slice of 5-dimensional anti-
deSitter space (maximally symmetric spacetime with constant negative curva-
ture), and is a solution to the 5-dimensional Einstein equations with 5-dimensional
Newton’s constant 1/M∗ if there is a negative cosmological constant of size
Λ = −24M∗ k 2 , and if 3-branes are located at ξ = 0 and ξ = π with tensions
18 ADELBERGER, HECKEL and NELSON
±24M∗ k. A negative-tension brane seems unphysical, but such bizarre objects
can be constructed in string theory, provided the spaces on each side of the brane
are identified with each other, that is, the brane represents a boundary condition
on the edge of space. For large krc , most of the extra-dimensional volume of this
space is near the positive-tension brane at ξ = 0.
To study the long-distance behavior of gravity in such a spacetime, one exam-
ines the behavior of small fluctuations of this metric of the form
ds2 = e−2krc ξ [ηµν + hµν (x)]dxµ dxν + rc dξ 2 . (12)
Here hµν is the 4-dimensional graviton. Plugging this metric into Einstein’s
equations and linearizing in h, one finds h is a zero mode, or massless solution to
the equations of motion, whose wavefunction in the compact dimension simply
follows the warp factor e−2krc ξ . Thus there is a massless 4-dimensional graviton
that is localized about the brane at ξ = 0 and exponentially weakly coupled
to matter on the brane at ξ = π. If we further hypothesize that the latter
brane is where the Standard Model lives, the weakness of gravity is explained
for a moderate value of krc ∼ 12. Both k and rc can be of the same order of
magnitude as the fundamental scale, and so there is no large hierarchy in the
input parameters.
As in the ADD case, the RSI model has a radion parameterizing the compact-
ification scale. Goldberger and Wise (89) have shown that krc in the desired
range can naturally be stabilized without large dimensionless inputs if the theory
contains a massive scalar that lives in the bulk and has source terms localized on
the branes. The radion then acquires a large mass of order 100 GeV. The curva-
ture in the extra dimension has a huge effect on the KK graviton spectrum and
couplings. The lightest KK modes have masses in the TeV region and large wave
INVERSE-SQUARE LAW TESTS 19
functions near our brane, and therefore O(1) couplings to ordinary matter. This
model has unusual experimental signatures at colliders(14), but is not testable
with feasible probes of the ISL.
The RSI model teaches us that warping can have significant effects on phe-
nomenology of the new dimensions. The coupling strength and masses of both
the KK modes and the radion can be altered, and the graviton can be local-
ized, or bound to a brane. Furthermore, warping is a generic phenomenon that
should also occur in the ADD scenario. Even a very small amount of warping
can greatly alter the coupling of the zero-mode graviton to our brane, making
this coupling either much stronger or much weaker than for the case of flat extra
dimensions (90), altering the relation of Eq. 6. Even in the case of M∗ = 1 TeV
and n = 2, with a very small amount of warping, the masses of the lightest KK
modes can be either higher or lower than the inverse-millimeter scale predicted
by the unwarped case.
2.3 Infinite-volume extra dimensions
In a second paper(91), Randall and Sundrum (RSII) explored phenomenology of a
graviton zero-mode that is localized about a 3-brane embedded in a noncompact,
infinite extra dimension. They found that although 5-dimensional gravity persists
at all distance scales, with no gap in the KK spectrum, at long distances the 1/r 2
force mediated by the zero-mode which is bound to the brane dominates, and the
extra dimension can be unobservable at low energy. A simple model of this effect
is given by the metric
ds2 = e−2k|z| ηµν dxµ dxν + dz 2 , (13)
20 ADELBERGER, HECKEL and NELSON
where z, the coordinate of the 5th dimension, is noncompact. This metric, which
represents two slices of anti-deSitter space glued together at z = 0, also solves
Einstein’s equations, provided there is a negative bulk cosmological constant
−24M∗ k 2 , and a single 3-brane at z = 0 of positive tension 24M 3 k. The total
gravitational potential between two masses m1 and m2 separated by a distance r
on the brane may be found be summing up the contributions of the bound-state
mode and the continuum KK spectrum, which, for distance scales longer than
1/k, gives
m1 m2 1
V (r) = GN 1+ (14)
r r2 k2
with GN = ¯ 2 k/M∗ . The experimental upper bound on 1/k from N = 3 terms in
h 3
Eq. 3 has not been explicitly computed, but should be similar to the bound on the
radius of an extra dimension. Therefore M∗ must be larger than about 109 GeV,
and there is still a gauge hierarchy. With 2 or more infinite new dimensions, and a
graviton confined to our 3-brane, it is possible to lower M∗ to a TeV (92). In such
a scenario, the weakness of gravity is due to the zero-mode graviton wavefunction
spreading over the extra dimensions, as in the ADD proposal, but the width of
the wave function is set by the curvature scale rather than by the size of the
dimension. Empirically, the main distinction between such weak localization and
a large new dimension is that there is no gap in the KK spectrum and the ISL is
modified by additional power-law corrections rather than by new Yukawa forces.
The RSI explanation of the weakness of gravity—we live on a brane, the gravi-
ton is confined to a different, parallel brane and its wave function here is small—
can also be realized in infinite extra dimensions (92, 93). Lykken and Randall
studied such a configuration with a single extra dimension and concluded that the
weakness of gravity could be explained without input of any large dimensionless
INVERSE-SQUARE LAW TESTS 21
numbers. The chief test of their scenario would be strong emission of graviton
KK modes at a TeV collider. The continuum of KK modes would modify the
ISL, but their effect would only be significant for distances smaller than ∼ 10 fm.
2.4 Exchange forces from conjectured new bosons
Even if new dimensions are absent or small, the ISL can be modified at accessible
distance scales by the exchange of new spin-0 or spin-1 bosons; spin-0 bosons
would mediate an attractive Yukawa force while spin-1 bosons give a repulsive
modification. Here we review some general considerations that apply to such
particles, and motivations for considering their existence.
2.4.1 Scalars: general theoretical considerations
In order for a scalar particle, φ, to exert a coherent force on matter it must have
a Yukawa coupling to electrons, u, d or s quarks, the square of the gluon field
strength, or to higher dimension operators such as certain four-quark operators.
The candidates of lowest dimension are
me md ¯ mu 1
φ¯e ,
e φdd , φ¯u ,
u φGa Ga,µν .
µν (15)
f f f f
When embedded in the standard model, these all arise from dimension-5 op-
erators, hence the common factor of 1/f , where f has dimensions of mass. We
have assumed that all chiral-symmetry-breaking operators should be proportional
to fermion masses. With this assumption, and with all of the above operators
present, the gluon coupling will dominate the scalar coupling to matter. Since
the matrix element of G2 in a nucleon is roughly the nucleon mass, MN , such
an interaction would lead to a Yukawa potential of the form given in Eq. 2 with
λ = ¯ /(mφ c) where mφ is the scalar mass and α
h 2
MP /(4πf 2 ).
22 ADELBERGER, HECKEL and NELSON
An interaction (φ/f )G2 produces radiative corrections to mφ . In the standard
model with cutoff Λ, one finds
δmφ < mφ . (16)
4πf ∼
Naturalness requires that this be no larger than mφ . For f = MN and mφ =
2×10−4 eV, corresponding to a Compton wavelength of 1 millimeter, naturalness
implies Λ < 5 TeV. This scale Λ approximately coincides with the scale at which
naturalness of the electroweak breaking sector demands new physics. A more
weakly coupled scalar would correspond to a higher value for Λ.
2.4.2 Forces from axion exchange
A major loophole in the above arguments is that the interactions between matter
and a new scalar may not arise from any of the operators in Eq. 15, but rather
from nonperturbative QCD effects. This is the case for the pseudoscalar axion
invented to explain why strong interactions conserve CP to high precision. A
pseudoscalar particle would normally not produce a Yukawa force between un-
polarized bodies, but instantons in the presence of CP violation induce a scalar
Yukawa coupling of the axion to matter that melts away above ΛQCD . The
softness of that coupling makes the radiative correction to the axion mass in-
significant. However, a CP-violating scalar axion Yukawa coupling to matter
scales roughly as mu ΘQCD /fa ¯
ΘQCD (mu ma )/(mπ fπ ), where mu < 5 MeV is
the up quark mass, and ΘQCD < 10−9 (94) is the strong CP- violating angle.
Thus for an axion mass ma = 10−4 eV, the scalar axion coupling is at most
about 10−4 times gravitational strength. ISL tests with unpolarized bodies probe
the square of this coupling so they are quite insensitive to the axion. On the other
hand, monopole-dipole tests(95), which search for a CP-violating force between
INVERSE-SQUARE LAW TESTS 23
unpolarized and polarized bodies, are linear in the coupling and should be a more
sensitive axion probe.
2.4.3 Scalars: cosmological considerations
A light, weakly interacting particle cannot decay or annihilate within a Hubble
time, so its relic energy abundance must be equal to or less than that of the
observed dark matter. However the cosmology of scalars presents an important
difficulty. A natural potential for a scalar in an effective theory below a cutoff Λ
has the form V ∼ Λ4 V (φ/f ), where Λ ≈ ˆ
mφ f, and V is an arbitrary function
that is assumed to contain no large dimensionless numbers. If all scalar couplings
are proportional to 1/f , then the scalar lifetime is of order 4πf 2 /m3 , essentially
stable. If at a temperature T ∼ Λ the thermal average of the scalar potential
energy is V ∼ T 4 , then the scalar field would have a large expectation value,
φ ∼ f . The infinite-wavelength component of this expectation value will be
frozen until the Hubble scale is of order 1/mφ , and will subsequently act like cold
dark matter. Assuming the standard-model spectrum and standard cosmology
for T < Λ (e.g., that the reheat temperature following inflation is above Λ), then
an initial scalar energy density of T 4 at T = Λ implies a ratio today of the energy
in cold scalars to the energy in baryons of order
ρw Λ
2 × 108 , (17)
ρB MN
which is clearly unacceptable.
Cosmology with light scalars can be made acceptable by invoking a very late
stage of inflation with Hubble constant H less than or of order mφ . Then φ rapidly
evolves to the minimum of its potential. Once inflation ends, the universe must
reheat to a temperature TR . However the minimum of the scalar potential at
24 ADELBERGER, HECKEL and NELSON
TR does not coincide with the minimum today, due to the tadpole generated by
the interactions Eq. 15 at finite temperature. One must therefore check that
coherent scalar oscillations to not get regenerated during the reheating process
after inflation. If the reheating causes the minimum of the potential to change
suddenly on a timescale compared with the oscillation time (of order 10−13 s),
then regeneration of the scalar condensate can be significant. We are almost
completely ignorant of both the late inflationary mechanism and the reheating
timescale tR , but a rough bound on tR may be estimated from the reheating
temperature using the sudden inflaton decay approximation
MP 90
tr ∼ (2/3)H −1 ∼ (2/3) 2 . (18)
TR 8π 3 g∗
For TR > 10 MeV, which is necessary for standard big-bang nucleosynthesis,
tR ∼ 3×10−3 s. Much higher reheat temperatures might be necessary to generate
the baryon number asymmetry. For example, a reheat temperature of order 100
GeV corresponds to a reheat time of order tR ∼ 3 × 10−11 s.
Provided this timescale is much longer than the scalar oscillation time h/(mφ c2 )
the evolution of the minimum of the potential can take place adiabatically, in-
jecting little energy into the coherent mode. The requirement of such a late stage
of inflation with acceptable reheating places constraints on theories of particle
physics near the weak scale, but does not rule out the existence of light scalars.
2.4.4 Bosons from hidden supersymmetric sectors
As we discussed in Section 2, new physics is expected at the TeV scale. One
candidate for this new physics is supersymmetry, which is predicted in unified
theories, and which can explain the gauge hierarchy. Unbroken supersymmetry
predicts an unobserved degeneracy between fermions and bosons, hence super-
INVERSE-SQUARE LAW TESTS 25
symmetry must be broken at a scale of 100 GeV or higher. The most popular
scenario involves supersymmetry breaking at a scale of MS ∼ 1011 GeV in a
“hidden” sector that couples to our visible world only via gravity and inter-
actions of similar strength. The apparent scale of supersymmetry breaking in
the visible world would then be of order MS /MP ∼ 103 GeV. In other scenar-
ios supersymmetry-breaking is communicated to the visible world by the gauge
forces of the Standard Model, and the supersymmetry-breaking scale is as low as
MS ∼ 104 GeV. The supersymmetry-breaking scale is linked to m3/2 , the mass
of the gravitino (the spin-3/2 superpartner of the graviton), through the relation
m3/2 = MS /MP . Well motivated theoretical expectations for the gravitino mass
range from an meV to 104 GeV. In some scenarios(96, 97, 122, 123) the gravitino
mass may be linked with the size of the cosmological constant inferred from the
supernova observations and should be about an meV.
If there are hidden sectors—particles coupled to the visible sector only via
gravitational strength interactions—the apparent scale of supersymmetry break-
ing in those sectors would typically be of order m3/2 . Scalar particles from those
sectors could naturally have a mass in the meV range and mediate gravitational
strength forces with a range of of order 100 microns.
Note that the severe cosmological problems typical of light weakly coupled
scalars discussed in the previous section do not necessarily occur for a scalar
that is part of a hidden supersymmetric sector exhibiting supersymmetry down
to the meV scale. Such scalars might have a potential coming from O(1) cou-
plings to particles in this sector, while maintaining a naturally small mass and
gravitational-strength couplings to particles in the visible sector. These couplings
will allow for the scalar field to relax to its minimum and for particle decay and
26 ADELBERGER, HECKEL and NELSON
2.4.5 Forces from exchange of stringy bosons
Supersymmetric hidden sectors are ubiquitous in string theory. All known ac-
ceptable vacua of string theory are supersymmetric, and contain a tremendous
number of “moduli”—massless scalar fields whose expectation values set the pa-
rameters of the effective theory. These moduli are extremely weakly coupled,
with couplings inversely proportional to the fundamental scale. In order to give
these fields a mass, it is necessary to break supersymmetry, however moduli
necessarily couple weakly to the supersymmetry-breaking sector and, for a low
supersymmetry-breaking scale, are expected to be extremely light. Current un-
derstanding is inadequate to predict the moduli masses, but a rough estimate
suggests these should be of order m3/2 (98). The best way to look for moduli is
therefore to test the ISL at submillimeter distance scales. The couplings of the
moduli in any given vacuum are computable, and so there are definite predic-
tions. The best-understood scalar is the dilaton, a modulus that determines the
strength of the gauge couplings. Its couplings to ordinary matter can be deter-
mined and are nearly free of QCD uncertainties, so its discovery could provide a
genuine smoking gun for string theory (99).
2.4.6 Forces from the exchange of weakly coupled vector bosons
A new repulsive Yukawa interaction would be a signal for the exchange of a mas-
sive spin-1 boson, presumably a gauge particle. In the ADD scenario, any gauge
fields that propagate in the bulk of the new dimensions would have their couplings
diluted by the same volume factor as the graviton and so would mediate a force
INVERSE-SQUARE LAW TESTS 27
with similar strength. Actually, since the gravitational force is also weakened by
the smallness of the MN relative to M∗ , one would expect any such gauge forces
to be stronger than gravity by a very large factor of (M∗ /MN )2 ∼ 106 —108 . This
is acceptable if the range is substantially shorter than a millimeter (see Sec. 4.4.3)
Gauge bosons could have a mass in an interesting range if the symmetry is broken
via a scalar condensate on a brane. The resulting mass will be diluted by the bulk
3 2
volume as well, and would naturally be in the range M∗ /(V M∗ ) ∼ M∗ /MP . For
M∗ of order a few TeV, the range would be about a hundred microns(70). If the
symmetry breaking occurs on the brane we live on, the gauge boson couplings to
standard model matter could be substantially suppressed (102).
Compactifications of string theory and other extra-dimensional theories often
contain new massless spin-1 particles, known as graviphotons, that arise from
components of the higher- dimensional graviton. These generally do not couple
to ordinary light matter, but it has been suggested that such bosons might acquire
small masses and small, gravitational-strength couplings to ordinary matter, e.g.
by mixing with other vector bosons (100, 101, 104, 105). Light spin-1 bosons
do not suffer from the naturalness or cosmological difficulties of scalar particles,
provided that they couple to conserved currents. However, spin-1 (and spin-0)
boson exchange necessarily “violates” the Equivalence Principle and the couplings
of bosons with masses less than 1 µeV are strongly constrained by the experiment
of Ref.(106).
2.5 Attempts to solve the cosmological constant problem
Comprehensive reviews of the cosmological constant problem and the many at-
tempts to solve it can be found in Refs. (107, 108, 109, 29, 110). Recent theo-
28 ADELBERGER, HECKEL and NELSON
retical activity on this topic has been intense but is still inconclusive. We will
not attempt an exhaustive discussion of this issue, but will simply mention a few
of the interesting recent proposals that imply modifications of the ISL at long
Beane (30) pointed out that in any local effective quantum field theory, nat-
uralness would imply new gravitational physics at a distance scale of order a
millimeter that would cut off shorter distance contributions to the vacuum en-
ergy. Sundrum (31) has speculated about the sort of effective theory that might
do this. Sundrum proposed that the graviton is an extended object, with size of
order a millimeter, and has been exploring how to construct a natural and viable
effective field theory arising from this picture (31, 111). It is still not clear how
self-consistent this effective theory is, but it does have the great virtue of mak-
ing a definite, testable experimental prediction—gravity should shut off below a
distance scale of order a 100 microns.
Many people have attempted to use extra dimensions to explain the small-
ness of cosmological constant, motivated by the alluring observation (112) that
in higher-gravitational theories with branes, the 4-dimensional vacuum energy or
brane tension does not necessarily act as a source of 4-dimensional gravity, but
can instead lead to curvature only in the new dimensions. So far no solved, con-
sistent example actually yields a small cosmological constant in the 4-dimensional
effective description without extreme finetuning or other problematic features.
Theories with branes and noncompact new dimensions allow for another sur-
prising phenomenon known as quasi-localization of gravity (113, 114, 115, 116).
In these theories, as in RSII, long-distance gravity is higher dimensional. How-
ever there is no zero-mode bound to our 3-brane. There is, instead, a metastable
INVERSE-SQUARE LAW TESTS 29
quasi-bound state that propagates 4-dimensionally along the brane over times and
distances short compared to some maximum scale. The ISL, and 4-dimensional
General Relativity, will approximately apply from rmin to rmax , but not to arbi-
trarily long distances. The consistency of various theories of quasi-localization is
still under debate and the theories themselves have been rapidly mutating.
The holographic principle insinuates that a local description of a gravitational
theory must break down somehow, since there are not enough degrees of free-
dom to allow for independent observables at different space-time points. Several
theorists have speculated that the breakdown of locality might even occur in a
subtle way at astronomical or even longer distances, and that this might explain
the size of the cosmological constant (117, 118, 119, 120, 121). In the scenario of
Banks (117, 120, 122, 123), supersymmetry ends up being broken at a scale of a
few TeV by nonlocal effects due to the cosmological constant, leading to masses
for the gravitino, dilaton and other moduli of order meV and deviations from the
ISL at 100 microns.
Many of the above ideas share the possibility that there is some scale rmax ,
beyond which Einstein gravity gets modified. Modifying gravity at long distance
allows for a new approach to the cosmological constant. The observed acceleration
of the universe might be caused by a change in the behavior of gravity at the
Hubble scale, instead of by dark energy(124). The prospect that the effective
Newton’s constant might be strongly-scale dependent at large distance scales
(gravity as a “high-pass spatial filter”) is fascinating, and leads to a new view of
the cosmological constant problem. Conventionally it is assumed that the vacuum
energy gravitates so weakly because, for some mysterious reason, this energy is
actually very small. But if the strength of gravity depends on the wavelength of
30 ADELBERGER, HECKEL and NELSON
the source, it becomes credible that the vacuum energy is indeed very large, but
that it gravitates weakly because it is very smooth. Ideas along these directions
have been pursued in Refs.(125, 126, 127).
Refs. (128, 129, 130, 131, 132) present an intriguing assertion about theories of
quasi-localization that may account for the acceleration of the universe. For any
localized gravitational source, there exists a distance scale r∗ , which is a function
of the gravitational radius of the source and rmax , beyond which the graviton will
acquire an extra polarization state that couples to the source so that the strength
of gravity will change. This scale r∗ decreases for less massive gravitating objects.
Dvali, Gruzinov and Zaldarriaga(132) argue that ultra-precise measurements of
the anomalous precession of the perihelion of planetary orbits can test models of
quasi-localization that explain the cosmological acceleration. For instance a 17-
fold improvement this measurement in the Earth-Moon system via LLR, would
test a particular model in Ref.(132).
3.1 Signals
The dominant problem in testing gravitation at short length scales, is the extreme
weakness of gravity. This forces the experimenter to adopt designs that maximize
the signal and minimize backgrounds and noise. For example, one could measure
the force between spheres as was done by (133), between cylinders as was done in
(134) and (135), between a sphere and a plane as was done in (136) and (137), or
in planar geometry as was done by (69) and (138). Clearly, at a given minimum
separation, the signal from a short-range interaction, per unit test-body mass, is
least for 2 spheres and greatest for 2 planes.
INVERSE-SQUARE LAW TESTS 31
The Yukawa force between two spheres of radii r1 and r2 and masses m1 and
m2 , whose centers are separated by s, is
r1 r2 s e−s/λ
FY = αG m1 m2 Φ Φ 1+ , (19)
λ λ λ s2
where Φ(x) = 3(x cosh x − sinh x)/x3 . For x >> 1, Φ(x) ≈ 3ex /(2x2 ), while for
x << 1, Φ(x) ≈ 1. Therefore, for λ << r, the ratio of Yukawa to Newtonian
forces for two spheres of radius r separated by a gap d is
FY 9 λ3 d
≈ α 3 (1 + )e−d/λ . (20)
FN 2r 2r
The potential energy from a Yukawa interaction between a flat plate of area
Ap , thickness tp and density ρp a distance d from an infinite plane of thicknesses
t, and density ρ, is
VY = 2παGρp ρλ3 Ap [1 − e−tp /λ ][1 − e−t/λ ]e−d/λ , (21)
if end effects are neglected. The corresponding force is
FY = 2παGρp ρλ2 Ap [1 − e−tp /λ ][1 − e−t/λ ]e−d/λ . (22)
In this case, for λ much less than the thicknesses, the force ratio becomes
FY λ2
≈ α e−d/λ . (23)
FN tp t
The potential energy of a Yukawa interaction between a sphere of radius r and
mass m above an infinite plane of thickness t and density ρp is
VY = παGmρλ2 Φ(r/λ)e−s/λ (24)
where s is the distance from the center of the sphere to the plane. The corre-
sponding force is FY = παGmρλΦ(r/λ)e−s/λ . In this case, for λ r, the force
ratio becomes
FY 3 λ3
≈ α 2 e−d/λ (25)
FN 4r t
where d is the gap between the spherical surface and the plane.
32 ADELBERGER, HECKEL and NELSON
3.2 Noise considerations
Thermal noise in any oscillator sets a fundamental limit on the achievable sta-
tistical error of its amplitude. A single-mode torsion oscillator subject to both
velocity and internal damping obeys the equation
¨ ˙
T = I θ + bθ + κ(1 + iφ)θ , (26)
where T is the applied torque, I the rotational inertia, θ the angular deflection
of the oscillator, and κ the torsional spring constant of the suspension fiber. The
velocity-damping coefficient b accounts for any losses due to viscous drag, eddy
currents etc., while the loss angle φ accounts for internal friction of the suspension
fiber. We compute the spectral density of thermal noise following Saulson’s (147)
treatment based on the fluctuation-dissipation theorem. The spectral density of
torque noise power (per Hz) at frequency ω is
Tth (ω) = 4kB T (Z(ω)) (27)
where kB is Boltzmann’s constant, T the absolute temperature, and Z = T /θ is
the mechanical impedance.
First consider the familiar case of pure velocity damping (b > 0, φ = 0) where
Z(ω) = iIω + b + κ/(iω). In this case, the spectral density of torque noise,
2 Iω0
Tth (ω) = 4kB T (28)
(ω0 = κ/I is the free resonance frequency and Q = Iω0 /b the quality factor of
the oscillator) is independent of frequency. The corresponding spectral density
of angular deflection noise in θ is
2 4kB T ω0
θth (ω) = 2 − ω 2 )2 + (ω ω/Q)2 . (29)
QI (ω0 0
INVERSE-SQUARE LAW TESTS 33
Note that the integral of Eq. 29 over all f = ω/(2π) is kB T /κ, consistent with
the equipartition theorem. The signal due to an external torque T is
T 1
|θ(ω)| = (30)
I 2
(ω0 − ω 2 )2 + (ωω0 /Q)2
so that the signal-to-noise ratio in unit bandwidth has the form
|θ(ω)| T
S(ω) = = (31)
2 2
θth + θro 2 2
4kB T ω0 I/Q + θro I 2 ((ω0 − ω 2 )2 + (ωω0 /Q)2 )
where we have included a noise contribution θro from the angular deflection
readout system. The signal is usually placed at a frequency ω ≤ ω0 to avoid
attenuating the deflection amplitude θ because of oscillator inertia.
Now consider the case of pure internal damping (b = 0, φ > 0) where Z =
iIω + κ/(iω) + κφ/ω. In this case the spectral density of thermal noise has a 1/f
Tth (ω) = 4kB T (32)
where now Q = 1/φ. The corresponding spectral density of thermal noise in the
angular deflection is
4kb T ω02
θth = 2 2 . (33)
QωI (ω0 − ω 2 )2 + (ω0 /Q)2
The signal-to-noise ratio in unit bandwidth is
S= (34)
2 2 2 2
4kB T Iω0 /(Qω) + θro I 2 ((ω0 − ω 2 )2 + (ω0 /Q)2 )
so that it is advantageous to boost the signal frequency above ω0 until θro makes
a significant contribution to the noise.
3.3 Backgrounds
Electromagnetic interactions between the test bodies are the primary source of
background signals and may easily dominate the feeble gravitational signal. In the
34 ADELBERGER, HECKEL and NELSON
following sections, we discuss the dominant electromagnetic background effects
in ISL experiments.
3.3.1 Electric potential differences and patch fields
Electric charges residing on insulating or ungrounded test bodies are difficult to
quantify and Coulomb forces acting on such bodies can exceed their weights. For
this reason, ISL tests typically employ conducting grounded test bodies. Even
so, a variety of effects can give the test bodies different electric potentials. If
dissimilar materials are used for the test bodies, a potential difference equal to
the difference between the work functions of the two materials is present, typically
of order of 1 V. Even if the same material is used for both test bodies or the test
bodies are both coated with the same material, such as gold, small differences
in the contact potentials connecting the test bodies to ground can leave a net
potential difference between the test bodies. With care, such contact potential
differences can be reduced to the level of a few mV(139)).
Neglecting edge effects, the attractive electric force between a conducting plate
with area A parallel to an infinite conducting plate is FE (d) = 2 /(2d2 ),
0 AV
where d is the separation between the plates, V is the potential difference between
the plates and 0 is the permitivity of free space. For 1 mm thick plates with
a density of 10 g/cm3 , separated by 0.1 mm, FE becomes as large as FN for
a potential difference of 10 mV, and the electric force grows with decreasing
separation while the Newtonian force is constant.
Even if test bodies are at the same average potential, they experience a residual
electric interaction from patch fields–spatially varying microscopic electric poten-
tials found on the surface of materials(140). Patch fields arise because different
INVERSE-SQUARE LAW TESTS 35
crystal planes of a given material have, in general, different work functions(141)
that can, in extreme cases be as big as 1 V. To the extent that the surface is a
mosaic of random microscopic crystal planes, there will be local potential differ-
ences with a scale size comparable to the size of the microcrystals. For example,
different planes of W crystals have work functions that vary by 0.75 V. Gold is
a good choice for test body coating as the work functions of its crystal planes
vary by only 0.16 V. Surface contaminants also contribute to the local variation
of the electric potential, altering the local work function and providing sites for
the trapping of electrical charge. In the limit that the patches are smaller than
the separation, the patch field force(140) scales as 1/d2 .
3.3.2 Casimir Force
Vacuum fluctuations of the electromagnetic field produce a fundamental back-
ground to ISL tests at short length scales. The Casimir force(142) between ob-
jects in close proximity may be viewed as arising either from the modification of
the boundary conditions for zero-point electromagnetic modes or from the force
between fluctuating atomic dipoles induced by the zero-point fields(143). The
Casimir force can be quite large compared to the force of gravity. The Casimir
force between two grounded, perfectly conducting, smooth, infinite planes at zero
temperature, separated by a distance d, is attractive
FC π2 ¯ c
= . (35)
A 240d4
For a 1 mm thick plate of area A near an infinite plate of thickness 1 mm (again,
both with density 10 g/cm3 ), FC becomes equal to FN at a separation of d = 13
Because of the difficulty of precisely aligning two parallel planes that involves
36 ADELBERGER, HECKEL and NELSON
4 degrees of freedom, experimenters usually measure the force between a sphere
(or spherical lens) and a plane. Assuming perfectly conducting, smooth bodies
at zero temperature, the Casimir force is attractive with a magnitude
π 3 R¯ c
FC = (36)
where R is the radius of the sphere and d is the minimum separation between
the surfaces of the sphere and plane. For a 1 mm radius sphere near an infinite
1 mm thick plane (both with a density of 10 g/cm3 ) FC becomes equal to FN at
a separation d = 2.5 microns.
The Casimir force expressions in Eqs. 35 and 36 must be corrected for finite
temperature, finite conductivity, and surface roughness (see below). All these cor-
rections vary with the separation, d, making it difficult to isolate a gravitational
anomaly from an electrical effect.
3.3.3 Electrostatic shielding
Fortunately, backgrounds from Casimir, electric potential differences and patch-
effect forces can be greatly reduced by using a moving “attractor” to modulate
the signal on a stationary “detector” and placing a stationary, rigid, conducting
membrane between the “detector” and the “attractor”. But this electrostatic
shield places a practical lower limit of some 10’s of µm on the minimum attainable
separation between the test bodies.
3.3.4 Magnetic effects
Microscopic particles of iron imbedded in nominally nonmagnetic test bodies dur-
ing their machining or handling, or in the bulk during smelting, can create local
magnetic fields so small they are difficult to detect with standard magnetome-
INVERSE-SQUARE LAW TESTS 37
ters, yet large enough to compete with gravitational forces. The magnetic force
between two magnetically saturated iron particles, 1 mm apart, each 10 microns
in diameter can be as large as 10−7 dynes, varying as the inverse fourth power of
the distance between the particles. This is as large as the gravitational attraction
between a 1 mm thick Al plate with an area of 3 cm2 near an infinite Al plate
that is 1 mm thick. Yet the magnetic field of such a particle is only 0.3 mGauss
at a distance of 2 mm.
Most ISL tests modulate the position of an attractor and detect the force this
modulation produces on a detector. Even if the attractor has no ferromagnetic
impurities, any magnetic field associated with the attractor modulation, say from
motor magnets or flowing currents, can couple to magnetic impurities in the
detector. Experimenters typically measure the magnetic field associated with the
modulation of the attractor and apply larger fields to find the response of the
detector. A variety of smaller magnetic background effects areassociated with
the magnetic susceptibilities of the test bodies. Standard magnetic shielding of
the experimental apparatus is usually sufficient to reduce the ambient magnetic
field to a level where the susceptibilities pose no problem.
3.3.5 Other effects
Modulation of the attractor position may introduce background effects that are
not electromagnetic. The most obvious is a spurious mechanical coupling whereby
the motion of the attractor is transmitted via the apparatus to the detector.
These unwanted couplings can be reduced by multiple levels of vibration isolation
and by experimental designs that force the signal frequency to differ from that
of the attractor modulation. Experiments are performed in vacuum chambers to
38 ADELBERGER, HECKEL and NELSON
reduce coupling between the test bodies from background gas.
3.4 Experimental strategies
ISL tests can be constructed as null experiments, partial-null experiments or as
a direct measurements. For example, Ref. (134) studied the force on a cylinder
located inside a cylindrical shell. To the extent that the length-to-radius ratios
of the cylinders are very large, this constitutes a null-test as the Newtonian
interaction between the cylinders gives no net force. Null tests have also been
made using planar geometry; the Newtonian force between two parallel, infinite
planes is independent of their separation. This basic idea, as discussed below, has
been exploited by Ref. (138). Null experiments have the advantage that apparatus
does not need to handle signals with a wide dynamic range and the results are
insensitive to instrumental non-linearities and calibration uncertainties.
A partial null experiment where the Newtonian signal was largely, but not
completely, cancelled has been reported in Ref. (69). As discussed below, the
partial cancellation greatly reduced the required dynamic range of the instrument,
but Newtonian gravity still gave a very characteristic signal that was used to
confirm that the instrument was performing properly, and whose form (as well
as magnitude) provided constraints on new physics.
Finally, Ref. (133) reported a direct experiment that compared the measured
force beween two spheres as their separation was switched between two values. In
this case, the results depended crucially on measuring accurately the separations
of the spheres and the forces between them.
INVERSE-SQUARE LAW TESTS 39
4.1 Low-frequency torsion oscillators
4.1.1 The Washington experiment
Hoyle et al.(69) at the University of Washington E¨t-Wash group developed a
“missing mass” torsion balance, shown in Fig. 1, for testing the ISL at short-
ranges. The active component of the torsion pendulum was an aluminum ring
with 10 equally spaced holes bored into it. The pendulum was suspended above
a copper attractor disk containing 10 similar holes. The attractor was rotated
uniformly by a geared down stepper motor. The test bodies in this instrument
were the “missing” masses of the two sets of 10 holes. In the absence of the
holes, the disk’s gravity simply pulled directly down on the ring and did not
exert a twist. But because of the holes, the ring experienced a torque that
oscillated 10 times for every revolution of the disk–giving sinusoidal torques at
10ω, 20ω and 30ω, where ω was the attractor rotation frequency. This torque
twisted the pendulum/suspension fiber and was measured by an auto-collimator
that reflected a laser beam twice from a plane mirror mounted on the pendulum.
Placing the signals at high multiples of the disturbance frequency (the attractor
rotation frequency) reduced many potential systematic errors. A tightly stretched
20 µm thick beryllium-copper electrostatic shield was interposed between the
pendulum and the attractor to minimize electrostatic and molecular torques. The
entire torsion pendulum including the mirrors was coated with gold and enclosed
in a gold-coated housing to minimize electrostatic effects. The pendulum could
not “see” the rotating attractor except for gravitational or magnetic couplings.
Magnetic couplings were minimized by machining the pendulum and attractor
40 ADELBERGER, HECKEL and NELSON
with non-magnetic tools and by careful handling.
The experiment was turned into a partial-null measurement by adding a second,
thicker copper disk immediately below the upper attractor disk. This disk also
had 10 holes bored into it, but the holes were rotated azimuthally with respect to
the upper holes by 18 degrees and their sizes were chosen to give a 10ω torque that
just cancelled the 10ω Newtonian torque from the upper attractor. On the other
hand, a new short-range interaction would not be cancelled because the lower
attractor disk was simply too far away from the pendulum. The cancellation was
exact for a separation (between the lower surface of the pendulum and the upper
surface of the attractor) of about 2 mm. For smaller separations the contribution
of the lower disk was too small to completely cancel the 10ω signal, while at
larger separations the lower disk’s contribution was too large (see Fig. 2).
Two slightly different instruments were employed; both had 10-fold rotational
symmetry and differed mainly in the dimensions of the holes. In the first ex-
periment the pendulum ring was 2.002 mm thick with 9.545 mm diameter holes
with a total hole “mass” of 3.972 g; in the second experiment the ring thickness
was 2.979 mm thick with 6.375 mm diameter holes having a total hole “mass” of
2.662 g. The resonant frequencies of the two pendulums were ω0 /2π = 2.50 mHz
and 2.14 mHz, respectively and the fundamental 10ω signals were set at precisely
10/17 ω0 and 2/3 ω0 , respectively. In both cases the 20ω and 30ω harmonics
were above the resonance. The observed spectral density of deflection noise was
close to the thermal value given in Eq. 33 for the observed Q-factor of 1500 (see
also Fig. 10 below).
INVERSE-SQUARE LAW TESTS 41
4.1.2 Signal scaling relations
The gravitational torque exerted on the pendulum by the rotating attractor is
Tg (φ) = −∂V (φ)/∂θ, where V (φ) is the gravitational potential energy of the
attractor when the attractor is at angle φ, and θ is the twist angle of the pen-
dulum. For cylindrical holes, four of the six Newtonian torque integrals can be
solved analytically but the remaining two must be evaluated numerically. Clearly
the Newtonian signal drops as the number of holes increases and their radii de-
crease because the long-range gravitational force tends to “average away” the
holes. It also drops rapidly for separations much greater than the thickness of
the upper attractor disk. Only 3 of the Yukawa torque integrals can be solved
analytically. However, when the Yukawa range, λ, becomes much smaller than
any of the relevant dimensions of the pendulum/attractor system a simple scaling
relation based on Eq. 21 governs the signal and
TY ∝ αGρp ρa λ3 e−s/λ (37)
where ρp and ρa are the densities of the pendulum and attractor, λ is the Yukawa
range, and A the overlap area of the holes in the pendulum with those of the
attractor when the attractor angle is φ.
4.1.3 Backgrounds
The effects from spurious gravitational couplings, temperature fluctuations, vari-
ations in the tilt of the apparatus and magnetic couplings were measured and
found to be negligible compared to the statistical errors. Electrostatic couplings
were negligible because the pendulum was almost completely enclosed by a gold-
coated housing. The 20 µm thick electrostatic shield was rigid to prevent sec-
ondary electrostatic couplings. The shield’s lowest resonance was about 1 kHz,
42 ADELBERGER, HECKEL and NELSON
and the attractor could only produce a false electrostatic effect by flexing the
shield at a very high m = 10 mode.
4.1.4 Alignment and calibration
Although all sub-millimeter tests of the ISL face an alignment problem, it was
especially important in this experiment because of the relatively large size of the
pendulum (chosen to increase the sensitivity). Alignment was done in stages.
First the pendulum ring was leveled by nulling its differential capacitance as the
pendulum rotated above two plates installed in place of the electrostatic shield.
The shield was then replaced and the tilt of the entire apparatus was adjusted
to minimize the pendulum-to-shield capacitance. Horizontal alignment was done
by measuring the gravitational torque as the horizontal position of the upper
fiber suspension point was varied. Determining separations from mechanical or
electrical contacts was found to give unreliable results so the crucial separation
between the pendulum and the electrostatic shield was determined from the elec-
trical capacitance.
The torque scale was directly calibrated using gravity. Two small aluminum
spheres were placed in an opposing pair of the 10 holes of the torsion pendulum
and two large bronze spheres, placed on an external turntable, were rotated
uniformly around the instrument at a radius of 13.98 cm. Because this was close
to the 16.76 cm radius(144) used in determining G and the ISL has been tested
at this length scale (see Fig. 9), the calibration torque could be computed to high
accuracy. The torsion constant of the fiber was about .03 dyne cm.
INVERSE-SQUARE LAW TESTS 43
4.1.5 Results
Data were taken at pendulum/attractor separations down to 197µm, where the
minimum separation was limited by pendulum “bounce” from seismic distur-
bances. The torque data, shown in Fig. 2, were analysed by fitting a potential of
the form given in Eq. 2 with α and λ as free parameters and treating the impor-
tant experimental parameters (hole masses and dimensions, zero of the separation
scale, torque calibration constant, etc.) as adjustable parameters constrained by
their independently measured values. Reference (69) reported results from the
first of the two experiments; the combined 95% confidence level result of both
experiments was given subsequently(145, 146) and is shown in Fig. 6.
The results exclude the scenario of two equal extra dimensions with a size giv-
ing a unification scale of M ∗ = 1 TeV; this would imply an effective Yukawa
interaction with λ = 0.3 mm and α = 16/3 if the extra dimensions are compacti-
fied as a torus. Because α ≥ 16/3 is consistent with the data only for λ < 130 µm,
Eq. 6 implies that M∗ > 1.7 TeV. A tighter bound on M∗ can be extracted from
the radion constraint, which in the unwarped case where 1/3 ≤ α ≤ 3/4 for
1 ≤ n ≤ 6, suggests that M∗ ≥ O(3 Tev).
More interesting and general is the upper limit Ref. (69, 145, 146) places on the
size of the largest single extra dimension, assuming all other extra dimensions
are significantly smaller. For toroidal compactification, this corresponds to the
largest λ consistent with α = 8/3, leading to an upper limit R∗ ≤ 155 µm. Other
compactification schemes necessarily give somewhat different limits.
44 ADELBERGER, HECKEL and NELSON
4.2 High-frequency torsion oscillators
4.2.1 The Colorado experiment
The modern era of short-range ISL tests was initiated by Long et al. at the
University of Colorado(148). Their apparatus, shown in Fig. 3, used a planar
null geometry. The attractor was a small 35 mm × 7 mm × .305 mm tungsten
“diving board” that was driven vertically at 1 kHz in its 2nd cantilever mode by a
PZT bimorph. The detector, situated below the “diving board”, was an unusual
high-frequency compound torsion oscillator made from 0.195 mm thick tungsten.
It consisted of a double-rectangle for which the 5th normal mode resonates at 1
kHz; in this mode the smaller 11.455 mm × 5.080 mm rectangle (the detector)
and the larger rectangle (one end of which was connected to a detector mount)
counter-rotated about the torsional axis with the detector rectangle having the
larger amplitude. The torsion oscillations were read out capacitively from the
larger rectangle. The attractor was positioned so that its front end was aligned
with the back edge of the detector rectangle and a long edge of the attractor was
aligned above the detector torsion axis. A small electrostatic shield consisting of
a .06 mm thick sapphire plate coated with 100 nm of gold was suspended between
the attractor and the detector. The attractor, detector and electrostatic shield
were mounted on separate vibration-isolation stacks to minimize any mechanical
couplings, and were aligned by displacing the elements and measuring the points
of mechanical contact.
In any null experiment it is helpful to know the precise form of a signal of new
physics. Long et al. did this by sliding away the electrostatic shield and applying
a 1.5 V bias to the detector to give a large, attractive electrostatic force; this
INVERSE-SQUARE LAW TESTS 45
determined the phase of the signal that would be produced by a new, short-range
4.2.2 Signal-to-noise considerations and calibration
The spectral density of thermal force noise in the multi-mode oscillator used
in Ref. (148) obeys a relation similar to Eq. 32. The Colorado experimenters
operated on a resonance with a Q = 25, 000 so the readout noise was negligible.
Data were taken with the attractor driven at the detector resonance as well as
about 2 Hz below the resonance (see Fig. 4). The means of the on-resonance
and off-resonance data agreed within errors, but the standard deviation of the
on-resonance data was about twice that of the off-resonance data. This is just
what one expects if the on-resonance data were dominated by thermal noise.
Furthermore, the on-resonance signal did not change as the geometry was varied.
This ruled out the unlikely possibility that the observed null result came from
a fortuitous cancellation of different effects, all of which should have different
dependences on the geometry. The torsion oscillation scale was calibrated by
assuming that the on-resonance signal was predominantly thermal.
4.2.3 Backgrounds
Although a net signal was seen, it had the same magnitude on and off-resonance
and presumably was due to electronic pickup. No evidence was seen for an addi-
tional, statistically significant background. Checks with exaggerated electostatic
and magnetic effects showed that plausible electrostatic and magnetic couplings
were well below the level of thermal noise.
46 ADELBERGER, HECKEL and NELSON
4.2.4 Results
The null results from this experiment, taken at a separation of 108 µm, were
turned into α(λ) constraints using a maximum-likelihood technique. For various
assumed values of λ, the expected Yukawa force was calculated numerically 400
times, each calculation using different values for experimental parameters that
were allowed to vary within their measured ranges. A likelihood function was
constructed from these calculations and was used to extract 95% level limits on
α(λ). The results(138), shown in Fig. 6, exclude a significant portion of the
moduli forces predicted by Dimopoulos and Giudice(98).
4.3 Micro-cantilevers
4.3.1 The Stanford experiment
Chiaverini et al. at Stanford(149, 150) recently reported a test of the ISL us-
ing a microcantilever apparatus that was suited for the 10 µm length scale, but
which did not have the sensitivity to see gravity. The apparatus consisted of a
silicon microcantilever with a 50µm × 50µm × 50µm gold test mass mounted on
its free end. The cantilever had a spring constant of about 5 dyne/cm and its
displacement was read out with a optical-fiber interferometer. The microcan-
tilever, which hung from a 2-stage vibration isolation system, oscillated vertically
in it lowest flexural mode at a resonant frequency of ω0 ≈ 300 Hz . The mi-
crocantilever was mounted above an attractor consisting of 5 pairs of alternating
100µm × 100µm × 1mm bars of gold and silicon. The attractor was oscillated hor-
izontally underneath the cantilever at about 100 Hz by a bimorph; the amplitude
was chosen to effectively resonantly excite the cantilever at the 3rd harmonic of
the attractor drive frequency. The geometry was quite complicated; the 3rd har-
INVERSE-SQUARE LAW TESTS 47
monic gravitational force on the cantilever depended sensitively and nonlinearly
on the drive amplitude. An electrostatic shield consisting of a 3.0 µm thick silicon
nitride plate with 200 nm of gold evaporated onto each side was placed between
the cantilever and the attractor. Data were taken with the vertical separations
between the cantilever and the attractor as small as 25 µm.
4.3.2 Signal-to-noise considerations
The dominant noise source in the Stanford experiment was thermal noise in the
cantilever, which was reduced by operating at about 10 K. The Q-factors of the
oscillating cantilevers in these measurements were typically about 1200.
4.3.3 Calibration and alignment
The cantilever spring constant k was found in two independent ways that agreed
to within 10%: by assuming that when the cantilever was far from the attractor
it was in thermal equilibrium with its surroundings, and by calculating k from
the measured resonant frequency. The the cantilever was aligned with respect to
the attractor using magnetic forces. The cantilever’s test mass had a thin nickel
film on one of its faces, and the attractor was equipped with a zig-zag conducting
path the followed the gold bars. When a current was run through the attractor
it placed a force on the cantilever that had half the frequency and phase as the
expected gravitational signal but with vastly greater amplitude. This force was
used to align the apparatus.
4.3.4 Backgrounds
This experiment was limited by a spurious force about 10 times greater than
the thermal detection limit. This force was clearly not fundamental, i.e. related
48 ADELBERGER, HECKEL and NELSON
to the mass distributions on the attractor, because the phase of signal did not
behave as expected when the horizontal offset of the attractor oscillation was
varied or as the attractor drive amplitude was changed. The most likely source
of a spurious force is electrostatics; the cantilever was not metallized so could
hold charge and the shield was observed to vibrate by a pm or so. A potential
on the cantilever of about 1 V would be sufficient to produce the observed force.
Although thin nickel layers were incorporated into the test mass and attractor,
the experimenters estimate that magnetic forces from the nickel (as well as from
iron impurities in the gold) were too small to explain the observed backgound
force. Vibrational coupling between the attractor and cantilever was minimized
because the attractor was moved at right angles to the cantilever’s flex.
4.3.5 Results
The experimenters saw a spurious (8.4 ± 1.4) × 10−12 dyne force at their closest
separation of 25µm. They assigned a 95% confidence upper limit on a Yukawa
interaction by computing the minimum α as a function of λ that would correspond
to this central value plus 2 error bars. Their constraint, which rules out much
of the parameter space expected from moduli-exchange as computed in (98) is
shown in Fig. 8
4.4 Casimir force experiments
Early attempts to detect the Casimir force between metal surfaces(151) and di-
electric surfaces(152, 153, 154, 155) had relatively large errors. Nonetheless, it
was recognized(156, 157, 158) that such measurements provided the tightest con-
straints on new hypothetical particles with Compton wavelengths less than 0.1
INVERSE-SQUARE LAW TESTS 49
mm. In recent years, three groups have reported measurements of the Casimir
force with relative errors of 1% to 5%. Although these experiments are orders
of magnitude away from providing tests of the ISL, they do probe length scales
from 20 nm to 10 µm, where large effects may occur (see Sec. 2.4.4).
4.4.1 Experimental methods
The first of the recent experiments, performed by Lamoreaux at the University
of Washington(136, 159), used a torsion balance to measure the force between
a flat quartz plate and a spherical lens with a radius of 12.5 ± 0.3 cm. Both
surfaces were coated with 0.5µm of Cu followed by 0.5µm of Au. A piezoelectric
stack stepped the separation between the plate and lens from 12.3µm to 0.6µm,
at which point the servo system that held the torsion pendulum angle constant
became unstable. The force scale was calibrated to 1% accuracy by measuring the
servo response when a 300 mV potential difference was applied between the plate
and lens at a large (≈ 10µm) separation. The absolute separation between the
lens and plate was obtained by applying a potential difference between the two
surfaces and fitting the measured force (for distances greater than 2µm where the
Casimir force was small) to the expected 1/d dependence, where d is the distance
between the plate and lens. After subtracting the 1/d component from the force
scans, the residual signals were fitted to the expected form for a Casimir force
and an agreement to within 5% was found(136, 159).
Mohideen and collaborators at the University of California Riverside reported
a series of experiments that used an atomic force microscope (AFM) to measure
the Casimir force between a small sphere and a flat plate(137, 160, 161, 162).
Their most recent measurement used a 191µm diameter polystyrene sphere that
50 ADELBERGER, HECKEL and NELSON
was glued to a 320µm long AFM cantilever. The cantilever plus sphere and a
1 cm diameter optically polished sapphire disk were coated with 87 nm of Au,
with a measured surface roughness of 1.0 ± 0.1 nm. The disk was placed on
a piezoelectric tube with the sphere mounted above it, as shown in Fig. 7. The
cantilever flex was measured by reflecting laser light from the cantilever onto split
photodiodes. The force scale was calibrated electrostatically by applying a ±3 V
potential difference between the sphere and disk at a separation of 3µm. The force
difference between the +3 V and −3 V applied potentials was used to determine
the residual potential difference between the disk and sphere when their external
leads were grounded together: 3 ± 3 mV. The force between the sphere and disk
was measured for separations ranging from 400 nm to contact. It was found that
the surfaces touched when their average separation was 32.7 ± 0.8 nm. This was
attributed to Au crystals protruding from the surfaces. The measured forces were
compared to the expected Casimir force for separations from 62 − 350 nm and
agreement to within 1% was found(162).
The record for measuring the Casimir force at the closest separation is held
by Ederth(163) at the Royal Institute of Technology in Stockholm who measured
the force between crossed cylindrical silica disks with diameters of 20 mm. A
template-stripping method(164) was used to glue 200 nm layers of Au, with an
rms surface roughness of ≤ 0.4 nm, to the silica disks. The Au surfaces were then
coated with a 2.1 nm thick layer of hydrocarbon chains to prevent the adsorption
of surface contaminants and the cold-welding of the Au surfaces upon contact.
One cylindrical surface was attached to a piezoelectric stack and the other to
a piezoelectric bimorph deflection sensor that acted as a cantilever spring. The
two surfaces were moved toward one another starting at a separation of greater
INVERSE-SQUARE LAW TESTS 51
than 1µm, where the Casimir force was less than the resloution of the force
sensor, and ending at a separation of 20 nm at which point the gradient of the
Casimir force was comparable to the stiffness of the bimorph spring, causing the
surfaces to jump into contact. The stiffness of the bimorph sensor was calibrated
by continuing to move the piezotube another 200 − 300 nm while the surfaces
were in contact. The absolute separation between the surfaces was found by
fitting the measured force curve to the expected Casimir signal (plus electrostatic
background which was found to be negligible) with the absolute separation as a
fit parameter. It was found that at contact the surfaces compressed by ≈ 10 nm.
The measured force was compared to the expected Casimir force over the range
of separations from 20 to 100 nm and an agreement to better than 1% was found.
4.4.2 Signal-to-noise and background considerations
The signal-to-noise ratio for Casimir force measurements as tests of the ISL may
be improved by using more sensitive force probes, thicker metallic coatings on
the test bodies, and operating at lower temperatures. Nonetheless, the dominant
limitation for interpreting the measurements as tests of the ISL come from under-
standing the Casimir force background to high accuracy. There is a growing liter-
ature on the corrections that must be applied to the Casimir force calculated for
smooth, perfect conductors at zero temperature (Eqns. 35 & 36). The dominant
corrections are for finite temperature, finite conductivity, and surface roughness.
Corrections for finite temperature are important for test-body separations greater
than d ≈ 1µm. For the Lamoreaux experiment, the finite temperature correc-
tions at 1µm and 6µm separations were 2.7% and 174% of the zero-temperature
Casimir force, respectively(165). The effects of finite conductivity on the tem-
52 ADELBERGER, HECKEL and NELSON
perature correction were considered by a number of authors(166, 167, 168) and
results believed to be accurate to better than 1% were obtained. The correction
to the Casimir force for the finite conductivity of the metallic surfaces is of or-
der 10% at d = 1µm and grows with smaller separations. Finite-conductivity
corrections using a plasma model for the dielectric function of the metal give
the correction as power series in λP /d where λP is the plasma wavelength of the
metal(169, 170, 171). Corrections have also been obtained using optical data
for the complex dielectric function(172, 162, 173, 174). Surface roughness of
the test bodies contributes a correction to the Casimir force that can be ex-
pressed as a power series in h/d where h is a characteristic amplitude of the sur-
face distortion(175, 176, 177, 171). For stochastic distortions, the leading-order
surface-roughness correction is 6(h/d)2 which is less than 1% of the Casimir force
at closest separation in the experiments of Ederth and the Riverside group.
4.4.3 Results
Constraints on Yukawa interactions with ranges between 1 nm and 10µm, shown
in Fig. 8, have been extracted from the Casimir-force measurements of Lamoreaux(165,
148), Ederth(178), and the Riverside group(179, 180, 6, 181). Also shown in Fig. 8
are constraints at even smaller ranges obtained from earlier van der Waals force
experiments(182). It should be noted that most of these constraints were ob-
tained by assuming that a Yukawa force could not exceed the difference between
the measured force and the predicted Casimir effect. To be rigorous, the raw
data should be fitted simultaneously with both Casimir and Yukawa forces, in
general, leading to significantly less stringent limits on |α|. Deviations from New-
tonian gravity in this region that follow a power law (Eq. 3) are constained more
INVERSE-SQUARE LAW TESTS 53
strongly by the much more sensitive longer-range gravity experiments discussed
4.5 Astronomical tests
A summary of constraints on Yukawa interactions with λ ≥ 1 mm may be found
in Figure 2.13 of the 1999 review by Fischbach and Talmadge(13) that we repro-
duce in part in our Fig. 9. Since the publication of Ref. (13), the constraints
for λ ≤ 1 cm have been substantially improved as discussed above. However, the
constraints at larger ranges from laboratory, geophysical and astronomical data
(see Fig. 9) are essentially unchanged from those given in (13). The astronomical
tests provide the tightest constraints on α. These are typically based on Kep-
lerian tests comparing G(r)M values deduced for different planets. However,
the tightest constraint comes from lunar-laser-ranging (LLR) studies of the lunar
orbit. Because this result may improve significantly in the next few years, we
give some details of the measurement here.
The LLR data consist of range measurements from telescopes on Earth to
retroreflectors placed on the Moon by US astronauts and an unmanned Soviet
lander. The measurements, which began in 1969, now have individual raw range
precisions of about 2 cm, and are obtained from single photon returns, one of
which is detected for roughly every 100 launched laser pulses(183). The vast
majority of the data come from sites in Texas(184) and in southern France(185).
The launched laser pulses have full widths at half-maximum of about 100 ps; the
return pulses are broadened to about 400 ps because the reflector arrays typically
do not point straight back to Earth due to lunar librations. The launch-telescope
to lunar-retroreflector ranges have to be corrected for atmospheric delay which is
54 ADELBERGER, HECKEL and NELSON
computed from the local barometric pressure, temperature and humidity. For the
Moon straight overhead, the range correction at the Texas site is about 2 m. The
dominant uncertainties in converting raw range measurements into separations
between the centers of mass of the the Earth and the Moon come from tidal
distortions of the Earth and Moon and atmospheric and ocean loading of the
Earth. The current model, using the entire world data set, gives an uncertainty
of about 0.4 cm in the important orbit parameters.
The most sensitive observable for testing the ISL is the anomalous precession
of the lunar orbit. If the Moon were subject only to a central Newtonian 1/r po-
tential from the Earth, the lunar orbit would not precess. The orbit does precess
due to the Earth’s quadrupole field and perturbations from other solar system
bodies, as well as from the small general relativistic geodetic precession and pos-
sibly also from a Yukawa interaction; the conventional sources of precession must
be accounted for to obtain the anomalous Yukawa precession rate. Ignoring terms
of order ε2 , where the Moon’s eccentricity is ε = .0549, the anomalous Yukawa
precession rate δω is (13)
δω α a
= e−a/λ , (38)
ω 2 λ
where ω = 2π radians/month and a is the mean radius of the Moon’s orbit.
The constraint on α(λ) is tightest for λ = a/2 and falls off relatively steeply
on either side of λ = a/2. The current LLR 2σ upper limit on δω is 270 µarc
s/y; this follows because the observed precession of about 19.2 milliarcseconds/yr
agrees with the general relativistic prediction to (−0.26 ± 0.70)% where the error
is “realistic” rather than “formal” (the error quoted in Ref. (186) should be
doubled; J Williams, private communication 2003). We conclude that at 95%
confidence δω/ω < 1.6 × 10−11 ; the corresponding LLR constraint is shown in
INVERSE-SQUARE LAW TESTS 55
Fig. 9.
5.1 Summary of experimental results
Because gravity is intimately connected to the geometry of space-time, ISL tests
could provide very direct evidence for the existence of extra space dimensions.
In addition, ISL tests are sensitive to the exchange of proposed new low-mass
bosons. A variety of theoretical considerations, outlined above, hint that new
effects may occur at length scales between 10 µm and 1 mm. This, as well as the
urge to explore unmapped territory, has motivated the development of new exper-
imental techniques that have produced substantial improvements in constraints
upon theories. The overall slope of the experimental constraints shown in Figs. 6,
8 and 9 reflects the rapidly decreasing signal strength of a new interaction as its
range decreases. At gravitational strength (α = 1 in Fig. 6), the ISL has been
verified down to a distance λ = 200 µm. At length scales between 20 nm and
4 mm, many square decades in Yukawa-parameter space have been ruled out.
These results have eliminated some specific theoretical scenarios, but many other
interesting ideas are still viable as their predicted effects lie somewhat below the
current experimental limits.
5.2 Prospects for improvements
5.2.1 Short-range tests of the ISL
To make a gravitational strength (α = 1) ISL test at a 20 µm length scale
requires an increase in the background-free sensitivity of at least a factor of
56 ADELBERGER, HECKEL and NELSON
103 . Fortunately such an increase is possible, although it will require years of
The E¨t-Wash group are currently running a new apparatus that features a
pendulum/attractor system having 22-fold rotational symmetry with 44 thinner,
smaller-diameter holes. The pendulum ring and attractor disk are made from
denser materials (copper and molybdenum, respectively). Noise has been im-
proved by a factor of 6. The closest attainable separation has been reduced by
a factor of 2 by adding a passive “bounce” mode damper to the fiber suspen-
sion system and the thickness of the electrostatic shield has been reduced to
10µm. Figure 10 shows the spectral density of the torque signal from this appa-
ratus. This instrument should probe Yukawas with |α| = 1 for ranges down to
λ = 60 µm. In principle, it is possible to use a low-frequency torsion balance in
a different mode, one that measures the attraction between two flat plates (JG
Gundlach, private communication 2002). This would provide a null test with
a sensitivity that scaled as λ2 e−s/λ rather than as λ3 e−s/λ in the partial-null
The Colorado group plans to optimize their geometry and to use a Washington-
style electrostatic shield to attain closer separations. This could improve their
limits between 10 µm and 50 µm by at least an order of magnitude. In the
long run both groups could run at liquid helium temperatures which will give
lower noise, not only from the decreased kB T factor, but also from the expected
increase in the Q-factor of the torsion oscillator. Newman(187) found that the Q-
factor of a torsion fiber has two components: one is temperature-independent but
amplitude-dependent (this is already negligible in the E¨t-Wash instrument be-
cause of the small amplitudes employed) and the other is temperature-dependent
INVERSE-SQUARE LAW TESTS 57
and amplitude-independent.
The microcantilever application exploited by the Stanford group has not yet
attained its full potential. Presumably lessons learned in this pioneering exper-
iment will reduce the backgrounds and allow the experimenters to exploit their
inherent sensitivity to new very small forces. Because corrections to the idealized
Casimir force can be large and depend upon properties of the the test bodies that
are troublesome to quantify, it may be difficult to compare Casimir force exper-
iments to theory at an accuracy much better than 1%. The finite-conductivity
corrections depend upon the dielectric properties of the actual metallic coating
of the test bodies that may differ somewhat from bulk dielectric properties used
in the calculation. As the experimental precision improves, parameters asso-
ciated with the conductivity correction (such as λP ) may need to be included
as adjustable parameters in fitting the measured force versus distance curves.
The surface roughness correction should consider distortions over lengths scales
larger than are easily accessible by AFM scans and it may necessary to vary
the roughness parameters as well. Both corrections scale as inverse powers of
the separation, d, as do the corrections for residual electric potential and patch
effects. Compounding the problem of multiple corrections with similar distance
dependences is the uncertainty in the absolute separation of the test bodies. The
Casimir force depends upon d0 + dr , rather than on d, where dr is the relative
displacement of the test bodies between force measurements (which can be accu-
rately measured) and d0 is the absolute separation at the origin of the relative
scale (which is difficult to determine accurately). Including d0 as a fit parameter
allows other short-distance parameters to vary(163), without affecting the fit at
large distances where the fractional error on the force measurements is larger.
58 ADELBERGER, HECKEL and NELSON
It is unlikely that the next few years will see large improvements in Yukawa
constraints from Casimir-force experiments.
5.2.2 Long-range tests of the ISL
Because any change in orientation of the Moon’s ellipticity grows linearly with
time, even with data of constant precision the LLR constraint should improve in
proportion as the data span increases (assuming that the modeling of conventional
precession sources is not a limiting factor). New LLR projects should improve
the raw range precision by an order of magnitude. For example, APOLLO(188)
will exploit a 3.5 m telescope at an elevation of 2780 m and sub-arcsecond image
quality. This instrument should receive several returned photons per laser shot,
giving a data rate about 103 times greater than existing facilities. It is expected
that more precise data will lead to corresponding improvements in the modeling.
Ranging to other planets, which is needed to probe longer length scales ef-
fectively, is currently done using radar (which is limited by the absence of a
well-defined “target” on the planet) or else microwave signals transmitted by or-
biting spacecraft (which are limited by uncertainties and the finite time-span of
the orbits). Furthermore, the accuracy of microwave ranges is limited by propa-
gation delay in the interplanetary solar plasma. It is impractical to laser range to
passive reflectors on other planets (if they could be placed) because the returned
signal falls as 1/r 4 . However, recent developments in active laser transponders,
whose sensitivity falls as 1/r 2 , make it practical to place such a device on Mars
and ultimately achieve range precisions of a few cm(189). This would yield sev-
eral interesting new gravitational measurements, including an improved test of
the Strong Equivalence Principle(190), which provides one of the best limits on
INVERSE-SQUARE LAW TESTS 59
massless gravitational scalar fields, as well as tests of the ISL that would give
interesting constraints on the quasi-localized gravity model of Ref. (125).
ISL tests at scales larger than the solar system typically rely on uncertain
astrophysical models. But Will(5) notes that the proposed LISA space-based
interferometer could test a pure Yukawa potential at a scale of 5 × 1019 m by
studying distortions of the gravitational waveform from an inspiraling pair of
106 M compact objects.
5.3 What if a violation of the 1/r2 law were observed?
Suppose that future experiments revealed a violation of the ISL at short length
scales. Of course one would try to tighten the constraints on its range and
strength by performing tests using instruments with varying length scales. But a
new question immediately arises: is the new physics a geometrical effect of extra
dimensions or evidence for exchange of a new boson? This can be decided by
testing whether the short-range interaction violates the Equivalence Principle:
boson exchange generically does not couple to matter in a universal manner and
therefore appears as a “violation” of the Equivalence Principle, while geometrical
effects must respect the Principle. Ref. (99) estimated that the Equivalence-
Principle “violating” effect from dilaton exchange is ≈ 0.3%.
This work was supported in part by the National Science Foundatation (Grant
PHY-997097) and by the Department of Energy. We are grateful to discussions
with Z. Chacko, K. Dienes, G. Dvali, S. Dimopoulos, J. Erlich, P. Fox, G. Giudice,
J. Gundlach, N. Kaloper, E. Katz, T. Murphy, R. Rattazzi and J. Williams. D.
60 ADELBERGER, HECKEL and NELSON
B. Kaplan collaborated significantly on sections 2.41—2.44. D. Kapner and E.
Swanson helped with the figures.
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72 ADELBERGER, HECKEL and NELSON
Figure 1: Schematic diagram of the 10-hole pendulums and rotating attractors
used in the two experiments of Hoyle et al.(69, 145, 146). The active components
are shaded.
INVERSE-SQUARE LAW TESTS 73
Figure 2: Upper panel: torques measured in the first experiment of Hoyle et
al. as a function of pendulum/attractor separation. Open circles are data taken
with the lower attractor disk removed and show the effect of uncancelled gravity.
Smooth curves show the Newtonian fit. Lower panel: residuals for the Newtonian
fit. The solid curve shows the expected residual for a Yukawa force with α = 3
and λ = 250 µm.
74 ADELBERGER, HECKEL and NELSON
to JFET
Torsion Axis
Detector Mount
Transducer Probe
Stiff Shield Detector
Source Mass
PZT Bimorph
Source Mount
Tuning Block
Figure 3: Schematic diagram of the instrument used by Long et al.(138).
INVERSE-SQUARE LAW TESTS 75
On Resonance Off Resonance
10000 10000
8000 8000
6000 6000
4000 4000
2000 2000
0 0
Channel 1 Data (mV) Channel 1 Data (mV)
10000 10000
8000 8000
6000 6000
4000 4000
2000 2000
0 0
Channel 2 Data (mV) Channel 2 Data (mV)
Figure 4: Data from the experiment of Long et al.(138) showing the two quadra-
ture signals from the torsion oscillator.
Y Z
X Fiber X
Test mass
Conducting shield
Current path
Top view, cutaway Side view
(shield not shown) (separation not to scale)
100 µm
Figure 5: Schematic diagram of the instrument used by Chiaverini et al.(149)
76 ADELBERGER, HECKEL and NELSON
Figure 6: 95% confidence level constraints on ISL-violating Yukawa interactions
with 1µm < λ < 1 cm. The heavy curves give experimental upper limits (the
Lamoreaux constraint was computed in Ref. (148)). Theoretical expectations for
extra dimensions(54), moduli(98), dilaton(99) and radion(80) are shown as well.
INVERSE-SQUARE LAW TESTS 77
Figure 7: Schematic diagram of the Casimir-force apparatus used in Ref. (162)
Figure 8: Constraints on ISL-violating Yukawa interactions with 1nm < λ < 1µm
adapted from Ref. (6). As discussed in the text, these upper limits, extracted
from Casimir force measurements, are not as rigorous as those in Figs. 6 & 9.
78 ADELBERGER, HECKEL and NELSON
Figure 9: 95% confidence level constraints on ISL-violating Yukawa interactions
with λ > 1 cm. The LLR constraint is based on the anomalous perigee precession;
the remaining constraints are based on Keplerian tests. This plot is based on Fig.
2.13 of Ref. (13) and upgraded to include recent LLR results.
INVERSE-SQUARE LAW TESTS 79
Figure 10: Spectral density of the torque signal in the 22-fold symmetric ex-
periment of the E¨t-Wash group. The peaks at 8.5 and 17 ω are gravitational
calibrations; the fundamental and first three overtones of the short-range signal
are at 22, 44, 66, and 88 ω. The smooth curve shows the thermal noise computed
using Eq. 33.
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Public Release: A new cost-effective genome assembly process
DOE/Joint Genome Institute
Despite tremendous advances in cost reduction and throughput of DNA sequencing, significant challenges remain in the process of efficiently reconstructing genomes. Existing technologies are good at cranking out short fragments (reads) of DNA letters that are computationally stitched back together (assembled) into longer pieces, so that the order of those letters can be determined and the function of the target sequence discerned. However, genome assembly, the equivalent of trying to put together a multi-million piece jigsaw puzzle without knowing what the picture on the cover of the box is, remains challenging due to the very large number of very small pieces, which must be assembled using current approaches.
As reported May 5 online in the journal Nature Methods, a collaboration between the DOE JGI, Pacific Biosciences (PacBio) and the University of Washington has resulted in an improved workflow for genome assembly that the team describes as "a fully automated process from DNA sample preparation to the determination of the finished genome."
The technique, known as HGAP (Hierarchical Genome Assembly Process), uses PacBio's single molecule, real-time DNA sequencing platform, which generates reads that can be up to tens of thousands of nucleotides long, even longer than those provided by the workhorse technology of the Human Genome Project era, the Sanger sequencing technology, which produced reads of about 700 nucleotides. The Sanger process involved creating multiple DNA libraries, conducting multiple runs, and combining the data, so that gaps in the code were covered and accuracies of a DNA base assignment were very high. Post-Sanger methods still typically require multiple libraries and often a mix of technologies to produce optimal results. Instead, with HGAP, "only a single, long-insert shotgun DNA library is prepared and subjected to automated continuous long-read SMRT sequencing, and the assembly is performed without the need for circular consensus sequencing," the team reported.
"We are always on the lookout for new approaches that will improve upon the efficient delivery of high-quality data to our growing community of researchers," said Len Pennacchio, DOE JGI's Deputy Director of Genomic Technologies. "This technique is one of many improvements that we are pursuing in parallel to achieve additional economies of scale."
The DOE JGI's sequencing efforts account for more than 20% of the more than 20,000 worldwide genome projects (microbes, plants, fungi, algae, and communities of microbes) completed or currently in the queue, and most of those are focused on the biology of environmental, energy, and carbon processing.
"We enjoyed a very productive collaboration with JGI on this project and benefitted tremendously from the expertise of JGI's scientists in both the fields of microbiology and microbial genome assembly and annotation," said Jonas Korlach, Chief Scientific Officer at Pacific Biosciences. "This expertise provided us with the ability to adapt our single molecule sequencing assembly methods to produce a higher level of finished quality than was previously possible using a gold-standard Sanger finishing approach, and at a speed and price point competitive with alternative next generation sequencing and assembly methods. We look forward to seeing what scientific advances will be enabled by this method as JGI's User Community assesses JGI's capabilities to assemble their microbial genomes using this new approach."
The team will now seek to extend the utility of this new assembly method beyond microbes to the genomes of more complex organisms.
The authors of the paper include Alex Copeland and Alicia Clum from the DOE JGI, Chen-Shan Chin, David Alexander, Patrick Marks, Aaron Klammer, James Drake, Cheryl Heiner, Stephen Turner, and Jonas Korlach from Pacific Biosciences, and John Huddleston and Evan Eichler from the University of Washington.
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Citizen Kurchatov: Stalin's Bomb Maker
A Russian Scale
Kurchatov launched a huge uranium mining operation, worked on a reactor to produce plutonium, started massive isotope separation plants, purification plants, and instructed his team to design a bomb.
The monastery town of Saint Sarov was chosen to house the scientists and their laboratories. The city was renamed Arzamas-16 and was ringed by barbed wire and patrols of troops.
Scientists worked under intense security, sometimes handwriting reports because they didn't trust the typists. Code words were used in reports to obscure the contents.
However, there was a sense of mission and common cause inside the facility. All the scientists believed they had to build the bomb to protect the Soviet Union and the rest of the world from imperialist domination. They all worked together on this daunting task, something many believed would take years to accomplish.
While the U.S. and Britain started with nothing, Kurchatov did have the espionage materials. However, he couldn't completely trust their claims and questioned some of their results.
Caught between the world of espionage and science, he could let only a few of his subordinates know the origin of the information. During discussions and formal seminars, he would occasionally inject something from the espionage materials as if he had thought of it himself. Then the other scientists would try out the idea and see if it gave the results they were looking for.
The Soviets named their secret facilities after a nearby town and a post office box.
Some of the scientists nicknamed the facility "Los Arzamas."
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© 2012 by Gary Vey
--Genesis 2:17
Are YOU afraid to die?
If this is all temporary, what does it matter?
According to Becker, people spend their entire lives trying to make sense of these conflicting thoughts. We are so afraid of death that we create alternate realities -- realities where we won't "cease to be". We take comfort in the fact that others share this alternate reality.
Often symbols are used to reinforce our confidence in what psychologists call our worldview.
Reminders of death: Mortality Salience
Psychologists speak of an event which stimulates awareness of our own death as mortality salience. Scientists are often curious how these reminders of death can change our thinking and behavior. They have done many experiments on this.
Mortality salience is usually achieved in experiments by inserting questions about such things as the subjects death plans (last Will & Testament or Life Insurance beneficiaries) or how old his grandfather was when he died. Half of the experimental subjects get the mortality salience and half get benign questions, then they measure the difference. Other times they flash the word DEATH at one twenty-forth of a second on a screen -- so fast that the subjects cannot see it even when they're told it is there. Yet, somehow it works. Their behavior changes.
The basis of human culture!
TMT psychologists view human culture as a belief system constructed to explain and give meaning to life and resist confronting the horror of death. One of the requirements of a successful culture is to substitute the reality of existential death with an achievable afterlife (i.e. belief in heaven or reincarnation). If not literally, then symbolically. Cemetery stones and burial monuments are examples of this. Cultures also reward enduring accomplishments to civilization with material awards, namesakes and inclusions in human history (Like naming a building or street after someone).
The worldview is the foundation of all human culture. History records that various symbols [above] that have been used to represent different worldviews. Each one offers its unique explanation of how we can coexist with death and attempts to lower our death anxiety.
The following research will show that when your worldview is threatened by another worldview, you will be so anxious that you will fight to defend your own belief system -- in fact, this is the basis of religious and political wars. It doesn't matter what you think consciously either. It's such a primal reaction that it happens anyway.
TMT Is Being Used Against Us!
When the idea was first introduced to psychology, a plethora of research was conducted with the idea of "Tell me it ain't so!" But multiple experiments have shown that TMT is able to predict and explain most of the behavior we both promote and experience.
TMT theorists believe that an individual will be so freaked out by being reminded of his death, or mortality salience, that he will invest even more belief in his worldview and resist or violently attack anything perceived as a threat to his worldview. So how did they test this?
Two famous experiments illustrate this phenomenon.
The Judges & the Prostitute
Research has shown that reminding subjects of their mortality encourages negative reactions towards others whose behaviour or attitudes deviate from the subject's cultural worldview [8]. According to TMT, these findings result from a heightened need for faith in the cultural worldview that is activated by reminders of one's mortality.
In this first study, a group of judges were asked to participate in answering a questionaire. The judges were divided into two groups. Each group was given more questions to answer but one group had subtle reminders of death contained in the questions. Both groups were then asked to review the case history of a hypothetical prostitute and to suggest a bail bond amount in dollars. Not surprisingly, the group who had received the mortality salience came down harshly on the "deviate", assigning an average bond of $455, while the control group averaged only $50.
But, it was argued, bad news of any kind could produce the same effect if it got the judge in a bad mood. Experimenters responded that the subjects did not report feeling any negative reaction, but they did more experiments anyway.
This time they reminded one group of their death and the other group received exposure to some other worrisome concern about the future. The same results were achieved with the mortality salience as before. The group that was reminded of death charged more for bond than the group who received other worrisome ideas [9]. The interesting fact was that the group who received the worrisome ideas reported feeling negative -- not the group who were reminded of their death. [2] Thus, consistent with Terror Management Theory, mortality salience effects seem to result exclusively from thoughts of death.
TMT interprets these results as the need for an individual to invest more faith and belief in their worldview when they are reminded of their mortality. Individuals will need to become more cohesive with their groups, such as religious or political affiliations.
Imagine, you can be made to be conservative and conform to the status quo by being exposed to the fear of dying. Is this a good thing?
Hot Sauce
Laboratory experiments investigating aggressive behavior pose a problem. If the aggression is directed towards a real person there is the risk of someone being hurt or injured. Psychologists have invented numerous means of assessing aggression in indirect ways. A group of experimenters recently developed a new method for measuring aggression, specifically, the amount of hot sauce administered to a target known to dislike spicy foods [10].
In this study, the experimenters induced participants to write about either their own death (suggesting mortality salience) or a control topic, presented them with a target who either disparaged their political views or did not, and gave them the opportunity to choose the amount of hot sauce the target would have to consume. As predicted by TMT, participants who were reminded of their death allocated a particularly large amount of hot sauce to their worldview-threatening target.
In additional studies, the authors found that following MS induction, if the subjects were given the opportunity to verbally express a negative attitude toward the critical target, their allocation of hot sauce decreased. These results showed that if the subjects could express their negative attitudes verbally towards their politically opposite targets, they were less likely to give them extra hot sauce (i.e. reduced aggression). This suggests that verbal degredation and acts of aggression are two alternative modes of responding to MS. [11]
Back in 2004, an experiment was conducted to assess the effect of a subtle reminder of death on voting intentions for the 2004 U.S. presidential election. On the basis of Terror Management Theory it was hypothesized that a mortality salience suggestion would increase support for President George W. Bush (the incumbent) and decrease support for Senator John Kerry (the challenger).
This would happen because the incumbent president represented the status quo -- the worldview as we knew it. Kerry was a threat to this.
In late September 2004, after receiving either a death reminder or a neutral suggestion, registered voters were asked which candidate they intended to vote for. In accord with predictions, Senator John Kerry received substantially more votes than George Bush in the control condition, but Bush was favored over Kerry following a reminder of death, suggesting that President Bush's re-election may have been facilitated by unconscious concerns about mortality in the aftermath of September 11, 2001, the anthrax attacks (which originated from a government lab) and the constant manipulation of security threat levels attributed to vaguely described "chatter" among ill-defined "enemies" of America.[3]
Are similar fears being used to control us today? While the Iraq and Afghanistan wars are winding down, threats of WWIII with Iran and Israel are keeping the mortality salience going at full speed. According to the TMT theory, this should benefit Obama's re-election, since he represents the status quo.
Death Anxiety Fuels Conservative Ideas
Increased prejudice toward worldview violators has been measured in a number of experiments assessing TMT. Following death reminders, anti-gay discrimination and affective prejudice toward gay men increased significantly. This is, according to the study, because being homosexual is not perceived as part of the standard world view. Deviation is a threat to the system that helps repress the knowledge of our certain death.[7]
In studies where men were exposed to a mortality salient event, they preferred a more earthy, domestic and ordinary looking woman over a sexy and seductive one. [6]
Terror management research has shown that after reminders of mortality, people show greater investment in and support for groups to which they belong.
In one study, subjects were presented two images of persons talking about their own race with pride. One was black and one was white. The White person expressing pride in his race was viewed by White participants as particularly racist relative to a Black person who gave a similar presentation. However, after White participants were reminded of their own mortality, they viewed the White presentation as less racist.[5] Even though the subjects were of different ancestral nationality, their identification with their own race was amplified by their reminder of their own inevitable death.
Skulls and Bones in the Whiskey
In my college years when the Vietnam war was raging, we used to all read and collect Playboy magazine. We were young and so mostly we didn't pay much attention to the ads -- that is until someone pointed out that all the liquor ads seemed to have subliminal messages in them. Our favorite hobby, well maybe not our favorite, was looking for hidden images in the ice cubes.
Normally, ice cubes have a montage of shadows, reflections and odd shapes. While we found occasional nude women in some of them, most seemed to portray images more suitable for Halloween. Skulls, skeletons and faces screaming in agony were the most common motifs.
For years I wondered why advertisers would put such horrific images in liquor ads. How could this possibly sell whiskey or bourbon?
TMT was obviously known to these ad men. Most addictions are diversions from the real horror -- the reality of our eventual demise. It seems plausible that by causing readers to experience mortality salience their death anxiety would increase to the point where... where... where did I put that drink?
It's all about self-esteem
As I hinted earlier, our appreciation of beauty has two tiers. First, we are hard-wired to be attracted to sexual partners by evolution. We can accurately determine good genes and fertility by our concept of what makes a beautiful person (i.e. symmetry of facial features, good proportions, etc.). But our appreciation of other forms of beauty seems to have origin in our preference for pattern, repetition, organization and symbolism. These are phenomenon in our environment associated with replication and growth -- signs of life. This appreciation of beauty -- esthetics -- results from our avoidance of entropy -- the breakdown of order which is characteristic of our own death.
Julian Jaynes, in his acclaimed work, The Origin of Consciousness in the Breakdown of the Bicameral Mind, showed that much of what we think and do is devoid of consciousness. He gives strong examples of how we can drive a car while thinking about another time and place; talk and write without awareness of the complex process going on to produce the vocabulary. Even learning does not require consciousness -- the phenomenon of self-awareness [12]. Or, "Being conscious of the fact that you are conscious." In fact, our recognition and reaction to mortality salience is without our conscious involvement.
But something feels the "ouch!" when we get a sub-conscious reminder that we are mortal.
In Jaynes' book, he credits the development of language as the prerequisite for the "inner dialog" that creates our awareness of the "I" and "Me". Language is made from metaphores. Each new concept or word is "sort of like" some other word. That's how dictionaries function. So in order to have a concept for selfhood, a previously understood "it's sort of like..." had to be available. We needed language before we could develop consciousness and selfhood. The concept of "self" is therefore not that old. Jaynes suggests it has its origins about 3000 BCE.
While it is true that there are earlier texts showing language in cuneiform, these are mere ledgers, records of land boundaries and crop tallies. There is no hint of self awareness until The Epic of Gilgamesh.
The Epic of Gilgamesh is among the earliest known works of literature. Scholars believe that it originated as a series of Sumerian legends and poems and was written just about five hundred years shy of Jaynes' assertions. Even more telling is what the epic is all about.
The protagonist of the story, Gilgamesh king of Uruk, has a close friend who shares adventures with him and unexpectedly dies. Gilgamesh becomes depressed and embarks on a journey to find "eternal life" -- the solution to death.
Ultimately the poignant words addressed to Gilgamesh in the midst of his quest foreshadow the end result: "The life that you are seeking you will never find. When the gods created man they allotted to him death, but life they retained in their own keeping." -- [13]
Death anxiety targets our self-esteem. It motivates us to keep busy and attempt to seek "eternal life" symbolically through our actions. An experiment which confirmed this was conducted as follows:
Death and Self-Esteem: The Experiment
The subjects were 603 soldiers who first reported on the relevance of automobile driving to their self-esteem. Then half of them were exposed to various reminders of death, and the remaining to a control condition.
Experimenters then tested each group in a driving simulator to assess their risk taking. The measures were either self-reported behavioral intentions of risky driving or driving speed in a car simulator. As expected, the subjects who linked their self-esteem to driving and also received death reminders took more risks in their driving than the control group. But what was happening here?
Another experiment had half of the participants in each condition receiving positive feedback about their quality of driving. Presumably this would bolster their self-esteem. Findings showed that being reminded of death led to more risky driving than the control condition -- but only among individuals who perceived driving as relevant to their self-esteem. Even more significant, the introduction of positive feedback elevated self-esteem and eliminated this effect.[4]
And besides self-esteem, mortality salience has one more conscious manifestation: evil.
Evil (Death) & The Hero
If we are conscious of ourselves, we are conscious of all that we will have to "give up" upon our death. There is tremendous anxiety over this and some of it is relieved in symbolic conquests where the real demon is substituted with lesser foes.
Some of this anxiety can be exhorcize in sports or games but more often the demons are symbols of a threat to our personal and collective self-esteem. A threat to a group that reduces our death anxiety is a real threat. I suspect this motivated the cruelty of Roman gladiators, the deadly ball games of the Mayans and the demonization of Hitler and binLaden. We need enemies to reduce our own death anxiety.
Terror Management Theory is really the theory of human culture and our many attempts to be conscious about "something else" -- anything but our death. That "something else" is often associated with maintaining our self-esteem. Our self-esteem improves when we receive confirmation from other people that we are meaningful and relevant in life. This counteracts the powerful anxiety that comes from our absolute surety that we will someday die and our "self" will not exist. So organizations, political parties and religions have developed to fill our need. Each offers a means to symbolically avoid non-existence.
St. George's defeat of the dragon [right] is a strong symbol for the fight against death.
The town had a pond, as large as a lake, where a plague-bearing dragon dwelled that envenomed all the countryside. To appease the dragon, the people of Silene used to feed it two sheep every day, and when the sheep failed, they fed it their children, chosen by lottery. It happened that the lot fell on the king's daughter, who is in some versions of the story called Sabra.[8] The king, distraught with grief, told the people they could have all his gold and silver and half of his kingdom if his daughter were spared; the people refused. The daughter was sent out to the lake, decked out as a bride, to be fed to the dragon.
Live it... or live with it
The lesson of St. George and the Dragon is that we may not be able to defeat death, but we can tame it. We can make the most of our life and forget about the inevitable. Death can become a quiet and subdued creature that follows after us like a pet. Rather than triumph over death, we can learn to coexist with it.
To recapitulate: Consciousness, the concept of "I" and "me", evolved only recently as a result of our development of language. With consciousness came the discovery that this "self" was mortal and would someday be "no more."
The most basic motivator of human culture is to create alternate realities in which we can achieve victory over the anxiety of our recognition of eventual death. This death anxiety is repressed in normal consciousness but is fully "awake" subconsciously. It influences our behavior and thoughts, makes us appreciate order and affirm life. It creates our worldview, which we share with other humans. Different worldviews sometimes conflict, resulting in wars and aggression.
When we are consciously reminded of our mortality, we invest more belief in our own worldview. We attempt to have victory over our environment, our bodies and even our instincts as a means to separate ourselves from the natural, animalistic creatures in the hope that we are something more permanent and worthy of immortality. This drive to symbolically overcome death is the primary driver of human culture and influences what we like and dislike, what is beautiful and ugly, and what is good and evil.
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[1] "Traces of Terror: Subliminal Death Primes and Facial Electromyographic Indices of Affect", Jamie Arndt, John J. B. Allen and Jeff Greenberg, Motivation and Emotion, 2001, Volume 25, Number 3, Pages 253-277
[2] Greenberg, J., Simon, L., Harmon-Jones, E., Solomon, S., Pyszczynski, T. and Lyon, D. (1995), "Testing alternative explanations for mortality salience effects: Terror management, value accessibility, or worrisome thoughts?" European Journal of Social Psychology, 25: 417-433.
[3] "Age-related differences in responses to thoughts of one's own death: Mortality salience and judgments of moral transgressions", Maxfield, Molly; Pyszczynski, Tom; Kluck, Benjamin; Cox, Cathy R.; Greenberg, Jeff; Solomon, Sheldon; Weise, David, Psychology and Aging, Vol 22(2), Jun 2007, 341-353.
[4] The impact of mortality salience on reckless driving: A test of terror management mechanisms. Ben-Ari, Orit Taubman; Florian, Victor; Mikulincer, Mario Journal of Personality and Social Psychology, Vol 76(1), Jan 1999, 35-45.
[5] "The siren's call: Terror management and the threat of men's sexual attraction to women", Landau, Mark J.; Goldenberg, Jamie L.; Greenberg, Jeff; Gillath, Omri; Solomon, Sheldon; Cox, Cathy; Martens, Andy; Pyszczynski, Tom, Journal of Personality and Social Psychology, Vol 90(1), Jan 2006, 129-146.
[6] Sympathy for the Devil: Evidence that Reminding Whites of their Mortality Promotes More Favorable Reactions to White Racists, Jeff Greenberg, Jeff Schimel, AndyMartens, Sheldon Solomon and Tom Pyszcnyski, Motivation and Eotion, Vol. 25, No. 2, 2001
[7] Russell J. Webstera; Donald A. Sauciera, "The Effects of Death Reminders on Sex Differences in Prejudice Toward Gay Men and Lesbians", Journal of Homosexuality, Volume 58, Issue 3, 2011, Pages 402-426
[8] Greenberg, Pyszczynski, Solomon, Rosenblatt, Veeder, Kirkland and Lyon 1990; Greenberg, Simon, Pyszczynski, Solomon and Chatel 1992; Rosenblatt, Greenberg, Solomon, Pyszczynski and Lyon 1989
[9] European Journal of Social Psychology Volume 25, Issue 4, pages 417-433, July/August 1995
[10] Joel D. Lieberman, Sheldon Solomon, Jeff Greenberg, Holly A. McGregor, "Advertising Opportunities with Wiley Online Library -- A hot new way to measure aggression: Hot sauce allocation", Aggressive Behavior, Volume 25, Issue 5, pages 331-348, 1999
[11] McGregor, Holly A.; Lieberman, Joel D.; Greenberg, Jeff; Solomon, Sheldon; Arndt, Jamie; Simon, Linda; Pyszczynski, "Terror management and aggression: Evidence that mortality salience motivates aggression against worldview-threatening others," Journal of Personality and Social Psychology, Vol 74(3), Mar 1998, 590-605.
[12] Jaynes, Julian, "The Origin of Consciousness in the Breakdown of the Bicameral Mind" (1976), ISBN 0-395-20729-0
[13] http://en.wikipedia.org/wiki/Epic_of_Gilgamesh
[14] http://en.wikipedia.org/wiki/Saint_George_and_the_Dragon
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I have to say that I really appreciated your article on the viewzone. I had read a little about TMT in regards to its origins and it's affects on human culture. Your article was very insightful and it definitely makes me think of myself and my surroundings differently. I really needed it as most people do. Thank you!
Henoch S.
"Time and ego are persistent illusions." Albert Einstein
After reading this article, I was reminded of the work of Alfred Korzybski, who like Einstein, was also a student of Minkowski. Korzybski pioneered the science of neuro-linguistics and the concept of time-binding. In essence, language structures neural pathways during early development and the dualistic nature of language contributes to a world view that is itself a limited abstraction of reality based upon opposing principles.
The fear of death is essentially the fear of losing one's ego. This is one of the characteristics that are overcome by those who have had a "near death experience". The real goal of most spiritual disciplines is to sublimate or conquer the illusion of ego. This concept pervades most of the world's mythologies as exampled by the reference to St. George and the dragon.
The fear of death and the illusion of ego are driving concepts that have formed all of the worlds established cultures. As the ego becomes aware it defines itself by the cultural context in which it develops and this is what fuels the desire to associate in groups with common ideologies.
John P. Walliser
I think that as human beings on this planet that we live in we tend not to think about the bigger picture and we always compartmentalize everything. We tend to only study and teach things we are more comfortable with that we can easily expalin that is not outside our box. When we get to an age that we know our existence on this planet will be no more most of us all of sudden become spiritual and seem to have a connection to a spiritual self. Wether it be with god or some other form or sense of being. Yet most of us question if there is life after death and if we are just finished and that's it. Do we die and get buried and that's it no more or is there something else more powerful than all of us. Some connection to another dimension or spiritual reality somewhere else.
I think there should be more research and more scientific work to be done on possible life after death and any connections to another dimension we know nothing about. I am saying this as I have a personal story concerning my mother. She had died when I was eleven years old. She killed herself by taking an overdose of tranqulizers that our family doctor prescribed to her. My fathers boss had stopped in to see if my dad was at home and noticed my mother laying on the floor. He called an ambulance and was rushed to the hospital. The doctors and nurses had her hooked up to the life support systems and heart monitor and were not able to get any pulse or brain activity they had given her the electric shocks to get her heart beat back with no avail nothing worked. They had placed the sheet over her body and came to see my dad and told him she was clinically dead. The priest came and asked if she was catholic and would give her the last rights. He entered her room and began giving them but did not realize she was still hooked up to the monitors. The machine came back to life and started to blip and showed a heart beat. He told the doctros who rushed back in and brought her back to life. As they checked her and asked her questions she seemed to have no brain damage or effects from the entire time she was transported to the hospital whicj took roughly 30 minutes and the time of her death which I was told until later in life was for about five to ten minutes. She remained in the hospital for a few days and was omitted in the psychiatric part of the hospital for counselling for depression.
My mother was released after a week and came back home and continued to get counseling for a period of three or four months for her depression and things worked out for her and she was able to manage it in a much better way. It was not until I turned about twenty years old she confided in me about something very personal. She told me she could remember everything about her death and that she remembers taking the pills and falling asleep. She remembers my dads boss looking over her the ambulance attendants checking her and picking her up and taking her into the ambulance. Here is the weird part she actually tells me she is watching them all do this from above she is looking down at them and she is watching it all. Now I kind of thought this was a joke or you know maybe the medication she was on or something or possibly some kind of connection to these people when they were dealing with her. Yet this get's better she tells me she can remember the hospital and the doctors working on her and she can remember the moment she died and she felt this tremendous warmth rush over her and could seea light appear in the distance and it was like a tunnel and it was calling her somehow telling her to go into it to follow the light. She told me she felt the most incredible feeling of happiness and love and started to go to the light she was going towrds it through this tunnel and all of a sudden there were four beings at the end of the light and they stopped her. They told her that it was not time for her to leave and she needed to complete three more things here before she could be accepted. She told me that she did not want to leave and she pleaded with them to stay and continue because she felt so wonderful and wanted to stay. They continued to instruct her to remain as she had to complete the three things on Earth before they could accept her and she would know in time what these three things were. All of a sudden she awoke and noticed the docotrs checking her and asking her some questions.
It was pretty freaky that she could remember all this and see everyhting that was happenning. Now I was not sure what to think of this and I told my mother I heard that some scientists and doctors had worked on this kind of thing and said that the light that people see is just the last few electric impulses our brains have before we die. My mother insisted that this is not so that she really experienced a spiritual meeting and conversed mentally with beings and saw everyhing in a different way. She told me that she now has no fear of death and if she were to die she would be completely happy and know there is another life after death.
Now I have heard other people having the same experiences and our family ancestry is native we are Algonquins and Ojibwe by blood. In the native cultures you hear the elders and other native people speak of spirits who talk to them or send them messages of how there life path or journeys' should be. They have out of body experiences. They make important decisions based on what they should be doing in life before they can meet with their ancestors in the other world. I also have read stories from the bible where Moses and other deciples are spoke to by god and spirits would visit him in his dreams and give him orders to or make decisions for him to help his people. Now how is this possible and how does the brain work? There is more to this than we can explain. How people have lived passed lives and can remember details no one else knows. Parasychologists,scientists, doctors, archealogists etc. do not like to talk about the things they cannot answer or have definite answers. They all love to be in there comfort zones and stay there. They can only answer what they know and will not progress beyond that. We need to have more of these professional think out of the box and research these ideas more. They need to be more cognizant of spiritual selves and maybe find a connection with our minds or brains that maybe is used as a kind of communication device with other beings or spirits. After all there are more questions to be answered in life we have no idea or answers for. We all live in a Univers billions and billions of years old that is full of other galaxies and universes how do we know that in some way we are not all connected together on some type of higher plane? I tend to believe my mother and I think when it is time for me to die I would like to be happy knowing that there is something more to my being than just living on Earth and dying never to be heard of again? |
Important Bees-Ness
Why one local expert is abuzz with concern
Across much of America, we’re losing our honeybees. It is estimated that we’ve lost more than one-quarter of our 2.4 billion bee colonies. (The phenomenon even has gotten an official name: Colony Collapse Disorder.) Why? Scientists theorize various reasons, from the Varroa mite, mild winters, and modified crops to the Israeli acute paralysis virus.
So, how do Westchester bees fare? We asked Evelyn Fetridge, resident bee expert at the Louis Calder Center Biological Field Station at Fordham University in Armonk. Fetridge studied and compared bee communities in Westchester County gardens to those in Black Rock Forest in Orange County and in New York City community gardens. And? “The bee diversity in Westchester gardens was intermediate between what was in Black Rock, which had the most species, to the fewest species found in New York City gardens,” reports Fetridge.
But, more important, according to Fetridge, Westchester has a thriving population of other bee species, which means that gardeners can depend on other bees to pollinate. She recommends that gardeners take a proactive approach next spring to attract bees of all types—and, hopefully, honeybees as well.
What do bees—all bees—like? The same thing as we humans: color and pretty blooms. So, if you want to grow your garden, plant away. Plants most highly recommended to attract honeybees: echinacea, also called the Purple Cone Flower, rudbeckia, nepeta, liatris, and flowering herbs like thyme, oregano, and mint.
// Kristin Larson
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The stress alliterative verse of Anglo-Saxon poetry is clearly the product of an oral court minstrelsy; it was intended to be recited by the scop (in Old English: "jester, one who scoffs"), a professional entertainer (poet and singer) also known as a gleeman. Many Scandinavian folktales became a part of the well organized Anglo-Saxon world and body of folklore and legend, and it was not long until "warrior-kings" had a "singer", or scop who lived attached to their courts and recited and sang a body of oral literature, particularly about the warrior-king's glorious deeds. The scop was an itinerant minstrel who frequented the halls of kings and chiefs and sometimes found continuous service with one master. The scopas were the conservers of the Old English oral tradition and they were makers of poetry as well as reciters. A number of them were members of royal households, like the skalds (Scandinavian bards or court singers). Few are known by name. One of the earliest surviving Anglo-Saxon poems, Widsith ( far traveller), is the autobiographical record of such a scop, who travels from court to court reciting his lays. The Beowulf-poet gives a valuable portrait of the scop in Hrothgar's court, as we have already seen. Hrothgar's scop was able to sing Beowulf's praises the day following his defeat of Grendel. The scop's purpose was to honour his noble patron or others who performed great deeds and to give praise and blame where applicable. He was expected to remember stories from the past and be able to sing them at any time. His job was to mentally and musically recall and perform these stories because the pride of the tribe depended upon a long genealogy of heroes. Moreover, by singing about heroes and about those who acted in non-heroic ways, the scop defined the moral values of his society, and his songs endorsed models of behaviour. The scop defined his society's code of heroic behaviour: he praised those who lived according to accepted social codes and criticized those who failed to perform according to the expectations of the group they belonged to.
Read the poem below which deals with the lament of a bard.
Deor's Lament is an Old English poem from the ninth or tenth century and it is contained in the Exeter Book . It is composed of 40 lines divided into seven unequal sections and containing a refrain repeated six times: That evil ended. So also may this!. We do not know who was the poet that wrote Deor's Lament and when. Nothing is known of the bard who names himself Deor (line 35).This poet is mentioned nowhere else and nothing is known of him except for the poem's implication that he was an exile.
Deor seems to be a minstrel who has fallen out of the favour and consoles himself by considering the past misfortunes of others such as Wayland the Smith, Theodoric, and Hermanric. It is one of the group of poems in the Exeter Book referred to as "elegies", short poems whose theme is usually the transience and unreliability of the World, sometimes ending, though not in Deor's Lament with a Christian consolation.
"Weland knew fully affliction and woe"
Weland (1) knew fully(2) affliction and woe
Hero unflinching(3) enduring distress;(4)
Had for companionship heart-break and longing,(5)
Wintry exile and anguish of soul,
When Nithad bound him, the better man, 5
Constrained him with sinewy bonds.(6)
That evil ended.(7) So also may this!
Nor was brother's death to Beadohild
A sorrow as deep as her own sad plight,(8)
When she knew the weight of the child in her womb, 10
But little could know what her lot might be.
That evil ended.(9) So also may this!
Many have heard of the rape (10) of Hild,(11)
Of her father's affection and infinite love,
Whose nights were sleepless with sorrow and grief. 15
That evil ended. So also may this!
For thirty winters Theodoric (12) held,
As many have known, the Maering's stronghold.
That evil ended. So also may this!
We have heard of Eormanric's(13) wolf-like ways, 20
Widely ruling the realm of the Goths;(14)
Grim was his menace, and many a man,
Weighted with sorrow and presage of woe,
Wished that the end of his kingdom were come.
That evil ended. So also may this! 25
He who knows sorrow, despoiled of joys,
Sits heavy of mood; to his heart it seemeth (15)
His measure of misery meeteth (16) no end.
Yet well may he think how oft (17) in this world
The wise Lord varies His ways to men, 30
Granting wealth and honor (18) to many an eorl, (19)
To others awarding a burden (20) of woe.(21)
And so I can sing of my own sad plight (22)
Who long stood high as the Heodenings'(23) bard,
Deor my name, dear to my lord. 35
Mild was my service for many a winter,
Kindly my king till Heorrenda (24) came
Skillful in song and usurping the land-right (25)
Which once my gracious lord granted to me.
That evil ended. So also may this! 40
(Late 9th century. Translated by C. W. Kennedy, An Anthology of Old English Poetry, 1960)
1.Weland: (Wayland or Welund): the name means "maker" or "workman," the smith of Germanic legend, a supernatural being corresponding to the Vulcan of classical mythology. He had been captured by Nithhad, set to work, and made lame to prevent his
escape. Nevertheless he managed to escape, killed two sons of Nithhad and raped his daughter Beadohild.
2. fully: completely.
3. unflinching: constant.
4. distress: sadness,sorrow,dejection.
5 .longing: wish, nostalgia, yearning.
6. sinewy bonds: bonds imposed by cutting the sinews(sinew: ligament,tendon) .
7. That evil ended: Weland escaped ( by flying, in one form of the story).
8. plight: condition, predicament.
9. That evil ended: The poet refers this consideration to Beadohild.In fact, as a result of the rape, Beadohild bore the hero
Widia.The poet considers that to be the mother of a hero is sufficient compensation for her.
10.rape: sexual seduction,abuse.
11.Hild: Beadohild.
12.Theodoric: (probably) Theodoric the Great, 454-526, king of the Ostrogoths, lord of Italy, or Theodoric the Frank, who also
suffered exile and defeat. The poet narrates he spent thirty years in exile.
13. Eormanric: He is the historical Eormanric, or Ermanric, king of the Ostrogoths, who died about 375, having made himself ruler
from the Baltic to the Black Sea; later legend made hoim a cruel tyrant.
14. Goths: The Ostrogoths, who originated in southern Russia and held Italy during the late fifth and early sixth century.
15. seemeth: (archaic) seems.
16. meeteth: (archaic) meets.
17. oft: (archaic) often.
18. honor: honour.
19. eorl: it means either a nobleman, man of the upper class(as it does her), or a warrior.
20. burden: a heavy load.
21. woe: (archaic) affliction, bitter grief, distress.
22. plight: an unfortunate condition or state.
23. Heodenings: ruling family, descended from Heoden.
24. Heorrenda: a bard we know nothing of.
25. land-right: estate granted to Deor as a reward for his poetry.
1. This poem, almost unique in Anglo-Saxon poetry, uses a stanza division. How many stanzas is it divided into? (Quote the lines)
2. Are the stanzas of the same length?
3. Each stanza is divided by a repeated line. How many times is it repeated?
4. What is the term that define a phrase, a line or lines repeated at intervals during a poem and especially at the end of a stanza?
5. What is the genre used by the poet in this poem?
6. Look up the term elegy in your glossary and see if this poetic form matches Deor's Lament. (Substantiate your answer).
- An Elegy is:
7. Quote the phrases that describe Weland's condition.
8. Which line reveals Beadohild's brother murder?
9. How do we know that Beadohild was raped? Quote the lines and paraphrase them.
10. Looking up the word "elegy" you have seen that the mood of "Deor's Lament" is elegiac. Its genre is usually said to be that of a "consolatio", used both by ancient and pagan writers (which go back at least as far as Homer, Horace), and by Christian writers, (Boethius's De Consolatione Philosophiae, was translated into English in 890s by King Alfred the Great). Can you substantiate the above statement?
11. Consider the general mood of Deor's Lament and say if its a pagan or Christian poem. Substantiate your answer.
12. Consider the refrain and say what it function is.
13. Where does the poet draw his examples of misfortune from? Who are the characters he speaks of? |
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For the Hebrew diacritic, see Rafe.
Raphe (/ˈrfɪ/; from Greek ῥαφή, "seam"[1]) has several different meanings in science.
In botany and planktology it is commonly used when describing a seam or ridge on diatoms or seeds.
In animal anatomy it is used to describe a ridged union[2] of continuous biological tissue. There are several different significant anatomical raphes:
2. ^ "raphe" at Dorland's Medical Dictionary |
Time to Abolish the American Dream
The Waning of the Modern Ages
La longue durée —the long run—was an expression made popular by the Annales School of French historians led by Fernand Braudel, who coined the phrase in 1958. The basic argument of this school is that the proper concern of historians should be the analysis of structures that lie at the base of contemporary events. Underneath short-term events such as individual cycles of economic boom and bust, said Braudel, we can discern the persistence of “old attitudes of thought and action, resistant frameworks dying hard, at times against all logic.” An important derivative of the Annales research is the work of the World Systems Analysis school, including Immanuel Wallerstein and Christopher Chase-Dunn, which similarly focuses on long-term structures: capitalism, in particular.
The “arc” of capitalism, according to this school, is about 600 years long, from 1500 to 2100. It is our particular (mis)fortune to be living through the beginning of the end, the disintegration of capitalism as a world system. It was mostly commercial capital in the sixteenth century, evolving into industrial capital in the eighteenth and nineteenth centuries, and then moving on to financial capital—money created by money itself, and by speculation in currency—in the twentieth and twenty-first. In dialectical fashion, it will be the very success of the system that eventually does it in.
The last time a change of this magnitude occurred was during the fourteenth and fifteenth centuries, during which time the medieval world began to come apart and be replaced by the modern one. In his classic study of the period, The Waning of the Middle Ages, the Dutch historian Johan Huizinga depicted the time as one of depression and cultural exhaustion—like our own age, not much fun to live through. One reason for this is that the world is literally perched over an abyss. What lies ahead is largely unknown, and to have to hover over an abyss for a long time is, to put it colloquially, a bit of a drag. The same thing was true at the time of the collapse of the Roman Empire as well, on the ruins of which the feudal system slowly arose.
I was musing on these issues some time ago when I happened to run across a remarkable essay by Naomi Klein, the author of The Shock Doctrine. It was called “Capitalism vs. the Climate,” and was published last November in The Nation. In what appears to be something of a radical shift for her, she chastises the Left for not understanding what the Right does correctly perceive: that the whole climate change debate is a serious threat to capitalism. The Left, she says, wants to soft-pedal the implications; it wants to say that environmental protection is compatible with economic growth, that it is not a threat to capital or labor. It wants to get everyone to buy a hybrid car, for example (which I have personally compared to diet cheesecake), or use more efficient light bulbs, or recycle, as if these things were adequate to the crisis at hand. But the Right is not fooled: it sees Green as a Trojan horse for Red, the attempt “to abolish capitalism and replace it with some kind of eco-socialism.” It believes—correctly—that the politics of global warming is inevitably an attack on the American Dream, on the whole capitalist structure. Thus Larry Bell, in Climate of Corruption, argues that environmental politics is essentially about “transforming the American way of life in the interests of global wealth distribution”; and British writer James Delinpole notes that “Modern environmentalism successfully advances many of the causes dear to the left: redistribution of wealth, higher taxes, greater government intervention, [and] regulation.”
What Ms. Klein is saying to the Left, in effect, is: Why fight it? These nervous nellies on the Right are—right! Those of us on the Left can’t keep talking about compatibility of limits-to-growth and unrestrained greed, or claiming that climate change is “just one issue on a laundry list of worthy causes vying for progressive attention,” or urging everyone to buy a Prius. Commentators like Thomas Friedman or Al Gore, who “assure us that we can avert catastrophe by buying ‘green’ products and creating clever markets in pollution”—corporate green capitalism, in a word—are simply living in denial. “The real solutions to the climate crisis,” she writes, “are also our best hope of building a much more enlightened economic system—one that closes deep inequalities, strengthens and transforms the public sphere, generates plentiful, dignified work, and radically reins in corporate power.”
In one of the essays in my book A Question of Values (“conspiracy vs. Conspiracy in American History”), I lay out some of the “unconscious programs” buried in the American psyche from our earliest days, programs that account for most of America’s so-called conscious behavior. These include the notion of an endless frontier—a world without limits—and the ideal of extreme individualism—you do not need, and should not need, anyone’s help to “make it” in the world. Combined, the two of these provide a formula for enormous capitalist power and inevitable capitalist collapse (hence, the dialectical dimension of it all). Of this, Naomi Klein writes:
(This is exactly what I argued 31 years ago in The Reenchantment of the World; it’s nice to see it all coming around again.) “Real climate solutions,” she continues, “are ones that steer [government] interventions to systematically disperse and devolve power and control to the community level, through community-controlled renewable energy, local organic agriculture or transit systems genuinely accountable to their users.” Hence, she concludes, the powers that be have reason to be afraid, and to deny the data on global warming, because what is really required at this point is the end of the free-market ideology. And, I would add, the end of the arc of capitalism referred to earlier. It’s going to be (is) a colossal fight, not only because the powers that be want to hang on to their power, but because the arc and all its ramifications have given their class Meaning with a capital M for 500+ years. This is what the Occupy Wall Street protesters—if there are any left at this point; I’m not sure—need to tell the 1%: Your lives are a mistake. This is what “a new civilizational paradigm” finally means. It also has to be said that almost everyone in the United States, not just the upper 1%, buys into this. John Steinbeck pointed this out many years ago when he wrote that in the U.S., the poor regard themselves as “temporarily embarrassed millionaires.” The Occupy movement, as far as I could make out, wanted to restore the American Dream, when in fact the Dream needs to be abolished once and for all.
Naomi then provides us with a list of six changes that must occur for this new paradigm to come into being, including Reining in Corporations, Ending the Cult of Shopping, and Taxing the Rich. I found myself writing “good luck” in the margins of much of this discussion. These things are not going to happen, and what we probably need instead is a series of major conferences on why they won’t happen. But note that part of the answer is already embedded in her essay: vested interests, in both the economic and psychological sense, have every reason to maintain the status quo. And as I said, so does the man or woman in the street. What would our lives be without shopping, without the latest technological toy? Pretty empty, at least in the U.S. How awful, that capitalism has reduced human beings to this.
In terms of recommendations, then, Klein’s essay is rather weak. But it offers something very important by way of analysis, and also by implication: Everything is related to everything else. Psychology, the economy, the environmental crisis, our daily mode of living, the dumbing down of America, the pathetic fetish over cell phones and electronic gadgets, the crushing debt of student loans, the farce of electoral politics, Mr. Obama’s rather rapid conversion from liberal hero to war criminal and shredder of the Bill of Rights, the huge popularity of violent movies, the attempt of the rich to impose austerity measures on the poor, the well-documented epidemics of mental illness and obesity—these are ultimately not separate spheres of human activity. They are interconnected, and this means that things will not get fixed piecemeal. “New civilizational paradigm” means it’s all or nothing; there really is no in-between, no diet cheesecake to be had. As Ms. Klein says, it’s not about single “issues” anymore.
What then, can we expect, as the arc of capitalism comes to a close? This is where Naomi shifts from unlikely recommendations to hard-nosed reality. She writes:
“The corporate quest for scarce resources will become more rapacious, more violent. Arable land in Africa will continue to be grabbed to provide food and fuel to wealthier nations. Drought and famine will continue to be used as a pretext to push genetically modified seeds, driving farmers further into debt. We will attempt to transcend peak oil and gas by using increasingly risky technologies to extract the last drops, turning ever larger swaths of our globe into sacrifice zones. We will fortress our borders and intervene in foreign conflicts over resources, or start those conflicts ourselves. ‘Free-market climate solutions,’ as they are called, will be a magnet for speculation, fraud and crony capitalism, as we are already seeing with carbon trading and the use of forests as carbon offsets. And as climate change begins to affect not just the poor but the wealthy as well, we will increasingly look for techno-fixes to turn down the temperature, with massive and unknowable risks….As the world warms, the reigning ideology that tells us it’s everyone for themselves, that victims deserve their fate, and that we can master nature, will take us to a very cold place indeed.”
To put it bluntly, the scale of change required cannot happen without a massive implosion of the current system. This was true at the end of the Roman Empire, it was true at the end of the Middle Ages, and it is true today. In the case of the Roman Empire, as I discuss in The Twilight of American Culture, there was the emergence of monastic orders that began to preserve the treasures of Graeco-Roman civilization. My question in that book was: Can something similar happen today? Naomi writes:
“The only wild card is whether some countervailing popular movement will step up to provide a viable alternative to this grim future. That means not just an alternative set of policy proposals but an alternative worldview to rival the one at the heart of the ecological crisis—this time, embedded in interdependence rather than hyper-individualism, reciprocity rather than dominance, and cooperation rather than hierarchy.” She believes that the Occupy Wall Street movement—remember, it was quite vigorous last November—embodies this; that they have taken “aim at the underlying values of rampant greed and individualism that created the economic crisis, while embodying…radically different ways to treat one another and relate to the natural world.”
Is this true? Four things to consider at this point:
1. I personally never visited Zuccotti Park, but most of what I saw on the Web, including very favorable reportage of the Occupy movement, seemed to suggest that the goal was a more equitable American Dream, not the abolition of the American Dream, as I indicated above. In other words, the basic demand was that the pie be cut up more fairly. I never had the impression that the protesters were saying that the pie, in toto, was rotten. This reminds me of an anecdote about Martin Luther King, who apparently said to Harry Belafonte, just before he (i.e., King) was assassinated, that he thought he might have been making a big mistake; that he sometimes felt like he was herding people into a burning church. This is a very different insight, quite obviously, than the notion that black people should be getting a larger share of the pie. After all, who wants a larger share of a rotten pie, or to live in a church that is burning down?
2. The Annales historians, along with the World Systems Analysis thinkers, have been accused of projecting an image of “history without people.” In other words, these schools tend to see individuals as somewhat irrelevant to the historical process, which they analyze in terms of “historical forces.” There is some truth to this, but “historical forces” can become a bit mystical. Just as it is forces that motivate people, so it is people that enact or manifest those forces. I mean,
someone has to do something for history to occur, and at least the Occupy crowd was trying to throw sand on the wheels of the machine, so to speak, as have their counterparts in Europe. But I confess that for a number of reasons, I was never very optimistic about the movement; at least, not as it existed in the United States. As many sociologists have pointed out, America has no real socialist tradition, and it is no surprise that the serious maldistribution of wealth that exists in the U.S. is no issue whatsoever in the forthcoming presidential election. In fact, a recent poll by the Pew Charitable Trust revealed that most Americans have no problem at all with the existence of a small wealthy class; they just want to be able to join it—which takes us back to the quote from John Steinbeck. My own prediction, several months ago, was that OWS would turn into a kind of permanent teach-in, where the disaffected could go to learn about a “new civilizational paradigm,” if that would indeed be taught. This is basically the “new monastic option” I wrote about in the Twilight book. On one level, it’s probably innocuous; it hardly threatens the power elite. But that may not be the whole story, especially in the long run—la longue durée. After all, as the system collapses, alternatives are going to become increasingly attractive; and you can be sure that 2008 is not the last crash we are going to live through. The two sides go hand in hand, and ultimately—I’m talking thirty to forty years, but maybe less—the weight of the arc of capitalism will be too onerous to sustain itself. In la longue durée, one is far smarter betting on the alternative worldview than on capitalism. Thus the biologist David Ehrenfeld writes: “Our first task is to create a shadow economic, social, and even technological structure that will be ready to take over as the existing system fails.”
4. This does not, it seems to me, necessarily mean a return to some type of feudalism; although that could well happen, for all I know. But we are finally talking about the passing not only of capitalism, but of modernity in general—the waning of the modern ages, in effect. In her interesting biography of the Hegelian scholar, Alexandre Kojève, Shadia Drury writes: “Every political order, no matter how grand, is doomed to decay and degenerate.” As for modernity in particular, she goes on:
“[M]odernity’s inception and its decline are like those of any other set of political and cultural ideals. In its early inception, modernity contained something good and beguiling. It was a revolution against the authority of the Church, its taboos, repressions, inquisitions, and witch burning. It was a new dawn of the human spirit—celebrating life, knowledge, individuality, freedom, and human rights. It bequeathed to man a sunny disposition on the world, and on himself….The new spirit fueled scientific discovery, inventiveness, trade, commerce, and an artistic explosion of great splendor. But as with every new spirit, modernity has gone foul….Modernity lost the freshness and innocence of its early promise because its goals became inflated, impossible, and even pernicious. Instead of being the symbol of freedom, independence, justice, and human rights, it has become the sign of conquest, colonialism, exploitation, and the destruction of the earth.”
Morris Berman’s latest book is Why America Failed.
©Morris Berman, 2012 |
Definitions for koanˈkoʊ ɑn
This page provides all possible meanings and translations of the word koan
Random House Webster's College Dictionary
ko•anˈkoʊ ɑn(n.)(pl.)-ans, -an.
1. a nonsensical or paradoxical question posed to a Zen student as a subject for meditation, intended to help the student break free of reason and develop intuition in order to achieve enlightenment.
Category: Eastern Religions
Origin of koan:
1945–50; < Japn kōan, earlier koũ-an < MChin, < Chin gōngàn public proposal
Princeton's WordNet
1. koan(noun)
a paradoxical anecdote or a riddle that has no solution; used in Zen Buddhism to show the inadequacy of logical reasoning
1. koan(Noun)
A story about a Zen master and his student, sometimes like a riddle, other times like a fable, which has become an object of Zen study, and which, when meditated upon, may unlock mechanisms in the Zen studentu2019s mind leading to satori.
2. koan(Noun)
A riddle with no solution, used to provoke reflection on the inadequacy of logical reasoning, and to lead to enlightenment.
3. Origin: From (), which was from 公案.
1. Kōan
A kōan; Chinese: 公案; pinyin: gōng'àn; Korean: 공안; Vietnamese: công án is a story, dialogue, question, or statement, which is used in Zen-practice to provoke the "great doubt", and test a student's progress in Zen practice.
The New Hacker's Dictionary
1. koan
A Zen teaching riddle. Classically, koans are attractive paradoxes to be meditated on; their purpose is to help one to enlightenment by temporarily jamming normal cognitive processing so that something more interesting can happen (this practice is associated with Rinzai Zen Buddhism). Defined here because hackers are very fond of the koan form and compose their own koans for humorous and/or enlightening effect. See Some AI Koans, has the X nature, hacker humor.
Anagrams of koan
1. kaon, KAON
2. NKAO
3. KAON
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Thursday, July 29, 2010
Let kids do their own cooking
In the same spirit as my call to "Bring cooking down to your child's level," here's a real-life photo journal of how our three-year-old does some of his own food preparation and cooking. I was there to supervise and assist as needed, but I mostly just stood back and watched him go.
When children prepare and choose their own foods, it makes them more likely to want to eat (if that's an issue around your house), and it can help make eating and cooking enjoyable rather than a power struggle or chore.
Plus, I think it's just good to realize how competent our children really are, and what kind of responsibility they can handle if we let them.
Preschooler makes his own fries
Would this be more impressive if it were a salad instead of frozen french fries?
Well, at least it's not Muddy Buddies.
toddler making fries - 1 opening freezer
Mikko chooses his own food and knows where to find it.
toddler making fries - 2 fry bag
toddler making fries - 3 holding frozen fry
He counts out how many he needs.
toddler making fries - 4 step stool
A sturdy step stool can help shorter kids navigate kitchen counters. We found a couple two-step ones at Target and Ikea, which are similar to this one at Amazon, but something even taller and sturdier like the Little Partners Learning Tower would be even better.
(Yes, I'm coveting.)
toddler making fries - 6 pushing toast button
An easy way for little kids to heat pre-cooked food is by pushing the toast button down on the toaster oven.
toddler making fries - toaster light on
Mikko lets me handle the food and oven once they're hot, and I got the plate down for him from our rather high cabinets. If our (non-precious) plates were stored accessibly, though, that would be a great way for kids to help themselves and learn to set the table, too!
toddler making fries - 7 opening fridge
Mikko knows his condiments.
toddler making fries - 8 picking out ketchup
toddler making fries - 9 squeezing ketchup on plate
His father helps with the aiming.
toddler making fries - 10 choosing fry
toddler making fries - 11 eating fry
I just want to point out that the rest of his meal is behind him: a banana, an orange, a butter sandwich, and some organic cookies. He's a grazer!
The one picture that turned out too blurry was when he first offered me a fry, which I thought was rather sweet! I guess he must have thought I was famished, what with my camerawoman duties and all.
It tasted very good!
How do your kids help choose and prepare their own food?
Megan said...
In my classroom, I put out plates with food on them, each covered with a dome. They go out first thing in the morning, and then as the children get hungry they can choose what to prepare. Usually I will have out orange halves for juicing, banana cutting (in half the long way, with a banana cutter) or apple halves for cutting (with an apple cutter)for the fruit. Hopefully next year our apple tree will start to produce and we can take it from the harvesting step :). Then I try also to include a vegetable like raw carrots (cut in half so they lie flat) or cucumber. Those they cut with a wavy cutter - it cuts through carrots with very little force for an adult and is manageable for a toddler, plus the health department doesn't have a problem with it because it doesn't have sharp edges. I try to do cheese with a wire cheese cutter or eggs with an egg slicer so that we also have a protein, but proteins can be hard to manage with all the allergies and dietary restrictions that people can have. I would love to put out nut cracking but I don't dare take the chance of an unknown reaction occurring. Also, we have an angled jar with a lid and tongs so the children can serve themselves a carbohydrate snack like animal crackers or pretzels. That's on a daily basis - we try to do baking activities with different parents during the year as well, but we have to bake it in another room because the health department is worried about children getting burned. I've seen toaster ovens out in classrooms in other states, though (I'm in AZ), with recipes that have the measuring cups color coded so the child doesn't have to understand math to mix the right batter. It just shows, for example, 2 red cups and a picture of sugar, so the child knows to fill up the red cup with sugar twice - very basic counting. Of course I give them a lesson before they do any work independently, and observe to make sure they aren't doing anything dangerous or having too much trouble - but I imagine any parent who reads this blog would do that without thinking :).
I also have to say thank you for bringing this up, because even in a Montessori school we have a lot of parents who still do EVERYTHING for their children, to the point where their child can't tell you where to find a bowl in their own kitchen. And it's important to teach them how to do things, because it makes children feel confident that they can fulfill some of their own needs and contribute to the family community in a meaningful way.
Christie - Childhood 101 said...
At two and a half my daughter cut up fruit for her fruit salad and yoghurt breakfast this morning.
Lindsey Muth said...
Oh my gosh your little Mikko could be a french fry model, a baby hair model, a toaster oven model, too cute! And he knows his way around the kitchen, that is awesome. I aspire to the same for our 19 month old! He has his own play kitchen within our kitchen and his own drawer in the kitchen (full of toys, but eventually it will be full of non-precious plates and kiddy silverware and stuff). Too cool. Thanks for the post!
cypress sun said...
my 2 year old is so proud of his ability to do just about anything in the kitchen. i try to give him as much independence as possible...and not get too itchy about the MESS. today he walked to the fridge and announced, "i'm hungry for soy sauce and apples." :) obviously, some guidance is needed. :)
CrunchyVTMommy said...
He is such a champ. When did he start helping with the cooking?
Dionna @ Code Name: Mama said...
Awesome! I love it when Kieran cooks with me.
It's funny, Acacia at Be Present Mama just did a fantastic post about kids in the kitchen, and I have been working on a post about easy/healthy toddler/preschooler snacks. I asked Acacia if she'd want to team up on something, but maybe we could do a trifecta - you could do one too :) Interested? I mean, I know you're not busy and all!
Lauren @ Hobo Mama said...
Megan: Your classroom sounds so right. I love your techniques and your philosophies. The more I learn about Montessori, the more I want to learn. Thanks for the ideas, too, for ways little kids could do more cutting and cooking. I'll have to find a wavy cutter, and I love the color-coding idea. My son's preschool is doing more cooking lessons for snacktime. Last time they made little pizzas (unbaked) — some sort of pre-cooked crust, then spreading tomato sauce and shredded cheese on top. The teacher said Mikko ate pretty much all of his, which I think is testament to the ownership kids take when they make something themselves.
Christie: Yea! Mikko's current joy is peeling oranges. He runs to the kitchen and gets a (butter) knife out of the drawer to pierce the skin, and then he goes to town. I love how much he enjoys it.
Lindsey: Thank you! :) I think it would be so fun to have a play kitchen, too. I know Mikko loves playing with pretend foods. That's a great idea to give your son his own drawer.
cypress sun: Soy sauce and apples! Maybe it's the new fusion cuisine trend. I also have to try not to worry so much about spills and waste, and it's hard.
CrunchyVTMommy: I don't even know when he started! It's been awhile, for sure. He's loved "helping" since he was able to get around on his own.
Dionna: Sure thing! Let me know. I'll have to go look for Acacia's post. Oh, here it is, if anyone else wants to go see: "Kids in the Kitchen: Snack Central." Those are some great ideas!
Megan said...
I found my wavy cutter at Bed Bath and Beyond for about $3. They have them in the Montessori catalogs too, but I'm not sure if it would be worth the shipping cost to order one.
Acacia @ Be Present Mama said...
Hey Lauren, read your post when it came out but didn't comment. Everett does a lot of his own food prep like PB toast but toaster oven is a great idea.
Hubby and I were just talking about getting one when we move in September. I told him we gotta get one so Ev can make his own fries, too! He could do mini pizzas, or "grilled cheese" too.
Related Posts with Thumbnails |
Glossary | Figures | Notes | Bibliog | Discuss | End
FromThe Crayfish, by T. H. Huxley, 1879
Chapter I
The Natural History of the Common Crayfish
(Astacus fluviatilis.)
MANY persons seem to believe that what is termed Science is of a widely different nature from ordinary knowledge, and that the methods by which scientific truths are ascertained involve mental operations of a recondite and mysterious nature, comprehensible only by the initiated, and as distinct in their character as in their subject matter, from the processes by which we discriminate between fact and fancy in ordinary life.
But any one who looks into the matter attentively will soon perceive that there is no solid foundation for the belief that the realm of science is thus shut off from that of common sense; or that the mode of investigation which yields such wonderful results to the scientific investigator, is different in kind from that which is employed for the commonest purposes of everyday existence. Common sense is science exactly in so far as it fulfils the ideal of common sense; that is, sees facts as they are, or, at any rate, without the distortion of prejudice, and reasons from them in accordance with the dictates of sound judgment. And science is simply common sense at its best; that is, rigidly accurate in observation, and merciless to fallacy in logic.
Whoso will question the validity of the conclusions of sound science, must be prepared to carry his scepticism a long way; for it may be safely affirmed, that there is hardly any of those decisions of common sense on which men stake their all in practical life, which can justify itself so thoroughly on common sense principles, as the broad truths of science can be justified.
The conclusion drawn from due consideration of the nature of the case is verified by historical inquiry; and the historian of every science traces back its roots to the primary stock of common information possessed by all mankind.
In its earliest development knowledge is self-sown. Impressions force themselves upon men's senses whether they will or not, and often against their will. The amount of interest which these impressions awaken is determined by the coarser pains and pleasures which they carry in their train, or by mere curiosity; and reason deals with the materials supplied to it as far as that interest carries it, and no farther. Such common knowledge is rather brought than sought; and such ratiocination is little more than the working of a blind intellectual instinct.
It is only when the mind passes beyond this condition that it begins to evolve science. When simple curiosity passes into the love of knowledge as such, and the gratification of the æsthetic sense of the beauty of completeness and accuracy seems more desirable than the easy indolence of ignorance; when the finding out of the causes of things becomes a source of joy, and he is counted happy who is successful in the search; common knowledge of nature passes into what our forefathers called Natural History, from whence there is but a step to that which used to be termed Natural Philosophy, and now passes by the name of Physical Science.
In this final stage of knowledge, the phenomena of nature are regarded as one continuous series of causes and effects; and the ultimate object of science is to trace out that series, from the term which is nearest to us, to that which is at the furthest limit accessible to our means of investigation.
The course of nature as it is, as it has been, and as it will be, is the object of scientific inquiry; whatever lies beyond, above, or below this, is outside science. But the philosopher need not despair at the limitation of his field of labour: in relation to the human mind Nature is boundless; and, though nowhere inaccessible, she is everywhere unfathomable.
The Biological Sciences embody the great multitude of truths which have been ascertained respecting living beings; and as there are two chief kinds of living things, animals and plants, so Biology is, for convenience sake, divided into two main branches, Zoology and Botany.
Each of these branches of Biology has passed through the three stages of development, which are common to all the sciences; and, at the present time, each is in these different stages in different minds. Every country boy possesses more or less information respecting the plants and animals which come under his notice, in the stage of common knowledge; a good many persons have acquired more or less of that accurate, but necessarily incomplete and unmethodised knowledge, which is understood by Natural History; while a few have reached the purely scientific stage, and, as Zoologists and Botanists, strive towards the perfection of Biology as a branch of Physical Science.
Historically, common knowledge is represented by the allusions to animals and plants in ancient literature; while Natural History, more or less grading into Biology, meets us in the works of Aristotle, and his continuators in the Middle Ages, Rondoletius, Aldrovandus, and their contemporaries and successors. But the conscious attempt to construct a complete science of Biology hardly dates further back than Treviranus and Lamarck, at the beginning of this century, while it has received its strongest impulse, in our own day, from Darwin.
My purpose, in the present work, is to exemplify the general truths respecting the development of zoological science which have just been stated by the study of a special case; and, to this end, I have selected an animal, the Common Crayfish, which, taking it altogether, is better fitted for my purpose than any other.
It is readily obtained, [note 1] and all the most important points of its construction are easily deciphered; hence, those who read what follows will have no difficulty in ascertaining whether the statements correspond with facts or not. And unless my readers are prepared to take this much trouble, they may almost as well shut the book; for nothing is truer than Harvey's dictum, that those who read without acquiring distinct images of the things about which they read, by the help of their own senses, gather no real knowledge, but conceive mere phantoms and idola.
It is a matter of common information that a number of our streams and rivulets harbour small animals, rarely more than three or four inches long, which are very similar to little lobsters, except that they are usually of a dull, greenish or brownish colour, generally diversified with pale yellow on the under side of the body, and sometimes with red on the limbs. In rare cases, their general hue may be red or blue. These are "crayfishes," and they cannot possibly be mistaken for any other inhabitants of our fresh waters.
[Figure 1: Astacus fluviatilis--Side view of a male specimen]
The animals may be seen walking along the bottom of the shallow waters which they prefer, by means of four pairs of jointed legs (fig. 1); but, if alarmed, they swim backwards with rapid jerks, propelled by the strokes of a broad, fan-shaped flipper, which terminates the hinder end of the body (fig. 1, t, 20). In front of the four pairs of legs, which are used in walking, there is a pair of limbs of a much more massive character, each of which ends in two claws disposed in such a manner as to constitute a powerful pincer (fig. 1; 10). These claws are the chief weapons of offence and defence of the crayfish, and those who handle them incautiously will discover that their grip is by no means to be despised, and indicates a good deal of disposable energy. A sort of shield covers the front part of the body, and ends in a sharp projecting spine in the middle line (r). On each side of this is an eye, mounted on a movable stalk (1), which can be turned in any direction: behind the eyes follow two pairs of feelers; in one of these, the feeler ends in two, short, jointed filaments (2); while, in the other, it terminates in a single, many-jointed filament, like a whip-lash, which is more than half the length of the body (3). Sometimes turned backwards, sometimes sweeping forwards, these long feelers continually explore a considerable area around the body of the crayfish.
If a number of crayfishes, of about the same size, are compared together, it will easily be seen that they fall into two sets; the jointed tail being much broader, especially in the middle, in the one set than in the other (fig. 2). The broad-tailed crayfishes are the females, the others the males. And the latter may be still more easily known by the possession of four curved styles, attached to the under face of the first two rings of the tail, which are turned forwards between the hinder legs, on the under side of the body (fig. 3, A; 15, 16). In the female, there are mere soft filaments in the place of the first pair of styles (fig. 3, B; 15).
Crayfishes do not inhabit every British river, and even where they are known to abound, it is not easy to find them at all times of the year. In granite districts and others, in which the soil yields little or no calcareous matter to the waters which flow over it, crayfishes do not occur. They are intolerant of great heat and of much sunshine; they are therefore most active towards the evening, while they shelter themselves under the shade of stones and banks during the day. It has been observed that they frequent those parts of a river which run north and south, less than those which have an easterly and westerly direction, inasmuch as the latter yield more shade from the mid-day sun.
During the depth of winter, crayfishes are rarely to be seen about in a stream; but they may be found in abundance in its banks, in natural crevices and in burrows which they dig for themselves. The burrows may be from a few inches to more than a yard deep, and it has been noticed that, if the waters are liable to freeze, the burrows are deeper and further from the surface than otherwise. Where the soil, through which a stream haunted by crayfishes runs, is soft and peaty, the crayfishes work their way into it in all directions, and thousands of them, of all sizes, may be dug out, even at a considerable distance from the banks.
It does not appear that crayfishes fall into a state of torpor in the winter, and thus "hybernate" in the strict sense of the word. At any rate, so long as the weather is open, the crayfish lies at the mouth of his burrow, barring the entrance with his great claws, and with protruded feelers keeps careful watch on the passers-by. Larvæ of insects, water-snails, tadpoles, or frogs, which come within reach, are suddenly seized and devoured, and it is averred that the water-rat is liable to the same fate. Passing too near the fatal den, possibly in search of a stray crayfish, whose flavour he highly appreciates, the vole is himself seized and held till he is suffocated, when his captor easily reverses the conditions of the anticipated meal.
In fact, few things in the way of food are amiss to the crayfish; living or dead, fresh or carrion, animal or vegetable, it is all one. Calcareous plants, such as the stoneworts (Chara), are highly acceptable; so are any kinds of succulent roots, such as carrots; and it is said that crayfish sometimes make short excursions inland, in search of vegetable food. Snails are devoured, shells and all; the cast coats of other crayfish are turned to account as supplies of needful calcareous matter; and the unprotected or weakly member of the family is not spared. Crayfishes, in fact, are guilty of cannibalism in its worst form; and a French observer pathetically remarks, that, under certain circumstances, the males "méconnaissent les plus saints devoirs;" and, not content with mutilating or killing their spouses, after the fashion of animals of higher moral pretensions, they descend to the lowest depths of utilitarian turpitude, and finish by eating them.
In the depth of winter, however, the most alert of crayfish can find little enough food; and hence, when they emerge from their hiding-places in the first warm days of spring, usually about March, the crayfishes are in poor condition.
At this time, the females are found to be laden with eggs, of which from one to two hundred are attached beneath the tail, and look like a mass of minute berries (fig. 3, B). In May or June, these eggs are hatched, and give rise to minute young, which are sometimes to be found attached beneath the tail of the mother, under whose protection they spend the first few days of their existence.
In this country, we do not set much store upon crayfishes as an article of food, but on the Continent, and especially in France, they are in great request. Paris alone, with its two millions of inhabitants, consumes annually from five to six millions of crayfishes, and pays about 16,000 pounds sterling for them. The natural productivity of the rivers of France has long been inadequate to supply the demand for these delicacies; and hence, not only are large quantities imported from Germany, and elsewhere, but the artificial cultivation of crayfish has been successfully attempted on a considerable scale.
Crayfishes are caught in various ways; sometimes the fisherman simply wades in the water and drags them out of their burrows; more commonly, hoop-nets baited with frogs are let down into the water and rapidly drawn up, when there is reason to think that crayfish have been attracted to the bait; or fires are lighted on the banks at night, and the crayfish, which are attracted, like moths, to the unwonted illumination, are scooped out with the hand or with nets.
Thus far, our information respecting the crayfish is such as would be forced upon anyone who dealt in crayfishes, or lived in a district in which they were commonly used for food. It is common knowledge. Let us now try to push our acquaintance with what is to be learned about the animal a little further, so as to be able to give an account of its Natural History, such as might have been furnished by Buffon if he had dealt with the subject.
There is an inquiry which does not strictly lie within the province of physical science, and yet suggests itself naturally enough at the outset of a natural history.
The animal we are considering has two names, one common, Crayflsh, the other technical, Astacus fluviatilis. How has it come by these two names, and why, having a common English name for it already, should naturalists call it by another appellation derived from a foreign tongue?
The origin of the common name, "crayfish," involves some curious questions of etymology, and indeed, of history. It might readily be supposed that the word "Cray" had a meaning of its own, and qualified the substantive "fish"--as "jelly " and "cod" in "jellyfish" and "codfish." But this certainly is not the case. The old English method of writing the word was "crevis" or "crevice," and the "cray" is simply a phonetic spelling of the syllable "cre," in which the "e" was formerly pronounced as all the world, except ourselves, now pronounce that vowel. While "fish" is the "vis" insensibly modified to suit our knowledge of the thing as an aquatic animal.
Now "crevis" is clearly one of two things. Either it is a modification of the French name "ecrevisse," or of the Low Dutch name "crevik," by which the crayfish is known in these languages. The former derivation is that usually given, and, if it be correct, we must refer "crayfish" to the same category as "mutton," "beef," and "pork," all of which are French equivalents, introduced by the Normans, for the "sheep's flesh," "ox flesh," and "swine's flesh," of their English subjects. In this case, we should not have called a crayfish, a crayfish, except for the Norman conquest.
On the other hand, if "crevik" is the source of our word, it may have come to us straight from the Angle and Saxon contingent of our mixed ancestry.
As to the origin of the technical name; astakos, was the name by which the Greeks knew the lobster; and it has been handed down to us in the works of Aristotle, who does not seem to have taken any special notice of the crayfish. At the revival of learning, the early naturalists noted the close general similarity between the lobster and the crayfish; but, as the latter lives in fresh water, while the former is a marine animal, they called the crayfish, in their Latin, Astacus fluviatilis, or the "river-lobster," by way of distinction; and this nomenclature was retained until, about forty-five years ago, an eminent French Naturalist, M. Milne-Edwards, pointed out that there are far more extensive differences between lobsters and crayfish than had been supposed; and that it would be advisable to mark the distinctness of the things by a corresponding difference in their names. Leaving Astacus for the crayfishes, he proposed to change the technical name of the lobster into Homarus, by latinising the old French name "Omar," or "Homar" (now Homard), for that animal.
At the present time, therefore, while the recognised technical name of the crayfish is Astacus fluviatilis, that of the lobster is Homarus vulgaris. And as this nomenclature is generally received, it is desirable that it should not be altered; though it is attended by the inconvenience, that Astacus, as we now employ the name, does not denote that which the Greeks, ancient and modern, signify, by its original, astakos; and does signify something quite different.
Finally, as to why it is needful to have two names for the same thing, one vernacular, and one technical. Many people imagine that scientific terminology is a needless burden imposed upon the novice, and ask us why we cannot be content with plain English. In reply, I would suggest to such an objector to open a conversation about his own business with a carpenter, or an engineer, or, still better, with a sailor, and try how far plain English will go. The interview will not have lasted long before he will find himself lost in a maze of unintelligible technicalities. Every calling has its technical terminology; and every artisan uses terms of art, which sound like gibberish to those who know nothing of the art, but are exceedingly convenient to those who practise it.
In fact, every art is full of conceptions which are special to itself; and, as the use of language is to convey our conceptions to one another, language must supply signs for those conceptions. There are two ways of doing this: either existing signs may be combined in loose and cumbrous periphrases; or new signs, having a well-understood and definite signification, may be invented. The practice of sensible people shows the advantage of the latter course; and here, as elsewhere, science has simply followed and improved upon common sense.
Moreover, while English, French, German, and Italian artisans are under no particular necessity to discuss the processes and results of their business with one another, science is cosmopolitan, and the difficulties of the study of Zoology would be prodigiously increased, if Zoologists of different nationalities used different technical terms for the same thing. They need a universal language; and it has been found convenient that the language shall be the Latin in form, and Latin or Greek in origin. What in English is Crayfish, is Écrevisse in French; Flusskrebs, in German; Cammaro, or Gambaro, or Gammarello, in Italian: but the Zoologist of each nationality knows that, in the scientific works of all the rest, he shall find what he wants to read under the head of Astacus fluviatilis.
But granting the expediency of a technical name for the Crayfish, why should that name be double? The reply is still, practical convenience. If there are ten children of one family, we do not call them all Smith, because such a procedure would not help us to distinguish one from the other; nor do we call them simply John, James, Peter, William, and so on, for that would not help us to identify them as of one family. So we give them all two names, one indicating their close relation, and the other their separate individuality--as John Smith, James Smith, Peter Smith, William Smith, &C The same thing is done in Zoology; only, in accordance with the genius of the Latin language, we put the Christian name, so to speak, after the surname.
There are a number of kinds of Crayfish, so similar to one another that they bear the common surname of Astacus. One kind, by way of distinction, is called fluviatile, another slender-handed, another Dauric, from the region in which it lives; and these double names are rendered by --Astacus fluviatilis, Astacus leptodactylus, and Astacus dauricus; and thus we have a nomenclature which is exceedingly simple in principle, and free from confusion in practice. And I may add that, the less attention is paid to the original meaning of the substantive and adjective terms of this binomial nomenclature, and the sooner they are used as proper names, the better. Very good reasons for using a term may exist when it is first invented, which lose their validity with the progress of knowledge. Thus Astacus fluviatilis was a significant name so long as we knew of only one kind of crayfish; but now that we are acquainted with a number of kinds, all of which inhabit rivers, it is meaningless. Nevertheless, as changing it would involve endless confusion, and the object of nomenclature is simply to have a definite name for a definite thing, nobody dreams of proposing to alter it.
Having learned this much about the origin of the names of the crayfish, we may next proceed to consider those points which an observant Naturalist, who did not care to go far beyond the surface of things, would find to notice in the animal itself.
Probably the most conspicuous peculiarity of the crayfish, to any one who is familiar only with the higher animals, is the fact that the hard parts of the body are outside and the soft parts inside; whereas in ourselves, and in the ordinary domestic animals, the hard parts, or bones, which constitute the skeleton, are inside, and the soft parts clothe them. Hence, while our hard framework is said to be an endoskeleton, or internal skeleton; that of the crayfish is termed an exoskeleton, or external skeleton. It is from the circumstance that the body of the crayfishes is enveloped in this hard crust, that the name of Crustacea is applied to them, along with the crabs, shrimps, and other such animals. Insects, spiders, and centipedes have also a hard exoskeleton, but it is usually not so hard and thick as in the Crustacea.
If a piece of the crayfish's skeleton is placed in strong vinegar, abundant bubbles of carbonic acid gas are given off from it, and it rapidly becomes converted into a soft laminated membrane, while the solution will be found to contain lime. In fact the exoskeleton is composed of a peculiar animal matter, so much impregnated with carbonate and phosphate of lime that it becomes dense and hard. [see End note 1]
[Figure 2: Astacus fluviatilis--Dorsal or tergal views.]
It will be observed that the body of the crayfish is naturally marked out into several distinct regions. There is a firm and solid front part, covered by a large continuous shield, which is called the carapace; and a jointed hind part, commonly termed the tail (fig. 2). From the perception of a partially real, and partially fanciful, analogy with the regions into which the body is divided in the higher animals, the fore part is termed the cephalo-thorax, or head (cephalon) and chest (thorax) combined, while the hinder part receives the name of abdomen.
Now the exoskeleton is not of the same constitution throughout these regions. The abdomen, for example, is composed of six complete hard rings (fig. 2, xv-xx), and a terminal flap, on the under side of which the vent (fig. 3, a) is situated, and which is called the telson (fig. 2, t, t'). All these are freely moveable upon one another, inasmuch as the exoskeleton which connects them is not calcified, but is, for the most part, soft and flexible, like the hard exoskeleton when the lime salts have been removed by acid. The mechanism of the joints will have to be attentively considered by-and-by; it is sufficient, at present, to remark that, wherever a joint exists, it is produced in the same fashion, by the exoskeleton remaining soft in certain regions of the jointed part.
The carapace is not jointed; but a transverse groove is observed about the middle of it, the ends of which run down on the sides and then turn forwards (figs. 1 and 2, cg). This is called the cervical groove, and it marks off the region of the head, in front, from that of the thorax behind.
[Figure 3: Astacus fluviatilis--Ventral or sternal views.]
The thorax seems at first not to be jointed at all; but if its under, or what is better called its sternal, surface is examined carefully, it will be found to be divided into as many transverse bands, or segments, as there are pairs of legs (fig. 3); and, moreover, the hindermost of these segments is not firmly united with the rest, but can be moved backwards and forwards through a small space (fig. 3, B; xiv).
Attached to the sternal side of every ring of the abdomen of the female there is a pair of limbs, called swimmerets. In the five anterior rings, these are small and slender (fig. 3, B; 15, 19); but those of the sixth ring are very large, and each ends in two broad plates (20). These two plates on each side, with the telson in the middle, constitute the flapper of the crayfish, by the aid of which it executes its retrograde swimming movements. The small swimmerets move together with a regular swing, like paddles, and probably aid in propelling the animal forwards. In the breeding female (B), the eggs are attached to them; while, in the male, the two anterior pairs (A; 15, 16) are converted into the peculiar styles which distinguish that sex.
The four pairs of legs which are employed for walking purposes, are divided into a number of joints, and the foremost two pairs are terminated by double claws, arranged so as to form a pincer, whence they are said to be chelate. The two hindermost pairs, on the other hand, end in simple claws.
In front of these legs, come the great prehensile limbs (10), which are chelate, like those which immediately follow them, but vastly larger. They often receive the special name of chelæ; and the large terminal joints are called the "hand." We shall escape confusion if we call these limbs the forceps, and restrict the name of chela to the two terminal joints.
All the limbs hitherto mentioned subserve locomotion and prehension in various degrees. The crayfish swims by the help of its abdomen, and the hinder pairs of abdominal limbs; walks by means of the four hinder pairs of thoracic limbs; lays hold of anything to fix itself, or to assist in climbing, by the two chelate anterior pairs of these limbs, which are also employed in tearing the food seized by the forceps and conveying it to the mouth; while it seizes its prey and defends itself with the forceps. The part which each of these limbs plays is termed its function, and it is said to be the organ of that function; so that all these limbs may be said to be organs of the functions of locomotion, of offence and defence.
In front of the forceps, there is a pair of limbs which have a different character, and take a different direction from any of the foregoing (9). These limbs, in fact, are turned directly forwards, parallel with one another, and with the middle line of the body. They are divided into a number of joints, of which one of those near the base is longer than the rest, and strongly toothed along the inner edge, or that which is turned towards its fellow. It is obvious that these two limbs are well adapted to crush and tear whatever comes between them, and they are, in fact, jaws or organs of manducation. At the same time, it will be noticed that they retain a curiously close general resemblance to the hinder thoracic legs; and hence, for distinction's sake, they are called outer foot-jaws, or external maxillipedes.
If the head of a stout pin is pushed between these external maxillipedes, it will be found that it passes without any difficulty into the interior of the body, through the mouth. In fact, the mouth is relatively rather a large aperture; but it cannot be seen without forcing aside, not only these external foot-jaws, but a number of other limbs, which subserve the same function of manducation, or chewing and crushing the food. We may pass by the organs of manducation, for the present, with the remark that there are altogether three pairs of maxillipedes, followed by two pairs of somewhat differently formed maxillæ, and one pair of very stout and strong jaws, which are termed the mandibles (4). All these jaws work from side to side, in contradistinction to the jaws of vertebrated animals, which move up and down. In front of, and above the mouth, with the jaws which cover it, are seen the long feelers, which are called the antennæ (3); above, and in front of them, follow the small feelers, or antennules (2); and over them, again, lie the eye stalks (1). The antennæ are organs of touch; the antennules, in addition, contain the organs of hearing; while, at the ends of the eyestalks, are the organs of vision.
Thus we see that the crayfish has a jointed and segmented body, the rings of which it is composed being very obvious in the abdomen, but more obscurely traceable elsewhere; that it has no fewer than twenty pairs of what may be called by the general name of appendages; and that these appendages are turned to different uses, or are organs of different functions, in different parts of the body. The crayfish is obviously a very complicated piece of living machinery. But we have not yet come to the end of all the organs that may be discovered even by cursory inspection. Every one who has eaten a boiled crayfish, or a lobster, knows that the great shield, or carapace, is very easily separated from the thorax and abdomen, the head and the limbs which belong to that region coming away with the carapace. The reason of this is not far to seek. The lower edges of that part of the carapace which belongs to the thorax approach the bases of the legs pretty closely, but a cleft-like space is left; and this cleft extends forwards to the sides of the region of the mouth, and backwards and upwards, between the hinder margin of the carapace and the sides of the first ring of the abdomen, which are partly overlapped by, and partly overlap, that margin. If the blade of a pair of scissors is carefully introduced into the cleft from behind, as high up as it will go without tearing anything, and a cut is then made, parallel with the middle line, as far as the cervical groove, and thence following the cervical groove to the base of the outer foot-jaws, a large flap will be removed. This flap of the carapace is called the branchiostegite (fig. 1, bg), because it covers the gills or branchiæ (fig. 4), which are now exposed. They have the appearance of a number of delicate plumes, which take a direction from the bases of the legs upwards and forwards behind, upwards and backwards in front, their summits converging towards the upper end of the cavity in which they are placed, and which is called the branchial chamber. These branchiæ are the respiratory organs; and they perform the same functions as the gills of a fish, to which they present some similarity.
[Figure 4: Astacus fluviatilis--gills.]
If the gills are cleared away, it is seen that the branchial cavity is bounded, on the inner side, by a sloping wall, formed by a delicate, but more or less calcified layer of the exoskeleton, which constitutes the proper outer wall of the thorax. At the upper limit of the branchial cavity, the layer of exoskeleton is very thin, and turning outwards, is continued into the inner wall or lining of the branchiostegite, which is also very thin (see fig. 15, p. 70).
Thus the branchial chamber is altogether outside the body, to which it stands in somewhat the same relation as the space between the flaps of a man's coat and his waistcoat would do to the part of the body enclosed by the waistcoat, if we suppose the lining of the flaps to be made in one piece with the sides of the waistcoat. Or a closer parallel still would be brought about, if the skin of a man's back were loose enough to be pulled out, on each side, into two broad flaps covering the flanks.
It will be observed that the branchial chamber is open behind, below, and in front; and, therefore, that the water in which the crayfish habitually lives has free ingress and egress. Thus the air dissolved in the water enables breathing to go on, just as it does in fishes. As is the case with many fishes, the crayfish breathes very well out of the water, if kept in a situation sufficiently cool and moist to prevent the gills from drying up; and thus there is no reason why, in cool and damp weather, the crayfish should not be able to live very well on land, at any rate among moist herbage, though whether our common crayfishes do make such terrestrial excursions is perhaps doubtful. We shall see, by-and-by, that there are some exotic crayfish which habitually live on land, and perish if they are long submerged in water.
[Figure 5: Astacus fluviatilis--viscera, dorsal view.]
With respect to the internal structure of the crayfish, there are some points which cannot escape notice, however rough the process of examination may be.
Thus, when the carapace is removed in a crayfish which has been just killed, the heart is seen still pulsating. It is an organ of considerable relative size (fig. 5, h), which is situated immediately beneath the middle region of that part of the carapace which lies behind the cervical groove; or, in other words, in the dorsal region of the thorax. In front of it, and therefore in the head, is a large rounded sac, the stomach (fig. 5, cs; fig. 6, cs, ps), from which a very delicate intestine (figs. 5 and 6, hg) passes straight back through the thorax and abdomen to the vent (fig. 6, a).
[Figure 6: Astacus fluviatilis--alimentary canal.]
In summer, there are commonly to be found at the sides of the stomach two lenticular calcareous masses, which are known as "crabs'-eyes," or gastroliths, and were, in old times, valued in medicine as sovereign remedies for all sorts of disorders. These bodies (fig. 7) are smooth and flattened, or concave, on the side which is turned towards the cavity of the stomach; while the opposite side, being convex and rough with irregular prominences, is something like a "brain-stone" coral. [see End note 2]
[Figure 7: Astacus fluviatilis--a gastrolith.]
Moreover, when the stomach is laid open, three large reddish teeth are seen to project conspicuously into its interior (fig. 6, lt, mt); so that, in addition to its six pairs of jaws, the crayfish has a supplementary crushing mill in its stomach. On each side of the stomach, there is a soft yellow or brown mass, commonly known as the liver (fig. 5, Lr); and, in the breeding season, the ovaries of the females, or organs in which the eggs are formed, are very conspicuous from the dark-coloured eggs which they contain, and which, like the exoskeleton, turn red when they are boiled. The corresponding part in a cooked lobster goes by the name of the "coral."
Beside these internal structures, the most noticeable are the large masses of flesh, or muscle, in the thorax and abdomen, and in the pincers; which, instead of being red, as in most of the higher animals, is white. It will further be observed that the blood, which flows readily when a crayfish is wounded, is a clear fluid, and is either almost colourless, or of a very pale reddish or neutral tint. Hence the older Naturalists thought that the crayfish was devoid of blood, and had merely a sort of ichor in place of it. But the fluid in question is true blood; and if it is received into a vessel, it soon forms a soft, but firm, gelatinous clot.
The crayfish grows rapidly in youth, but enlarges more and more slowly as age advances. The young animal which has just left the egg is of a greyish colour, and about one quarter of an inch long. By the end of the year, it may have reached nearly an inch and a half in length. Crayfishes of a year old are, on an average, two inches long; at two years, two inches and four-fifths; at three years, three inches and a half; at four years, four inches and a half nearly; and at five years, five inches. They go on growing till, in exceptional cases, they may attain between seven inches and eight inches in length; but at what degree of longevity this unusual dimension is reached is uncertain. It seems probable, however, that the life of these animals may be prolonged to as much as fifteen or twenty years. They appear to reach maturity, so far as the power of reproduction is concerned, in their fifth or, more usually, their sixth year. However, I have seen a female, with eggs attached under the abdomen, only two inches long, and therefore, probably, in her second year. The males are commonly larger than females of the same age. [see End note 3]
The hard skeleton of a crayfish, once formed, is incapable of being stretched, nor can it increase by interstitial addition to its substance, as the bone of one of the higher animals grows. Hence it follows, that the enlargement of the body, which actually takes place, involves the shedding and reproduction of its investment. This might be effected by insensible degrees, and in different parts of the body at different times, as we shed our hair; but, as a matter of fact, it occurs periodically and universally, somewhat as the feathers of birds are moulted. The whole of the old coat of the body is thrown off at once, and suddenly; and the new coat, which has, in the meanwhile, been formed beneath the old one, remains soft for a time, and allows of a rapid increase in the dimensions of the body before it hardens. This sort of moulting is what is technically termed ecdysis, or exuviation. It is commonly spoken of as the "shedding of the skin," and there is no harm in using this phrase, if we recollect that the shed coat is not the skin, in the proper sense of the word, but only what is termed a cuticular layer, which is secreted upon the outer surface of the true integument. The cuticular skeleton of the crayfish, in fact, is not even so much a part of the skin as the cast of a snake, or as our own nails. For these are composed of coherent, formed parts of the epidermis; while the hard investment of the crayfish contains no such formed parts, and is developed on the outside of those structures which answer to the constituents of the epidermis in the higher animals. Thus the crayfish grows, as it were, by starts; its dimensions remaining stationary in the intervals of its moults, and then rapidly increasing for a few days, while the new exoskeleton is in the course of formation.
The ecdysis of the crayfish was first thoroughly studied a century and a half ago, by one of the most accurate observers who ever lived, the famous Réaumur, and the following account of this very curious process is given nearly in his words. [note 2]
A few hours before the process of exuviation commences, the crayfish rubs its limbs one against the other, and, without changing its place, moves each separately, throws itself on its back, bends its tail, and then stretches it out again, at the same time vibrating its antennæ. By these movements, it gives the various parts a little play in their loosened sheaths. After these preparatory steps, the crayfish appears to become distended; in all probability, in consequence of the commencing retraction of the limbs into the interior of the exoskeleton of the body. In fact, it has been remarked, that if, at this period, the extremity of one of the great claws is broken off, it will be found empty, the contained soft parts being retracted as far as the second joint. The soft membranous part of the exoskeleton, which connects the hinder end of the carapace with the first ring of the abdomen, gives way, and the body, covered with the new soft integument, protrudes; its dark brown colour rendering it easily distinguishable from the greenish-brown old integument.
Having got thus far, the crayfish rests for a while, and then the agitation of the limbs and body recommences. The carapace is forced upwards and forwards by the protrusion of the body, and remains attached only in the region of the mouth. The head is next drawn backwards, while the eyes and its other appendages are extracted from their old investment. Next the legs are pulled out, either one at a time, or those of one, or both, sides together. Sometimes a limb gives way and is left behind in its sheath. The operation is facilitated by the splitting of the old integument of the limb along one side longitudinally.
When the legs are disengaged, the animal draws its head and limbs completely out of their former covering; and, with a sudden spring forward, while it extends its abdomen, it extracts the latter, and leaves its old skeleton behind. The carapace falls back into its ordinary position, and the longitudinal fissures of the sheaths of the limbs close up so accurately, that the shed integument has just the appearance the animal had when the exuviation commenced. The cast exoskeleton is so like the crayfish itself when the latter is at rest, that, except for the brighter colour of the latter, the two cannot be distinguished.
After exuviation, the owner of the cast skin, exhausted by its violent struggles, which are not unfrequently fatal, lies in a prostrate condition. Instead of being covered by a hard shell, its integument is soft and flabby, like wet paper; though Réaumur remarks, that if a crayfish is handled immediately after exuviation, its body feels hard; and he ascribes this to the violent contraction which its muscles have undergone, leaving them in a state of cramp. In the absence of the hard skeleton, however, there is nothing to bring the contracted muscles at once back into position, and it must be some time before the pressure of the internal fluids is so distributed as to stretch them out.
When the process of exuviation has proceeded so far that the carapace is raised, nothing stops the crayfish from continuing its struggles. If taken out of the water in this condition, they go on moulting in the hand, and even pressure on their bodies will not arrest their efforts.
The length of time occupied from the first giving way of the integuments to the final emergence of the animal, varies with its vigour, and the conditions under which it is placed, from ten minutes to several hours. The chitinous lining of the stomach, with its teeth, and the "crabs'-eyes," are shed along with the rest of the cuticular exoskeleton; but they are broken up and dissolved in the stomach.
The new integuments of the crayfish remain soft for a period which varies from one to three days; and it is a curious fact, that the animal appears to be quite aware of its helplessness, and governs itself accordingly.
An observant naturalist says: "I once had a domesticated crayfish (Astacus fluviatilis), which I kept in a glass pan, in water, not more than an inch and a half deep, previous experiment having shown that in deeper water, probably from want of sufficient aëration, this animal would not live long. By degrees my prisoner became very bold, and when I held my fingers at the edge of the vessel, he assailed them with promptness and energy. About a year after I had him, I perceived, as I thought, a second crayfish with him. On examination, I found it to be his old coat, which he had left in a most perfect state. My friend had now lost his heroism, and fluttered about in the greatest agitation. He was quite soft; and every time I entered the room during the next two days, he exhibited the wildest terror. On the third, he appeared to gain confidence, and ventured to use his nippers, though with some timidity, and he was not yet quite so hard as he had been. In about a week, however, he became bolder than ever; his weapons were sharper, and he appeared stronger, and a nip from him was no joke. He lived in all about two years, during which time his food was a very few worms at very uncertain times; perhaps he did not get fifty altogether." [note 3]
It would appear, from the best observations that have yet been made, that the young crayfish exuviate two or three times in the course of the first year; and that, afterwards, the process is annual, and takes place usually about midsummer. There is reason to suppose that very old crayfish do not exuviate every year. [see End note 4]
It has been stated that, in the course of its violent efforts to extract its limbs from the cast-off exoskeleton, the crayfish sometimes loses one or other of them; the limb giving way, and the greater part, or the whole, of it remaining in the exuviæ. But it is not only in this way that crayfishes part with their limbs. At all times, if the animal is held by one of its pincers, so that it cannot get away, it is apt to solve the difficulty by casting off the limb, which remains in the hand of the captor, while the crayfish escapes. This voluntary amputation is always effected at the same place; namely, where the limb is slenderest, just beyond the articulation which unites the basal joint with the next. The other limbs also readily part at the joints; and it is very common to meet with crayfish which have undergone such mutilation. But the injury thus inflicted is not permanent, as these animals possess the power of reproducing lost parts to a marvellous extent, whether the loss has been inflicted by artificial amputation, or voluntarily.
Crayfishes, like all the Crustacea, bleed very freely when wounded; and if one of the large joints of a leg is cut through, or if the animal's body is injured, it is very likely to die rapidly from the ensuing hæmorrhage. A crayfish thus wounded, however, commonly throws off the limb at the next articulation, where the cavity of the limb is less patent, and its sides more readily fall together; and, as we have seen, the pincers are usually cast off at their narrowest point. When such amputation has taken place, a crust, probably formed of coagulated blood, rapidly forms over the surface of the stump; and, eventually, it becomes covered with a cuticle. Beneath this, after a time, a sort of bud grows out from the centre of the surface of the stump, and gradually takes on the form of as much of the limb as has been removed. At the next ecdysis, the covering cuticle is thrown off along with the rest of the exoskeleton; while the rudimentary limb straightens out, and, though very small, acquires all the organization appropriate to that limb. At every moult it grows; but, it is only after a long time that it acquires nearly the size of its uninjured and older fellow. Hence, it not unfrequently happens, that crayfish are found with pincers and other limbs, which, though alike useful and anatomically complete, are very unequal in size.
Injuries inflicted while the crayfish are soft after moulting, are apt to produce abnormal growths of the part affected; and these may be perpetuated, and give rise to various monstrosities, in the pincers and in other parts of the body.
In the reproduction of their kind by means of eggs the co-operation of the males with the females is necessary. On the basal joint of the hindermost pair of legs of the male a small aperture is to be seen (fig. 3, A; vd). In these, the ducts of the apparatus in which the fecundating substance is formed terminate. The fecundating material itself is a thickish fluid, which sets into a white solid after extrusion. The male deposits this substance on the thorax of the female, between the bases of the hindermost pairs of thoracic limbs. [see End note 5]
The eggs formed in the ovary are conducted to apertures, which are situated on the bases of the last pair of ambulatory legs but two, that is, in the hinder of the two pair which are provided with chelate extremities (fig. 3, B; od).
After the female has received the deposit of the spermatic matter of the male, she retires to a burrow, in the manner already stated, and then the process of laying the eggs commences. These, as they leave the apertures of the oviducts, are coated with a viscid matter, which is readily drawn out into a short thread. The end of the thread attaches itself to one of the long hairs, with which the swimmerets are fringed, and as the viscid matter rapidly hardens, the egg thus becomes attached to the limb by a stalk. The operation is repeated, until sometimes a couple of hundred eggs are thus glued on to the swimmerets. Partaking in the movements of the swimmerets, they are washed backwards and forwards in the water, and thus aërated and kept free of impurities; while the young crayfish is formed much in the same way as the chick is formed in a hen's egg.
The process of development, however, is very slow, as it occupies the whole winter. In late spring-time, or early summer, the young burst the thin shell of the egg, and, when they are hatched, present a general resemblance to their parents. This is very unlike what takes place in crabs and lobsters, in which the young leave the egg in a condition very different from the parent, and undergo a remarkable metamorphosis before they attain their proper form.
[Figure 8: Astacus fluviatilis--newly hatched.]
For some time after they are hatched, the young hold on to the swimmerets of the mother, and are carried about, protected by her abdomen, as in a kind of nursery.
That most careful naturalist, Roesel von Rosenhof, says of the young, when just hatched:--
"At this time they are quite transparent; and when such a crayfish [a female with young] is brought to table, it looks quite disgusting to those who do not know what the young are; but if we examine it more closely, especially with a magnifying-glass, we see with pleasure that the little crayfish are already perfect, and resemble the large one in all respects. When the mother of these little crayfish, after they have begun to be active, is quiet for a while, they leave her and creep about, a short way off. But, if they spy the least sign of danger, or there is any unusual movement in the water, it seems as if the mother recalled them by a signal; for they all at once swiftly return under her tail, and gather into a cluster, and the mother hies to a place of safety with them, as quickly as she can. A few days later, however, they gradually forsake her." [note 4]
Fishermen declare that "Hen Lobsters" protect their young in a similar manner. [note 5] Jonston, [note 6] who wrote in the middle of the seventeenth century, says that the little crayfish are often to be seen adhering to the tail of the mother. Roesel's observations imply the same thing; but he does not describe the exact mode of adherence, and I can find no observations on the subject in the works of later writers. [see End note 6]
It has been seen that the eggs are attached to the swimmerets by a viscid substance, which is, as it were, smeared over them and the hairs with which they are fringed, and is continued by longer or shorter thread-like pedicles into the coat of the same material which invests each egg. It very soon hardens, and then becomes very firm and elastic.
When the young crayfish is ready to be hatched, the egg case splits into two moieties, which remain attached, like a pair of watch glasses, to the free end of the pedicle of the egg (fig. 8, A; ec). The young animal, though very similar to the parent, does not quite "resemble it in all respects," as Roesel says. For not only are the first and the last pairs of abdominal limbs wanting, while the telson is very different from that of the adult; but the ends of the great chelæ are sharply pointed and bent down into abruptly in-curved hooks, which overlap when the chelæ are shut (fig. 8, B). Hence, when the chelæ have closed upon anything soft enough to allow of the imbedding of these hooks, it is very difficult, if not impossible, to open them again.
Immediately the young are set free, they must instinctively bury the ends of their forceps in the hardened egg-glue which is smeared over the swimmerets, for they are all found to be holding on in this manner. They exhibit very little movement, and they bear rough shaking or handling without becoming detached; in consequence, I suppose, of the interlocking of the hooked ends of the chelæ imbedded in the egg-glue.
Even after the female has been plunged into alcohol, the young remain attached. I have had a female, with young affixed in this manner, under observation for five days, but none of them showed any signs of detaching themselves; and I am inclined to think that they are set free only at the first moult. After this, it would appear that the adhesion to the parent is only temporary.
The walking legs are also hooked at their extremities, but they play a less important part in fixing the young to the parent, and seem to be always capable of loosing their hold.
I find the young of a Mexican crayfish (Cambarus) to be attached in the same manner as those of the English crayfish; but, according to Mr. Wood-Mason's recent observations, the young of the New Zealand crayfishes fix themselves to the swimmerets of the parent by the hooked ends of their hinder ambulatory limbs.
Crayfishes, in every respect similar to those found in our English rivers, that is to say, of the species Astacus fluviatilis, are met with in Ireland, and on the Continent, as far south as Italy and northern Greece; as far east as western Russia; and as far north as the shores of the Baltic. They are not known to occur in Scotland; in Spain, except about Barcelona, they are either rare, or have remained unnoticed.
There is, at present, no proof of the occurrence of Astacus fluviatilis in the fossil state.
Curious myths have gathered about crayfishes, as about other animals. At one time "crabs'-eyes" were collected in vast numbers, and sold for medicinal purposes as a remedy against the stone, among other diseases. Their real utility, inasmuch as they consist almost entirely of carbonate of lime, with a little phosphate of lime and animal matter, is much the same as that of chalk, or carbonate of magnesia. It was, formerly, a current belief that crayfishes grow poor at the time of new moon, and fat at that of full moon; and, perhaps, there may be some foundation for the notion, considering the nocturnal habits of the animals. Van Helmont, a great dealer in wonders, is responsible for the story that, in Brandenburg, where there is a great abundance of crayfishes, the dealers were obliged to transport them to market by night, lest a pig should run under the cart. For if such a misfortune should happen, every crayfish would be found dead in the morning: "Tam exitialis est porcus cancro." Another author improves the story, by declaring that the steam of a pig-stye, or of a herd of swine, is instantaneously fatal to crayfish. On the other hand, the smell of putrifying crayfish, which is undoubtedly of the strongest, was said to drive even moles out of their burrows.
[Author's Notes to Chapter 1]
[Note 1]: If crayish are not to be had, a lobster will be found to answer to the description of the former, in almost all points; but the gills and the abdominal appendages present differences; and the last thoracic somite is united with the rest in the lobster. (See Chap. V.)
[Note 2]: See Réamur's two Memoirs, "Sur les diverses reproductions qui se font dans les écrevisses, les omars, lee crabes, etc.," "Histoire de l'Académie royale dee Sciences," année 1712; and "Additions aux observations sur la mue des écrevisses données dans les Mémoires de 1712." Ibid. 1718.
[Note 3]: The late Mr. Robert Ball, of Dublin, in Bell's "British Crustacea," p. 239.
[Note 4]: "Der Monatlich-herausgegeben Insecten Belustigung." Dritter Theil, p. 336. 1755.
[Note 5]: Bell's "British Crustacea," p. 249.
[Note 6]: "Joannis Jonstoni Historiæ naturalis de Piscibus et Cetis Libri quinque. Tomus IV. 'De Cammaro seu Astaco fluviatili.'"
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Guide to Epoxy Surfboard Construction
Surfers Guide to Epoxy Surfboard Construction
Isle manufactures the highest quality epoxy surfboards and this is a helpful guide to explain the sometimes confusing details between the different surfboard construction methods of Epoxy Vrs Fiberglass.
What is an Epoxy surfboard?
Epoxy surfboards are stronger and lighter than traditional fiberglass boards. Epoxy resin is used in many applications other than surfboard building such as boats, electronics and aerospace parts. The epoxy resin is stronger and more ding resistant than the polyester resin used in traditional boards. Epoxy resin can only be used with EPS foam and boards made in this fashion are referred to as EPOXY/EPS surfboards. EPOXY for the resin and EPS for the core.
Understanding the Acronyms for Epoxy vs. Fiberglass Surfboards
Let’s get our surfboard terms straight - In order to speak like you know a thing or two about surfboards you need to learn and understand these below terms and exactly what they mean -
EPOXY - This is a hard type of resin used in the construction of epoxy surfboards with an EPS foam core
- Acronym for Expanded Polystyrene, This is light weight beaded foam used in the production of all epoxy surfboards
- Acronym for Polyester resin used in the production of the (traditional) polyurethane foam core surfboard
- Acronym for Polyurethane blank used as the core of a board glassed with polyester resin
- Weighted cloth used in the construction of epoxy glassed surfboards and poly glassed surfboards.
All surfboards use FIBERGLASS CLOTH for the most part and the type of construction is determined by the type of resin used and foam in the core. Here are the standards: EPOXY/EPS and POLY/PU. The first acronym describes the resin and the second the core. Both of these methods of construction are laid up with FIBERGLASS CLOTH. So when you say the phrase "fiberglass surfboard" it is not correct. You need to specify EPOXY/EPS or POLY/PU. This determines one type from the other. We know it's a bit confusing! So first we will explain the traditional “fiberglass” surfboard construction and then go on to explain the most popular types of epoxy surfboard constructions.
Traditional “Fiberglass” Vs. Epoxy
1. Traditional Fiberglass (POLY/PU) Surfboard Technology: PU or polyurethane foam is the foam of the traditional fiberglass board along with polyester resin and fiberglass cloth. The correct way to refer to this type of board is POLY/PU. POLY for the polyester resin and PU for the polyurethane core. This type of board is hand shaped or CNC machine shaped out of a PU foam core. The foam core is laid up with weighted fiberglass cloth and laminated with POLY resin. The board is cured and then sanded to a desired smoothness and voila! you have a traditional “fiberglass” surfboard or POLY/PU.
1. Epoxy Surfboard Technology (EPOXY/EPS): Epoxy surfboards have risen in popularity for many reasons in the last 20 years and especially in the last decade. The boards are constructed from EPOXY resin and EPS foam cores and glassed with fiberglass cloth. The epoxy resin is much stronger and less toxic than polyester resin and the EPS foam core is much lighter than a polyurethane core found in a traditional POLY/PU board. This makes for less toxic, stronger and lighter boards than a typically POLY/PU.
The 2 types of foam cores used with Epoxy Resin
1. Expanded Polystyrene: The EPS is beaded foam and the foam is much like that of your beer coolers in the grocery store or inside your bumper on your Mazda Miata. Since the foam maintains a structure based on an open cell it will absorb water like a sponge if exposed to water. Some limitations are the poor strength, low resistance to compression, and difficulty of shaping due to the small round spheres. If you are buying a lower priced epoxy board you can basically count on it to be expanded polystyrene in the core. These epoxy boards hold up well when paired with epoxy resin. Just make sure that if you crack your expanded polystyrene epoxy board, that you repair it before taking it back into the water! Isle Ecore Epoxy Surfboards are constructed of EPS foam.
1. Extruded Polystyrene Core: This is a closed cell core and since it is “closed” it repels water and is more resistant to compression and damage. One of the most notable differences from the Expanded Styrene Cores is the flex patterns are greatly enhanced due to its closed cell structure which will allow for greater response under pressure. All your higher end epoxy boards utilize this type of construction. Our Isle XPS Epoxy Surfboards are made with this type of core.
3 Types of Epoxy Surfboard Layups
1. Hand Shaped Epoxy Surfboard:.This type of EPOXY surfboard is quite similar to the fiberglass board as explained above. The only difference is the polyester resin is substituted for epoxy resin and the polyurethane core is substituted for an EPS core. The EPS is hand shaped or machine shaped and then laminated with EPOXY resin and FIBERGLASS CLOTH. In the aftermath of the Clark foam shutdown, many shapers quickly switched to this method as EPS foam cores were readily available in the marketplace in order to meet demand when traditional polyurethane foam was unavailable. They are very common amongst big brand name shapers and are widely available and customizable due to the fact they are all finished by hand. Our Isle Ecore Epoxy Surfboards and Isle XPS Epoxy Surfboards are both hand shaped
1. Molded (POP-OUT) Epoxy Surfboard: In this type of epoxy rather than hand shape the polystyrene core, a mold is created based on the dimensions of a traditional fiberglass plug. The hollow mold is then injected with the EPS foam to mold it into shape based on the master, and then covered with several layers of FIBERGLASS COTH, EPOXY RESIN, and typically a layer of high density foam to reinforce the structure and placed in a vacuum or press to compress all the materials together, hence the term sandwich construction. Typically a heating element can be built into the mold to allow the EPOXY resin to cure at a higher temp increasing the strength. The techniques employed during these steps can be varied by different companies to get the desired strength, flex, weight, etc..
1. Epoxy with High Density PVC Compression Step: A very strong PVC (lightweight composite) layer is compressed onto the EPS and glassed with epoxy resin. This compression step adds tremendous extra strength. It is much more difficult to build and is typically adhered to the core with vacuum compression. These boards are all either molded or machine shaped and refined to duplicate the master copy it is being modeled after.
For everything you would want to know about EPS foam check out
Marc Miller fro Isle Surf and SUP
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The Basics of RSS Explained
Want RSS explained in a simple, easy-to-understand way without a lot of bells and whistles? The purpose of RSS is to simplify your Web browsing, so RSS explanations shouldn't make this task more difficult.
What Is RSS?
Depending on who you ask, RSS either stands for Really Simple Syndication, or Rich Site Summary. Both descriptions give you a basic hint at what RSS does, but neither really tells you how RSS works.
For RSS to work, you first need a URL for the feed. In some contexts, a content provider has an option to enable RSS feeds. When you start a blog with some blogging platforms, you'll have the option of enabling RSS. If a content provider enables RSS, then readers are able to use RSS feed readers or RSS aggregators to grab data.
RSS feeds set the content up so that people who use RSS readers get it sent to them automatically, without having to visit the page. RSS sets out a specific series of guidelines for the way the content is generated; this enables RSS readers to download the content from the page.
Benefits of RSS
Why would people want to make it possible for other folks to "grab" their content? Quite simply, it gets people reading. When you find a Web site that you like, you might bookmark it and intend to come back. But most people have sporadic browsing patterns; you might forget to come back for days, or even weeks, and miss out on a lot of content. Additionally, when content providers update sporadically, you'll probably forget to go altogether because there's rarely any new information.
RSS feeds enable you as the reader to look at all of your favorite content in a single spot. When you subscribe to RSS feeds, they'll display new content in your RSS reader; you won't have to go to seven different Web sites to check seven different blogs. You can look at the content in your reader when you have time, and you'll automatically see all the new content; you don't have to go hunting for it.
How to Use RSS
It's relatively simple to use RSS to keep track of your favorite content. First, you'll need an RSS reader. You can use a Web-based RSS reader if you don't want to download software or if you want to be able to access your feeds from any computer. Web-based readers can also give you more functionality and search options.
If you prefer being able to read your RSS content even when you're offline, you can get desktop RSS readers that download content when you're connected to the Internet. You won't get updated content while you're offline, but you will be able to read what's there without an Internet connection.
Once you have an RSS reader or RSS aggregator, all you need is the RSS URL. The RSS URL isn't the same as the source URL; for example, to subscribe to a LiveJournal RSS feed, you'll need the regular user URL, plus the unique RSS URL. Most RSS sources make it very easy to find the RSS URL, which you can plug into your RSS reader. Once that's done, content will stream to you automatically and you'll never need to visit the site again.
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Insomnia: Get the Facts on Symptoms and Treatment
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Hanke Family Test Results (Clip 3 of 3)
In the third clip from the In the Family lesson plan, the Hankes, a family of three sisters, get the results of their genetic tests and find that two of the three sisters tested positive for the breast cancer gene. Students should discuss how factors (e.g., age, marital status, family history) might influence a person's decisions about genetic testing. What might happen if genetic testing for this mutation were not available? |
Marriage Equality Act
New York state passed the Marriage Equality Act this past week. This is a historic moment for New York state, as New York joins Connecticut, Iowa, Massachusetts, New Hampshire, and Vermont, plus Washington D.C., in marriage equality for the sexes.
According to the New York Law Journal, quoting Governor Andrew Cuomo, the Marriage Equality Act amends the Domestic Relations Law to state:
• A marriage that is otherwise valid shall be valid regardless of whether the parties to the marriage are of the same or different sex
• No government treatment or legal status, effect, right, benefit, privilege, protection or responsibility relating to marriage shall differ based on the parties to the marriage being the same sex or a different sex
• All relevant gender-specific language set forth in or referenced by New York law shall be construed in a gender-neutral manner
Exempt from this new law is protection for religious entities. Specifically as explained by the New York Law Journal governor Cuomo noted the Act states that no religious entity, benevolent organization or not-for-profit corporation that is operated, supervised or controlled by a religious entity, or their employees can be required to perform marriage ceremonies or provide their facilities for marriage ceremonies, consistent with their religious principles. In addition, religious entities will not be subject to any legal action for refusing marriage ceremonies.
This is a remarkable accomplishment for the state of New York and is bound to have a strong influence on the judicial system in the years to come.
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Archive | February, 2011
SD Weather Records of January 1911 and January 2011 Show Subtle Changes—In Data Keeping
Posted on 24 February 2011 by John Rippo
Though San Diego has always been known for its wonderful weather, measuring and observing it has only a 160 year history here. The first recorded observations were taken on July 1, 1849 at the Mission San Diego. Later, the US Army placed instruments at the Presidio where they were tended by the Medical Corps, whose duty it was to monitor weather for army operations. In 1860, San Diego’s weather watchers moved to the army barrack in what is downtown now and in 1911, when the century-old table at right was compiled, the weather office stood at 5th and F. Now, there are several around stations around the County and the media tends to settle on the findings from the weather measuring station at Lindbergh Field, from where the data for last month’s data is taken.
Two months’ data a hundred years apart is not going to give conclusive proof of global warming or anything else. What it does show is the slight variations we have come to expect during the season. We can also wonder at the utility of weather observation over a century and how that observation has been homogenized into modern data forms.
The photo of the San Diego’s Weather Bureau Office above shows the kinds of primitive machinery used to aid observation and recording a century ago. The office then was the preserve of Ford Carpenter, “Local Forecaster” for the US Weather Bureau, who wrote a book titled The Climate and Weather of San Diego published in league with the SD Chamber of Commerce in 1913. Carpenter spent much time winding up barographs, oiling anemometer bearings and marking cedar sticks used as rain gauges. He also spent many waking hours logging changes that occurred daily. He noted that San Diego is full of microclimates caused by its terrain and that some official low temperatures didn’t correspond to the actual lows found in some valleys, canyons and areas that channel the wind. The same concern was and still is true for humidity and wind speed—all of which still tend to make residents view some weather readings as flawed.
Like many things a century ago, San Diego seemed to have a more organic relationship to weather than may be said to be common now. “June Gloom” was unknown in 1911; the term in vogue for the month’s overcast of low stratus cloud was “El Velo”—Spanish for “the veil.” Carpenter urged that the term replace the then-current “high fog” that dated to the early American period of local history and was the product of mildly literate ship captains. 356 days of sunshine were claimed then for San Diego in 1911; the current information from the US Weather Bureau claims 339 days of sun here; a loss of 17 days.
Almost gone from current weather commentary are any mention of cloud formations over San Diego. Yet in 1911, these were rightly considered of primary importance when it came to understanding weather and its changes. The four basic kinds; stratus, cumulus, nimbus and cirrus were divided into ten subtypes and their layered interplay over the region often foretold rain and serious weather change. Carpenter mentions that early aviator Glenn Curtiss took careful measure of cloud formations before flight from North Island, and he comments on a now forgotten form of summer rainstorm to the east then known as the “Sonora” storm. Evidently, the formation of the cumulo-nimbus over Cuyamaca was enough to give challenges to early airmen over Coronado a century ago, since disturbed air patterns had a long reach that could endanger the frail planes.
One of Carpenter’s best recommendations for predicting weather is based on cloud formation. The directionof thetopmost of any sandwiched layer of cloud tends eventually to become the wind direction at sea level. If that top layer of cloud shows ragged wisps at its ends that tend from south to north, rain will soon follow. This becomes even more definite when the seagulls begin to fly layered, tight circular patterns in order to get ready for sligh pressure changes that weather will bring to their sense of balance and direction.
Nowhere in the US Weather Bureau’s site is any of this kind of thing mentioned now, and it is one small bit of perspective to keep in mind when long term weather is predicted, or when dire forecasts of dire change in weather is made. Weather is as much how it is observed than how its interpreted, even in San Diego.
See the accompanying charts for 1911 and 2011 in this site.
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1960 Manual on How to Run a Coffeehouse In San Diego Illustrates Half Century of Changes in the Trade
Posted on 17 February 2011 by John Rippo
In 1960, a successful coffeehouse didn’t need an espresso machine, but it did need entertainment that was live and original and a “clean-up man” to handle the dishes filled with the residue of chocolate covered caterpillars, caviar and smoked octopus. There have been a lot of changes in fifty years of San Diego coffeehouses and the primitive manual illustrated at right is ground zero for a vanished earlier age of café culture here.
How To Run a Coffeehouse was a slight compendium filled with the considered observations of Bob Stane, owner of The Upper Cellar, once located at 6557 El Cajon Boulevard in the 1960′s. The Upper Cellar enjoyed a good deal of success in its years of operation since it was near SDSU and there were few competitors around. Stane’s manual was as much a promotion of his place as it was a way to help other aspiring coffeehouse owners understand the business as it then was. How To Run a Coffeehouse was a spirited, yet shrewd series of observations on building a successful business from the ground up that still resonates today—when it doesn’t stop the reader abruptly with recommendations that seem like they came from another planet.
For instance, in 1960, coffee was still an experiment for many people and was merely the hook on which customers fixed their money while enjoying the atmosphere, conversation and music. Specialty coffee wasn’t single origin, organic, fair trade anything; it was mixed drinks that anticipated the Starbucks menu by fifty years. Stane’s coffee offerings, while imaginative and complex, even by contemporary standards, were brutally amateurish and primitive. Anise flavored some coffee drinks at four bits a cup—Stane recommended measuring the spice on a matchstick. Russian Coffee was an espresso flamed in a stove-top mocha pot to which a dollop of Hershey’s Chocolate syrup was added. Described in the menu as “the strength of a Cossack and the authority of a Czar” it wouldn’t likely rate high on a house’s offerings today. A now-forgotten form was Stane’s Rum & Butter Coffee—extract of rum mixed with butter and poured into a cup of French Roast. It was a pricey item, too; selling for 70 cents a cup. Slightly less expensive was the Café Creole, a coffee and chicory blend topped with whipped cream and shaved almonds for 55 cents per cup. Tea, cider, Italian sodas and Turkish coffee were available at The Upper Cellar, too; all retailed for less than 85 cents per serving.
Food was important too, and in 1960, no one seemed prone to the specialty diets common today. The Upper Cellar offered corned beef and salami sandwiches, served on onion rye with Monterey Jack cheese, tomato and lettuce at 70 cents each; kippers and sardines with soda crackers cost 45 cents per plate. But the specialties of the house—which Stane shrewdly used as a tool to promote his house and set it apart from the rest, were smoked cuttlefish, caviar, smoked octopus and chocolate covered ants, bees, caterpillars and grasshoppers—all of which could be had for less than 85 cents a serving, with sherbet for dessert.
One can only imagine how modern coffeehouse patrons would react to food offerings like this today; calls to 911 would likely be common.
But there was fine method to Stane’s seeming Eisenhower-era madness, and if the menu was primitive and amateurish, it was nothing compared to the bare bones approach to the business itself. Much of that advice is still golden today.
To quote Stane, “…as an owner and manager, the coffee house is one thing; a business. Granted it is a fascinating, sometimes weird, sometimes whimsical business, but a dollars and cents, sweat and efficiency business. When reading this book, keep this in mind or all will be lost.” Stane set out the basics: theme and atmosphere, location, interior arrangement, employees, menu and above all, entertainment in a few paragraphs that relate everything to everything else and made the Upper Cellar a profitable business from its mutually supporting parts. The theme of the coffeehouse was of course an upper cellar and everything from the entrance to the interior decor (if that’s what it could be called) recalled the notion of one. Pipes ran across the ceiling; windows were above eye level just under the bare beams. Lighting came only from candles on the tables; bulbs were shaded behind the counter. The Upper Cellar had the lock on a kind of dignified shabbiness that was all its own and its patrons loved it.
Stane chose his El Cajon Boulevard site because it was near SDSU and El Cajon Boulevard was a mecca for drag racers and other youth that filled the neighborhood then. The outer door was hard to miss. His kitchen was a one-man epitome of efficiency; everything was laid out so that one person could operate it with a minimum of wasted steps and motion. All of his equipment was used and paid for in cash. “The credit system will ruin you,” appears several times in the manual and as too many modern coffeehouse operators have learned to their sorrow, Stane’s words are as true now as they were in 1960. Portable, easily stored and easy to clean tables, chairs, movie projectors and puppet stages were important; every square inch of the Upper Cellar was for business use and nothing, not even the restroom that was labelled “The People’s Sandbox” was bigger than it needed to be.
Perhaps the biggest difference in coffeehouse operations fifty years ago from today concerns entertainment. Stane believed that both canned and live entertainment was the soul of his establishment. Silent movies and bullfight films, newsreels and anything that wouldn’t be seen on television flickered on the coffeehouse’s screen, usually double-billed with folksingers. The only other canned stuff were jazz or folk records that were run between acts. Live acts were on tap every night of the week, from opening time at 7 p.m. to closing at 3 a.m. Poetry readings, artists offering a running repartee to the audience as they created works before their eyes, comedians, puppet shows and fortune tellers were usual fare. But the real juicy stuff were the musicians; folk, jazz, blues, pop or anything else that was acoustic and preferably the work of no more than two musicians at a time. Stane frowned on paying for a group when a single singer or duo would suffice. In July, 1960 Stane boasted a run of “a blues and American folksinger, a classical voiced folksinger, a ‘Slick’ folksinger, a comedian, a puppet show and old time movies.” And he had reserves of entertainers just in case. The Upper Cellar was home to several Spanish singers and those of other cultures and Stane had some sympathy with the more progressive movements of his day. He recommended that other budding coffeehouse operators cast as wide a net on the public as possible and it was good business to let all kinds of the right kinds rub shoulders in his Upper Cellar.
Stane’s stage stood nine inches above the floor and was only three feet by three feet when the upright piano was figured in. Sets flipped every twenty minutes and all his musicians were talented people just finding a first audience—one of whom was a kid from Coronado by the name of Jim Morrison—later of the Doors. Stane recommended that as soon as entertainers got on radio or TV, others should be found to take their place since audiences could listen at home.
Practices like these are a night and day contrast to the world coffeehouses face now. Restrictive laws hamper entertainment in all but the smallest houses and in the little ones, entertainment is usually unable to make a profit. Coffeehouses with fifty seats or more have to apply for costly entertainment permits that come with many strings attached that limit business operations, and it is no simple matter for a musician looking for a first audience to play in a coffeehouse without being harassed by BMI or ASCAP, claiming that the new tunes on a six string are actually derived from a famous name and liable to infringement penalties. Coffeehouses like The Upper Cellar could not exist today under current laws and modern coffeehouses have been forced to find other forms of attracting and holding a clientele. One can only wonder what Stane would have thought of free WiFi or coupons. We do know what he thought of local laws and customs, however. He was explicit in his manual on the need to proactively approach law enforcement that often took a dim view of coffeehouses and their patrons.
Stane recommended a neighborly visit to the cops before a coffeehouse opened; where an owner could explain the nature of the house, assure the cops that no booze or dope would be tolerated and that vigilance would be maintained. He urged the prospective coffeehouse owner to work with and befriend officialdom at all levels. It worked—for awhile, though Stane explicitly stated that he discouraged servicemen from coming to the Upper Cellar and recommended other coffeehouse owners to do the same. In his opinion, uniforms and the free spirit kind of atmosphere a coffeehouse needed to thrive were incompatible. Stane had it right, unfortunately, and his manual merely foreshadowed the conflicts that all but killed coffeehouses in San Diego in the late ’60′s.
Conservative to its core, San Diego was a Marine and Navy town that saw ever-growing conflict with college types at SDSU, USD and eventually UCSD. Many young people were against the draft and Vietnamese War then, and many of the growing antiwar youth organized themselves in the Upper Cellar and other coffeehouses that sprouted all over San Diego. The powers that be didn’t like that and soon passed new cabaret licensing laws that made it harder and more expensive for coffeehouses like the Upper Cellar to keep entertainers on stage. As the war continued and feelings polarized, many coffeehouses were routinely harassed and raided by local PD in search of pot, pinkos and perversion in a drive to enhance conformity. Stane and others realized that they couldn’t fight city hall and by 1966, The Upper Cellar had passed from the scene. By 1970, very few coffeehouses remained in San Diego. Their numbers dwindled steadily until the late 1970′s when coffeehouses began to come back to San Diego—though usually without entertainment.
The battle against the coffeehouses didn’t end there. In 2000, another series of laws aimed at curtailing coffeehouse entertainment gathered momentum—until a combination of entertainers, coffee traders and media thwarted the campaign. A re-worked set of laws made it more expensive to apply for the desirable entertainment permit and the wait for bureaucratic review is now enough to discourage many house operators from bothering with one. As a profitable substitute, more coffeehouses have added beer and wine to their offerings, as well as food which also require costly permits and changes the character completely from what Bob Stane would have known in 1960. The net result has limited the kinds of culture that coffeehouses were once known to produce as a byproduct of their existence and the net effect of bureaucracy is to make more coffeehouses poorer and just like all the others. This helped giants like Starbucks undermine the independents; from the mid-1990′s, chain coffee became a serious threat to independent coffeehouses throughout San Diego and this state of affairs continued until it was moderated by the economic disaster of 2008. As Starbucks lost market share, independent coffeehouses got a reprieve from an uneven contest.
Bob Stane’s thin manual from 1960 is filled with the shrewd observations of a businessman bent on making his profits by enabling his customers to play in a world of Stane’s making; one that allowed people to step comfortably out of their regular lives and enter a happy place filled with fun, good things to eat and drink and perhaps some great entertainment from performers making their rise to stardom. It really didn’t matter if the Upper Cellar lacked an espresso machine or if the anise was measured on a matchstick or if the coffee was warmed in a diner’s cast off coffee pot. Coffee was the excuse and the means to make a buck; the real profit came from patrons that would drive twenty miles one way regularly to buy from Bob Stane in the dingy coffeehouse on El Cajon Boulevard and later proudly tell friends, “I go to the Upper Cellar.” Stane knew what the sentence meant—his customers were the loyal citizens of the place he created and he underscored this meaning in his manual. For those yearning to make their coffeehouse dream into a unique and character-filled place of coffee-powered human interaction, Stane had one word: “Go.”
Fifty years later, that hasn’t changed.
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A Century of Flight at North Island Marks Another Kind of Commemoration: How Coronado’s Earliest Aviators Paid Their Towing Charges
Posted on 17 February 2011 by John Rippo
Contemporary postcard of a Curtiss biplane over North Island, 1911.
“Here comes the king of the fools again,” muttered Agostino Zolezzi, an Italian fisherman who, like the rest of his kind, struggled to make a living fishing in the waters around San Diego. Zolezzi watched as yet another hated airplane went silent and fluttered down onto the water near his boat; its engine dead, its pilot waving frantically for a tow and its wings covered with salt water thrown up from its pontoon.
Zolezzi was used to the drill; for months these airborne annoyances had disrupted fishing in the early mornings when the tuna men hunted for anchovies and sardines in the bay to use as bait for the tuna that paid them their hard won living from the sea. The first time it happened, the shrewd Italian thought to claim salvage rights on the helpless plane and make some fast money merely by hooking his line to the plane’s nose, according to maritime law. But after looking at the clumsy frame of bamboo and wire with its wings patched together without even the skills of an apprentice sailmaker in evidence and an engine that obviously couldn’t run right, he’d given up the idea. As for flying, to him it was a fool’s way to die. Zolezzi took his life in hands every day on the sea in a one-man boat and his occupation was dangerous enough. He couldn’t understand why anyone would want to chance death in a flimsy boxkite over the ocean. But it wouldn’t be right to ignore a vessel in distress. So he hooked a line to the nose of the plane, took the pilot on board and headed for the tide flats at North Island.
Though the aviators were usually good for a fist full of money whenever they got towed back and the fishermen welcomed whatever they could get, Zolezzi had more than his share of interference in his work from them. When the planes crossed over a school of fish, their shadows would spook them and make the school dive away from the fishermen’s nets. Sometimes the noise of the plane’s motor would do the same if the plane was low enough and if a plane alighted in a good fishing area, the fish wouldn’t show for hours afterward. This meant a loss of income for Zolezzi and his fellow fishermen and since more planes seemed to be around to suffer from engine trouble and hurried forced landings this meant the problem needed to be addressed. Zolezzi saw to it that it was.
The pilot was a skinny, tough fellow with a mustache and an attitude. He obviously didn’t think much of the fishing boat carrying him back and made the mistake of smirking at the single cylinder Sulzer engine that powered it. Zolezzi recalled that he said it was “primitive”. “My engine runs fine,” Zolezzi pointed out. “Yours has many cylinders and none of them work? How unfortunate; you paid too much .” Not the kind of man to stop when he had an opening, Zolezzi then gave the wet pilot an earful about how the flyers at North Island caused grief to the fishermen of San Diego Bay and he ended the sharp tirade by indicating that the pilot knew what he could do with his plane, engine and propeller, too. The pilot listened with gritted teeth. A long silence passed until the shore was reached.
When they got there, they saw some other boats catching a large school of bait fish not far from North Island. Zolezzi had missed the chance for them and would have to roam the bay to find enough bait before he could go out to sea for the tuna he needed. The pilot asked some questions about fish that Zolezzi answered. The parting was civil, and true to form, he got a few dollars for his trouble.
Days passed and fishing continued, and soon after, Zolezzi noticed a change in the air—literally. While roaming the bay for anchovies, a Curtiss biplane from North Island appeared, diving at his boat and wagging its wings. The pilot looked at the fisherman and pointed off to his right and buzzed away to his left—away from where he came. Zolezzi sailed in the direction indicated and soon found a school of anchovies that he netted all for himself.
Such things would happen from time to time and it seemed that every pilot who had a forced landing on the water and needed a tow home got into the act. Since early airplane engines were notoriously unreliable, the number of fish-spotting pilots grew to nearly 100 percent of the airmen at North Island. Zolezzi remembered one man who had no end of bad luck—a haughty Japanese who stayed with his plane on the way back and would never set foot on a mere fishing boat. Zolezzi got used to the note of the man’s engine and recalled years later that it always sounded “wet”. When he heard it, he knew that very soon the Japanese would make a sudden dive for the water with a dead engine and that he or one of the other fishermen would tow the arrogant, undersized Japanese back. Maybe the pilot ran too rich a mixture and froze his carburetor or maybe he couldn’t master the throttle control. Soon the Italian and Portuguese fishermen nicknamed him “Little Pelican” after his forced landing technique.
Anchovies are a silvery fish that reflect sun in distinctive patterns. Sardines are visible in schools; their swarms ripple the water and the waves catch the observer’s eye. Early airmen at North Island soon became accustomed to finding the schools of fish and some of them—but by no means all—would alert the fishermen to their presence. Early pilots had to read the water as part of their training. They could tell the wind direction at the surface from the ripples on the bay and perhaps gauge windspeed to safely land their frail planes. Some of those men who troubled to learn how to see beneath the surface using the sun’s reflection and cloud shadows to find fish were officers in two navies. Later, the same technique was used to spot submarines in two world wars. The arrogant Japanese pilot eventually became the chief of Japanese naval aviation during WWII. He and others were the first to learn the secrets of sea flying over San Diego Bay a century ago, repaying men like my grandfather for bringing them home when their engines failed them. From a comic opera beginning came the means to take war beneath the seas from above the clouds. The centennial of this history is now being celebrated this month by the navy at North Island.
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oldest story on earth
The Oldest Datable Story on Earth
approx. 12, 000 years
Ngadjonji History of the Rainforest People
Note: this site contains images of aboriginal people now deceased
The Ngadjonji people have a story that describes the formation of a local volcano. Carbon 14 dating of the crater gives it an age of 12,000 years. This means the legend is likely the oldest datable story on earth , pre-dating writing by about 2000 years. Here is the story.
The Ngadjonji originally occupied an area of upland rainforest country at the headwaters of the Russell and North Johnstone Rivers in north east Queensland, Australia. Their original language is Dyirbal or Jirrbal.
The Ngadjonji told stories that would describe volcanic activity, changes in sea-level, and changes in vegetation. One of these stories explains that two newly-initiated men broke a taboo and angered the rainbow serpent, major spirit of the area. As a result 'the camping-place began to change, the earth under the camp roaring like thunder. The wind started to blow down, as if a cyclone were coming. The camping-place began to twist and crack. While this was happening there was in the sky a red cloud, of a hue never seen before. The people tried to run from side to side but were swallowed by a crack which opened in the ground. This explained volcanic eruption.
Large tribes tend to hold around 200-250 people while the smaller family tribes tend to have around 20-25. Marriages were usually arranged and were between two of the same tribe. Women are to carry all of the baggage and to do all of the hard work. She has to gather, cook, and build, besides bearing and caring for the children. While gathering food, the Ngadjonji would take poisonous plants and, using complicated methods, would make them edible.
The main meal of the day was when the hunting and gathering parties returned. While small food items were cooked quickly at the edge of the campfire, large game or fish were cooked in an earth oven.
When someone died, the body was placed on a platform about 2m above the ground with a small, very smoky fire lit under it and kept burning so that as the body juices ran out so that it was smoke-dried and preserved. While the body was being smoked, certain near relatives had the privilege of smearing themselves with ashes and standing under the dear departed and allowing the drips to fall on them. When the process was complete certain near relatives were supposed to carry certain specified parts with them in a dilly bag at all times for a set period.
This funeral ritual was described by Palmerston as taking place near Wairambar Creek on September 24th 1886 as follows: (remember these are his words of 1886)
September 24th. - It is still raining. I am much better, but weak. During the afternoon I cleaned out a blue slate crevice, at the upper end of the beach, dishing off 5 oz. of shotty gold, and washing 1 oz. to the dish several times. I am tortured all over with pains, and have no more energy than a snail. I omitted to mention, on 24th of September, that, although I was so very ill, I managed to cross Wairambar Creek and surmount the plateau beyond it, to witness the 'Coway' ceremony over 'Nooychoo's' dead body. The word 'Coway' is the native name for 'mummy.' There are several hundreds of aborigines called together for the special purpose of mummifying the corpse. These blacks were loitering about the body in crowds. On being notified of my approach, they formed themselves into two long lines, as a sort of body-guard for me to pass between to the dead body, which was fixed on a stage about two feet high, with a back to it. The deceased was placed in a sitting posture, in the usual native style known as 'tajoj' fashion. A slow fire was alight on the ground immediately under the stage; the arms were bent and upraised, with the hands open, as if in exclamation; the head rested, with a cadaverous lean, on its left shoulder; the mouth was open and showed a swollen tongue; the head was freed from the white hair by which I had known it; the features were bloated beyond recognition; the arms and legs were much withered, and the trunk was unnaturally bulky, being between a semi-cooked and putrid-blown state. 'Wallajar,' mentioned elsewhere here, an elder brother of the deceased, stood close to the latter's left side, and seemed to be the only sorrowful being in the crowd. On the same stage, on the other side of the dead body, sat a well-cured mummy of a still older brother, named 'Monumbaloo', seeming singularly large, even in its anciently shrivelled state. I would have liked to have taken it for the Brisbane Museum, but was afraid to ask the blacks for it, though not from any personal fear of them. If the above scene was disgusting, there is immeasurably worse to follow - a scene that fired my soul with indignation and revolt, almost putting me to the point of rifling as many as I could of the foul brutes, but discretion regarding future personal considerations held me curbed, thus it was that I allowed them, unrebuked, to wallow in their dead's filth. My boy 'Poinkee' told me that, if I had seen sufficient, I had better go, for never before had white-man witnessed the offensive operations they were in a hurry to perform. However, I asked to be allowed the 'privilege'. They demurred, and much talk ensued, ending with a promise from me to give a pocket-handkerchief to each, on my returning from Geraldton. That proved rather an expensive promise. I believe there were a dozen of the dead man's sons present – all young men. One of them named 'Ninkah', was the principal actor in what I saw. He took the dead body of his father astride his shoulders, carrying it uprightly, so that its exuding matter trickled down his naked back. In that fashion he carried it between the files of niggers, all the while murmuring something. Then, with the help of others, he laid the body on its right side amid some green fronds spread for the purpose. 'Ninkah' then borrowed my pocket knife, and commenced nicking the body just below the ribs, on the left loin, moaning at the end of each nick, while the crowd corroboreed, stamping their feet and clapping their hands. With the piercing of the trunk the corroboree ended; and as many as could well lay over the body, and wedge their faces over the incision, did so, to catch the obnoxious gases that issued there from. When these had escaped, the incision was made large enough to admit 'Ninkah's' hands. From that time, the knife was not used, the son slowly tore out his father's intestines, stripped them of any grease which he distributed to other relatives to grease their heads and bodies. Indeed, many of them could not wait to be presented with grease, but rushed up and plunged their hands into the dead body, raking out whatever they could get to smear themselves with. Pulling out the entrails seemed to be tough work, for they were a considerable time about it, several times squeezing their heads into the body, as if to sever something with their teeth. At last the whole of the offal came out. One powerfully built fellow, with the whole of his head's crown bald, though the remainder was plentifully dark haired, that hung down about his shoulders in long matted twigs, that might be mistaken for ringlets in the distance, carried the offal away in his arms - hugging the filthy burden as if it was as precious as a new-born babe. He disappeared in the jungle, with several others following him; after a considerable time, he appeared from quite a different direction, with it still in his arms, and laid it down near his fire, covering it with some green bushes. The heart, liver and lungs were torn out, a small piece at a time handed about and prepared for a cannibalistic meal straight away. The body was again lifted upon the stage, and laid on its side over the fire. A blanket was thrown over it, and it was left to be cooked to the proper stage of mummy preservation. But, before this was done, the gins took their turn at wallowing in the internals of the corpse, in like manner to the men. One aged gin lay full length along it, and many times kissed the crawling maggoty face. The grave old 'Wallajar' took no hand in the ceremony, but stood and sat some fifteen yards off by me, with one arm round me. Large tears trickled down his wrinkled cheeks the whole time. A shirt being the only garment on me, I took it off and gave it to him; and distributed a box of matches amongst the rest. I left the camp amid a babble of aboriginal gaiety and stinking embraces. The sickening smell hovered about me for days; even the little food I ate, and the very pannikins from which I drank, seemed to be polluted with it. Before leaving the scene, I selected between twenty and thirty of the ablest youths to accompany me to Geraldton, in the capacity of swagmen, immediately starting some of them to the more elevated tablelands for a supply of 'coohoy' nuts for food on our way. Ignoring dates for a while, I may state that I started for the abovementioned township amid torrents of rain. On the second day's travel, about mid-day, we struck and crossed the North Johnstone River at the old diggings, there learning from some Chinamen that Mr. G. E. Clarke and Mr. W. Joss had passed up the Johnstone on a prospecting tour on the day previous. I brought my boys to a halt, and started four black-trackers after them. Mr. Clarke returned with these, and I showed him my gold and directed him to the places where I had discovered it. Being well pleased with the sight of the fruits of my exploration, he graciously gave me food that he knew he could in a short time ill-spare. I ate this with a relish that sank the best of blackfellows' fare to the level of mere animal existence that no civilized being could envy. Next morning, in spite of the Johnstone River's wild appalling stream, despite its dark, repugnant, thorny jungle, which had to be chopped in separate bits for every foot of access or examination, despite its vapours of poisonous humidity, and not less eludable vile crawling leaches, I started the party, consisting of Mr. G. E. Clarke, Mr. W. Joss, and one aboriginal, painfully piled with about 80 Ib. per man, in quest of the yellow metal, while I went down the river for Geraldton, via Goondi Plantation.
Earth Science in cooperation with the Wairambar Rainforest Nature Refuge is preserving a section of Wairambar Creek together with some old gold workings as it was in the time of Palmerston. At the time of writing, apparently no mechanisms exist in Queensland to maintain sites of geological significance. This particular area has both historical and geological (first payable gold in north Queensland) significance.
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The cheiroballistra (Greek) or manuballista (Latin), which translates in all its forms to 'hand ballista', was a late Roman siege engine. Designed by Hero of Alexandria and mostly composed of metal (the spring mechanism and the skeins), it shot bolts that were smaller than those in other forms of ballistae and generally made of metal. It was the next major improvement after the scorpio.[1]
The name of the weapon implies that portable versions might also have existed, similar to crossbows.[dubious ]
1. ^ Warry, J. (1995). Warfare in the Classical World. P. 178 Salamander Books Ltd., London: United Kingdom. ISBN 0-8061-2794-5.
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Ethics of War
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Ethics of War (1901)
by Khwaja Kamal-ud-Din
To ensure peace we have often to disturb peace, and then the martial spirit that has been implanted in us by God for our safety comes into play. The protection of life and property is a common instinct, but it has often served as a pretext for oppression and tyranny, We are not free from inordinacy, and if we need something to put us on the right path, war is indispensable in order to restrain those who would otherwise be beyond our control, In other words, we need ethics of war, as war is one of the essentials of our civilization, and a Warrior-Prophet was needed to act as an exemplar in this respect. We fail to find any healthy principle of war in the Bible, The Israelite fighting aimed at the extinction of enemies, and sowed vengeance and rancour in human hearts. Since the Prince of Peace did not come for peace but for fire and sword, as he said himself, he asked his disciples to sell even their clothes in order to purchase weapons of war. His mind seems to have been agog with various other high-flown but contradictory ideas, but he could neither digest them nor reconcile them to each other. He left his followers, as it were, in a maze as regards military matters, and they began to walk knee-deep in human blood after him. They still do the same, though in a more refined manner, when any occasion arises.
Man, however, felt the need of some guidance here. The Hague Conference was constituted for this very object, but it failed miserably in its aims. The League of Nations has now begun to move in the same groove, but the intention of its framers is not above suspicion. It is alleged that the institution has been formed to crush down the aspirations of the East towards self-determination.[1]
Europe already possesses enough of arms and ammunition to keep others under her subjection, and the proposal of disarmament in the League is simply to disable the East from recouping their shattered military Materiel.
These institutions are, after all, human institutions. No man can be bound by another s injunction if it is at all likely to go against his interest. But if he finds himself so bound he tries to find means to get rid of the obligation. Treaties in Europe are meant for the waste-paper basket. They are honoured more in the breach than in the observance.
We need a word from God Himself on this subject which may act as an article of our faith. This is not a mere theory. The history of warring peoples has proved it. Those who were once an embodiment of oppression and a curse to humanity on account of their prowess became as gentle as lambs under the salubrious influence of Divine Revelation, and won the title of the "Gentleman Soldier" from the world. They were once reckless in the matter of life, and wielded their swords ruthlessly ; but these unscrupulous people became clean lighters under the teachings of God.
The country surrounding the Caspian Sea has produced fighting people from the very beginning. They were a nomad race in olden days, and filled others with terror. They were the Gog and Magog of the ancient days, and Darius of Persia had to build a wall between the Caucasian Mountains as a protection against their incursions. Later on, they appeared under the name of Scythians. Even India did not remain safe from their inroads at that time. They overran Europe under another name ; in the days before Jesus they appeared in Europe - as a formidable people in the shape of the Huns and Goths. Their ferociousness can be traced in their present descendants India saw members of the same stock in Aryan invasions. They drove the ancient people of India to their mountain fastnesses. They would not leave even a breathing-space to their enemies- We often hear nowadays the Hindus in India boasting of Aryan civilization, but if it inspired its people with the worst kind of hatred against the Untouchables the residue of the Indian aborigines it could not claim even a semblance of refinement and good manners, The Untouchables, even to-day, are not allowed, in India, many of the rights of humanity ; their shadow was once shunned and even now they are kept at a distance from others ; and this is only a vestige of the tyranny that the ancient Aryans used to exercise towards those who were only guilty of owning India as their motherland.
The units of the same stock the people living around the Caspian Sea were the Tartars of Central Asia in pre-Islamic days. They overran the whole country and reduced it to ashes. They brought destruction and devastation wherever they went. The sound of their drum was a death-knell to those who feared their depredations. They adopted Buddhism for their faith, but the names of Halakoo and Changez still cause terror among the Caspian races. Afterwards they came under the influence of various religions. As the Tartars were Buddhists, the Aryans followed the Vedic persuasion while the Huns and Goths became Christians, but no religious dispensation mitigated their ferocity or reformed their bloodthirsty nature.
Thus, the question of war has always remained a most difficult and intricate problem. War could neither be dispensed with in the interest of peace nor could it be pursued on the lines laid down in bygone days. The world had urgent need of a true reform in this respect, and it has come in the form of Islam.
Without making any introductory remarks, I approach the subject directly and give the essentials of Islamic teachings in this matter.
Fighting, to satisfy the hankering after land or property belonging to others, has been repeatedly condemned in the Qur-an. But these motives havr always induced fighting in the world from the very beginning ; even to-day the same hankering makes civilized nations covetous of others. They may engineer various schemes and come with plausible pretexts, but cupidity and usurpa tion is at the bottom of all their movements. Islam, however, forbids all fighting for such objects. It allows war only under the same conditions for which the Creator endowed us with a martial spirit. Islam permits fighting for three reasons :
(1) To restrain disturbances and keep every land free from others* incursions.
(2) To defend life and property from others hands.
(3) To enable every person to follow his religious convictions, whatever persuasion he may belong to.
I need not emphasize the first two things - they are self-evident. I only quote the following verses from the Holy Qur-an on these points :
(1) " . . . If you will not do it [fight], there will be in the land persecution and great mischief" (viii. 73).
(2) " Permission (to fight) is given to those upon whom war is made because they are oppressed, and most surely Allah is well able to assist them " ; " Those who have been expelled from their homes without a just cause ..." (xxii. 39, 40).
The third object of war is, however, a vexed question. It has furnished enemies of Islam with a pretext for carping against the faith, though the Holy Qur-an has given the most desirable and humane teachings on the subject.
" No compulsion in Religion " is the universal immunity given by the Qur-an to an adherent of every faith, no matter what its form. Islam came to establish freedom of conscience and action in general, but particularly in religion. A Muslim is bound to wage war against any person, whether of his <iwn kin and kitli and religion or not, if they interfere with the beliefs even of a non- Muslim. This state of affairs in religion has been called " Faith for God " in the Qur-an, that is to say, everyone must be allowed to choose his own faith and worship his God in the manner he thinks right. It is a disturbance of this state of things that makes a Muslim draw the sword against any person, Muslim or other wise, who violates the above conditions. Even a Freethinker could take no exception to this Golden Rule. Thus liberty of conscience was a thing unknown before Islam. People used to believe in the Divine origin of their respective faiths. They would neither allow others to come within their own fold nor would they allow themselves to contemplate their own co-religionists as renegades from their faith, Islam gave the required permission, and in so doing (if the word be permitted) complemented civilization. The feeling in Islam for religious freedom is so strong that a Muslim is enjoined to act as a policeman, as it were, in the protection of all religious houses. For example, a Muslim is ordered to protect a Christian church even from a Muslim attack, The Qur-an is too clear on the point to allow of any other conduct ;
" . . . And had there nat been Allah s repelling some people by others, certainly there would have been pulled down cloisters and churches and synagogues and mosques in which God s name is much remembered ; and surely Allah will help him who helps His cause . . ." (xxii. 40).
In this verse the Qur-An identifies the maintenance of religious houses of every faith with the Cause of God. It is to be noted that Muslims are ordered to sacrifice their lives not only to save their own mosques but the religious houses of other peoples as well. The civilized world, with Christian notions of intolerance lurking in its breast, is still far from holding the noble principle thus enunciated in the Holy Qur-an. And there is yet another lesson in Islam to be learned by Christian rulers of other nations. A Muslim king is enjoined by his religion to help in the maintenance of others temples and shrines. This was done by the Emperor Aurangzeb, in Benares. It is not a solitary and unique example in the history of Islam, but I have advisedly chosen the above two names (a ruler and a town) for certain reasons. Modern historians of India whether European or Indian under Western influence have, for political reasons, concocted lie after lie to discredit Muslim rule in the eyes of the Hindus, and the said Moghul Emperor has been chosen as a fit subject for all their carpings, who, they say, demolished most of the Hindu temples and abolished their rites in Benares, one of the chief centres of the Hindu religion. The real case is just the, reverse. The Emperor gave big estates and endowments for the maintenance of Hindu temples in Benares. Fortunately for us, the custodians of these temples hold " firmans " (orders) of Aurangzeb entitling them to such estates, otherwise they would have been confiscated by the British rule. I have photo graphs of those " firmans * with me. Kashmir, at present a Hindu State, maintains a large number of Hindu temples out of the estates created by the Moghul Kings for them, and most of the endowments came from Aurang zeb. Even to-day I find the same Muslim liberality in Hyderabad (Deccan) and in the State of Bhopal, where a large portion of the State revenue goes to maintain non-Muslim shrines, including Christian and Zoroastrian churches.
Even in time of war a Muslim soldier is forbidden to touch an alien s house of worship. He has to spare the lives of religious teachers. 1 IThe words of Abu Bakr, the immediate successor of the Holy Prophet Muhammad, read as follows :
. . . Let there be no perfidy nor falsehood in your treaties with your enemies, be faithful in all things,, proving yourself ever upright and noble, and main taining you^ word and promise truly. Do not disturb the quiet of the monk or hermit and destroy not their abodes, but inflict the rigour of death upon all who shall refuse the conditions you may impose upon them (The Law Quarter!* Review, J908.}
It is a pity, therefore, to find that the civilized nations of to-day, when engaged in the Great War, could not observe the above rules. Churches were demolished, mostly in France and Belgium, and priests were murdered in the war.
Muhammad, as I have said before, appeared as a Warrior-Prophet, not only to protect his own faith and the lives of his followers from the ruthless tyranny of his adversaries, but to lay down rules of guidance for the coming world in the matter of war. The story of the Great War is palpable proof that man-made rules are either insufficient to meet the situation or can be set at naught by those whose interests are opposed to them. Muhammad had to fight several campaigns and thus left tracks on the pages of history for our guidance. He always respected treaties made with his enemies. I will now attempt briefly to describe the events of his life in this connection, and give the beautiful Quranic injunctions to which they gave rise.
From the commencement of his ministry, Muhammad, with his small band of followers, was put to a series of unimaginable persecutions for full thirteen years. The enemies of Islam left no stone unturned in striving to nip it in the bud One s hair would stand on end if one were to try even to imagine what was meted out to early Muslims in Arabia. What Jesus was apprehending from his enemies, when he delivered his well-known Sermon on the Mount to his people, became materialized in the days of the Prophet. Resistance to evil on such an occasion was only to invite destruction, and was tantamount to an act of suicide ; but to act on homilies pronounced by Jesus in this respect for example, to turn the other cheek to a buffeting enemy was only to emasculate the spirit of manliness from his people. So Muhammad ordered them^f t either to bear the persecution with patience but never reject their principles, or to leave the country and remove themselves from the scene of affliction ; but never to submit to resistance in such a way as to reject their own beliefs. Some of his followers fled to Abyssinia, but the time came when the enemy s persecu tions exhausted all patience. The Prophet asked his followers to leave the country. In the thirteenth year of his ministry only a few of his disciples remained with him in Makka. The enemy now conspired to kill the Prophet
himself This made him leave the place. Some few months before his emigration to Madina, he received the following revelation
from Above :
" Permission (to fight) is given to those upon whom war is made because they are oppressed, and most surely Allah is well able to assist them " ; " Those who have been expelled from their homes without a just cause except that they say : Our Lord is Allah . . . " (xxii. 39, 40).
This revelation was, in a way, a warning to the Muslims that they would soon be attacked by their enemies. Hardly one year had passed after the emigration of the Prophet to Madina when an army of a thousand mighty archers marched from Makka to crush down the new dispensation. The Prophet heard of it. He could not count on the people of Madina, with the exception of the few who had joined the ranks of Islam. With a small band of three hundred and thirteen, many of whom were young men in their teens, the Prophet left Madina to meet the coming army. The two forces met at Badr, some thirty miles from Madina. Most of the Makkan army
were killed and few of the rest remained to carry the bad news to the Makkans, who were enraged at the defeat. Their fears drove them to another campaign against the Prophet : this time their force numbered three thousand. The Prophet had to leave Madina again to meet them. Muhammad could not collect more than nine hundred men to back him at Uhud, the scene of the second battle. Though the Muslims were not victorious, the Makkans gained no advantage. The latter now deter mined to crush Islam for ever. They entered into a confederacy with other Arabian tribes. They raised a force of ten thousand men and besieged Madina suddenly. No regular fight took place, but one night a severe sandstorm suddenly arose. It extinguished all the lights of the Makkans and blew down their tents. They lost their presence of mind and fled from the scene in a wretched plight. Though the enemies of Islam could not make any other alliance after this siege of Madina, the event roused a war-spirit in the whole of Arabia. Muslims had enemies all round them and it was on this occasion that most of the following injunctions were given to them in the Holy Qur-an. No one could speak too highly in praise of these temperate teachings :
" And prepare against them what force you can and horses tied at the frontier, to frighten thereby the enemy of Allah and your enemy and others beside them, whom you do not know (but) Allah knows them ; and whatever thing you will spend in Allah s way, it will be paid back to you fully and you shall not be dealt with unjustly " (viii. 60).
" Say to those who disbelieve, if they desist, that which is past shall be forgiven to them ; and if they return, then what has happened to the ancients has already passed.
" And fight with them until there is no more persecution, and religion should be only for Allah ; but if they desist, then surely Allah sees what they do.
(viii. 3840).
" If you demanded a judgment, the judgment has then indeed come to you ; and if you desist, it will be better for you ; and if you turn back (to fight) We (too) shall turn back, and your forces shall avail you nothing.
though they may be many, and (know) that Allah is with the believers " (viii. 19).
All these verses allow fighting only in
the case of self-defence. They clearly provide
that as soon as the enemy desists from fighting, Muslims bhould not continue the battle, though it may be to their own disadvantage, as the following quotations say : " And if they incline to peace, then incline to it and trust in Allah." . . . u And if they intend to deceive you then surely Allah is sufficient for you . . ." (viii. 61, 62).
Many of the tribes now entered into treaties of defence with the Prophet. The main object of most of them was to deceive the Muslims, as the Qur-an says, " Those with whom you make an agreement, then they break their agreement every time and they do not guard (against punishment)"
(viii. 56).
Every conciliatory term was offered to non-Muslims to bring the war-spirit to an end, but no sooner did they get some advant age over the Prophet than they paid no regard to the ties of relationship or to those of covenant. The continuance of such re-
lations endangered the very lives of Muslims They mixed with those whom they regarded a^ their friends, under covenants, but they, the Muslims, were often cheated, and a large number of them were killed. The only alter native left to them was to declare war. Many- were under no obligation to the people who proved to be untrue to their engagements ; so the following proclamation was made :
" And an announcement from Allah and His Apostle to the people on the day of the greater pilgrimage that Allah and His Apostle arc free from liability to the idolaters ; there fore, if you repent, it will be better for you, and if you turn back, then know that you will not weaken Allah ; and announce painful chastisement to those who disbelieve
" Except those of the idolaters with whom you made an agreement, then they have not
failed you in anything and have not backed up anyone against you, so fulfil their agree ment to the end of the term ; surely Allah loves those who are careful (of their duty).
• And if one of the idolaters seeks protec^
tion from you, grant him protection till he hears the word of Allah, then make him attain his place of safety ; this is because they are a people who do not know " (ix. 1 6).
The fourth verse of the above quotation clears the whole situation and comes as a saving clause in favour cf those who kept the treaties. The punishment mentioned in verse 5 of the above quotation refers only to those who could not come under the above saving clause. The hostilities were resumed against the breakers of the treaties who continued to persecute the Muslims. But though the former Knd no ru?ht to be saved, having
forfeited their lives and liberty, yet they were given a chance of life in verse 6.
This verse has, however, given rise to some misconception. It appears to have suggested the ludicrous charge commonly brought against Islam. It is alleged that the early Muslims offered the sword or Islam to the non-Muslims of the world. " They were to be converted to Islam or destroyed by the sword. " So says a critic of Islam. Could there be a clearer example of the distortion which the Qur-an has to meet at the hands the defa- mers of Islam than the one seen here ? It is wickedness to draw such a conclusion from a verse which has verses 4 and 6 before and after it. The former verse makes exceptions in the case of such idolaters as remained true to their agreement with the Muslims, and the latter gives a chance of life to those who had no right to live on the earth after such perfidy against Islam. The verse, on the other hand, leaves no doubt that the idolaters and the non-Muslims were not to be slain on account of their religion. In the words of Sale, as he notes under the very verse, " The Muslim had to give such idolaters a safe conduct that they may return home again, in case they should
not think fit to embrace Mohammedanism " I have failed to find such liberal treatment of a man, an enemy, by his adversary anywhere else. I will refer here my readers to a few more verses of the Holy Qur-an which will, I fancy, decide the question of the place of war in Islam. They are verses 12, 13, and 14 of Chapter xi. That the Muslim wars in those days were against those who tried to extirpate Islam from the surface of the earth, and not against the non- Muslims of the world, appears clearly enough from verse 123 of the chapter on Immunity : i O you who believe! fight those of the unbelievers who are near to you and let them find in you hardness ; and know that Allah is with those who guard (against evil)."
The commandment is not general and should act as a rule of guidance in interpreting all the injunctions relating to Muslim fighting.
In the above quotations I have also given all the verses from the Qur-dn which have from time to time furnished a weapon against Islam to adverse camps. A critic ought to be just and fair in his comments. I wonder how it fits the mouth of a learned and honest Christian missionary (most of the adverse cirtics of Islam being found among that class)
to select some stray verse from the Qur-an to suit his evil intentions, and ignore the verses that precede or succeed his favourite quotation.
In short, the world has always needed good ethics of war, and Islam came to meet the demand. It prohibited all such fightings as were waged for the sake of gaining possession of the land and property of others, or was entered into the name of religion. Islam came to maintain the peace of the world, as its very name shows, and permitted the un sheathing of the sword in defence of life and property and religion, where they were dis turbed without any just cause.
" Let there be from among you a party who should ini good and enjrin what is right and forbid the wrong." Al-Qj
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Monday, January 17, 2011
Today’s essay focuses on the training of the young and contains the last references to Native American culture.
To give yourself a measuring stick for this essay I strongly recommend that you refer to my essay Cubists, which I have linked below.
Four American Indian views on the training of the young follow:
Something is wrong with the white man’s council. When the Micmac people used to have council, the old men would speak and tell the young men what to do—and the young men would listen and do what the old men told them to. The white men have changed that, too. Now young men speak and the old men listen. I believe the Micmac Council was far better.
Peter Paul
Several of our young men were brought up in your colleges. They were instructed in your sciences; but when they came back to us they were bad runners, ignorant of every means of living in the woods, unable to bear either cold or hunger. They didn’t know how to build a cabin, take a deer, or kill an enemy. They spoke our language imperfectly.
We send our little Indian boys and girls to school, and when they come back talking English, they come back swearing. There are no swear words in the Indian languages, and I haven’t yet learned to swear.
And what is to say farewell to the swift and the hunt, to the end of living and the beginning of survival? We might understand if we know what it was that the white man dreams, what he describes to his children on the long winter nights, what visions he burns into their minds, so that they will wish for tomorrow. But we are savages. The white man’s dreams are hidden from us.
Chief Seattle
To draw a comparison to these teachings I think back to when I lived in an upper scale neighborhood consisting primarily of business and professional people. The talk among men usually focused on the economy, what they were going to buy, where they would go on vacation, and on whether the Yankees would win the World Series. It annoyed me that discussions never left the shallowness of the material realm.
In reflecting on Chief Seattle’s inquiry, what do these men describe to their children on winter nights, what visions are burned into their minds that they will wish for tomorrow?
None and nothing!
Those who live in cubes have no concept of sitting around the fire on a cold winter night. Cubes do not have cold winter nights or hot summer nights, or dry days or humid days, or dark nights or star-studded nights. The temperature and lighting of the cube is always the same. The only concern about the elements for cubists is how it affects their travel from cube to cube. The news channels burst into chatter with the advent of heavy rain, deep snow, heat waves, blustery winds, and frigid temperatures all to describe their affect on travel from cube to cube.
To the Lakota Indians winds, snow, rain, sunshine, day, night, and change of seasons were endlessly fascinating. They provided some of the grist for the teachings of the elders on cold winter nights. The changing temperament of Mother Earth provided the basis for an understanding of the relationship of humans to the earth and the relationship of the earth to God. The great American poet Walt Whitman said, “I think all great deeds were conceived of in the open air.” Living in a cube does not enable one to become cognizant of the open air.
Those who live in cubes do not sit around in quietude—a necessary requirement for listening, contemplating, and understanding. The children (and adults as well) have multitudes of distractions such as texting, watching television, using computers, playing video games or making inane phone calls for hours. They no longer have the attention spans to sit in silence and absorb.
What little advice father’s pass down focuses on going to school, getting an education, making money, and becoming somebody; hardly the stuff that makes for the development of men. The values held by Chief Canassatego of the Iroquois never made it into the Western mindset; men are not taught the ethics necessary to maintain the well-being of society. The behavior of their children reflects the lack of ethics.
Zitkala-Sa, an Indian mother lamented that children came back swearing after learning English, whereas in her language there were no swear words. People raised in the cube do not look upon swearing negatively; it is considered a manifestation of freedom of speech. The Constitution calls for the pursuit of happiness. If swearing makes a person feel good, then Western thought feels it should not be restricted. The negativity that swearing generates does not concern Western thought, for it has no race consciousness. It only has a self-consciousness. It strives to satisfy the ME.
America has the distinction of having the most violent boys in the world; it also possesses most of the wealth of the world. Could moral behavior and material accumulation vary inversely? Does material accumulation affect the relationship of youth to their elders as Chief Peter Paul lamented on the change of who spoke and who listened at councils?
Among those who live in the cube, the value of a person is determined by his contribution to productivity and the amassing of wealth. Productivity is governed by technology, which changes at an accelerating rate; fathers and elders have less and less to hand down to their children in the way of technological knowledge. What fathers and elders did to earn a living has become obsolete; therefore the value to society of the elders becomes marginalized. They are old people who tend to get put someplace and cared for by the state.
A review of the four comments made by Native Americans in this essay indicates that they considered training of the young to include self-sufficiency, moral rectitude, respect for the elders, care of society, and spiritual unfoldment.
That society had no prisons, little thievery, a high level of honor, good health, and a great deal of sharing. Mental illness, depression, and suicide were unheard of.
A fundamental difference between the indigenous people of the Americas, Africa, and the Pacific, as compared to those raised in Western thought, is that the former live in the world that God has made and the latter live in the world that man has made. When people leave the world that God has made they lose the natural connection with the Creator and all that He has bestowed upon humankind. A friend of mine runs a farm museum in Queens and he told be the children that arrive want to see the pumpkin tree and the cow that delivers chocolate milk. They have lost most of the awareness of the relationship of the food they eat and where it comes from, a condition that typifies Western society.
As Western schooled children progress into adulthood they become less cognizant of the world that God made and increasingly limited to the confines of what man has made. Life inside the cube is an aberration of natural living. As Chief Seattle foretold, we stopped living and started surviving. Western activity has become a battle of survival; the joy of living has passed.
Friday, January 7, 2011
Today’s essay will continue offering examples of the understanding of the indigenous people of the Americas, Africa, and the Pacific concerning gender and spirituality. To give yourself a measuring stick for the next several essays I ask that you refer to my essay Cubists, which I have linked HERE.
The emphasis of this essay focuses on American Indian opposition to ownership, especially ownership of land; a value structure opposite to that of Western and Asian thought.
Below are American Indian views on ownership.
Some of our chiefs make the claim that the land belongs to us. It is not what the Great Spirit told me. He told me that the lands belong to Him, that no people owns the land; that I was not to forget to tell this to the white people when I meet them in council.
No tribe has the right to sell even to each other much less to stranger. Sell a country! Why not sell the air, the great sea, as well as the earth? Didn’t the Great Spirit make them all for the use of his children?
This is what was spoken by my great-grandfather at the house he made for us. These are the words that were given him by the Master of Life: “At some time there shall come among you a stranger, speaking a language that you do not understand. He will try to buy the land from you, but do not sell it.”
Red Lake Ojibwe
Red Cloud
Once I was in Victoria, and I saw a very large house. They told me it was a bank and that white men place their money there to be taken care of, and that by and by they get it back, with interest.
We are Indians and we have no such bank; but when we have plenty of money or blankets, we give them away to other chiefs and people, and by and by they return them, with interest, and our hearts feel good. Our way of giving is our bank.
Nootka Chief
One does not sell the earth upon which people walk.
Crazy Horse
The white man’s desire for possessions is like a disease.
Sitting Bull
Black Hawk
The greatest object of their (white people) lives seems to be to acquire possessions—to be rich. They desire to posses the whole world.
Santee Sioux
That last statement sums up the activities of the Western world. Not only does it have a desire to possess the whole world—it already owns it.
Every American grade school child learns that early European settlers bought the island of Manhattan from the Indians for $24 worth of trinkets. The inference is made that the Indians had no concept of value in letting the island go so cheaply. The Indians on the other hand wondered why the settlers would want to buy something that could be utilized freely.
European thinking obviously prevailed, and eventually Brooklyn, Queens, and all the other boroughs were purchased; then the states of New York and New Jersey. Eventually the whole country was purchased. The land of other countries was purchased as well. Now international financial interests own the entire world. Tecumseh’s question, “Why not sell the air, the great sea, as well as the earth?” has become a reality. Do you know of any free access to drinking water? All of the land and potable water of the world is now owned. The territorial control of the waters of the oceans includes 12 mile zones to 200 mile zones. Gifts from God have been taken from us by Euro-Asian thought and we have become indentured servants working for the right to get our daily sustenance of food and drink from those who own the world.
To all who read this essay regardless of where in this world you stand; realize that you toil more and more each day because the price of the world continues to rise. Each time world financial markets rise it means the value of the land and water has increased and you must work more in order to survive. The financial interests of this world have become your God. You must serve them or you will not eat.
We have accepted this way of life and adapted to it well. The major concern of the world is money, the economy, finances and ownership. The social and spiritual well-being of people has become irrelevant and does not garner mention in the media. Our interests focus on material matters; all other matters occupy a distant second place.
“What does it serve a man to gain the whole world and lose his own soul?” The indigenous people of the Americas, Africa, and the Pacific understood the meaning of that message. They also understood the meaning of Paul’s message “There is no single gift that you have not received.” Too bad most of the Eurasian world can’t or won’t.
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"Java" entries
Where apps end and the system begins
Exploring the system calls and control flow that underpin high-level languages.
Editor’s note: Sometimes we can forget how important it is to truly understand how a system works, and how the nuts and bolts affect our everyday activities. Marty Kalin asks us to dive a little deeper and strengthen our computational thinking abilities.
It’s clear that applications need system resources to execute: a processor, memory, and usually I/O devices such as the keyboard and screen. It’s less clear how applications gain access to these shared resources, which are under operating system (OS) control. The OS, like any good manager, is efficient and unobtrusive as it handles resource requests from applications. Let’s take a look at how applications interact with the OS, in both routine and dramatic fashion.
Consider what happens when a print statement executes. Here’s a Ruby example:
The Ruby puts statement wraps a call to a high-level I/O function in the standard C library (in this case, printf), which acts as the interface between resource-requesting applications and resource-granting OS routines. In this example, the screen is the requested resource. The standard library interacts seamlessly with the OS, which also is written in C with some assembly language. The library function printf is high-level because, as the f in the name indicates, the function can format the bytes to be written as integers, floating-point values, and character strings such as Hello, world!. In systems-speak, the Ruby application and the C library function execute in user space, which does not bestow the rights and privileges needed to control system resources such as the screen.
Read more…
Java 8 functional interfaces
Read more…
5 ways developers win with PaaS
Powering your app with open source and OpenShift
No More Tedious Config Tasks
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Six Degrees of Kevin Bacon in six languages
20 years of efficiently computing Bacon numbers
1995-1999: C
2004-2005: Perl
Read more…
Comments: 3
Java 8, now what?
What you'll need to know to start your Java 8 migration process today
There was recently a thread on the London Java Community mailing list about when people should think about adopting Java 8. Lambdas, an improved collections library, new date and time support, and a host of under-the-hood tweaks, add up to a lot of compelling reasons for people to upgrade. There’s still a lot of confusion over when and how to accomplish it, though, so here’s a helpful guide.
When will Java 8 be released?
The GA (General Availability) release of Oracle’s JRE and JDK, which is probably the JVM that you’re using, released March 18th. It may take other JVM vendors a while to release their implementations if you aren’t using an OpenJDK or the Oracle JDK.
So I should just upgrade on release date, right?
That would be a very brave move to make. A huge amount of resources go into testing Java 8 and ensuring that things will work out of the box on the day of release. However, the massive ecosystem of Java libraries means that not everything can be tested to destruction in time. It’s incredibly likely that there will be outstanding bugs upon release. You should expect update releases a month or two after GA, they’ll solve the major problems.
It’s also important to think about what libraries or frameworks your application depends on. If you’re just writing plain old Java then an existing codebase is likely to work fine. If, on the other hand, you depend on a library or framework that tries to do something clever then you may run into problems.
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WORA Can Be Better Than Native
Targeting the highest common denominator
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Comments: 2
Think Functionally to Simplify Code
Let the environment do more of the work
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From BASIC to HyperTalk to JavaScript to Rails to Erlang
Every programming experience teaches
I’ve never formally trained to be a programmer, outside of occasional conference workshops and a week of XSL tutorials. In some ways, that’s terrible, because it’s taken me about thirty years to learn what some friends of mine appear to have learned in four. I’ve written some code that goes way beyond spaghetti, though fortunately the worst of it was probably when I was 15.
On the bright side, when I look past my many mistakes, I can see what I learned from a large number of various different experiences, and the pieces they helped me see. It’s a little easier to tell this story through the parts than it might be through a formal curriculum.
My parents’ FORTRAN books
I was reading computer books—dry ones—before I even got to play. I have vague memories about program structure, but mostly I learned that knowledge sticks better if it includes hands-on work, and not just a book.
Sinclair ZX81
1K of memory! The sheer thrill of seeing my creations on screen was amazing. I had just enough logic to get things done, and leave myself puzzled. The Sinclair community seemed focused on making great small things. I learned simple logic in BASIC and that sometimes it takes a hack to get things done.
Applesoft BASIC
After Sinclair BASIC, Applesoft seemed vast. Much of what I did was transfer what I’d done on the Sinclair (itself a lesson in platform-shifting). As I settled, I started writing larger and larger programs, eventually forcing myself to restructure everything into subroutines…with global variables, of course.
6502 Assembly
I knew there was more than BASIC. My early adventures with assembly language were mostly about graphics, and didn’t work all that well, but I picked up two key things: recursion and the importance of registers.
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Comment: 1
Scaling People, Process, and Technology with Python
OSCON 2013 Speaker Series
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Google Glass: What Developers Need to Know about This New Platform
Creating Glassware today and what's in store for tomorrow
Key highlights include:
You can view the full interview here:
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Kid's illustration of Neptune.
Neptune is the most distant planet from our sun.
The Windiest Planet
Neptune is the fourth largest planet in our solar system. About 60 Earths could fit inside it. Neptune is named for the Roman god of the sea.
Neptune is one of four 'gas giants'
in our solar system. What are the
names of the other gas planets?
Color image of Neptune.
Windy. Neptune may be the windiest planet in the solar system. Winds tear through the clouds at more than 1,200 mph (2,000 kph). The winds blew Neptune's Great Dark Spot -- a storm as big as Earth -- across the planet at 700 mph (1,100 kph). That spot has since disappeared. A new one appeared on a different part of the planet.
Neptune gets its blue color from a layer of methane gas above the clouds. Methane absorbs red light so only blue colors show up when we look at Neptune.
Scientists think that there might be an ocean of super hot water under Neptune's cold clouds. It does not boil away because of the incredible pressure. That same pressure makes it impossible for a spacecraft -- or a person -- to drop deep into the clouds.
Neptune has six rings and 13 known moons. Neptune's largest moon, Triton, gets colder than Pluto. Voyager 2 spotted geysers of nitrogen gas on Triton. |
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I've recently discovered an interesting way to create a new instance of an object in Google Guava and Project Lombok: Hide a constructor behind a static creator method. This means that instead of doing new HashBiMap(), you do HashBiMap.create().
My question is why? What advantage do you have of hiding the constructor? To me I see absolutely no advantage of doing this, and it seems to break basic object creation principles. Since the beggining you create an object with new Object(), not some Object.createMe() method. This almost seems like creating a method for the sake of creating a method.
What do you gain from doing this?
share|improve this question
Note that you'll get warnings using the raw new HashBiMap(), where you won't using HashBiMap.create(). This is the primary reason Guava uses this pattern, as I mentioned in my answer. – ColinD Oct 4 '10 at 2:53
8 Answers 8
up vote 17 down vote accepted
There are a number of reasons why you might prefer a static factory method instead of a public constructor. You can read Item 1 in Effective Java, Second Edition for a longer discussion.
1. It allows the type of the object returned by the method to be different than the type of the class that contains the method. In fact, the type returned can depend on the parameters. For example, EnumSet.of(E) will return a different type if the emum type has very few elements vs if the enum type has many elements.
2. It allows caching. For instance, Integer.valueOf(x) will, by default, return the same object instance if called multiple times with the same value x, if x is between -128 and 127.
3. It allows you to have named constructors (which can be useful if your class needs many constructors). See, for example, the methods in java.util.concurrent.Executors.
4. It allows you to create an API that is conceptually simple but actually very powerful. For instance, the static methods in Collections hides many types. Instead of having a Collections class with many static methods, they could have created many classes, but that would have been harder for someone new to the language to understand or remember.
5. For generic types, it can limit how much typing you need to do. For example, instead of typing List<String> strings = new ArrayList<String>() in Guava you can do List<String> strings = Lists.newArrayList() (the newArrayList method is a generic method, and the type of the generic type is inferred).
For HashBiMap, the last reason is the most likely.
share|improve this answer
Great explanation! Thanks for the help – TheLQ Oct 10 '10 at 14:39
This is usually done because the class actually instantiated by the create() method might be different than the type upon which you are invoking the method. i.e. a factory pattern where the create() method returns a specific subclass that is appropriate given the current context. (For example, returning one instance when the currrent environment is Windows, and another when it is Linux).
share|improve this answer
Shouldn't that be for special cases only? Because HashBiMap in Guava doesn't do any special caching, just returning a new instance. And you can't override it (or TMK mock it) because its static. code.google.com/p/guava-libraries/source/browse/trunk/src/com/… – TheLQ Oct 4 '10 at 0:39
@TheLQ, I wasn't speaking about the library specifically. Just in general terms about what a create() factory method could be used for. Also, what does overriding it have to do with anything? If you're suggesting that it's difficult to unit-test this pattern, I completely agree. – Kirk Woll Oct 4 '10 at 0:43
@TheLQ, oh, definitely do not use this for everything. Nothing wrong with the new operator. Just keep this in mind as a nice tool to solve certain problems. – Kirk Woll Oct 4 '10 at 0:54
There is no pattern that should be used for everything. – matt b Oct 4 '10 at 1:43
You can't mock a constructor, either (in other words, from a mocking standpoint, a static factory method is not any less flexible than a public constructor) – NamshubWriter Oct 4 '10 at 3:06
This is called a Factory method pattern. Where the factory lies within the class itself. Wikipedia describes it pretty well but here are a few snippets.
Factory methods are common in toolkits and frameworks where library code needs to create objects of types which may be subclassed by applications using the framework.
Parallel class hierarchies often require objects from one hierarchy to be able to create appropriate objects from another.
share|improve this answer
The factory pattern works well in things like BorderFactory, but I'm not understanding why you would do the factory pattern and your class in one class. What are you gaining by doing this? – TheLQ Oct 4 '10 at 0:34
See: code.google.com/p/guava-libraries/source/browse/trunk/src/com/… I'm curious to why would use this pattern when your accomplishing the same thing but with more code. – TheLQ Oct 4 '10 at 0:40
@TheLQ I have updated the answer. – Ólafur Waage Oct 4 '10 at 0:52
I don't believe this is true. A factory method will be an instance method. Swing uses the pattern a fair amount. – Tom Hawtin - tackline Oct 6 '10 at 2:43
Unlike constructors, static methods can have method names. Here's a recent class I wrote where this was useful:
* A number range that can be min-constrained, max-constrained,
* both-constrained or unconstrained.
public class Range {
private final long min;
private final long max;
private final boolean hasMin;
private final boolean hasMax;
private Range(long min, long max, boolean hasMin, boolean hasMax) {
// ... (private constructor that just assigns attributes)
// Static factory methods
public static Range atLeast (long min) {
return new Range(min, 0, true, false);
public static Range atMost (long max) {
return new Range(0, max, false, true);
public static Range between (long min, long max) {
return new Range(min, max, true, true);
public static Range unconstrained () {
return new Range (0, 0, false, false);
You couldn't do this using just constructors, as atLeast and atMost would have the exact same signature (they both take one long).
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Well it would be possible for SomeClass.create() to pull an instance from a cache. new SomeClass() won't do that without some shenanigans.
It would be also be possible for create() to return any number of implementations of SomeClass. Basically, a Factory type of dealio.
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Although not applicable to this particular code example, the practice of hiding the constructor behind a static method is Singleton Pattern. This is used when you want to ensure that a single instance of the class is created and used throughout.
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Thats a bit of a stretch of what I was getting at, but I guess for a single constructor hiding method you could do this. – TheLQ Oct 4 '10 at 2:18
Even without the singleton pattern, this way of object creation does come in handy if you want the object to be instantiated in a particular way alone for e.g.: a hash-map with an optimized initial size instead of relying on the API user to provide it for you. – Sagar V Oct 4 '10 at 2:20
In this particular case, the reason why there aren't public constructors is because there are factory methods that do the same thing, and the reason why there are factory methods is because they're superior.
It's between static factories and constructors, and it's well-established which one is superior. So I don't expect we will be providing these constructors.
NamshubWriter is actually spot on about the justification for why they're considered superior:
In Java, the simple fact is that static factory methods are superior to public constructors. For the reasons why, please re-read item 1 in Effective Java, second edition.
It also makes the API fairly consistent, I suppose.
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There are many reasons to use this factory method pattern, but one major reason Guava uses it is that it lets you avoid using type parameters twice when creating a new instance. Compare:
HashBiMap<Foo, Bar> bimap = new HashBiMap<Foo, Bar>();
HashBiMap<Foo, Bar> bimap = HashBiMap.create();
Guava also makes good use of the fact that factory methods can have useful names, unlike constructors. Consider ImmutableList.of, ImmutableList.copyOf, Lists.newArrayListWithExpectedSize, etc.
It also takes advantage of the fact that factory methods don't necessarily have to create a new object. For instance, ImmutableList.copyOf, when given an argument that is itself an ImmutableList, will just return that argument rather than doing any actual copying.
Finally, ImmutableList's factory methods return (non-public) subclasses of ImmutableList such as EmptyImmutableList, SingletonImmutableList and RegularImmutableList depending on the arguments.
None of these things are possible with constructors.
share|improve this answer
I'm pretty sure HashBiMap<Foo, Bar> bimap = new HashBiMap() would work just fine since the <Foo, Bar> is implied. – TheLQ Oct 4 '10 at 2:52
It will work, yes, but it'll also generate warnings for use of the raw type instead of the parameterized type... you shouldn't do it. Static methods can infer the type parameters and do the same thing without warnings. – ColinD Oct 4 '10 at 2:55
I should also note that it's incorrect to say that the <Foo, Bar> is implied. It's not. You're just using the raw type, pre-generics style. In JDK7, you'll be able to use the diamond operator, like this Map<Foo, Bar> map = new HashMap<>(), which does infer the types similar to the way static methods do. – ColinD Oct 4 '10 at 3:28
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Social Media Influences on Generational Behavior and Vice Versa
By Phyllis Weiss Haserot
Social Media – it's much more than Facebook, Twitter, Linkedin, YouTube, and even Foursquare, Pinterest, Tumblr, blogs, podcasts – it seems new platforms are created every hour wherever sharing is happening. Not only is the accelerating use of these outlets affecting our behavior and use of time, but also social media are influencing behavior of the different generations – and vice versa.
For example, Boomers and Gen Xers, who still do most of the hiring, evaluating and promoting, now routinely check out social media as part of sourcing qualitative "data." This has effectively caused students on spring break travel to rein in their behavior for fear of damaging cell phone camera photos turning up on Facebook, YouTube, and e-mail. The New York Times quoted students and hospitality workers industry admitting potential social media exposure rendered behavior markedly more conservative than in past years (The New York Times, "Spring Break Gets Tamer as World Watches Online," 3/16/12).
Generational Definitions
• Traditionalists: Born between1925 and 1942
• Baby Boomers: Born between 1943 and 1962
• Generation X: Born between 1963 and 1978
• Generation Y/Millennials: Born between 1979 and 1998
In February I served as the generations expert on a panel about use of social media to reach and bridge audiences of difference generations. It was presented by Women in Communications Inc. in New York during Social Media Week. In preparation I outlined answers to several questions posed in advance, and I am sharing some of them with you below.
How do different generations use social media - what do they share with their work/personal contacts?
• They share information and free advice to get followers. Gen Yers, particularly, expect information to come free. They expect free samples before buying, games and contests with prizes.
• What is shared across generations? Gen Yers are eager to connect with Baby Boomers for business contacts. I get lots of LinkedIn invitations from Gen Yers, including students, after networking events.
• Gen Y shares everything – a blur of personal and professional.
Do baby boomers use social media differently than other generations? Yes and no. Some differences are:
• They tend to separate professional and personal information on sites. Younger generations make less distinction between professional and personal.
• Boomers are more concerned about privacy.
• They are not as continually on social media.
• They may have different notions of what's news. (Gen Yers tend to think whatever they do is news and worthy of an update to their world.)
• Gen Yers use social media for invitations, checking in at venues, meeting up and getting recognition for use.
• There is more "selling" from the younger generations on social media. (One of Gen Y's labels is "Generation Sell.")
How can you "teach" older generations to communicate effectively and efficiently on various social media platforms?
• Boomers are active on LinkedIn and are business- and job-oriented.
• Boomers need to become more concise in their messaging (think 140 characters) and use more visuals.
• There are many free webinars/teleclasses teaching effective use, including copywriting using keywords and search engine optimization (SEO).
What are the biggest mistakes communicators make when trying to reach multi-generational audiences through social media?
• Not challenging assumptions about who uses social media and who doesn't and how.
• Using only one message and one format. Offer a choice of media; though video seems to be taking over, it is not everyone's preferred way of learning.
• Not varying the degree of directness of a "sell." Older generations especially need to develop a relationship first.
• Not considering the image of celebrities and spokespeople used so that the audience relates (young, old, thin, athletic, etc.).
Social media and its use will continue to evolve and become even more central to our lives in positive and negative ways, depending on your viewpoint. Critical are taming the time demand beast and creating situationally relevant metrics for ROI.
Please share your thoughts on this topic, which is significant in the commercial and personal realms as well as the workplace.
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Spice it up
The next time you're rummaging through all those who-knows-how-old containers of dried seasonings, desperately searching for tarragon for that new tuna recipe, remember that herbs and spices were once so rare and considered so valuable that wars were waged over them.
In fact, during the Middle Ages pepper was counted out one peppercorn at a time, and in many towns, taxes and rent were paid with it. The guards of London's docks were required to have their pockets sewn shut lest they steal the treasured spices.
Today herbs and spices are readily available and relatively inexpensive, making it easy to enjoy a world of flavors at home. Even better, these fragrant bits of leaves, bark, roots and seeds not only delight your taste buds, they also benefit your health.
Disease fighters
Adding herbs and spices to your food is a great way to increase flavor without adding fats and sugars. What they do add, though, are disease-fighting phytochemicals and antioxidants. "Herbs and spices have a lot of potential as cancer-fighters," says Karen Collins, spokesperson for the American Institute for Cancer Research. For example, oregano and rosemary are powerful antioxidants, which ward off unstable molecules called free radicals that damage cells and may lead to cancer.
Many other herbs and spices also affect the enzymes that deactivate cancer-causing compounds, Collins explains. Curcumin, the source of turmeric's bright yellow color, offers protection against cancers of the mouth, stomach, colon, skin and liver.
Herbs and spices have the same types of health-boosting phytochemicals that fruits and vegetables contain, like flavanoids, carotenoids, sulfides and others touted in reports as helping prevent disease. For example, when cut or crushed, garlic releases allicin, which inhibits a variety of bacteria, molds, yeasts and viruses. And eating a garlic clove a day may help drop cholesterol levels by as much as 10 percent. Cinnamon also has been shown to lower cholesterol and triglyceride levels in people with type-two diabetes.
However, herbs and spices shouldn't replace fruits, vegetables and whole grains, but rather be part of an overall healthy diet. "The lesson we learned about fruits and vegetables is that it's variety that's important, not honing in on one fruit or just one herb or spice," says Collins.
A world of flavors
When you're learning to cook with new herbs and spices, think about the ethnic foods you enjoy, suggests Lola O'Rourke, R.D., culinary expert and spokesperson for the American Dietetic Association. If you enjoy Indian food, add curry powder to stews and sauces or flavor chicken with cinnamon, cloves, cardamom and turmeric.
If Mexican food is a favorite, sprinkle your meats with cumin and add dried or fresh chili peppers. For a taste of Asia, saut meat with ginger root and add sesame seeds and soy sauce. Season dishes with garlic, marjoram, oregano and parsley for an Italian flair. O'Rourke also suggests mixing sweet spices into savory foods--cinnamon and cardamom on chicken or beef, for example. Or blend sweet and savory spices together such as cinnamon, nutmeg and chili pepper in a red bean and beef chili.
The art of seasoning
When cooking with fresh herbs, rinse and pat them dry with a paper towel just before you're ready to add them to a dish. You can use both the leaves and the stems of herbs with thin, tender stalks such as dill and cilantro. But with rosemary and others with tough stems, eat only the leaves. Strip the leaves by running your index finger and thumb from the top of the stem to the bottom. Chop them using a sharp knife or snip them with kitchen shears. The more finely you chop fresh herbs, the more flavor you'll get.
Add fresh herbs toward the end of cooking to preserve their flavor; dried herbs can go in early. For dips, dressings, cheeses and other cold foods, mix in herbs several hours before serving. And just about any fresh herb adds zing to a mixed green salad.
Unless they have passed their prime, the flavor of dried herbs is stronger than that of fresh herbs, so you'll need to adjust recipes when substituting one for the other. Here's a good rule of thumb: 3/4 teaspoon dried herbs = two teaspoons fresh herbs
If your garden is producing more herbs than you and your neighbors can use, experiment with making flavored vinegars. Bruise one cup of leaves by gently crushing them with the back of a large knife or spoon, and then add them to two cups of white wine vinegar. Use a bottle that can be sealed tightly (screw-top is good), and make sure it's very clean to avoid contamination.
Store the vinegar in a cool, dark place for two to three weeks to bring out the fullest flavor. The herbs will likely decompose, so strain the vinegar into another clean bottle. Homemade vinegar presented in an attractive container makes a great gift.
When cooking with fresh spices, toast whole spices, like cinnamon, cloves and cardamom, before grinding them to release more of their oils and flavors. Over medium heat, toast the spices in a dry pan for two to five minutes until they're fragrant and lightly browned. Shake the pan often to brown them evenly and prevent burning. Crush the spices in a coffee grinder, and clean it thoroughly after each use by grinding a few tablespoons of raw rice.
Keeping the flavor
Store dried herbs and spices in an airtight container away from the heat of your stove. Generally, whole spices and seeds will last for three to four years, ground spices for two to three years, and herbs will stay fresh for one to three years.
Fresh herbs, however, should be stored in the refrigerator in an open or perforated plastic bag to allow some airflow. Trapped moisture will hasten their demise. They'll last even longer if you cut the stems diagonally and put them in a tall glass with about an inch of water and cover them loosely with a plastic bag.
Sturdier, thicker-stemmed herbs such as rosemary and thyme will last longer than more delicate ones like dill and parsley. Depending on the herb and how fresh they were when you got them, fresh herbs can last from a few days to longer than a week.
You can also preserve the flavor of fresh herbs by freezing them. After chopping them finely, place herbs into ice cube trays until about half full and cover them with water and freeze. Or try freezing basil, oregano and other Italian herbs in olive oil. Store the cubes in a freezer bag, and use them in soups, stews and sauces.
What's the difference?
Herbs are the leaves of plants that don't have woody stems, so they come from plants other than trees and shrubs. Whereas spices come from the other parts of all kinds of plants -- the stems (chives,) bark (cinnamon,) roots (ginger,) seeds (cumin, nutmeg, anise) and fruit (allspice, cardamom.)
Healthy seasonings
In addition to having antioxidant properties, which help protect cells from damage, these herbs and spices have been shown to have the following potential health benefits:
• Cinnamon may lower blood sugar, cholesterol and triglycerides in individuals with type-two diabetes.
• Garlic may decrease cholesterol and kill bacteria and viruses.
• Ginger may deactivate cancer-causing compounds, fight nausea and boost immune function.
• Rosemary may deactivate cancer-causing compounds.
• Turmeric may help prevent cancer, reduce inflammation and relieve pain.
• Cloves may have antimicrobial properties.
Jill Weisenberger, M.S., R.D., is a registered dietitian and certified diabetes educator for Hampton Roads Center for Clinical Research in Norfolk, Va.
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Comparison between ancient Egyptian doctors and Mayan healers
Criteria Egyptian Doctor Mayan Healers
ImagesEgyptian doctor Mayan Healer
Social Status - Egyptian doctors were highly respected in the ancient world,
- Doctors had their own hierarchy there were ordinary doctors, senior doctors, masters of physicians and the Chief of Physicians of the South and the North. Royal and palace doctors had special hierarchy and titles.
- Mayan healers combined their activities with another profession, such as housewives, carpenters and farmers.
Medical Schools - Doctors learnt their profession at schools called Houses of Life
- Reputed schools included Bubastis in the New Kingdom and Abydos and in the Late Kingdom .
- There were no schools or formal training centers where traditional healing practices could be learned.
Methodology - Egyptian Medicine was based on an integrated scientific methodology and a system of medical schools.
- There was specialization since each physician used to treat a specific disease.
- Egyptian doctors were very advanced in their knowledge of herbal remedies and surgical techniques.
- Doctors were aware, they could not treat every injury or disease. When faced with such cases, it was often that the following passage would be written: "An affliction for which nothing can be done". No doctor, not even ones in antiquity could have been happy about facing such cases. In the Edwin Smith Papyrus there are 58 cases, only 16 of which were deemed to be without treatment, leaving 42 detailed accounts as to diagnosis and treatment, most of which are of a purely surgical nature.
- Mayan healers were specialized in spiritual matters, emotional affairs and the use of herbs. Their treatment of disease was mainly psychological and spiritual.
- Healers did not understand disease by focusing on specific organs, They rather interpreted diseases as a response of the body to natural, social and spiritual constraints.
Famous Doctors - The most famous of the Egyptian physicians is Imhotep, an Old Kingdom physician and architect who was declared a god in his own right. Even today, many medical schools, including the University of Iowa Hospitals and Clinics have a statue of Imhotep that watches over them. - Ordinary healers - no famous personalities
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Poll: Whom do you consider the most important scientist and physician worthy to be recognized as the true Father of Medicine?
467 votes
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By Ayman Fadl - Copyright © 2001-2014 |
Sorry for my silly question: To my best knowledge, C=C means a double bond between C and C, like in butene and the likes. Vaguely remembering high school chemistry, I think benzene does not contain such a double bond, instead its six excess electrons for some funny orbital, hence neither hydroquinone, nor catechol have any real C=C in their structure. If that is correct, how does this Kendall-Pelz rule really work? What did I miss? |
Summary: Tips and information on how to calculate the size of radiator required to heat a room including a BTU calculator to help you. In this project learn about the ideal temperatures for different rooms in the home such as living rooms, dinning rooms, bedrooms and kitchens. With this information you can then calculate the total BTU's for your entire house and what size boiler you will need.
What Temperature Do You Want Your Radiators To Heat Your Room To?
The size of radiator required for a room depends on two factors.
Firstly, the temperature that you want it to be able to maintain which is a relatively straightforward task and you can use the table below as a guide.
Room Ideal Temperature (deg C)
Lounge 21
Dining Room 21
Kitchen 16
Bedrooms 15
Bathroom 23
Stairs 18
How Much Heat From The Radiators Is Going To Escape From My Rooms?
The second consideration to take into account is the the heat loss from your room. The calculations for this are quite complex since they depend upon the size of windows, numbers of doors and, in particular, the construction materials used in the building.
Too big and the system will overshoot its temperature and be less economical to run, to small and it won't reach its desired temperature.
Some of the poorer installers get round this complex step by putting in radiators that are too big, and then fitting thermostatic radiator valves to every radiator to cut the heat down.
This calculation produces a heat loss figure in watts, of how much heat you need to warm that room up to the design (and desired) temperature from -3 deg C in one hour.
Calculate The Size Of Your Radiators Using A BTU Calculator
A quick and easy way to calculate the size of the radiator required for any room in your house is by measuring the room in cubic feet and then entering the information into a BTU (British Thermal Units) calculator or using the table below to estimate the total BTU's required to correctly heat your room.
Room Multiplication Factor
Lounges and dining rooms Multiply cubic feet by 5
Bedrooms Multiply cubic feet by 4
Common areas and kitchens Multiply cubic feet by 3
For rooms facing north Add 15%
For French windows Add 20%
For double glazing Deduct 10%
This will give you the output of any radiator in BTUs (British Thermal Units). Adding the total for all the rooms in your home will give you the approximate demand in BTUs for the whole house. Add 20% to the total for a hot water circulating tank and 10% for general losses. This will give you the boiler size you need for your house.
Obviously these calculations are approximate and while giving you an excellent idea of the sizes you will require, it would be best to get this checked by the installer.
It is very unlikely that any radiator will match the exact heat required, so select the first size of radiator above the heat requirement.
With rooms greater than 6 meters (18ft) in any one direction, it is worth considering distributing a number of radiators to minimise the thermal gradient within the room.
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UN resolution would condemn Syria rights abuses
Created: 10/30/2013 4:35 PM
(AP) UNITED NATIONS - A draft U.N. resolution initiated by Saudi Arabia would strongly condemn "widespread and systematic gross violations of human rights" by the Syrian government and "any" abuses by anti-government armed groups.
Saudi Arabia, which backs rebels fighting to overthrow President Bashar Assad, has strongly criticized the Security Council’s failure to resolve Syria’s civil war and other conflicts, citing this as one reason for rejecting a seat on the U.N.’s most powerful body earlier this month.
U.N. diplomats said the draft resolution, obtained Wednesday by The Associated Press, is expected to be submitted to the human rights committee of the less powerful but much larger General Assembly by Friday’s deadline. The committee is expected to discuss it next week and vote on it in late November. If approved, it is virtually certain to be adopted by the 193-member General Assembly in December.
Unlike Security Council resolutions, General Assembly resolutions are not legally binding, but they do reflect world opinion and carry moral and political weight.
The draft resolution is highly critical of the Assad government, expressing "outrage" at the continuing escalation of violence that has killed more than 100,000 people in 2 1/2 years of fighting and "alarm" at the regime’s failure to protect its people.
It blames Syrian authorities for a wide range of human rights abuses including the indiscriminate use of ballistic missiles and cluster munitions; the killing and persecution of protesters, human rights defenders and journalists; attacks on schools and hospitals; and torture, sexual violence and rape in detention.
The draft strongly condemns the use of chemical weapons in Syria and "strongly points" to their use by the Syrian government in an Aug. 21 poison gas attack that killed hundreds of civilians in the Damascus suburb of Al-Ghouta.
It notes that the Arab League and the Organization of the Islamic Conference have held the Syrian government "fully responsible" for the Al-Ghouta attacks, and calls on the Security Council to take "the necessary measures against all those responsible for the chemical weapons attack" to ensure accountability.
Diplomats said the resolution’s strong demand for accountability and an end to impunity could be a problem for some countries when it comes to a vote, because of the precedent it could set.
The draft also expresses "grave concern at the spread of extremism and extremist groups."
It strongly condemns all foreign fighters in Syria, singling out those fighting for the government, especially Hezbollah militants from neighboring Lebanon.
"Their involvement further exacerbates the deteriorating human rights and humanitarian situation, which has a serious negative impact on the region," it says.
Saudi Arabia, Qatar and Turkey are providing arms, money and logistical support to the rebels. The Saudis and other Sunni Arab governments are eager to counter their regional rival Iran, which supports Hezbollah and has thrown its weight behind Assad.
The draft calls for an end to all violence, including terrorist acts and intimidation "that may foment sectarian tensions."
It also demands an end to all human rights abuses, the immediate release of all detainees and immediate steps by the Syrian government to expand humanitarian relief operations.
The draft supports a new Geneva peace conference aimed at establishing a transitional government and the Syrian people’s aspirations "for a peaceful, democratic and pluralistic society ... in which there is no room for sectarianism or discrimination on ethnic, religious, linguistic, gender or any other grounds."
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Push Endoscopy: Get Facts on Preparation for the Procedure
Push Endoscopy
(Push Enteroscopy)
Medical Author:
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What is endoscopy?
Standard upper gastrointestinal endoscopes (120 cm flexible tubes with a light and camera on their tips) are capable of reaching only a foot or so past the stomach into the small intestine. If abnormalities are located within this area, these endoscopes have working channels through which surgical instruments can be passed so that diagnostic and therapeutic procedures such as biopsy and electrocautery can be done.
Many abnormalities of the small bowel, however, lie further along the small intestine beyond the reach of the standard upper gastrointestinal endoscopes. Sometimes a colonoscope, similar to the upper gastrointestinal endoscope but 180 cm in length, can be used to reach a little further into the small intestine, but the additional reach of colonoscopes is limited.
It is not the length of the endoscope that is the most important problem in reaching further into the small intestine. The problem is that the path of the endoscope through the stomach and duodenum is twisty and the endoscopes curl in the stomach. In addition, the small intestine is not fixed in place, and this makes advancement of the endoscopes even more difficult.
What is push endoscopy?
Push endoscopy (also referred to as push enteroscopy) is a procedure that allows diagnosis and treatment of diseases in the upper small intestine. Push endoscopy reaches further into the small intestine than the standard upper gastrointestinal endoscopy (also known as esophagogastroduodenoscopy, EGD).
Endoscopes for push endoscopy are similar in length to colonoscopes, approximately 200cm and have working channels for diagnostic and therapeutic procedures. After the endoscope is passed into the duodenum, a more rigid overtube is passed over the endoscope to straighten its path. With the overtube in place, the endoscope then can be advanced without coiling in the stomach.
What are the advantages of push endoscopy?
Push endoscopy is a useful procedure for examining and delivering therapy in the small intestine. For example, for patients with intermittently bleeding angiodysplasias (clusters of weakened blood vessels) located in the small intestine beyond the reach of a standard upper endoscope, push endoscopy can be helpful in both diagnosing the bleeding site as well as in stopping the bleeding.
What are the limitations of push endoscopy?
Push endoscopy has its limitations. Its reach is still limited and cannot diagnose lesions in the distal small intestine (intestine closer to the colon). The major risks of push endoscopy are the same as other endoscopic procedures, bleeding and perforation of the intestine, either due to passage of the endoscope or the accompanying therapeutic procedures. Because of the use of an overtube, the risk of perforation probably is increased over the risks of an endoscope alone.
Medically Reviewed by a Doctor on 10/16/2014 |
Charity: The Place of the Poor in the Biblical Tradition
Gary A Anderson, Author
Reviewed on: 07/29/2013
Release date: 08/01/2013
Open Ebook - 233 pages - 978-0-300-18373-3
Open Ebook - 1 pages - 978-1-299-78104-7
Paperback - 232 pages - 978-0-300-19883-6
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The award-winning author of Sin: A History provides another must-read for lay reader and scholar alike, especially those in critical dialogue on how Judeo-Christian biblical values influence the role of the state in caring for the vulnerable. The Greco-Roman empire didn't identify the poor as a priority of the gods. In fact, Roman emperor Julian noted that charity was the defining marker of Christian and Jewish identity, not pagan. How did giving alms and caring for the poor become such a central religious concept? Anderson unpacks the book of Tobit and other biblical literature to reveal a complex and radically countercultural story of how service to the poor became the most privileged way to serve God. "Charity," he argues, "was construed as a loan to God, which was then converted into a form of spiritual currency and stored in an impregnable divine bank." Given the current economic crisis and the low esteem in which our financial industry is held, perhaps "storing up treasure in heaven" by depositing wealth into the hands of the poor is a less volatile economic strategy that offers greater long-term security for all. (Aug.)
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Theory of gender performativity
The theory of ‘Gender Performance’ or ‘Gender Performativity’ was first coined in Judith Butler’s 1990 book titled Gender Trouble. Butler’s theories on gender identity and gender performativity were based on the notion of destabilizing gender identities and categories. Butler’s work can be linked with J. L. Austin’s work on the notion of the performative, and ties into Derrida’s work on reiteration and repetition. She considered the definition of what is meant by the signifier ‘woman’, in relation to the post-structuralist position of examining signs and signifiers. This paper will examine how Butler’s gender performance theories originated in a wider context of the feminist movement and discourse; whereby Butler moved away from the essentialist and centralized ideology of feminism and went on to encompass ideas of ‘Queer Theory’. There is also a consideration of the effect and significance of the gender performativity in literary texts.
The initial starting point for Butler’s work is that gender identity cannot be biologically determined. In Gender Trouble Butler initiated a reinterpretation of Simone de Beauvoir’s statement that “one is not born a woman, but rather becomes one” (de Beauvoir 1949 quot. In Barry p125). De Beauvoir distinguishes between gender and sex, whereby gender can be seen as a social creation centred on the ‘natural’ or biological differences of the sexes. Butler argues that:
"there is no recourse to a body that has not always already been interpreted by cultural meanings; hence, sex could not qualify as a pre discursive anatomical facticity. Indeed, sex, by definition, will be shown to have been gender all along". (Butler 1990, p.8).
Butler also uses Foucault’s ideas on how the self-identity is constructed in order to develop the performative theories of gender, in which she argues that sex is not something stable and fixed, but should be considered as something which is open to fluidity. Butler sees body as a ‘prison’ of gender and sexuality in reference to Foucault’s chapter on "Docile Bodies" whereby “the body was in the grip of very strict powers, which imposed on it constraints, prohibitions or obligations” (Foucault 1975 p136), although there is some scope for resistance and malleability. Butler follows this in her work by arguing that society inscribes on our external physical bodies our internal gender and sexuality. This idea may also be a reference to Foucault’s work in Discipline and Punish, in that Butler is observing the physical form of the body as a personal ‘prison’ for individual identity. In the same way that Foucault’s work on “Panopticism” which enforces that prisoners are observed all the time (Foucault 1975 p227). Butler’s theories of gender performativity mean that our gender identities are performed or played out for observation by society.
Although there is an emphasis in Butler’s work on the manner in which discourses affect our behaviour: rather than gender performance being a role played and created by the individual creatively, gender performance is habitually continually acted and performed on a daily basis in everyday life. Although as she suggests in her examination of drag performance creativity can serve to subvert the performativity of the roles we are assigned to perform. Butler’s key ideas are therefore based on the notion that gender is not a simplified ‘role’ but a deep seated psyche playing out of identity and behaviour, there is also not casual link between sex, gender and sexuality. The performative gender roles are dependent upon repetition and re-iteration in creating identity, which in turn result in instability of the ‘gendered roles’ we are assigned.
Judith Butler’s work arose out of a wider context of feminism and the feminist movement, and must be considered within the political, theoretical and social debates of feminist discourse. The first wave of the feminist movement occurred between the 1800s and the 1950s and challenged the status of women but not the gender roles or sexualities of women in society. The second wave of feminism and the precursor for modern feminist literary theory occurred between the late 1960s and 1980s and asserted that gender roles and questions of sexuality needed to be examined in relation to both the personal and political spheres. This wave of feminism addressed questions of gender inequality, critiqued patriarchy and identified the problem of androcentrism and the assertion that sex or gender is an unchanging, fixed, and biological given. The question of gender identity was now considered to be socially constructed and historically contingent, and described by Henrietta Moore as part of a “symbolic construction or as social relationship” (Moore 1988: 13). A further examination of gender roles was provided by Gayle Rubin who investigated the role of gender and sex and stated that a “ “sex/gender system” is the set of arrangements by which a society transforms biological sexuality into products of human activity and in which those transformed needs are satisfied”(Rubin 1975:159). She further states that the “Sex/gender system” is a “social organization of sexuality and the reproduction of the conventions of sex and gender” (Rubin 1975:168).
This work lay the foundations for the third wave of feminism which emerged in the late 1980s and is prevalent today. The modern and current feminist theory prefers to deconstruct and demystify gender roles and sexuality. Gender is socially constructed but also is socially constructed and historically contingent, and biological gender does not does not necessarily determine gender, while at the same time there is a recognition that not all cultures historically or culturally believe in the existence of only two genders. Rubin also anticipated the movement of the feminism towards “the elimination of the oppression of women…[through]…the elimination of obligatory sexualities and sex roles” (Rubin 1975:102). The traditional idea of gender and sexuality involve the idea of ‘heteronormativity’ which refers to a view of heterosexuality as normalized behaviour in a society. This is characterized by two binary notions of sex or gender as male and female, where heterosexuality is the natural and normal accepted view of sexuality. Gender is determined biologically and not an assigned role of identity and sexuality is normative and natural if it fits into the framework of heterosexuality.
Judith Butler presents her fundamental theories of gender as performative in Gender Trouble: Feminism and the Subversion of Identity, with the arguments that drag is performative and in its destabilization of the performative iterations of gender, drag performances can be construed as a political escape from the structures of gender binary oppositions. In her follow up work Bodies That Matter : On the Discursive Limits of Sex, Butler states that there should be no confusion that gender performativity is a qualified daily choice made by individuals. Here Butler argues that there is an iterability and repetition involved in gender performativity, which results in immense difficulty in trying to escape the constructions of naturalized restrictions of sex and gender through making conscious daily performative choices.
The question of gender performance is related to ideas of gender identity in society, whereby certain codes of behaviour are assigned according to gender. There is an initial essentialist view of social identity whereby gender is determined biologically and gender is an immutable and recognizable physical essence. However the concept of gender performance questions the essence of gender roles and identity as being determined by purely physical and biological factors. Instead gender identity is a performance or construction made up of behaviours and roles which are then assigned to a specific gender.
Gender then becomes a repetition of behaviours and acts, which are not natural or inevitable, are open to change and fluidity, and dependent on the context in which they are performed, and are part of a wider discourse of gender, sexuality and sex in society. Butler insists that :
“The reading of ‘performativity’ as wilful and arbitrary choice misses the point that the historicity of discourse and, in particular, the historicity of norms (the ‘chains’ of iteration invoked and dissimulated in the imperative utterance) constitute the power of discourse to enact what it names” (Butler 1990 187)
Gender performance is learned both consciously and ingrained unconsciously on the psyche of the individual, who is unaware that they are performing a gender role, but accept the gender identity assigned to them by their own behaviour or performance and which is again interpreted and repeated within the discourse of gender relations in a cultural and social context. A key element of gender performativity is the iteration of the act, “Performativity must be understood not as a singular or deliberate “act,” but, rather, as the reiterative and citational practice by which discourse produces the effects that it names” (Butler 1990 2). Butler’s stance is that gender performativity is a repetitive act which serves to perpetually reproduces itself:
“Sex is not an ideal construct which is forcibly materialized through time. It is not a simple fact or static condition of the body, but a process whereby regulatory norms materialize “sex” and achieve this materialization through a forcible reiteration of those norms” (Butler 1-2)
The subjectivity of the individual is produced through producing and creating these norms and as individuals are constantly reinforcing and recreating the norms that experienced.
Butler uses post structuralist theories and applies a feminist perspective to explore and theorize gender male and female gender roles. Butler combines the concept of gender identity with the concept of performativity from J. L Austin. Butler’s main points in relation to gender roles are founded in her assertion that gender identity is constructed and is effectively a form of performance or reiterated ‘acting out’, of what it means to be gendered either male or female. This gender performance means that people become tied in to a static or ‘normalized’ gender role which is culturally and socially defined as being a ‘normal ’male or female. Butler finds the idea of ‘normal’ gender roles restrictive as she asserts that an individual’s gender behaviour or performance can have contradictory aspects, which result in instability in the gender performance. Butler asserts that the idea of ‘true gender’ is a difficult one, because the definition or qualities of gender are only part of a wider narrative that reinforces stereotypes and expectations of what it means to be male or female. She states that
“…words, acts, gestures, and desire produce the effect of an internal core or substance but produce this on the surface of the body, through the play of signifying absences that suggest, but never reveal, the organizing principle of identity as a cause. Such acts, gestures, enactments, generally construed, are performative in the sense that the essence of identity that they otherwise purport to express are fabrications manufactured and sustained through corporeal signs and other discursive means.” (Butler 1990 p.185.)
Butler states that although bodies are initially of indeterminate gender and are destabilized further in the performativity of gender, as well as by other categories of race, class and sexuality, which only serve to further destabilize the performative. Gender identity is therefore constructed as a fluid performance and not an essential essence of being. Under this construction, identity is free-floating and not connected to an “essence”, but instead to a performance. The acts which are performed, are according to Butler, indicative of a wider social performance of behaviour in society and culture, which is not recognized as being a ‘performance’. Rather these acts, performances and behaviours are so entrenched in the psyche of the individual that they are regarded as ‘natural’ both to the individual concerned and in their appearance to society. She states that “Performativity is neither free play nor theatrical self-presentation; nor can it be simply equated with performance” (Butler1990 95). Butler argues that gender is performative, and that no identity actually exists behind the acts that are supposedly expressing gender. These acts only serve to constitute an illusion of a stable gender identity rather than expressing it.
In her essay “Imitation and Gender Insubordination” Butler states that she doesn’t want to be labelled as a ‘lesbian’ theorist, although she at the time she realises that labels are important. Nevertheless she insists that the ‘fixitivity’ of categories must be challenged and that no category captures a person’s identity; she goes on to say that if a signifier labels a person as ‘woman/black/lesbian’ this still doesn’t have sufficient meaning to give a definitive account of a person’s identity (Salih 2004 119). This essay is Butler’s reaction to the political and social effects of women’s liberation and gay liberation, and in it she presents her ideas for a new version of her own identity, in challenging the essentialism of gay politics. She begins by stating that identity categories should be regarded as “efficacious phantasm” (Salih 2004 p120) as they are superficial and problematic because they are too rigid and restrictive (Salih 2004 121). Butler wants identity to be both unified and fluid, and she promotes the idea that gender is performative and can subvert and challenge notions of self-identity and gender roles, nevertheless gender is “troublesome” (Salih 2004 p120). The piece is paradoxical in that Butler is performing a gender identity and the same time deconstructing her lesbian identity, in the course of writing the paper. She is also challenges the notion of ‘theory’ in a similar manner to Adorno’s critique of ideological societies (Butler 1990 p121). Butler reacts to criticism of being ‘high theory’ and not engaging with real life experience of homophobia, however she states that theory is practical and practice is theoretically informed. She prefers the idea of a subject who is free of categorisation and labels such as lesbian and raises the question of whether a sexuality can ever be ‘achieved’ once it is defined or signified by a label (Butler 1990 p122). For Butler the subject or the “I” cannot be a totalisation of identity, and this raises the further question of what is a lesbian identity? All lesbians cannot share the same characteristics in the same way that all heterosexuals don’t all share the same characteristics therefore the term lesbian may be a signifier but what it signifies is never defined.
She also challenges the whole process and discourse of “coming out” as a lesbian, because this implies that there is a place or “closet” to come out from, and states that “outness can only produce a new opacity; and the closet produces the promises of a disclosure that can, by definition never come” (Butler 1990 p123). The act of gay liberation may be signified in the ‘coming out of the closet’, but questions arise in that ‘coming out’ means that you’re ‘in’ at some point, and further more what are you coming out of, and what are you going into? The coming out of closet reinforces the existence of the ‘closet’. Although the act of ‘coming out’ becomes a collective act of homosexuality discourse, challenging the ‘normative’ primary collective discourse of heterosexuality; for Butler the ‘coming out’ of the closet means to lose one totalisation of identity to simply take on another form of totalising elements of identity.
She also suggests that there is a mysteriousness to sexuality which cannot be revealed or captured in language. Butler says that anyone speaking or writing can use the signifier “I” but the meaning of the “I” is out of the control of the subject and in the understanding of the receiver. She uses binary oppositions to explain that it is heterosexuality which defines the understanding of the other supplementary term homosexuality; however this is only in relation to a homophobic discourse whereby heterosexuality is privileged as binary and homosexuality is the derived or supplementary term. Butler says it is necessary to turn it around or invert the binary oppositions and make homosexuality the primary signifier and heterosexuality the supplementary term (Butler 1990 p123). Although Butler recognises the need to have signifying terms and labels in a political sense, she doesn’t believe they are positive in the long term, as she would rather have the fluidity and destability of no categories and labels to define sexuality (Butler 1990 p123).
In the next part of the essay examines the performance of drag artists and states that the social constructions of gender are seen in drag performances. She explores the ideological construction of all gender roles, and rejects the view of drag as copy or imitation of true gender identity. She analyzes drag performances to explain how the gender performativity used by drag artists are not a subversion of the normative gender roles as they initially appear to be. Although drag performances are superficially a presentation of gender binaries, it is more useful to construe the drag act a hyper-masculine or hyper-feminine gender performance. This then raises questions as to what is ‘normal’ for any given gender and undermines the binary oppositions set up for gender roles. Instead Butler asserts that drag exposes the truth that there is no such thing as gender and all gender roles are imitations of an ‘idealised fantasy’ of superficial ‘normative’ gender roles. The performance of the drag act and the extreme carnivvelesque nature of drag roles, illustrates how masculine/feminine gender performances are culturally defined attributes, and not tied to physical bodies. Butler states: “There is no proper gender, a gender proper to one sex rather than another, which is in some sense that sex’s cultural property…there is no original or primary gender that drag imitates, but gender is a kind of imitation for which there is nor original…” ((Butler 1990 p127).
She also asserts that drag should not be exemplified as a deliberate subjective gender identity. She states that an individual in drag is not ‘one’ prior to gender performance, who then decides to adopt the ‘wardrobe’ of a particular gender; as such drag is not an ‘honest expression’ of the performer’s intent. She concludes the essay in her assertion that the terms ‘heterosexual’ and ‘homosexual’ are constructions, and illustrates this in reference to Aretha Franklin singing “You make me feel like a natural woman”. Butler challenges the notion of what constitutes a ‘natural’ woman and the suggestion that this can only be construed in the completion of binary opposition in that one can only feel like a ‘natural woman’ if it is in relation to a man (Butler 1990 p128). Because Aretha wants to feel ‘like’ a natural woman, this implies that she wants to be ‘like’ a heterosexual woman; it also means that the feeling is a repeat of something, or copied from what a ‘real’ woman should be (Butler 1990 p133). Butler concludes the essay by saying that gender produces performance of gender identity but that nothing is essential or on the inside, everything is on the surface and external and in the signs of gender performance (Butler 1990 p135).
The performativity of gender can be examined through the notion that all gender roles are constructions which are performances being played out by an individual, and which are then either upheld or refuted by society. These gender ‘performances’ utilize and reenact the definition of what it means to be gendered male or female, and the gender identities are reinforced by the reiteration of the behaviour of the gender. This means that because the performance of the gender role is repeated it becomes a recognizable behaviour of that particular gender as part of a wider societal discourse. However Butler also states that the performances of the gender roles are open to interpretation and may not be exact copying, a process which she terms as ‘slippage’. She is also concerned with the authenticity of these gender performances which can be changed, becoming exaggerated and fictional; they are nevertheless incorporated into wider social and cultural context as being natural and universal as true and legitimate gender roles. The fact that the performances can be reenacted and repeated by a multiple of different individuals means that they become a powerful and recognizable mode of behaviour, with recognizable qualities assigned to a particular gender.
Butler’s theories of gender performance can be used to examine literary representations of gender roles. Helen Zahevi’s Dirty Weekend there is a representation of the fluidity of gender performativity. The main female character Bella begins the novel as a ‘weak’ victimized’ female character, who through the course of the narrative defies and challenges the gender role of the female victim which is assigned to her by wider society. She is often referred to as “a Bella” (Zahevi 1991 p118), whereby she is somehow representative of all such ‘types of women’; these women are identified as passive, weak, docile, and identifiable as the “sort of women” that are ignored or abused by men and society in general. The character of Bella undergoes a transformation where although physically on the outside she remains the same, internally she discards the role of a docile weak female gendered victim of stalking, abuse and sexual violence, and progresses to adopt a new role of the violent ‘male gendered’ avenger. Whereas the female Bella shirks away from violence and “stays a away from pain”, once she adopts the gender role of the male avenger she is not afraid of violence and is ready to accept a little pain if it means she will exact revenge and punishment on the male aggressors and transgressors of her female gendered self. At the same time she is willing to adopt key aspects of her female identity which she takes on a sort of ‘drag’ act in wearing a ‘seductive’ the red dress and high heels late out at night in search of her first victim(Zahevi 1991 p93). She is willing to sit in a bar and wants a stranger (Norman) buy her a drink(Zahevi 1991 p95), even when she is purchasing a gun she wants to have the Mr Brown to buy her the drink, simply because as a female she likes to have a drink bought for her in a bar by a man, because, “She likes it when they buy her things. To make them pay is a woman’s way.” (Zahevi 1991 p83) . The key turning point in the novel occurs when Bella visits an Iranian clairvoyant Nimrod, and during the course of the exchange between them, Bella shows the first signs of aggression and resistance to being identified as a female victim. He recognises the ‘lack’ in ‘female Bella’ and hands her a flick-knife; this is symbolic of Bella taking possession of the male phallus. When he asks her “Does it feel good?” (Zahevi 1991 p38) there are deliberate sexual undertones to the conversation; by holding the knife in her hand Bella’s repressed urges for avenging the abuse she has endured as a female come to the surface and she retorts to Nimrod with harsh, aggressive and even racist abuse. During the course of the conversation Bella sheds the identity of the female victim and takes on the male aggression and anger which she most fears – so much so that she then becomes the abuser and Nimrod becomes her victim, albeit of verbal (and not physical) abuse(Zahevi 1991 p36-38). Yet at the same time, towards the end of the conversation Bella reveals that this is not “really what she is like” (Zahevi 1991 p38) as she has been brought up with good manners and is generally polite to most of the people most of the time. Another key scene is the first murder of the academic Norman in the hotel, here Bella stands on the hotel balcony and listens to drunken male louts passing in the street. As she stands on the balcony, she imagines and fantasises what it would be like to possess a penis, and is absorbed in what she imagines as the potential power of the phallus, and imagines the shift in gender power relations if she were able to urinate on the men passing below her. At the end of the scene Bella recognises the duality of her new and old gender performance and identity, when she refers to her polite nature, good manners and general ‘niceness’ as girls are ‘”nice” (Zahevi 1991 p 117. Bella used to be nice, but she is no longer prepared to adopt and perform the female gender roles, as she is no longer prepared to be abused or victimised. The new Bella is fluid in her gender performativity and adopts elements of feminine ‘naivety’ externally while experiencing ‘masculine’ anger and aggression internally.
The fluidity of gender performativity can enable the gender assigned to a character to be undetermined throughout the course of a novel as in Jeanette Winterson’s Written on the Body. Here the gender of the narrator is obtuse and undisclosed all the way through the novel. At times the narrator displays a typically male gendered role in a the lack of emotional commitment to past partners, promiscuity with both male and female partners, and is violent towards a female partner Jacqueline (Winterson 1992 p86) and towards Louise’s husband Elgin (Winterson 1992p170) There is a fluidity in the gender of the narrator which is dependent on the ‘mood’ of the narrator/character and how they are feeling towards a partner at the time. For example with Louise the main object of the narrator’s desire and love, the narrator can be positioned as a female in the emotional turmoil and angst that they are experiencing. At the same time the search for resolution to Louise’s cancer and the ‘quest’ to understand the physicality and demise of the female body in the section titled “The Skelton” (Winterson 1992 p127), can be taken from either a male or female perspective. As a male gendered narrator this could be taken as a yearning to understand the alien female body of his lover which is turning against itself through the nature of the disease. In the same vein, the female gendered narrator can be taken as searching for resolution and deeper understanding of the cancer disease in relation to both Louise’s cancer, and in the context of the narrator understanding their own female form which has become alien to ‘her’. The choice of cancer as the disease becomes significant because it is a disease which ‘turns the body against itself’, in the same way the absence of a gender for the narrator is a ‘turning against’ the natural order of binary male/gender roles in society. Everyone must be man or woman, and the lack of ‘gender’ or the fluidity of the performance of the character’s gender roles all lead up to the point where the object of their love and infatuation must be destroyed or endangered in order to ‘make sense’ of the world.
Patricia Duncker’s novel Hallucinating Foucault is a presentation of gender performativity and queer theory. Initially as in Winterson’s novel we are unsure of the gender of the narrator, as he/she is only signified as ‘the narrator’ or the ‘reader’ throughout the novel. It is only about eighteen pages into the novel when the narrator is invited to a meal with the Germanist’s father that there is any reference to the gender of the narrator. Although this scene indentifies the narrator as male in the discussion of whether he should wear the ultimate phallic symbol of clothing, the tie (Duncker 1996 p18), markedly the narrator does not own a tie, and could be symbolic of the narrator lacking the phallus. At the meal the father flirts with the ‘boy’ narrator (Duncker 1996 p19), there was in my own personal experience of the text room for interpretation of the narrator as a female. The character of the Germanist and the relationship with the narrator, still allows for the reader even at this point to position the narrator as female and part of a lesbian relationship, where the narrator is playing at being male in order to please the Germanist. There are numerous other instances of gender performativity which challenge the role and nature of gender identity in the characterisation of the main protagonists in the key characters of the Germanist, the Narrator and Paul Michel; where we can consider the key ideas of gender performativity and homosexual ‘subcultures’. Paul Michel is described as ‘beautiful’ in his younger days and as a homosexual man he is reluctant to take on the mantle of the ‘establishment of the gay movement’ and “he cherished the role of the sexual outlaw, monster, pervert” (Duncker 1996 p28). For Michel his homosexuality is a space for rebellion and he wants to rebel against the ‘institutionalisation’ of homosexuality, in the same way that Butler is expresses unease about the restrictiveness of ‘Gay liberation’ as a movement.
The key female character of the Germanist is crucial as a facilitator to all the other characters, to the plot, and is essential in the gender performativity of the novel. She is the only significant female character and yet is not a ‘sympathetic’ character that can be identified with, and is complicated to understand and empathise with initially. The complications of the gender performativity of the Germanist lie in a number of factors of the expectations of her as a lead female character such as when the Narrator says “Never before had I been told to take my trousers off while the woman watched” (Duncker 1996 p12). In naming her character as the ‘Germanist’ Duncker signifies a harshness and coldness; this ‘coldness’ and is reinforced in the ‘cold’ relationship of the Germanist with us as readers and with the narrator with whom she has an atypical male/female love affair (Duncker 1996 p17). The narrator leaves the heterosexual relationship he is having with the Germanist and travels South to the warmth of Southern France to experience overwhelming intense love and emotion in his homosexual relationship with Paul Michel.
The Germanist is constantly described as having a “hard, bony body” (Duncker 1996 p23) and “scrawny arms” (Duncker 1996 p40), and physically almost like a pubescent boy, which raises the question of the attraction of the narrator to her as an atypical example of femininity. In fact in her initial encounter with Paul Michel as a child, Michel ‘misrecognises’ her as a ‘feminised’ boy with a mop of “brushed curls” (Duncker 1996 p164), Michel ‘falls in love with the boy’ he imagines her to be as a child and says “I had certainly been deceived in her sex” (Duncker 1996 p164). The coldness and aloofness of the Germanist as an adult female are not symbolic of femininity, and her attitude towards sex with narrator where she takes on the male role are also challenging to the narrator’s expectations of a ‘girlfriend’. More significantly her comment in the lift to the Narrator when she says “I left my womb at the bottom of the shaft” in front of the young black man (Duncker 1996 p40), carries sexual overtones, is flirtatious, yet at the same time illustrates her desire to shed her ‘female’ gendered self . The Germanist has an absent mother, and ‘two fathers’ and is perfectly adapted and content with this, which implies a rejection of the biological and female gender roles of the mother. In her relationship with her father the Germanist regresses into ‘girlish’ behaviour (Duncker 1996 p18). The narrator’s flatmate Mike is “mightily intimidated” and uneasy in her company (Duncker 1996 p23), doesn’t like her, and feels uncomfortable around her, which could be construed as her lack of coherence in her gender performance as a ‘typical’ girlfriend fitting into stereotypical female gender roles. Of course if the narrator is gendered as a female at this point, then the flatmate’s unease can be explained as sexual jealousy towards the lesbian relationship between the narrator and the Germanist.
Most importantly the duality and fluidity of sexuality is examined in the complicated affections of the Germanist. She is a heterosexual female in love with a homosexual male, who initially falls in love with her when she is a ‘boy-like’ child; as an adult she then manipulates her own heterosexual lover, to befriend and enter into a love affair with her homosexual object of desire. The narrator also destabilises the role of the heterosexual male by engaging in a homosexual relationship with Michel; the desire for Michel is paramount for the narrator and his sexual relations with Michel feel natural. The ensuing complication of the interwoven relationships are essentially created by the Germanist, but can on another level be read as a passionate ‘love story’, in that she loves Michel from childhood, and can only express and consummate this love physically through sending him the narrator her male boyfriend. The Germanist’s comments to the narrator about rescuing the object of her love are reiterated by Michel when he tells the Narrator about the Germanist’s statement to him as a child when he says:
“…children like that girl, always keep their promises. She said, “If you love someone- you know where they are and what has happened to them. And you put yourself at risk to save them if you can. If you get into trouble I promise that I’ll come to save you.”
I think that’s the strangest, most romantic declaration I’ve ever had.” (Dunker 1996 164)
This ‘declaration’ makes sense at the end of the novel to the Narrator when he realises that she has sent him to ‘rescue’ Michel, because she loves Michel so intensely. On realising the extent of the manipulation that the Germanist has exerted over him, the Narrator’s only comment to Michel is, “She never forgot you. She kept her promise” (Duncker 1996 p164). The difficulty arises again where Duncker compares the physical appearance of the Germanist to the image of an owl (Duncker 1996 p17) and this symbolism becomes crucial at the end of the novel wherein Michel’s death is caused by an owl (Duncker 1996 p166). This is also perhaps inevitable and only serves to confirm the futility of Michel’s life, as the Germanist’s desire for him is unfulfilled as a heterosexual female, he as a homosexual man must die and end her longing for him, despite her attempts to fulfil this desire vicariously through her boyfriend. The nature of the Germanist’s desire is thus positioned as dangerous to the homosexual Michel who physically dies, and to the narrator who undergoes the traumatic loss of his love and object of desire. In conclusion gender performativity in the novel is complicated, and there is a dearth of female characters other than the Germanist. But the Germanist is the key to everything from characterisation and the untypical femaleness of her gender performance, to the plot development and how she instigates the narrator’s personal interest in Michel. The final scenes at Michel’s funeral where she puts a letter in the coffin for Michel could have been written by her or the narrator (Dunker 1996 p173). This shows how intense emotional longing and desire are the same feelings regardless of gender, there is no distinction in the desire both characters have for Paul Michel emotionally and the only difference is their physicality as male and female.
Although there have been certain criticisms of Butler’s work such as the potential political limitations of gender performativity, which can be construed as restrictive to notions of gender performance while disregarding ontology (MacKenzie 2008). This means that without taking the physical elements of gender identity into account sufficiently, “Ontology, rather than existing independently outside of or preceding discourse, has the appearance of a prediscursive existence only as a result of being posited as such from within discourse itself” (Mackenzie 2008). Aalthough Butler attempted to readdress this in Bodies That Matter, this is a key argument and goes against the very notion of limited constrained gender identity which Butler was aiming to address.
Butler suggests that drag performances highlight the limitations of heterosexual gender roles, there is no suggestion from Butler on how the limitations of heterosexual gender roles and performance can be exposed in a more prolific manner. More importantly Butler states in Bodies That Matter that drag performance is not a ‘conscious’ decision to discard one gender performance in favour of another as a form of fancy dress and that this is a ‘bad reading’ of the Gender Trouble. In the practical experience of drag performance artists this was found to be exactly the case as Judith Halberstram states in her study:
“Some people, in other words, had advanced voluntarist interpretations of gender performativity and believed that Butler's book described identities that we took on at will. Such readings, of course, actually ran counter to the much more prescripted notion of gender performance that Butler laid out so carefully in the earlier book. Imagine my surprise then to find that drag kings, in New York at least, produced some version of the "bad reading" of Butler as their rationale for drag, performance.” (Halberstam 1997 108)
Once again the theoretical interpretation of gender performance does not connect or relate the everyday lived experience of those who are involved in the practicalities of ‘subverting’ gender performance, and that perhaps their practice of gender performance is not as subversive as Butler imagines.
More importantly Butler does not differentiate between the notions of performativity as a process of discursive production and performance as a specific type of self-presentation. A further key criticism that Butler acknowledges in her essay “Imitation and Gender Subordination” is that Butler’s work is high theory, language based and overcomplicated. This makes it distant and therefore removed from the practical everyday experience of the homosexuals (lesbians and gay men) who experience homophobia, abuse and aggression in the wider community, and implies that the theories of gender performativity are based and restricted to the world of academia without having any relevance to everyday life.
Nancy Fraser critiques Butler's "destabilization" argument from a Marxist perspective(Fraser 1997 P287), whereby she feels Butler does not address the historical perspective of gender performativity adequately in relation to the effects of capitalism and states that “In my account, then, injustices of misrecognition are fully as serious as distributive injustices.” (Fraser 1997 P281). This key criticism of not providing an adequate solution to the issues of gender identity in Butler’s work is raised by Judith Roof who also states:
“…such theorists deploy gender re-production and re-invention as a way to bring sex/gender systems into question, interrogating the correlations among productions of gender, desire, and sexual practice. This demonstrates in another way the ideological quality of sex/gender formations, again by focusing on the relation between gender's production and the stability of the institutions (such as heterosexuality) it underwrites. (Roof 2010 )P54
The criticism here is again based on the assertion that although gender practices are questioned by Butler, there is no offer of an alternative solution to issues raised by gender identities and sexualities, but rather these questions only go to reinforce the heterosexual institutions which are challenged by Butler.
Despite the criticisms and questions raised here, Butler’s work on gender performativity is crucial in raising important issues of gender performance and identiy. The performativity of gender can be concluded as providing a key link in theoretical feminist frameworks within the discourses of feminism, postmodernism and queer theory. Butler’s work on gender performance highlights the issue of the destabilisation of the categories of sex and gender and is anti-essentialist in nature as Butler highlights the problems of categories of woman or women. At the same time she deconstructs the binary oppositions of male female gender roles, and masculinity and femininity, yet she recognises the need for the label of ‘identity’ as a necessary ‘fiction’. With regards to queer theory butler highlights the deconstruction of binary oppositions such as heterosexual and homosexual, normal and abnormal, natural and unnatural and centre and margins. She provides a critique of the regulatory regimes and normalizing discourse in society that try to fix gender and sexuality. Instead Butler aims to provide a discussion on the deregulation and multiplication of sexualities, rather than providing purely ‘positive images’ of homosexuality which will assimilate homosexuality into a societal status quo. The theories of gender performance include discussion of the lesbian postmodern where ‘lesbian’ is a privileged sign of fluidity, destabilization, indeterminacy, and ‘gender trouble’.
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A science blog with Eric Berger
Spacewalk updates, first hour
4:45 a.m. I’m going to try live-blogging this, meaning you’ll need to refresh this page to get the most recent updates. I’m going to provide blow-by-blow coverage of the spacewalk with added commentary.
Right now the astronauts have just powered up their suits, marking the official beginning of the spacewalk.
4:53 p.m. The spacewalkers are about 224 miles above Earth, and the first one, Soichi Noguchi, just stepped out into space.
He said exactly what I probably would have said in the same place.
“Wow, what a view.”
And yes, I’m jealous.
5:01 a.m. Pretty mundane stuff so far — but boy is it important. The astronauts are tethering themselves to the orbiter.
They have two tethers, and if for some unexpected and very unfortunate reason they are cut loose from the shuttle, they also have a small jet pack strapped to their backs.
That gives them a shot at making it back to the shuttle. There is no capacity for the spacecraft or space station to go get them if they tumble away.
5:19 a.m. So far the imagery from the spacewalk hasn’t been great. It’s grainy and fuzzy, the kind of stylized picture a filmmaker might use to set a gritty scene apart from the rest of the movie.
5:28 a.m. Why are spacewalks dangerous?
The primary reason is the potential for an accident resulting from violent impact of a collision with space debris.
At an orbit of 200 miles or so above the Earth, where the astronauts are now, the speed objects are traveling is 7.7 km/s, or about 10 times the speed of a bullet fired from a gun.
This means the impact of even a grain of sand or fleck of paint is equal to that of a regular bullet fired on Earth weighing 100 times as much as the grain of sand.
Every space mission creates more orbiting debris, so this problem will continue to become worse for spacewalkers.
There’s also the emotional stress of trying to accomplish a number of difficult, non-routine tasks in a bulky space suit with these dangers.
In other words, the stakes are high.
5:40 a.m. Why are spacewalks difficult?
Because things never go as planned. Already the spacewalkers have had difficulty closing hatches and opening tool boxes.
The temperature changes by hundreds of degrees as the astronauts move in and out of view of the sun.
And it can be very dark one moment, and blinding the next.
Lasting more than six hours, they’re also exhaustive.
Maybe I’m not so jealous.
Categories: General
Eric Berger
Comments are closed. |
From Wikipedia, the free encyclopedia
(Redirected from Shaheed)
Jump to: navigation, search
"Shaheed" redirects here. For other uses, see Shaheed (disambiguation).
Main article: Istishhad
Quranic references[edit]
The Quranic passage that follows is the source of the concept of Muslim martyrs being promised Paradise:
In Hadiths[edit]
The importance of faith is highlighted in the following Hadith
Further more, Samura narrated
Death in warfare[edit]
Early modern usage[edit]
In the course of the 18th century, there were several wars of independence within the colonial territories of the Muslim World. Many of the soldiers who died during these conflicts were given the title Shahid upon their burial.[13]
20th century conceptions[edit]
Malcolm X, who was assassinated by the Nation of Islam in 1965 is considered to be one of the most prominent martyrs of the 20th century. The soldiers, clergy, and other individuals who died during the 1979 Islamic Revolution in Iran were regarded as martyrs and have often been buried in special martyrs' cemeteries. In the 1980–88 Iran–Iraq war, commanders of both the Sunni Iraqi and the Shi'ite Iranian forces in particular commonly used martyrdom as a source of motivation for their fellow combatants. Tens of thousands of Iranian youths—many motivated by the religiously-based ideas of Ayatollah Khomeini and the Islamic Revolution—volunteered to serve in the armed forces during the conflict, sometimes participating in human wave attacks against the Iraqis. Those who died in battle were considered martyrs.[14]
Twenty-first century jihadism[edit]
In contemporary jihadism, it has become common for Islamic militants to portray themselves as martyrs; especially the perpetrators of suicide bombings typically record "martyrdom videos" to inspire emulation in others.
Militants responsible for terrorism in the Gaza Strip and West Bank of Palestine have referred to their suicide bombers as martyrs. Whether suicide bombings are a valid practice of jihad has been disputed, as the Qur'an explicitly prohibits suicide.[15] However, it has been reported that 70 – 80% of Palestinians still support suicide bombing as an essential requirement for the eradication of the Israeli occupation in Palestine.[16]
In a martyrdom video from 18 January 2000, titled ’19 martyrs’, the hijackers in the September 11 attacks justify their beliefs and profess their last will and testament.[17]
Recent years[clarification needed] have seen many Islamic extremists use the term "Shahid" in their efforts to make "legitimate the use of violence, warfare, and terrorism" against Western groups of "unbelievers."[19]
As a consequence, the most prevalent use of the term in western media is with respect to Islamic terrorism. Nerina Rustjomi has argued, "Americans" have used a skewed perception of the Islamic "Shahid" and "Houri" to depict Islam as "a religion characterized by sensuality, violence, and irrationality."[20]
Other uses[edit]
A Muslim who is killed defending his or her property is considered a martyr.[21]
Over a period of time, the word "shahid" began to be used by non-Muslims such as Arab Christians to denote their own martyrs. In South Asia, Hindus adopted the word "shahid" as a synonym to the Sanskrit word "hutaatmaa" (हुतात्मा in Devanagari and হুতাত্মা in Eastern Nagari; हुत् and হুত্ hut = sacrificing, आत्मा and আত্মা aatmaa = soul, thus hutaatmaa = sacrificing soul/martyr), to denote Hindu martyrs. The Sikhs also adopted the word to denote their martyrs;[22] examples include Shahid Bhai Mati Das and Shahid Bhagat Singh.
Main article: Shaheeda
A woman is considered "Shahida" (شَهِيدَة šahīdah) if she dies during the fulfillment of a religious commandment. A woman can also be considered a martyr if she dies during childbirth.[23] There are examples of women fighting in war such as Nusaybah bint Ka'ab. The first martyr (male or female) in Islam was Sumayyah bint Khayyat, who was executed for her conversion to Islam. She died after Abu Jahl, an anti-Muslim leader of the Quraysh stabbed her in the abdomen.[24] Though her name is not common in the modern Muslim dialogue, ancient Islamic literature makes note of the events at the end of her life.[25]
See also[edit]
• Shahada, the Islamic creed
• Shahid (name)
• Jihad, an Islamic religious duty, meaning struggle
• Shahidka, a term for Islamist Chechen female suicide bombers
• Martyrdom video, a video recording the acts of Islamic martyrs
References & Footnotes[edit]
1. ^ "The word shahid (plural shahada) has the meaning of “martyr” and is closely related in its development to the Greek martyrios in that it means both a witness and a martyr [...] in the latter sense only once is it attested (3:141)." David Cook, Oxford Bibliographies
2. ^ Quran 3:169–170
3. ^ Quran 9:111
4. ^ Quran 22:58
5. ^ Sahih Muslim, 020:4694
16. ^ "Martyrdom." In The Islamic World: Past and Present. Ed. John L. Esposito. Oxford Islamic Studies Online. 5 December 2012. <>(subscription required)
17. ^ Popkin, Jim, and NBC News. "Video Showing Atta, Bin Laden Is Unearthed." MSNBC Digital Network, 1 October 2006. Web. accessed 5 December 2012.
18. ^ Reuters. "Afghans Describe Bin Laden as Al Qaeda's "No 1 Martyr"" Reuters, May–June 2011. Web. Accessed 5 December 2012.
21. ^ Sahih al-Bukhari, 3:43:660 |
Take the 2-minute tour ×
For me those are references to the same thing.
On Wikipedia there are references to both but I still don't see the difference. http://en.wikipedia.org/wiki/Cartesian_coordinate_system#Cartesian_space
Is there any difference? If yes, is there a simple way to describe it?
Note: I am a programmer so please don't be mean if it's obvious for you.
share|improve this question
2 Answers 2
up vote 6 down vote accepted
Point in Euclidean plane can be written in many ways: either using Cartesian coordinate system, or polar coordinate system. That is same point $p$ can be written in two ways... If we are saying Euclidean plane, It simply means that we are giving some axioms and using theorem based on that axioms. But if we are saying Cartesian plane, it means that with euclidean axiom we are giving some method of representing of points.
This means: Euclidean Plane means we have only some set of axiom
Cartesian plane means Euclidean plane+ One fixed method of representing points.
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Thank you. Now it's clear for me. – Aalex Gabi Feb 23 '12 at 9:39
The Cartesian system is Euclidean space with coordinates. The Cartesian Coordinate System unified geometry and algebra into one system of analytic geometry.
If you know MATLAB, A weak way of explaining it is:
ezplot('sin(x)'); %Euclidean
grid ON; %Cartesian
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Your Answer
|
Take the 2-minute tour ×
I'm using the ternary numeral system, i.e. numbers in base 3. There's a catch: The numbers I'm representing will never have a 2 as a digit. For instance, I use 0,1,10,11,100,101,110,111,... I.e. they look like binary digits, but they're really ternary numbers.
Now I'd like to know, for a random ternary number, in this form, of $m$ digits, what is the probability that the first (least significant) $n$ bits are all zero?
For $m=3$, we'd have the following numbers written out in base 3 (remember they only look like they're bits): 000,001,010,011,100,101,110,111. These correspond to the decimal values 0,1,3,4,9,10,12,13 respectively. So representing these in binary, they are 0,1,11,100,1001,1010,1100,1101 respectively. If I take $n=2$, I'd be finding the probability that the 2 least significant bits are all zero. Of the numbers in binary, 0,100, and 1100 have the 2 least significant bits as zero. So out of the 8 possible numbers that I have, 3 have this property. So the probability that I'm looking for is 3/8.
Now, I'm asking, for generalized $m$ and $n$ using this system, what are the probabilities?
share|improve this question
Wait, so you want to know about the binary expansion of ternary expansions with no digit equal to $2$? – Alex Becker Mar 31 '11 at 17:00
@Alex: Yes. I believe that there could be a very simple relation here, I just can't see it yet. – Matt Groff Mar 31 '11 at 17:08
My instinct is that your random ternary numbers, when represented in binary, will look just like random numbers. In particular their probability of ending in $n$ zeros should be about $2^{-n}$. – Michael Lugo Mar 31 '11 at 18:01
The $n$ least significant bits of a binary number are zero iff the number is divisible by $2^n$. So your question is equivalent to counting the number of ternary numbers for $c \cdot 2^n \leq 3^{m}-1$ with $c \in \mathbb{N}_0$ and every digit is $0$ or $1$. – Marc Gillé Mar 31 '11 at 19:30
Hmm...Proof that they are distributed close to randomly is more than acceptable. I think that difference calculus (summations) can give formulas, but it's getting complicated. Get a formula for bit i in number j of the corresponding binary value and call this f(i,j). Then, for number j, we can determine if the least significant bits are zero by taking the product of (1-bit) for the least significant bits, which gives 1 if all bits are 0 and 0 otherwise. Sum these products over the first 2^m numbers and that's the result. This seems a bit much, though. – Matt Groff Mar 31 '11 at 19:43
2 Answers 2
up vote 4 down vote accepted
Let $X(m)$ be the $\mathbb{Z}_{2^n}$-valued random variable $\sum_{0\leq k<m} \varepsilon_k\ 3^k \pmod {2^n}$ where $(\varepsilon_k)$ are i.i.d with $\mathbb{P}(\varepsilon=0)=\mathbb{P}(\varepsilon=1)=1/2$.
You want a formula for $\mathbb{P}\left(X(m)=0\right)$. Writing $$\sum_{0\leq k<m} \varepsilon_k\ 3^k =\varepsilon_0+3 \sum_{0\leq k<m-1} \varepsilon_{k+1}\ 3^{k}$$ we see that $X(m)$ has the same distribution as $\varepsilon +3 X(m-1)$, where $\varepsilon$ and $X(m-1)$ are independent. This suggests the following approach.
Define a Markov chain on $\mathbb{Z}_{2^n}$ that starts at zero, and when in state $x$ randomly jumps to one of $3x$ or $3x+1$. The probability you want is the $(0,0)$th entry of $P^m$ where $P$ is the transition matrix of the chain. For instance, here is the transition matrix for $n=2$, that is, in the case when we are working modulo 4:
$$P=\pmatrix{1/2&1/2&0&0\cr 1/2&0&0&1/2\cr 0&0&1/2&1/2\cr 0&1/2&1/2&0}$$
And here is its third power
$$P^3=\pmatrix{3/8&3/8&1/8&1/8\cr 3/8&1/8&1/8&3/8\cr 1/8&1/8&3/8&3/8\cr 1/8&3/8&3/8&1/8}.$$
We see your calculated value of $3/8$ in the top left corner. By diagonalizing the matrix we find that, for $n=2$, $$\mathbb{P}(X(m)=0)={1\over 4}+{1\over 4} 2^{\lfloor {(1-m) /2} \rfloor}.$$
Back to the general case. Since $3$ is invertible modulo $2^n$, the Markov chain is doubly stochastic (its column sums are all equal to 1) and so has the uniform distribution on $\mathbb{Z}_{2^n}$ as its unique invariant distribution. In the long run, all states are equally likely.
In short, $\mathbb{P}(X(m)=0) \to 1/2^n$ as $m\to\infty$.
share|improve this answer
I'm taking a generating function approach here. The numbers you are considering are those whose ternary representation contains a total of $m$ digits and have only 0 or 1 as digits. The numbers that are allowed in your ternary representation are essentially the powers of $x$ in the following function
\begin{equation} f(x) = (1+x)(1+x^3)(1+x^{3^2})\ldots(1+x^{3^{m-1}}) \end{equation}
The total number of such numbers is simply $2^m$.
We want to count the number of such numbers which have zeros in the n least significant bits in the binary representation. A number $k$ will have n zeros in the least significant bits of its binary representation only if $k$ is divisible by $2^n$.
In order to count this, we can use a trick involving the $2^n -$th roots of unity. I'll illustrate with an example.
For $m = 3, n=2$, we start with
\begin{equation} f(x) = (1+x)(1+x^3)(1+x^9) \end{equation}
The number of powers of $x$ with 2 zeros in the least significant digits in binary is the same as the number of powers of $x$ which are divisible by 4. Consider the $4^{th}$ roots of unity (I'll call them 1,$\omega$, $\omega^2$ and $\omega^3$). Then, the number of powers of $x$ which are divisible by 4 is
\begin{equation} N = \frac{1}{4}(f(1)+f(\omega)+f(\omega^2)+f(\omega^3)) \end{equation}
You get $N=3$ by evaluating the above expression and the probability is $\frac{3}{8}$. This method can be generalized to other values of $m$ and $n$ easily. This is essentially a mechanical approach that requires a reasonable amount of calculation to get the answer, but those calculations can be done easily using software like mathematica.
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Your Answer
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Take the 2-minute tour ×
Started to learn programming 2 months ago, in one of my little projects i encountered the need to generate permutations of list of objects. I knew that i'll find how to do this if i'll just searched for it, but i wanted to make one of my own, so i worked up and made my own permutation generator code:
def perm(lst, c = [], x = 0):
i = -1
g = len(lst) - 1
if x == g:
while i < g:
i += 1
if lst[i] in c:
del c[-1]
i = g
while i < g:
if x == 0:
del c[:]
elif g == x:
del c[-1]
elif len(c) > x:
del c[-1]
i += 1
if lst[i] in c:
x + 1
perm(lst, c, x + 1)
This is what it gives if i run it:
[0, 1]
[1, 0]
perm([1, 4, 5])
[1, 4, 5]
[1, 5, 4]
[4, 1, 5]
[4, 5, 1]
[5, 1, 4]
[5, 4, 1]
It works as i expected, but when i use bigger lists it take some time for it to generate all the permutations of the list. So all i want is hints on how to improve my code, only hints. Or if you can tell me what should i learn to be able to make a better generator?
Thanks in advance for all the helpers.
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6 Answers 6
up vote 2 down vote accepted
The best way to understand what is making your code slow is to actually measure it. When you attempt to guess at what will make something fast, it's often wrong. You've got the right idea in that you're noticing that your code is slower and it's time for some improvement.
Since this is a fairly small piece of code, the timeit module will probably be useful. Break the code up into sections, and time them. A good rule of thumb is that it's better to look at an inner loop for improvements, since this will be executed the most times. In your example, this would be the loop inside the perm function.
It is also worth noting that while loops are generally slower than for loops in python, and that list comprehensions are faster than both of these.
Once you start writing longer scripts, you'll want to be aware of the ability to profile in python, which will help you identify where your code is slow. Hopefully this has given you a few places to look.
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Thanks a lot, i don't know how to give credit, and i think that i can't cause i am not registered! I would love to see more of those answers, i really appreciate your help. – justesting Jul 26 '10 at 17:01
Registered, and thanks. Your answer alongside mfukar answer gave me a new level of understanding on the subject. – justesting Jul 26 '10 at 17:34
Generating permutations is often done recursively. Given a list of 5 items, the permutations can be created by picking each of the 5 elements in turn as the first element of the answer, then for each of them permuting the remaining 4 elements, and appending them together.
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>>> from itertools import permutations
>>> list(permutations(range(2)))
[(0, 1), (1, 0)]
>>> list(permutations([1, 4, 5]))
[(1, 4, 5), (1, 5, 4), (4, 1, 5), (4, 5, 1), (5, 1, 4), (5, 4, 1)]
In the docs there is Python code available for legacy versions.
A note re your code, x + 1 doesn't do anything as you're not assigning result of that expression to anyting.
share|improve this answer
Thanks, but if you really read my post till the end you would notice that i am not searching for a way to do it, but for a hint on how to improve my own code. Or what should i learn to be able to improve it. – justesting Jul 26 '10 at 16:34
@just: do you want to have your code to run in a constant time no matter input? What is your aim? – SilentGhost Jul 26 '10 at 16:36
@justesting: The way to make it better is to use the standard library that already has it implemented. – Daenyth Jul 26 '10 at 16:36
I certainly understand your desire to learn, but this answer definitely deserves credit for helping you learn that python comes with a best way to do things. +1 – Wilduck Jul 26 '10 at 16:37
Also, you can just read the code in the standard library and learn from that. In the case of itertools, you don't even have to look at the source - the docs have it, too: docs.python.org/library/itertools – Tim Pietzcker Jul 26 '10 at 16:47
OK, for large lists, a recursive solution will take more and more time & space, and eventually reach the recursion limit and die. So, on the theoretical side, you could work on ways to save time and space.
Hint: tail-recursive functions (such as the one you've written) can be rewritten as loops
On a more practical side, you may consider the use cases of your function. Maybe there's somebody who doesn't want the whole list of permutations at once, but a single one each time - there's a good opportunity to learn about yield and generators.
Also, for something generally not directly applicable to your question: k-combinations and multisets are closely related to permutations. Perhaps you can extend your function (or write a new one) which will produce the k-combinations and/or multiset the user asks for.
share|improve this answer
Another facinating answer, Thanks A LOT! – justesting Jul 26 '10 at 17:04
The first thing I notice is that the code is hard to understand. The variable names are completely meaningless, replace them with meaningful names. It also seems like you're using i as a loop index, which is almost always bad style in python, because you can do for item in list:.
share|improve this answer
This is not really performance related, but there is a glaring bug in the code. Using a list as a default parameter does not do what you think it does - it will create one list object that will be shared by every call to perm(), so the second time you call perm you will have the value in c of whatever it contained when the last call finished. This is a common beginner's error.
You also say "when I use bigger lists it takes some time to generate all the permutations of the list". What did you expect? The number of permutations is equal to the factorial of the length of the list, and that grows big fast! For example a list of length 20 will have 2432902008176640000 permutations. Even the most efficient algorithm in the world is "going to take some time" for a list this size, even if it did not run out of memory first. If our hypothetical algorithm generated a billion permutations a second it would still take 77 years to run. Can you be more specific about the length of lists you are using and how long it is taking?
share|improve this answer
Thanks for the info, I'll appreciate it if you'll be able to explain the glare thing. Anyway currently my code can handle lists of length 8 in 1second or less, but when i try to generate permutations of list of length 10 it takes 25 seconds or so. But i think that i have a general idea that will improve my code. – justesting Jul 26 '10 at 22:21
Ok i understood what you meant. Changed it to perm(lst, x + 1), Thanks for pointing this out. – justesting Jul 27 '10 at 8:23
Ok timed it and it takes more than 25 seconds with a list of length 10, it takes 59 seconds or so. Anyway working on a better code right now. – justesting Jul 27 '10 at 8:32
10! is 3628800, so if it takes 59 seconds then it is producing 61505 permutations per second. most of this time is probably spent allocating and freeing memory in your list - it is far more efficient to use a generator to return the result one at a time instead of in a huge list. It will also use far less memory. – Dave Kirby Jul 27 '10 at 20:06
Your Answer
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Brown Bullhead - Ameiurus nebulosus
Also known as: Brown Catfish, Common Pout, Squaretail Catfish
The brown bullhead is native to the eastern United States (both sides of the Appalachians) and southern Canada, but has been widely introduced elsewhere. It occurs in larger and deeper bodies of water than other bullheads.
The brown bullhead may vary from yellow-brown or chocolate brown to olive, gray, or bluish-black. The sides are often lighter and may be mottled with brown blotches and the belly is yellow or white. Very round brown bullheads are jet black and are often mistakenly believed to be black bullheads (A. melas). Coloration is not a dependable distinguishing characteristic with this species and it is important to observe other physical characteristics in order to make a positive identification. The brown bullhead and the yellow bullhead (A. natalis) have sharp, tooth-like serrations along the rear edge of the pectoral spine, found at the top of the pectoral fin. The black bullhead lacks any such serrations or has only extremely weak serrations that are negligible by comparison. In the brown and black bullheads, the tail is squarish (truncate) or slightly emarginate, while in the yellow bullhead the tail is slightly rounded. The brown bullhead is frequently mottled while the yellow is never mottled and its chin barbels are yellow, buff, or pale pink in color (the upper barbels are light to dark brown). In the brown bullhead all of the barbels are dark brown to nearly black, but in some cases there may be pale yellow or white at the base of the chin barbels only.
The brown bullhead is relatively small at around 5 lbs compared to other similar species, but is an extremely popular fish with anglers. The meat is firm, reddish to pink, and of excellent quality and taste. It is also a popular fish stocked in farm ponds.
Shoreline Shallows
Sunken Objects
Spring Holes
When water boils up from the bottom of the lake, it creates a spring hole. In the summer, deep-water fish are attracted to these holes because the water coming out is always cooler relative to the surrounding waters. Even when the hole is not in deep water, spring holes can attract unsuspecting, deep-water lunkers.
Inlets and Outlets
All natural lakes are fed by a river or a stream of some sort. So they have inlets and outlets for the water. Wherever there is incoming or outgoing water, there’s going to be a lot of food and a lot of fish.
Gradual Shores
Like any structure that tilts gradually down and into deeper water, a gradual-sloping shoreline can provide plant food, attract fish and create a path out of and back into deeper water. However, a really gradual slope will create a large expanse of shallow water that will not attract fish.
Open Water
Sometimes, in early spring and late fall, when there’s very little vegetation anywhere, baitfish will roam open lake waters in search of plankton. During those times, you can look for small fish on the surface in the open water. If you see a bunch of small fish, it’s a good bet larger fish are lurking below.
Piers, Docks and Pilings
Holes are glacially formed basins that are lower than the rest of the lake. Water in these holes is cooler, attracting deep-water fish on hot, summer days. You’ll need a topographical map to find them.
Walkways and Bridges
Overhanging Trees and Bushes
Points and Break lines
A point extends out from the shoreline and slopes gradually down and into deeper water. It’s a good place to fish. But a point with a quick drop-off or one that doesn’t extend into deeper water isn’t a good place to fish.
- The sloping-out formation of a point creates a break line.
- A break line draws fish from deeper water to shallow water in search of food.
- Fish the point of the point and the corners of the point (the part that curves back into the shore).
Inside Turns and Coves - The Opposite of a Point
Rocks are structure. They provide fish with shelter, cover, food and a possible place to mate. Remember, fish structure. If the rocks are in deeper water or on the edge of deeper water, they provide an even better place to fish. Just avoid snagging your bait on the rocks.
Cliffs and Steep Shore Banks
Freshwater Lakes and Ponds
Current Edges
Rock and Boulder Pockets
Dams and Falls
Fishing Methods
Bait Casting
Drift Fishing
Spin Casting
Still Fishing
Bait & Lures
Bread or Dough Balls
Bread and dough balls make for excellent baits for bottom feeding fish. The bread or dough leaves a nice scent trail in the water that can be detected by bottom dwelling fish suck as catfish and carp. Any bread or dough will work but if making your own dough, make sure the dough is nice and firm so that it will remain on the hook when submerged in water. When using a piece of bread, add a little bit of moisture to the bread by chewing on it or splashing a small amount of water over the piece. Shape the bread or dough into a compact round ball and bury your hook in the ball so that only the hook tip sticks out.
Cut Bait
Minnows and Nightcrawlers
For still fishing with a bobber, hook the minnow through the back just in front of the dorsal fin. Take care not to damage the spinal cord. The key is to keep the fish moving on its own.
Tricks and Tips for Minnows
Worms are a good bait for nearly all freshwater fishing. You can find enough worms for fishing from a few shovels of dirt in your garden or from a shaded, damp area. Worms can also be purchased in fishing tackle stores and bait shops. For walleyes and bass use earthworms or night crawlers.
For pan fish, sunfish and trout use smaller manure worms. You can find them in cattle and horse pastures.
Trick and Tips for Worms
To prevent smaller fish from nibbling the worm without biting down on the hook, you can use just a piece of the worm.
If you have small worms, thread the hook through the side of the worm at several places along its body. For bait-stealing fish such as sunfish, thread the worm on the hook until the hook is completely covered. |
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Bako National Park
From Wikitravel
Revision as of 10:51, 29 September 2013 by Malaysia-asia (Talk | contribs)
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Proboscis monkey
Bako is the oldest national park in Sarawak, established shortly before Malaysia achieved full independence in 1957
Bako consists of coastal cliffs and rolling hills, and boasts fine sandy beaches surrounded by jungle. Coastal erosion has produced interesting sea stacks and rock formations.
Flora and Fauna
In particular, Bako is famous as a home to around 150 of the highly endangered proboscis monkey. Macaques are more fearless as well as more common, and thus much easier to spot. Another distinctive mammal indigenous to Borneo is the bearded boar. The common monitor lizard, growing up to 2m long, is the largest of the park's many types of lizard; flying lizards may also sometimes be spotted
Wildlife is most active just before dusk, which means that an overnight stay may be needed to fully appreciate it.
Bako contains almost every type of vegetation to be found in Sarawak, including highly distinctive carnivourous plants. There are seven distinct types of ecosystem: beach vegetation, cliff vegetation, heath forest (kerangas), mangrove forest, mixed dipterocarp forest, grasslands vegetation (padang) and peat swamp forest
Pitcher plant
Get in
The journey to Bako has two stages; the first stage can be made overland but the park itself is reached only by boat.
A bus ride from Kuching to Bako Market takes about 45-60 minutes (red public bus number 1, originating from the wet market) and costs RM3.50 each way. Buses leave to/from Bako about once every hour starting from about 7AM from Kuching and finishing about 6PM from Bako, but the schedule is not firm. Schedule as of June 2013: Kuching->Bako every full hour 7:00, 8:00 ... 17:10, Bako->Kuching at half past every hour 6:30, 7:30 ... 17:30.
The other travel option is by minivan, which departs from the same location as the bus throughout the day. Minivans depart when full, or when the waiting passengers offer the driver enough money. A minivan can be chartered for around RM30, and seats 5-7 people. They can reach Bako in half the time of the public bus. Note that the minivan driver may try to mislead you, claiming that the last bus to Kuching will not show up. In such a case, politely ask him to wait until 17:30 and see.
Hotels and tour operators also offer regular shuttle buses; as a pricier but more reliable alternative.
When you arrive at the Bako Market right in front of the jetty/visitor center, register, purchase your entrance ticket, and buy your boat ticket (RM94 round trip per boat, max. 5 passengers). The 20 minute ride on small motor launches is all part of the Bako experience as you pass through stunning scenery, but it isn't for the faint hearted. Depending on tides, you may either be deposited at a small jetty on the northern end of the headquarter's beach or on the beach opposite them (take your shoes off and prepare to wade).
Tell your boatman when you plan to return and he'll wait for you at the dock. Note that the boatmen are a small, close-knit community and so other boatmen are likely to refuse to take your group if you are waiting for a previously agreed pickup, even if he is late. Departure times might depend on the tides (boats do get stuck at low tide), and the weather, as the small speedboats are ill-suited to stormy conditions.
As of June 2012, a new two-tier pricing system is in place. Foreigners have to pay doubled entrance fees, compared to Malaysian nationals.
Foreign Adult (single entry): RM20
Foreign Child/Senior (single entry): RM7
Get around
Small boats similar to those that take you to and from the park wait on the beaches at busy times of day and can be chartered to take you to other beachside destinations. A boat pick-up can also be arranged to help ease the return journey from some of the park's longer trails that finish on beaches. The following prices are for a one way trip from Bako NP HQ, per boat: Teluk Paku RM18, Teluk Pandan Kecil RM35, Tanjong Rhu RM47, Teluk Tajor(waterfall) RM105, Pulau Lakei RM164, Teluk Keruin RM250. And you'll need to double the price for a return trip.
Pulau Lakei, some distance offshore, can only be reached by boat.
You can also see the seastacks and a lots more.
• Bearded Pigs. Another highlight here is the very unique Bearded Pig which can be seen walking around the park grounds, beaches and sometimes around your chalet area. Most of them are very friendly but it is not recommended to approach them or touch them. Photos for the unique Bearded Pig Pictures taken at Bako National Park: []
The Seastacks
* ==Do== Walks radiate from the centre offering a variety of difficulties in the heat and humidity and provide access to the habitats of the wide range of animal, bird and plant life in the park. The hikes are over some pretty rugged terrain for the most part, with lots of exposed tree roots and vegetation sometimes blocking trails that are less frequented. * Paku trail. has the distinct advantage of being both relatively short and flat and offering one of the best opportunities to see the park's wildlife. It finishes at an attractive beach; one of the colonies of proboscis monkeys lives on the headland above * Tajor trail. takes the visitor through varied terrain, including hilltops with extensive views, before finishing at a small but attractive waterfall, with calm pools that are safe for swimming in * Limau trail. Continuing onwards from the Tajor train, the park's longest and most arduous trek ends on a beach, though by the time you've scrambled down to it it may be too late to enjoy; it's possible to arrange to be picked up by boat from the beach to save your weary legs further punishment; ask the boatmen at the jetty if they could pick you up at Limau beach because sometimes the sea is too rough for them to reach Limau; please inform the park staff about your intention to do the Limau/Kruin trail as there have been cases where trekkers get lost or couldn't continue due to exhaustion * Lintang trail. A circular loop taking the trekker through all the park's types of vegetation in half a day. Nice sightseeing. With a little negotiation, a boatman will take you to nearby Pulau Lakai, a small island just off the mainland. The views on the way here are spectacular and it's special to have an island to yourself for a day. *For maps and full details of the trails in Bako national park, see: []. ==Eat== There is a local cafeteria that serves breakfast, lunch and dinner for about RM5 - 7 as well as cold can drinks for RM2.50, and 1.5l water bottles for RM3.50. There are no cooking facilities within the lodges. ==Drink== Visitors to the park should ensure they carry large quantities of water with them; trekking in subtropical rainforest is thirsty work. If you're looking for nightlife you should probably arrange to be somewhere else in the evenings. The cafeteria has a variety of drinks including beer and soda. ==Sleep== There are bungalows for rent at the park headquarters. A stay of a night or two is highly recommended to experience the full diversity of Bako, although accomodation can be stuffy and may have some mold growing on the ceilings, and expensive accommodation is entirely absent. The city of Kuching offers a much broader range of accommodation and the luxury of air-conditioning ===Camping=== There is a designated campsite behind the park headquarters; bring your own equipment. RM5 per person. Beware of the monkeys, though, as they have been known to rip into tents to take food and belongings. ===Budget=== * Hostel, (park headquarters), +60 (0)82 248088, [2]. 4 bed dorms with shared bathroom RM15.90 per bed; RM 42.40 per room. * Lodge, (park headquarters), +60 (0)82 248088, [3]. Each room contains 2 single beds; each lodge contains 2 rooms RM53.00 per room; RM 79.50 per lodge. (,2 nights) * Chalet, (park headquarters), +60 (0)82 248088, [4]. Each room contains 3 single beds; each chalet contains 2 rooms RM106 per room; RM159.00 per chalet. ==Stay safe== Visitors are advised to stick to the marked trails, and visitors attempting the longer trails are required to register their arrival and itinerary at park headquarters. Read the estimated times the park suggests you allow for each trail and ensure that you allow enough time to return to park headquarters - or else arrange a meeting time at a selected beach with the boatman. Virtually all of the trails are unsuitable for people suffering from limited mobility. Some parts of trails are negotiable only by wooden ladders and rickety bridges and boardwarks. Judging by the huge number of people passing through, these are better maintained than it might appear, but you'll still want to tread carefully Saltwater crocodiles (Crocodylus porosus) may be found near river mouths and in mangrove swamps. Beware of jellyfishes, cuttlefishes and stingrays when you go swimming in the sea. ==Get out== *Kuching, the regional capital and transport hub, is the nearest town of interest. *Kubah National Park offers more hillside trekking options *The Santubong Peninsular offers more sandy beaches and coastal jungle, with a much classier choice of accommodation
Destination Docents
In other languages |
Mily Alexeyevich Balakirev
Russian Born 02 Jan 1837 Died 29 May 1910
In the second half of the 19th century, Balakirev was the guiding spirit of a group of Russian ‘nationalist’ composers called the Moguchaya Koochka, literally "the mighty handful", but better known in English as the Mighty Five, which included César Cui, Mussorgsky, Borodin and Rimsky-Korsakov.
Balakirev was the only one of the group to begin as a professional musician, though he suffered periods of extreme poverty.
Born in Nizhny-Novgorod in 1837, the son of a minor government official, he received his first music lessons from his mother.
Study at the Alexandrovsky Institue and University of Kazan followed, and in 1855 he embarked on a musical career, playing the piano and composing. An introduction to Glinka prompted a lifelong dedication to the older composer's music, with Balakirev editing and publishing Glinka's complete works.
Though idolising the Western composers ChopinSchumannBerlioz and Liszt, it was Glinka who provided him with the inspiration to use folk song in his composition. As early as 1862, Balakirev spent time in the Caucasus collecting folk tunes.
His success as a composer was intermittent, largely owing to his irascible personality and a tendency to make enemies as a result of his overwhelming enthusiasm and intolerance of other ideas.
As director of the St. Petersburg Free School of Music he was in particular opposition to the Germanic-influenced institutions (the Conservatory and Russian Musical Society).
In 1871, Balakirev suffered a mental crisis and from 1872 to 1876 took no part in musical life. For a short period of time he took a job at the Warsaw Railway in the goods department.
Gradually he resumed his musical life and, after retiring from the Imperial Chapel in 1895 with a large pension, was free to resume composition. He died from pleurisy in 1910.
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63 Cards in this Set
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What is Mutual Assent?
To constitute mutual assent, which is the first requirement of a contract, the parties must manifest to each other their agreement to the same bargain. This is done in the form of an offer and acceptance.
How does the court determine if there is mutual assent to the bargain?
The courts apply an objective test that asks whether a RPP in the shoes of the offeree would believe if he accepted to the proposal of the offeror a contract would be complete and no further negotiations would be necessary to bind both parties.
Is the subjective state of the parties necessary to determine mutual assent?
Parties should be able to rely on the obvious and apparent intentions and not have to rely on the secret thoughts of the other party. This is fundamental in achieving secure business transactions that protect a RPP's expectations on relying on the promise.
However, while subjective intent is irrelevant - why would the court allow testimony about a person's thoughts regarding the contract?
As stated in Kabil Developments Corp v. Mignot, a party can testify to what he thought he was doing b/c words are not everything and a fact-finder might believe that what a party thought he was doing would show in what he did.
In determining mutual assent, what is a question of fact for the jury and what is a question of law for the judge?
If words/actions of the parties are ambiguous, the question of their intention is a question of fact for the jury. However, whether those actions would lead a RPP to believe a contract was made is question of law for the judge.
What is the effect of written stipulations denying intention to contract in employment handbooks?
They are either: (1) of no consequence b/c the disclaimer was not conspicuous and wording of the K created reliance (McDonald v. Mobil Coal Producing) or (2) treated as an offer to negotiate (Kari v. GM Corp)
What is the effect of an indefinite offer and why?
An offer the lack essential components is treated as an offer to negotiate b/c it would be too difficult to calculate the damages.
What special protection to suppliers have in making offers?
Supplies offers are always considered "offers to negotiate" because the need to be able to accept/reject offers based on the amount he can supply. (Moulton v. Kershaw - offer to supply indef. amt of salt is offer to negotiate)
What of an agreement w/a material term left for future negotiation?
An agreement w/a material term left for future negotiation is unenforceable. (Joseph Martin, Jr. Delicatessen v. Schumacher - Option to renew lease at a “price to be agreed upon” after five years. B/c the price is not agreed upon, there is no contract for renewal of the lease.)
How do courts circumvent indefiniteness of a contract under the UCC?
Under UCC§2-204: (1) if the parties intended to K and a remedy can be fashioned OR (2) if the code's gap fillers eliminate the indefiniteness.
What are the gap fillers used by the UCC to eliminate the indefiniteness of an offer to contract?
§ 2-305: If PRICE is omitted or left open, the price is “a reasonable price at the time set for delivery”
2-308: If PLACE OF DELIVERY is omitted, it is the seller’s place of business unless the goods are known to be elsewhere at the time of contracting
§ 2-309: If the TIME OF SHIPMENT or delivery is not specified, it is a “reasonable time” after contracting
§ 2-310: If TIME FOR PAYMENT is not specified, payment is due at the time and place where the buyer is to receive the goods
Does the contemplation of a later written contract w/future negotiations constitute a contract?
No (Empro Mfg. Co. v. Ball-Co, Mfg. Inc.) HOWEVER - if the parties have entered into a valid K, it will not be voided b/c of their intent to have the agrmt formally written up as a memorial. RPP is test.
How do calculate damages for indefinite contracts?
1. If contract is not enforceable, but plf detrim. relied on supposed contract, plf can recover reliance damages under PE (Wheeler v. White)
2. If contract IS enforceable, but expectancy damages are too speculative (the terms are indefinite), plf can recover reliance damages
3. Quasi contract – restit. damages
What of the contract if there is a material misunderstanding by both parties to a key element?
Where both parties have a material misunderstanding (no meeting of the minds) to a key element to a contract, the contract is defeated. Peerless Case (2 boats named the same)
If the terms of the contract are ambiguous, but both parties have a meeting of the minds, can the contract still exist?
There will be a contract ONLY IF IN FACT both parties attach the SAME MEANING to the ambiguous words.
What if one party has knowledge of what the other party thinks of the contractual terms?
A contract will exists where one party knows or should have known of the other parties interpretation, there is a contract as ignorant party thinks (Flower City Painting v. Gumina Constr. Co - guy didn't know trade practices - could haven't been aware of other parties intentions)
What is the general rule regarding an offeror's right to control offer?
The offeror has the power to control how long the offer lasts by specifying duration or condition. (Caldwell v. Cline - Offer sent by letter and lasts for 8 days. Offeree accepts within 8 days of receiving letter. Offeror states that it was supposed to be accepted w/in 8 days of mailing. Crt held no - 8 days to receive.
If an offeror requests a return promise, and the promisee renders performance of that which was requested to be promised within the allowed time is the contract?
The promisee's performance will constitute acceptance and the promisor must perform. (Allied Steel & Conveyors, Inc. v. FMC - FMC sent waiver for liability to Allied and suggested it be returned, Allied began work and someone was injured. Crt held contract was established).
How does the UCC deal with reasonable acceptance?
UCC § 2-206(1)(a) – Unless otherwise unambiguously indicated by language or circumstances (a) an offer to make a contract shall be construed as inviting acceptance in any manner and by any medium reasonable in the circumstances.
Difference between acceptance for unilateral and bilateral contracts?
Unilateral contract is generally accepted by beginning performance, whereas bilateral contract is generally accepted by a return promise.
What are the offeree's options for acceptance when the offer is ambiguous?
Old times - it was assumed to be a bilateral contract - return w/promise.
Modern law - R2K § 32
oGives the offeree the choice of unilateral or bilateral contract.
1. If the offeree starts performance, unilateral.
2. If the offeree makes return promise, bilateral. (Davis v. Jacoby – Crt found that the whiteheads offered a bilateral contract which was acceptance upon the promise to take care of the family in exchange for promise to care for family.)
Can an offeror revoke an offer to enter into bilateral contract?
An offeror has right to revoke offer prior to acceptance. An offeror can revoke even if he expressly promises not to, or gives a definite period during which offer is to remain open. Once an offeree has been notified of the revoke, he cannot then accept.
When does acceptance of a unilateral contract take place (aka - when can an offeror revoke a unilateral offer)?
1. Accept. occurs at complete performance so revocation can occur anytime prior to complete performance
2. Accept. occurs at the beginning of performance so revocation cannot occur anytime after performance begins.
3. Beginning performance creates an option contract.
What are the risks of have a unilateral contract created at the completion performance?
Risky for performer b/c he may get ½ way through before offeror revokes. However, performer may be able to sue for partial performance under promissory estoppel or quasi K. (Petterson v. Pattberg
Held that the offeror can revoke a unilateral offer at any time, even immediately before acceptance by the offeree—even if the offeror sees the offer coming to accept)
What are the risks of having a unilateral contract created at the beginning of performance?
Risky for performer b/c he can’t back out once he start w/out breaching.
What are the risks of creating an option contract upon beginning of performance?
Lease amount of risk - places both parties in a position where they can't back out.
R2K FOLLOWS THIS. (Brackenbury v. Hodgkin - Mom can't deny daughter whose is taking care of her the promised land just b/c they are arguing)
How can an offeree's power of acceptance be terminated?
(1)(a) rejection or counter-offer by the offeree, or (b) lapse of time, or
(c) revocation by the offeror, or (d) death or incapacity of the offeror or offeree
(2) in addition, an offeree’s power of acceptance is terminated by the nonoccur. of any condition of acceptance under the terms of the offer
Generally, the offeror can revoke the offer at anytime. However, there are situations where the offeror cannot revoke the offer. What are those situations?
1. Payment of Consideration
2. Reliance on the Offer (Exceptions to Promissory Estoppel)
3. Firm Offer Rule for the Sale of Goods
4. Reliance During Negotiations
The offeror does not have the ability to revoke the offer when consideration has been paid (creates option contract). What are the characteristics of this consideration?
1. Consideration can be nominal
(Thomascon v. Bescher)
2. Consideration does not have to be rec’d (Smith v. Wheeler)
3. R2K: Option Contract
(1) An offer is binding as an option contract if it(a) is in writing and signed by the offeror, recited a purported consideration for the making of the offer, and proposes an exchange on fair terms within a reasonable time; OR (b) is made irrevocable by statute
Can promissory estoppel apply to an offer to enter into a bilateral contract?
Promissory estoppel does not apply to enter into a bilateral contract since the action expected to be induced is acceptance. (James Baird Co. v. Gimbel Bros., Inc.)
Generally promissory estoppel does not apply to an offer to enter into a bilateral contract. However, there are two exceptions - what are they?
1. If the offer is stated in such a way that a promise is to hold the offer open can be implied, the implied promise removes the ability of the offeror to revoke the offer, which if accepted creates a contract. (Minority) (Drennan v. Star Paving Co.)
2. If the offeror should expect his offer to induce action and it does, then an option contract is created. Damages are limited to reliance or restitution (SEE R2K § 87)
An offeror cannot revoke an offer to enter in a contract when dealing with the UCC firm offer rule. What does this constitute?
UCC § 2-205 Firm Offer Rule
A signed, written offer by a merchant to buy/sell goods, which states that it will be kept open, is irrevocable for whatever period of time is stated in the offer (if no time stated – then reasonable time SO LONG AS IT DOES NOT EXCEED 3 MOS)
(E.A. Coronis Assoc. v. M. Gordon Constr. Co.)
What are the element of promissory estoppel as applying to offers?
Elements of Promissory Estoppel as Applied to Offer
1. Promisee rec’d clear and defining offer
2. Promisor could expect reliance of substantial nature
3. Actual reasonable reliance on promisee’s part
4. Promisee suffers detriment
Does reliance on promises made during negotiations prevent an execution of an offer?
Promissory estoppel can apply to promises made during negotiations that do not rise to the level of an offer that. The effect is to remove contract defenses and limit recovery to reliance and restitution damages. (Hoffman v. Red Owl Stores)
What is the effect of a counter offer on an original offer?
A counter offer kills the original offer.
What is the effect of deviant terms in an attempted acceptance of an offer?
Deviant terms in an attempted acceptance constitute a counter offer which rejects and kills the original offer.
What are special considerations to the counter offer rule that destroys the original offer?
1. Request for info is not a rejection or counter-offer
2. If offeror stipulates that offer will be open until a given date, the offeree rejects, the offer is NOT terminated, it remains open until the specified date.
3. If an offeror says he will entertain counter-offers, tender of counter-offers does NOT terminate original offer.
4. If offeree makes counter-offer and say she’s still considering original offer, orginal offer is NOT terminated.
5. Offeree may make inquiry and then accept original offer.
6. Original offer still good if offeror renews it after counter-offer.
The general rule of counter offers is altered for sale of goods, what is the exception?
Deviant terms in acceptance are NOT counter-offers, but are proposals for modification, requiring additional acceptance only for those deviant terms; UNLESS acceptance is expressly conditioned on assent to the deviant terms.
What does the UCC state for the exception to counter offers for sale of goods?
UCC § 2-207: (2) When the contract is between merchants, additional terms become part of the contract unless:
(b) they materially alter it; or
(Idaho Power Co. v. Westinghouse Electric Corp. UCC § 2-204 (3). Conflicting terms cancel each other out. As long as damages may be calculated, courts will imply terms using commercial industry standards.
What does acceptance occur for shrinkwrap cases (aka - cases where product is delivered before learning all terms of K)?
For contracts where money is paid upfront and product delivered prior to learning all terms of the contract, the courts treat the seller as inviting acceptance by conduct and the buyer’s use of the product after learning of the additional terms as the acceptance. (UCC § 2-204) For shrinkwrap cases, buyer has the opportunity to inspect the goods and return them if he does not agree to terms of the contract (UCC § 2-206).(ProCD, Inc. v. Zeidenberg)
What is the exception to acceptance/counter offers is defined by the mailbox rule?
Acceptance is valid when sent; rejections and counteroffers are valid when received. Places risk on offeror b/c he doesn’t know whether offer accepted or not. EXCEPTION: 1. option contracts - acceptance until rec'd; or 2. bilateral contracts where receipt of ltr is integral for legal effect (states in K)
When does silence constitute acceptance of an offer?
Silence is acceptance if (1) the offeree takes services when he could have rejected them and knew they were made for compensation, (2) the offeror gave reason to know silence would be acceptance and the offeree intended silence to be acceptance, or (3) prior dealings imply the same will happen again. R2C 69 (Hobbs v. Massasoit Whip Co. - guy kept eel skins like normal, but decided he didn't want them -- too late)
Does silence constitute acceptance for gratuitous services?
No, because there is no compensation for gratuitous services, acceptance must be expressed. (Morone v. Morone - non married couple broke up - lady says man orally promised to take care of her, so she stayed with him)
What is the parol evidence rule?
When parties to a contract create a contract with the intent that it be their full and final agreement, any other expressions (oral agreements, actions of parties, or another written document) made prior to or contemporaneous w/the writing may NOT be used to vary the terms of the written contract.
What does the parol evidence rule have to do with integration?
The parol evidence rule only applies to those contracts that are fully integrated, meaning that the contract is a full and final expression of contractual terms between both parties.
What is the jury/judge's role in determining admissibility of parol evidence?
Decisions regarding parol evidence are made by the judge. The only question presented to a jury will occur if there is a factual dispute on what the parol evidence is.
What are the exceptions to the parol evidence rule?
1. Mutual Mistake
2. Oral Conditions Precedent
3. Partial Integration
4. Interpretation
5. Fraud in the Inducement
7. Collateral agreements
How does a mutual mistake affect the parol evidence rule?
Parol evidence may be used to reform the contract when both parties made the same mistake in the written contract. However, if the mistake is unilateral (only by one party - parol evidence is inadmissible) Hoffman v. Chapman - draftsman made a mistake in lot description - not either parties' fault, both knew what the true intention was
How do oral conditions precedent affect the parol evidence rule?
Parol evidence may be used to indicate that the parties did not intend to have a contract until some condition was satisfied. However, this evidence CANNOT vary the terms of the written agreement. (Long Island Trust Co. v. International Inst. for Packaging Educ., Ltd. - oral agreement regarding all signators be present for loaning additional $ allowed b/c it did not contradict w/terms of K)
Can parol evidence be allowed in partial integrated contracts?
Parol evidence may be used if teh written contract was not intended to be the entire deal between the parties, using the RPP standard. Hatley v. Stafford - tenant had buyout clause, but wheat increased value - was allowed to recover b/c timing issue was not included in K and it was obv. imp - NOTE - integration clause serves the function of showing that the written K was intended to be the final deal
What does parol evidence serve in interpreting ambiguous terms of a contract?
Parol evidence may be used to explain terms if the written terms are ambiguous. Cannot vary the terms of the writing , but rather to show what the parties meant by the words in the writing. MODERN TREND - allow parol evidence to show subj. intent of parties even when words are "plain" WHY - no language is infallible - even Judge might have a diff understanding (TRAYNOR) Pacific Gas & Elec. Co. v. GW Thomas Drayage & Rigging Co.
How does the UCC interpret the parol evidence rule?
UCC Rule § 2-202 - Parol evidence may be used to explain or supplement the written k, but not to contradict it by pointing to:
1. Usage of trade
2. Course of dealing
3. Course of performance
NOTE - Traynor's interpretation basically uses the UCC view but expands for doc susceptible to that view) ALSO does not presume fully integrated k unless parties intend to be so
How does fraud interact w/the parol evidence rule?
Parol evidence may be used for at tort action. (Lipsit v. Lipsit - owner got guy to work for him promising he would have share of business when that wasn't true) Damages: • Majority = reliance (an integration clause negates the reliance element for fraud in the inducement)Minority = restitution
What are the reqs for fraud in the inducement (so parol evidence can apply)?
Elements of Promissory Fraud (Fraud in the Inducement):
1. Intent (scienter)
2. False representation of material fact
3. Deception/Reliance
4. Damages/Injury
How does the parol evidence rule effect collateral agreements?
Common law presumes the written k is integrated, and parol evidence cannot be used to vary its terms UNLESS:
1. It is in the form of a collateral agreement, IE – w/out separate consideration
2. It doesn’t contradict the terms of the written agreement; and
3. It ordinarily is NOT a type of agreement that would have been embodied in a written contract of that type.
(Mitchill v. Lath - destroying ice house is void by #3 b/c it should have appeared in the written k)
What is the duty to a party to a standardized form and why?
A party to a standardized form (of any agrmt for that matter) has a duty to read it before signing so that the signing means the k was read and there is mutual assent to the terms contained UNLESS (1) prevented from reading (2) induced not to read the k before signing.
(Allied Van Lines, Inc. v. Bratton)
What are the exceptions to the general duty to read?
K's involving (BISS):
1. brochures
2. insurance renewal
3. sale of goods k's w/consumers
4. service k's w/consumers
Why is there an exception to the duty to read for insurance renewals?
To overcome the inducement of the insured not to read the renewal, the insurer must provide adequate notice of the changes. (Mundy v. Lumbermans - renewal changes on separate heading w/large font - that is adequate notice)
How does the duty to read effect brochures?
If there is a reasonable expectation that brochure terms are part of the contract and knowing assent to the brochure, then there is a meeting of the minds and a contract. (Weiz v. Parke-Bernet Galleries - no meeting of the minds, the clients would have never noticed the disclaimer - Crt used RPP standard)
What is the basis for providing extra protection to consumers in sale of goods k's?
B/c there are some situations where the consumer has little power to bargain, the crt will find some public policy ground to void the k provision promulgated by industry associations. - NJ Avant Garde (Henningsen v. Bloomfield Motors - provision eliminating PI lawsuit by limiting cost of repair)
What is the UCC approach to extending protection to consumers in sale of good k's?
UCC approach Businesses can disclaim implied warranties if prominent unless court finds enforcement of provision unconscionable (unfair surprise).
In service k's with consumers, how does the court protect the consumer?
1. Public policy approach - find some policy ground to void contract provision (Richards v. Richards - overbroad liability exculpatory provision contained in permission to ride eliminating PI lawsuit)
What is the R2K approach to protect the consumer in personal service k's?
If the parties have reasont to belive teh standardized form is used regularly in trx, then signing the form signifies a meeting of the minds and a contract unless the user of the form has reason to believe that the consumer would not sign if the consumer had known of that provision. Broemer v. Abortion Services of Phoenix (Plf’ didn’t have knowing consent b/c there it was not reasonable to expect her to understand the form.) |
Lecture 21: Two-Three Trees. 5/1
Not in DJW.
Two-three trees are one form of balanced search trees. These in general have the following properties:
Weiss discusses a lot of these: AVL trees, Red-Black trees, Splay trees. We're only going to do B-trees.
Two-three tree
A 2-3 tree has the following structure.
Searching for an element
Variant on search in a binary search tree.
search(node T, value X) { // look for value X under node T
if (T is a leaf)
if (T.value == X) return T
else return null;
else if (X < T.key1)
return search(T.firstChild,X)
else if (T.key2 != null && X >= T.key2)
return search(T.thirdChild,X)
else return search(T.secondChild,X)
How high is a 2-3 tree of size N?
The thinnest 2-3 tree of height H has 2 branches at each node and therefore N=2H.
The bushiest has 3 branches at each node, and therefore N=3H.
Therefore for any tree, 2H < = N < = 3H.
Taking log to the base 2 we get H <= log2N.
log23H = H*log23 > = log2N so H >= log2N / log23.
Therefore H is O(log N).
Adding an element
Add(X) {
Using the same technique used in search,
find where X would go if it were a leaf;
if X is already there, return;
create a node N for X, and attach it to the
correct parent P;
loop {
if (P now has 3 children)
else { // P now has 4 children
create a sibling P1 for P;
give the second two children of P to P1;
// P and P1 now have 2 children
F = parent of P;
if (F==null) exitloop;
make P1 a child of F;
P = F;
} // end loop
// if you have reached this point,
// then you have split the root
create a new root R
make P1 and P2 children of R;
What I haven't done is explain how to fix the keys on the internal nodes. Note that the only nodes that have been changed are those on the path from the added node to the root and their neighboring siblings, so at most 2*height of the tree. However, if you implement the key changes in the obvious way, getting the key changes right will take time O(height) for each node being changed and therefore O(height2) overall. But by being clever about passing values up the tree, all the changes can in fact be carried out in time O(height). All that's needed is a careful case analysis, but I am not going to go through it.
Adding without splitting
Adding with splitting
Deleting an element
delete(X) {
use the search technique to find the leaf N for X;
if (X is not in the tree) return;
loop {
P = parent of N;
delete N;
if (P now has two children) return;
else { // P now has one child.
if (P is the root) {
delete P;
if (P has a neighboring sibling P1 with three children) {
transfer the nearest child from P1 to P;
} // now both P and the sibling have two children
else { // P has one child and all neighboring siblings have two;
transfer P's child to a neighboring sibling;
N = P;
} // end loop
Another Example
Again, I haven't explained how to fix the keys. Again, using an even more elaborate case analysis, you can show that this can be done in time O(height). |
Exposure Basics, lesson three?
Started Mar 18, 2013 | Discussions thread
Veteran MemberPosts: 4,598
Re: Quick correction.
In reply to Great Bustard, Mar 21, 2013
By the end of the course they would know that Light Exposure is the amount of light falling on the recording surface controlled by the Aperture and Shutter Speed and that ISO is a setting that controls how the camera processes that light into their image.
The exposure is the density of light falling on the sensor, which is all together different than the total amount of light falling on the sensor:
Total Light = Exposure x Effective Sensor Area
and different from the total amount of light used to create the photo:
Total Light Collected = Exposure x Effective Sensor Area x QE
where QE (Quantum Efficiency) is the proportion of light falling on the sensor that gets recorded.
For example, four times (two stops) more light falls on a FF sensor than an mFT sensor for a given exposure. A sensor with a QE of 50% records twice the light as a sensor with a QE of 25% for a given exposure.
It is the total amount of light used to make the photo, not the exposure itself, that is the relevant measure in terms of the IQ of the photo that has to do with exposure. In short, exposure is relevant only insofar as it is a component of the total amount of light that makes up the photo.
If we are working with a single camera, there is no need to make the distinction between exposure and total light, just as there is no need to make the distinction between mass and weight when in the same acceleration field.
However, if we are comparing different formats and/or sensors with different QEs, then the distinction is rather central.
And that's why techies should't try to teach beginners.
Alternatively, it's why beginners often stay beginners, more often than not, at least so far as technical understanding goes. They start out learning something wrong that seemed to make sense, and leads to comments such as "Total Light = Total BS", "f/2 = f/2 = f/2", "larger pixels means less noise", etc., etc., etc., that, try as one might, they cannot let go of the dumbed down incorrect version they "learned".
Do you honestly believe that the concept of exposure as the density of light falling on the sensor is too hard for a beginner to grasp? Do you honestly believe that the concept that the more light a photo is made from the less noisy it will be is too hard for a beginner to grasp? Do you honestly believe that the idea of sensor efficiency, in terms of the proportion of light falling on it that is recorded, and the additional noise added by the sensor and supporting hardware, is a concept too difficult for a beginner to grasp?
Myself, I tend to think that the correct understanding is the more simple understanding:
• Exposure is the density of light falling on the sensor.
• Wider aperture and/or longer shutter speed means more exposure.
• Greater exposure, larger sensor, and/or more efficient sensor means more light recorded.
• More light recorded means less noise.
• Sensors can absorb only so much light, beyond which you will get blown highlights.
• Camera's ISO setting adjusts the brightness of the LCD playback and/or OOC jpg, as well as influencing the camera's choice of f-ratio, shutter speed, and/or flash power depending on the AE (auto exposure) mode you are using.
• Image files have a limited bit-depth, so increasing the ISO may push portions of the photo outside the range of the image file, resulting in blown highlights.
Is it really that confusing?
Try it. Offer your services to a local college. Put the course together and get it approved by the college. Get them to include the course in their night class program, see if people want to sign-up and pay money for it. And if it all goes ahead, deliver the course and get a critique about how well the course was received.
It's really great fun, you meet interesting people, and it's one way to know for sure.
But to give some partial answer. I believe if I submitted a beginners course with terms/equations like Total Light Collected = Exposure x Effective Sensor Area x Quantum Efficiency, the course would be rejected as having missed the brief that it is aimed at complete beginners.
I'm a little different than many in that I have some experiences that are not at all common. I was the advanced programming course designer for Hoskyns. I was also the chief trouble-shooter consultant, meaning my name was listed in the experts directory, known as the "Oh shlt, who we gonna call, guide" (it was the post Ghost Busters era). That would be me. I solved issues with IBM Systems that IBM had failed to solved, "dam, who we gonna call now?". I was called on to out-geek the geeks who were hiding stuff from their bosses. I was the sole representative of the UK (in my specific field) invited by IBM to attend their technical seminars at their labs in Italy. One each from certain European countries, two from America and one from Canada. A small group the IBMer insisted on calling the elite.
I don't say this to brag or elevate myself, I say it because I want you to understand, I can do techie. I was, in that career, the techie's techie. However, I am somewhat different because I can also do beginner and this isn't all that common. The intro lecturers didn't have the knowledge for the advanced courses, while the advanced lecturers didn't have the patience or dumbed down (simplified, being more polite) vocabulary to keep the beginners on track. They would sometimes try if the scheduled lecturer was off sick, but it would more likely lead to 'brain-dump' tactics and end in tears. Yes, both delegates and lecturers do end up crying when faced with a group situation that overwhelms them into feeling they can't cope.
An insurance company client ran an annual program taking six virgins; people with a degree in anything other than computer sciences. If could be Business Administration, Medicine, Legal, Drama, Languages, Photography and Media, whatever, just so long as it wasn't Computer Sciences. These would then be trained to become computer programmers, by me, in a 6 week intensive course (30 full days) over an eight week period.
Their rationale was that Computer Science Geeks were in general, geeks, and didn't make particularly useful additions to the business, lacking both business and communications skills. Dismissive, aloof and intolerant. More likely to hold the business to ransom than help drive it forward.
As an honorary computer science geek I was naturally a little skeptical, but we ran it for three years before the recession hit and they stopped the new hires. It was hugely successful.
The point of all this rambling is, teaching beginners is a lot more than just having the knowledge they lack. You need empathy and imagination to put yourself into their position, to understand where they struggle. A little psychology to figure out a way to help them over their hurdles. You need to pace the learning so people don't get bored while others struggle. And the biggest mistake the more techie lecturers make in this situation is in believing it is easy. Some even make the mistake of saying it in just the wrong way, directly at someone who is struggling, in the innocent hope it will help. Might as well just light the blue touch-paper.
So what do you think, are techies dismissive, aloof and intolerant? Seen any evidence of it here in the m43 forums?
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What number of shares determines adequate liquidity for a stock?
By Investopedia Staff AAA
Liquidity refers to how easy it is to buy and sell shares without seeing a change in price. If, for example, you bought stock ABC at $10 and sold it immediately at $10, then the market for that particular stock would be perfectly liquid. If instead you were unable to sell it at all, the market would be perfectly illiquid. Both of these situations rarely occur, so we generally find the market for a particular stock somewhere in between these two extremes.
The bid-ask spread and volume of a particular stock are closely interlinked and play a significant role in the liquidity. The bid is the highest price investors are willing to pay for a stock, while the ask is the lowest price at which investors are willing to sell a stock. Because these two prices must meet in order for a transaction to occur, consistently large bid-ask spreads imply a low volume for the stock while consistently small bid-ask spreads imply high volume.
For example, a bid of $10 and an ask of $11 for stock ABC is a fairly large spread, meaning the buyer and seller are far apart. No transactions can take place until the buyer and seller agree on price. Should this large bid-ask spread continue, few transactions would occur and volume levels would be low, implying poor liquidity: either the bid or ask price (or both) would have to move for a transaction to take place. On the other hand, a bid of $10 and an ask of $10.05 for stock ABC would imply that the buyer and seller are very close to agreeing on a price. As a result, the transaction is likely to occur sooner and, if these prices continued, the liquidity for stock ABC would be high.
However, liquidity is more of a qualitative measure, meaning there is no one quantity of stock volume that can tell us how liquid an investment is.
(For more on the bid-ask spread, read our article Why the Bid/Ask Spread Is So Important.)
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Saltos de línea: an¦tith|esis
Pronunciación: /anˈtɪθəsɪs
Definición de antithesis en inglés:
sustantivo (plural antitheses /-siːz/)
1A person or thing that is the direct opposite of someone or something else: love is the antithesis of selfishness
Más ejemplos en oraciones
• The Edmonton Oilers dynasty of the 1980s was the direct antithesis of the Flyers.
• Again, one could infer that it is the direct antithesis to works.
• Yet Edward always saw reconciliation in the form of its antithesis or opposite.
(direct) opposite, converse, reverse, reversal, inverse, obverse;
the other extreme, the other side of the coin
informal the flip side
1.1A contrast or opposition between two things: the antithesis between occult and rational mentalities
Más ejemplos en oraciones
• This opposition provides the most convincing rationale for his famous antithesis between bureaucracy and charisma.
contrast, opposition
1.2 [mass noun] A rhetorical or literary device in which an opposition or contrast of ideas is expressed: figures of speech such as antithesis [count noun]: his sermons were full of startling antitheses
Más ejemplos en oraciones
2 [mass noun] (In Hegelian philosophy) the negation of the thesis as the second stage in the process of dialectical reasoning. Compare with synthesis.
Example sentences
late Middle English (originally denoting the substitution of one grammatical case for another): from late Latin, from Greek antitithenai 'set against', from anti 'against' + tithenai 'to place'. The earliest current sense, denoting a rhetorical or literary device, dates from the early 16th century.
Definición de antithesis en:
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Palabra del día emulous
Pronunciación: ˈɛmjʊləs
seeking to emulate someone or something |
Who's Who of Ancient Egypt - Egyptian people, queens and family: Ipuwer
14th Dynasty
Ipuwer was a prophet who had heaped reproaches upon the king, who was likely the last of the Memphite line, for his weakness and indolence. This king was thought to have been too young to have any sense. Ipuwer was also a sage who wrote a lengthy set of lamentations on disorder. He is respected because his teachings spoke straightforwardly. He offered an apocalyptic view of the world with drama and detail, and it haunted the people's imaginations and was irresistible centuries after its composition.
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Last Updated: June 19th, 2011
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Rancho Posolmi
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Rancho Posolmi was a 1,696-acre (6.86 km2) Mexican land grant in present day Santa Clara County, California given in 1844 by Governor Manuel Micheltorena to Lupe Yñigo.[1] The name refers to Posolmi village of the Ohlone. The grant encompassed present day Moffett Field in Sunnyvale.[2][3]
Lupe Yñigo (1781-1864), an Ohlone Indian, who was appointed an alcalde at Mission Santa Clara, was given a land grant in 1844, and retained over 800 acres (3 km2) until his death in 1864.[4]
Robert Walkinshaw was a native of Scotland, who came from Mexico in 1847 to take charge of the New Almaden Quicksilver Mine for Baron, Forbes and Company, a British trading firm.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho Posolmi was filed with the Public Land Commission in 1852, [5] and the grant was patented to Thomas Campbell, Robert Walkinshaw, and Lopez Yñigo in 1881.[6]
In 1931, 1,000 acres (4.0 km2) were purchased by Bay Area communities and sold to the military for $1, to be used for an air base, later named Moffett Field.
2. ^ Diseño del Rancho Posolmi
3. ^ Early Santa Clara Ranchos, Grants, Patents and Maps
4. ^ Laurence H. Shoup, Randall T. Milliken, 1999, Inigo of Rancho Posolmi: The Life and Times of a Mission Indian, Malki-Ballena Press, Novato, California, ISBN 978-0-87919-142-9
5. ^ United States. District Court (California : Northern District) Land Case 410 ND
6. ^ Report of the Surveyor General 1844 - 1886
Coordinates: 37°25′12″N 122°03′00″W / 37.420°N 122.050°W / 37.420; -122.050 |
Posts Tagged ‘trembling earth’
This is the second of two posts on this blog that consist of asking Austin Elliott, who’s working on a Ph.D in geology at UC-Davis focused on seismology, a few questions about the nature of earthquakes in the Northwest and California and the general science of seismology. (Part one is Living With Earthquakes on the West Coast.) Austin also has a blog, The Trembling Earth, which is connected to his Ph.D work and looks at various topics in the earthquake field. In this post, Austin gives some details on the nature of seismology, new developments in the field (including early warning systems for earthquakes), and how being a seismologist changes his perspective on earthquake risks.
What are the biggest new or ongoing developments in seismology research since you started studying the subject? Is it analyzing the Tohoku quake?
We have had to radically shift existing paradigms about how earthquakes happen and how big they can be. Many of them come as a surprise to us because we’ve made insufficient assumptions about how individual faults interact, or how prior earthquakes on a single fault have changed the stress state to promote or inhibit subsequent earthquakes, as in the case of Tohoku. The earthquake rupture process is hugely complicated, and each quake is quite unique in its source process, relieving stress on one fault, loading stress onto another, jumping from one crack and continuing on another. Increasing volumes of seismograph data afford us increasingly detailed views of how an earthquake evolves, and they’re nothing like the simple breaks you learn about in your intro textbook.
I can’t list modern developments in seismology without mentioning Earthquake Early Warning. Systems that alert citizens of impending shaking are already operational in Japan and Mexico, and in the U.S. there has just been a huge push (read: influx of funding) to develop our own system. Conceptually this is as close as we can get to “predicting” earthquakes: knowing one is in progress and warning people who are far enough away and still have time to protect themselves. Our capabilities are there, but in practice we lag Japan and Mexico because we don’t have enough seismometers in the right places, and, ironically, we have barely enough earthquakes to run robust trials of the system. On top of that, we’ve built big dense cities directly on top of major fault lines, meaning in many places there would be no time for warning. There are still enough hypothetically damaging quakes that could happen far enough from population centers that the system is worthwhile, and you’ll be seeing and hearing much more about it in the coming years.
The other big thing that’s developing–seismologically speaking–is global social awareness of quake risk, and remarkable preventative/preparatory action. I think the internet is a huge driver of this awareness since more people than ever before are exposed to stories and imagery from earthquakes. In past centuries earthquakes were the things of distant legend, or rare occurrence, but now everyone the world over has witnessed their destruction. This is huge, because the primary problem with earthquake preparedness is how remote people consider their own risk.
How does seismology impact your day-to-day apprehension and awareness of earthquakes? Are you more or less nervous about them as a result of knowing more about how and how often they happen? For example, after Japan’s earthquake and the SE Asia Boxing Day earthquake in 2004, did you have a lot of foreboding about the destruction the following tsunamis would do?
I would say my understanding of seismology makes me immensely more attuned to the reality of earthquake risks than the average person. I think the biggest thing people fail to realize is the inevitability of earthquakes. Fault lines exist because the Earth’s crust has been jostling and grinding for hundreds of millions of years. The San Andreas Fault alone has accommodated the Pacific Plate sliding over 350 miles north past North America, and this of course will continue for the foreseeable geological future. If each big earthquake (a la 1906) stems from fault slip of 10-20 feet, this means the San Andreas has accommodated something like 150,000 earthquakes of that size in its history. That just floors me, and that doesn’t include damaging quakes that stem from subsidiary faults like the Hayward and the San Jacinto, or the myriad thrust faults terrorizing Los Angeles. Relatively to a human generational timescale, the error bars are large on when any given fault will slip to produce an earthquake, but the faults most certainly will slip, and we will most certainly have no warning*. The universal observation about earthquakes is that they always take a populace by surprise. You won’t know until it’s too late that it’s the day of The Big One, and they’ll most certainly happen in our future, just like they’ve happened to every generation in the past.
*Except for the ~10-20 seconds afforded by an early-warning system that’s triggered once a big quake starts.
My impression is that seismology, even more than most sciences, is a very data-hungry field. In the Northwest, the PNSN seems to have seismometers all over the place, including a lot of people’s homes. Is the basic goal in seismology to get as much data as you can about earthquakes and stresses that are building underground, and then find patterns in that data that tell you about how often, where, and why (maybe even when) earthquakes happen?
This question has hints of earthquake prediction, which I’m just gonna nip in the bud. One very minor component of seismology is detecting precursory signals, but decades of effort on that front have proved generally fruitless. There’s a fantastic review of the history of earthquake prediction in the book Predicting the Unpredictable by Susan Hough, if you’re interested in that.
You’re right though that seismology is a supremely data-hungry field. Seismology per se–the mathematical analysis of seismic signals–has two broad goals: understanding why earthquakes happen by painting detailed pictures of how they happen, and understanding what effects earthquakes may have through interaction of seismic waves with subterranean features, for example the hard bedrock edge of a sedimentary basin, which reflects seismic waves like the concrete wall of a pool does water. These goals are most often characterized as different approaches to the mathematical problem: to understand the earthquake source you have to piece together from multiple seismic recordings what the original pattern of seismic waves radiated from the fault was, making some assumptions about how they travelled to each station. To understand the effects of subterranean features you have to work out how those radiated waves were modified as they traveled from their source on the fault to your seismometer–or your house–making some assumptions about their original form.
Both of these approaches are immensely aided by more data. The Tohoku earthquake is a perfect example. Japan’s network of seismic measuring instruments (seismometers, accelerometers, GPS…) surpasses the quality and density of any other country’s, and so it captured a huge earthquake with more detail than ever in history. In the same way a musical performance sounds better if you mic all the instruments and not just one, an earthquake is far better represented with a huge suite of recording devices.
The other goals you mention–finding patterns that tell you how often and where earthquakes happen–are addressed by related fields that aren’t technically “seismology.” Geologic investigations of disrupted, deformed, and offset rocks constitute structural geology and can focus on a specific record of earthquakes that happened in the past–“paleoseismology.” Geodesy is measurement of the location and velocity of Earth’s surface, and is routinely conducted using GPS to assess the potential for earthquakes due to increasing strain around faults. One might claim that an ultimate goal of all of these fields (collectively, I’ll call them earthquake science) is to understand, model, and “predict” the occurrence of earthquakes from the evolving stresses that lead to them all the way to the detailed behavior of that patch of ground the new hospital sits on when it’s subjected to shaking from a nearby quake.
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The Beacon
Ranger Discovers Deep-Sea Coral
The Oceana Ranger, our roving catamaran, has discovered deep-sea white coral in the Aviles Canyon in the Bay of Biscay, off the northern coast of Spain. The coral was identified using an underwater robot, which can work down to 600 meters.
The deep-sea coral can take centuries, or even millennia, to form -- some European coral formations are more than 8,000 years old, and their age makes them especially vulnerable. Recent studies estimate that almost half of the deep-sea coral reefs in Europe have disappeared, particularly due to destructive fishing methods such as bottom trawling.
Oceana's chief scientist Mike Hirshfield said the discovery is "very exciting." He continued, "It's so amazing and depressing how little ROV [remotely operated underwater vehicle] science has been done in the Bay of Biscay."
Rove on, Ranger!
[Image from the Oceana Ranger]
Browse by Date |
Mercyb US History First Semester Final Review
46 terms by lindatownsend
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taxes on imported goods
a law forbidding the sale of alcoholic beverages
Nineteenth amendment
granted women the right to vote in 1920
Red Scare
a period of general fear of communists
payments for war damage
Buying on margin
An option that allowed investors to purchase a stock for only a fraction of its price and borrow the rest
a share of a company
people who believe there should be no government
Mitchell Palmer
conducted raids on suspected anarchists and radicals
Dawes Plan
developed by an American banker to rescue Germany's economy
Sacco and Vanzetti
Anarchists and Italian immigrants accused of murder. Sentenced to death.
Dow Jones
Oldest indicator of the ups and downs of the stock market . 30 leading blue chip stocks
Hated not only blacks but also jews, catholics, immigrants, and groups believed to represent "Un-American" values.
Hawley Smoot Tariff
Scopes Trial
1925 trial in Tennessee on the issue of teaching evolution in public schools
Tea Pot Dome
Oil scandal during the Harding administration
Woodrow Wilson
U.S. President, who led USA into WWI. He proposed the 14 points. He attended the peace conference at Versailles.
Versailles Treaty
1919 treaty that ended WWI
Zimmerman Note
Message proposing an alliance between Germany and Mexico
German Submarine
Articles of Confederation
the document that created the first central government for the United States; it was replaced by the Constitution in 1789
Louisiana Purchase
Jefferson bought this from France
Monroe Doctrine
The period when the South rejoined the Union.
13th Amendment
slavery abolished
Homestead Act
Pendleton Act
began a transfer of federal jobs from the patronage to the merit system
the steel king
a journalist who uncovers abuses and corruption in a society
Political Bosses
Leaders of political machines that bribed citizens in order to receive votes
Boss of Tammany Hall
cartoonist who exposed the Tweed Ring
Collective bargaining
process in which workers negotiate as a group with employers
Gentlemen's Agreement
Agreement with Japan and the US, mutual restrictions of immigration
a policy of extending your rule over foreign countries
USS Maine
a U.S. warship that mysteriously exploded and sank in the harbor of Havana, Cuba on February 15, 1898
Common Sense
Three fifths compromise
agreement at the constitutional Convention that 3/5 of the slaves in any state be counted in its population
Jim Crow Laws
Laws designed to enforce segregation of blacks from whites
Women's suffrage
the right for women to vote
Laissez faire
policy allowing business to operate with little or no government interference
Trust buster
Roosevelt's nickname
Philippines annexation
given to U.S. for a payment of $20 million; very controversial because we had promised independence
Bull Market
a period of increased stock trading and rising stock prices
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Sample code:
import socks
import socket
import urllib2
socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS4, "", 9050, True)
socket.socket = socks.socksocket
print urllib2.urlopen("http://almien.co.uk/m/tools/net/ip/").read()
TOR is running a SOCKS proxy on port 9050 (its default). The request goes through TOR, surfacing at an IP address other than my own. However, TOR console gives the warning:
"Feb 28 22:44:26.233 [warn] Your application (using socks4 to port 80) is giving Tor only an IP address. Applications that do DNS resolves themselves may leak information. Consider using Socks4A (e.g. via privoxy or socat) instead. For more information, please see https://wiki.torproject.org/TheOnionRouter/TorFAQ#SOCKSAndDNS."
i.e. DNS lookups aren't going through the proxy. But that's what the 4th parameter to setdefaultproxy is supposed to do, right?
From http://socksipy.sourceforge.net/readme.txt:
setproxy(proxytype, addr[, port[, rdns[, username[, password]]]])
rdns - This is a boolean flag than modifies the behavior regarding DNS resolving. If it is set to True, DNS resolving will be preformed remotely, on the server.
Same effect with both PROXY_TYPE_SOCKS4 and PROXY_TYPE_SOCKS5 selected.
It can't be a local DNS cache (if urllib2 even supports that) because it happens when I change the URL to a domain that this computer has never visited before.
share|improve this question
3 Answers 3
The problem is that httplib.HTTPConnection uses the socket module's create_connection helper function which does the DNS request via the usual getaddrinfo method before connecting the socket.
The solution is to make your own create_connection function and monkey-patch it into the socket module before importing urllib2, just like we do with the socket class.
import socks
import socket
def create_connection(address, timeout=None, source_address=None):
sock = socks.socksocket()
return sock
socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS5, "", 9050)
# patch the socket module
socket.socket = socks.socksocket
socket.create_connection = create_connection
import urllib2
# Now you can go ahead and scrape those shady darknet .onion sites
share|improve this answer
worked for me ;) thanks – opc0de Dec 29 '12 at 18:46
NOTE: The new SOCKS port seems to be 9150. I literally spent an hour, disabling the firewall etc. trying to figure out why it didn't connect... – mastergalen Nov 3 '13 at 14:33
I've published an article with complete source code showing how to use urllib2 + SOCKS + Tor on http://blog.databigbang.com/distributed-scraping-with-multiple-tor-circuits/
Hope it solves your issues.
share|improve this answer
The problem is that you are importing urllib2 before you set up the socks connection.
Try this instead:
import socks
import socket
socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS4, '', 9050, True)
socket.socket = socks.socksocket
import urllib2
Manual request example:
import socks
import urlparse
SOCKS_HOST = 'localhost'
SOCKS_PORT = 9050
SOCKS_TYPE = socks.PROXY_TYPE_SOCKS5
url = 'http://www.whatismyip.com/automation/n09230945.asp'
parsed = urlparse.urlparse(url)
socket = socks.socksocket()
socket.setproxy(SOCKS_TYPE, SOCKS_HOST, SOCKS_PORT)
socket.connect((parsed.netloc, 80))
socket.send('''GET %(uri)s HTTP/1.1
host: %(host)s
connection: close
''' % dict(
print socket.recv(1024)
share|improve this answer
Actually that was the code I originally had, and doesn't seem to work any differently – OJW Feb 28 '11 at 23:12
@OJW: are you 100% sure that you don't import urllib2 somewhere else before that? The above code works perfectly for me if I simply paste it in some file. – Wolph Feb 28 '11 at 23:38
By "it works", do you mean that it downloads the page via the proxy (that bit works for me too), or are you also watching the TOR STDOUT to confirm that DNS requests are going via TOR and not direct? – OJW Mar 1 '11 at 0:34
@OJW: I didn't use TOR for my test but simply an ssh connection while monitoring the connection for DNS requests with Wireshark. Although there is a chance that I didn't see the DNS request because of the caching DNS server that I run locally. – Wolph Mar 1 '11 at 3:09
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Swim is built on top of the Pour framework, which is a general-purpose framework for reconciling information from periodic, on-demand, and user-specified sources. Swim consists of a set of Perl modules for extracting software information from a system, an XML schema defining the format of data that can be added by users, and a Pour XML configuration file that describes how these elements are utilized to generate periodic, on-demand, and user-specified information. The Pour framework provides the user interface and the basic back-end information storage and retrieval.
Pour validates user-specified information against the Swim XML schema and calls the appropriate Swim modules when information is required on-demand. Periodic information is generated by cron jobs that run Swim scripts on each grid resource and invoke the appropriate Pour method to add the information to a Pour repository on some host. Periodic software information is derived mainly from the package managers used on each system.
Swim collects information from native package managers on FreeBSD, Solaris, and IRIX, as well as the RPM, Perl, and Python package managers on multiple platforms. It is advantageous to use package managers since in most cases they are the tools used by administrators to install the software in the first place. Since not all software is available or installed in package form, however, Swim also crawls the set of relevant paths from the Filesystem Hierarchy Standard, which defines the standard filesystem structure used by all major Unix distributions. Using these two techniques, the vast majority of software installed on a system will be located.
Information that is too expensive to compute for all software components or that is specific to individual users can be computed on-demand based on the query arguments. Swim currently supports three types of on-demand information. It derives software dependencies for ELF executables and libraries, Java classes, and Perl and Python modules. It computes the same information gathered by the periodic routines for specific files on specific hosts. Finally, it locates software on a system given only its name and type.
• Swim
Swim is a software information service for the grid built on top of Pour, which is an information service framework developed at NASA. Swim provides true software resource discovery integrated with the tools used by administrators to install software. In particular, software information is periodically gathered from native package managers on FreeBSD, Solaris, and IRIX as well as the RPM, Perl, and Python, package managers on multiple platforms. Swim has additional facilities for collecting on-demand information about arbitrary software on any grid-enabled resource including software dependencies and Unix "stat" information.
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Water: Two Liquids Divided by a Common Hydrogen Bond.
MedLine Citation:
PMID: 21612286 Owner: NLM Status: Publisher
The structure of water is the subject of a long and ongoing controversy. Unlike simpler liquids, where atomic interactions are dominated by strong repulsive forces at short distances and weaker attractive (van der Waals) forces at longer distances, giving rise to local atomic coordination numbers of order 12, water has pronounced and directional hydrogen bonds which cause the dense liquid close-packed structure to open out into a disordered and dynamic network, with coordination number 4 - 5. Here I show that water structure can be accurately represented as a mixture of two identical, interpenetrating, molecular species separated by common hydrogen bonds. Molecules of one type can form hydrogen bonds with molecules of the other type, but cannot form hydrogen bonds with molecules of the same type. These hydrogen bonds are strong along the bond, but weak with respect to changes in the angle between neighbouring bonds. The observed pressure and temperature dependence of water structure and thermodynamic properties follow naturally from this choice of water model, and it also gives a simple explanation of the enduring claims based on spectroscopic evidence that water is a mixture of two components.
Alan Kenneth Soper
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DCR Workshop: How to use your CILC like a pro
by Chris Gampat - 8/15/2010
You've entered the world of the Compact Interchangeable Lens Camera, and you are wondering how you can step up your game to take better photos. Well, by getting a camera with a larger sensor and interchangeable lenses, you've made a start. But put a professional level DSLR in the hands of someone that doesn't know how to use it, and you'll get similar results to a point-and-shoot. Here are some tips to keep in mind and to keep you going as a budding photographer.
Invest into the System
This could mean something as small as a better lens, an external flash, a snazzy leather case, or an electronic viewfinder. Get these items and you'll see that your photography will not only take a step up, but that you'll be getting more out of the sensor's potential.
Understand Exposure
Exposure, in the photography world, is a very broad term and you'll need to understand it better. Your camera has manual modes like Aperture, Shutter, Program, and Manual. Aperture Mode allows you to control the f-stop on the camera and the camera will adjust everything else. Shutter is similar to Aperture but controls the shutter speed. Program is essentially an auto setting and Manual allows for full manual control over the camera. Most professionals tend to use Manual. Reading your camera's meter also comes into play here.
With shooting in Manual exposure comes learning a couple of key new terms:
Shutter Speed: Your camera has a shutter, and it can stay open for certain amounts of time depending on what the user dials into the camera. It is typically displayed as a fraction or a whole number. For example:
The longer the shutter speed the more motion that will be captured and the steadier the photographer needs to remain. This is great for capturing nighttime scenes. As a note, use a tripod.
The faster the shutter speed the less motion will be captured. This is great for capturing fast moving objects like sports action. On your camera, this can be seen with the S mode.
F-Stop: This is also known as your Aperture. Your aperture not only controls how much of your image is in focus or not, but like your shutter speed it can also control how much light comes into the lens of your camera and hits the sensor (the equivalent of film.) In general:
On your camera this is also known as AV mode.
ISO: The ISO (or ASA as it was in the film days) is the current light sensitivity setting of your camera's sensor. The general rule is the higher the ISO, the more sensitive your camera will be to light and the grainier your images will be. The grain is also known and often referred to as image noise. In contrast, the lower the ISO, the less sensitive the camera will be to light and the less grain will appear on your images. Higher ISOs allow for faster shutter speeds. Similarly, larger sensors allow for less grain at higher ISO settings.
Don't Get Trapped into the Bokeh Effect!
If you're sitting in front of your computer screen scratching your head and wondering what Bokeh is, it is a term used for the out of focus/blurry area of a photo. When amateur photographers usually get a brand new lens with a wider aperture, they tend to just shoot with the aperture wide open all the time and lose a lot of great details in their photos because of this.
One of the most purchased lenses is the 50mm f/1.8. The larger f-stop value allows for lots of light to hit the sensor but doesn't get very much in focus. If you want to shoot a portrait of your daughter or puppy, try changing the f-stop to f/2.8 or f/4 so that more gets into focus and the details in their eyes are crisp.
Hold It Like a Pro
There are some big giant red flags as to what not to do when holding your camera.
Use the Rule of Thirds
The rule of thirds is displayed on your camera's LCD or viewfinder as two lines going horizontally and vertically and therefore dividing the frame into nine sections. When you compose your photos by placing your subjects on those lines, the results are much more interesting photos that the human eye tends to look at for a longer period of time.
Pay Attention to The Details
The very minor details in a photo can totally change it around. Body language is a big one as placement of a bride's hands can tell us a lot about how she is feeling in wedding photography. Others are how the lens is making the body look. In portrait photography, wider lenses tend to distort body parts: making heads look small or legs look like a person is half-giraffe.
Take Careful Notice of Light
Light is extremely important in photography. Shooting a photo of someone with the sun in the background will give you a photo with lots of shadows on the person's face. In the professional world, a reflector, soft lighting or some fill flash will solve this. Your camera will typically meter your images based upon what your focusing on, and there are often very dark and very bright areas where the light caries. Use your LCD screen to preview what your image will look like and try to find a good balance.
Edit, Edit, Edit!
Editing is very important in the photo world. For starters, to get better photos you should be shooting in RAW mode. This mode is much more forgiving to mistakes that you may make. When shooting in RAW, you can process the photo in Photoshop, Lightroom, Aperture or the provided program with better results. Variables like the white balance (color temperature of the photos), saturation and fill light can all be manipulated.
Great photos are created by the photographer, which also means that there is processing in both the Darkroom (film) and programs (digital). Get ready to spend some time creating better photos that you'll be very, very proud of. What you'll need to do is look at your photos, apply different changes and ask yourself certain questions. Perhaps you didn't follow the rule of thirds in your first shot, here is where you can correct that by cropping!
Now that you're at a higher stage in your photography and you have a Compact Interchangeable Lens Camera, you'll need to take the steps to make your photography better. Taking and creating better pictures isn't easy as it requires fresh new ideas, different perspectives, knowledge and understanding gained from making mistakes, and constantly keeping at it. Keep shooting and you'll eventually be able to use your camera like a pro. |
Homework Help
How does the secular music differ from sacred music ?
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temi07 | (Level 1) Honors
Posted October 4, 2011 at 11:16 AM via web
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How does the secular music differ from sacred music ?
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stolperia | (Level 1) Educator Emeritus
Posted October 4, 2011 at 11:31 AM (Answer #1)
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Secular music is defined as being music that is not intended for religious use. Sacred music is defined as being music written for purposes of worship, whether in a religious service or in another setting. This distinction regarding the purpose of the music is the only real difference between secular and sacred music.
Both types of music can be found in many different genres, or forms, of music. Secular music, which may also be known as popular music, can include jazz, country-western, rock, hip-hop, rap, new age, folk, and ethnic varieties of music from other cultures. Church musicians use these same genres to create music for religious purposes.
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shannonandchuck | Elementary School Teacher | (Level 1) eNoter
Posted October 10, 2011 at 9:05 PM (Answer #2)
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Sacred music is music that is written for or performed for religious purposes. Dating back to Medieval times, the Catholic church commissioned composers to write music for various services and events related to the church. Today sacred music is still used in church services. Sacred music is also produced and sold for personal purchase and enjoyment.
The essence of secular music boils down to any music that is not sacred. Music that is about a wide variety of topics such as love, loss, hope, joy, and every day events (without explicitly referencing religious concepts) is considered secular.
Some music is considered to be of the "crossover" category if it doesn't focus on God or religion but still hints about spiritual themes. You might hear a crossover song on either religious or secular radio stations.
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Public Release: Heart bypass for uncomplicated heart surgery does not reduce neurocognitive function in children
Children's Hospital of Philadelphia
School-aged children who undergo cardiopulmonary bypass (CPB) during surgery for less complicated congenital heart defects do not appear to suffer any impairments in neurocognitive abilities, such as intelligence, memory, motor skills and behavior.
Researchers from The Children's Hospital of Philadelphia, in a study in the August issue of Pediatrics, reported on neuropsychological effects after surgery for acyanotic heart defects. Acyanotic heart defects, which include abnormal heart valves or a hole between the heart's chambers, are milder and less complex than heart defects which require surgery during infancy.
"Most previous studies of the neurocognitive effects of CPB for pediatric heart surgery have focused on surgery during infancy for complex congenital heart disease," said Michael Quartermain, M.D., pediatric cardiologist and primary investigator of the study. "Those children often have multiple risk factors for cognitive decline, such as genetic syndromes, abnormal brain development and the need for multiple operations. We decided to minimize those confounding factors by focusing on a group of asymptomatic older children with isolated heart disease, and the results are encouraging."
"Cardiopulmonary bypass has long been implicated as a causative factor in abnormal neurocognitive outcomes after cardiac surgery, said Dr. Quartermain. "However, in this study which controlled for the non-bypass effects of open-heart surgery, there was no significant decrease in neuropsychological status in these children and adolescents six months after surgery."
The Children's Hospital of Philadelphia recently launched a unique multidisciplinary, long-term follow-up program to assess congenital heart patients for neurodevelopmental complications, learning disabilities and behavioral concerns, such as ADHD. In the NeuroCardiac Care Program, children and their families are evaluated by a pediatric cardiologist, pediatric neurologist, developmental pediatrician, occupational and physical therapists, a speech and language pathologist, a dietician and social worker - all during one outpatient visit.
Dr. Quartermain's co-authors were Thomas B. Flynn, Ph.D., J. William Gaynor, M.D., Xuemei Zhang, M.S., Daniel J. Licht, M.D., Rebecca N. Ichord, M.D., Michael L. Nance, M.D., and Gil Wernovsky, M.D., all from The Children's Hospital of Philadelphia, and Richard F .Ittenbach, Ph.D., from Cincinnati Children's Medical Center.
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October, 2006
Regional Report
The Soil Food Web
Teaming with Microbes, by Jeff Lowenfels (Timber Press, 2006; $24.95), is the most important garden book written in decades. Believe me on this one, as I have read scores of them. In clear, concise, incredibly well-researched text, Jeff explains what works for growing healthy plants and why the soil food web is the gardener's best friend. While organic practitioners have always been able to demonstrate how beneficial it is to continually replenish the soil, the electron microscope has revealed exactly what's going on in the soil. Jeff is the longest-running garden newspaper columnist in the U.S., a Harvard lawyer who gardens in Alaska. His remarkable ability to communicate makes the dry material quite readable, and the rest a pure pleasure.
Favorite or New Plant
Oak Leaf Lettuce
If you never could understand why people want their lettuce to be different colors, or if you're tired of mesclun, try oak leaf lettuce. It is simply the easiest, 50-day (from transplanting) lettuce in the rack. Light green, velvety leaves, delicious taste, and enough integrity to put on a sandwich, oak leaf is reliably heat tolerant and no more prone to pests than other greens. It grows about 8 inches tall and forms a loose head. You'll recognize the youngest sprouts -- they're one of many lettuces included in mesclun mixes.
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From: Sears, Ellen (ESears_at_TeacherArtExchange)
Date: Wed Oct 23 2002 - 10:37:16 PDT
Pressed recycled cardboard (egg carton) palettes - that come in a stack and
peel off as needed - like a pad of paper with depressions -
Art tables that 'mountain fold' down the middle and become a 'group' easel -
spaces for two on each side to clip their paper and paint away -
a 'drawing paper dispenser' - like a paper towel dispenser that the youngers
can get 'free time paper' for drawing -
napkin dispensers like a diner might have that holds folded paper towels,
and has suction cups on the bottom to hold them to the art table -
a teeny tiney 'dish washer' that sits on the counter to run loads of
palettes, tools etc... (I have an old kitchen sink - the kids really can't
reach it or they would be washing more - I've tried buckets of water -
works for some things - but not for all - ) - boy I hate washing my own |
By Investopedia AAA
Insurance Selection and Annuities - Annuities
An annuity is a periodic or immediate payment to begin at a specific date for a fixed period or for the rest of the policyowner's life. Simply put, an annuity is a vehicle for liquidating a sum of money. Annuities have received a bad reputation in the last few years because of advisors abusing them for high commission payouts. They can however, be a very useful tool in saving for retirement and accomplishing savings goals.
When individuals select an income option as a death benefit from a life insurance policy, they are actually purchasing an annuity and selecting an annuity payout option. We will look at the most common types of annuities and the premium options to fund these vehicles. The name of the annuity is usually very descriptive of the type and premium option available. For example, single premium immediate annuity (SPIA) is paid by the annuitant in one single premium up front and starts paying out benefits immediately.
There are four common types of annuity's uses; refund, single life, joint and survivor, and period certain.
a. Refund - This payout is designed pay the beneficiary the difference between the purchase price of the annuity and the sum of monthly payments. The two types of refunds available are:
• Installment - payments continue until full cost is recovered.
• Cash - remaining lump sum is paid.
b. Single life annuity - Pays the annuitant a guaranteed income for his or her lifetime then ceases upon the annuitant's death.
c. Joint and survivor - If either insured dies the same income payments continue to the survivor for life. When the surviving annuitant dies, no further payments are made to anyone.
d. Period certain - Guarantees benefit payments for a certain period of time, such as 10, 15 or 20 years, whether the annuitants is living.
Final Note: The single life annuity will always have the highest income per dollar of outlay. It is not suitable for everyone.
Practice Question:
Which distribution option would be most appropriate for a retired married couple with no other source of income?
A. Joint-and-survivor annuity
B. Single life annuity
C. An interest-only option
D. Joint life annuity
Answer: A
Do not confuse the joint life annuity with the joint-and-survivor annuity. A joint life annuity ceases payments after the death of the first annuitant, whereas, the joint-and-survivor continues to pay benefits until the second annuitant dies. The Premium Method of Annuities
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Acid-Base Imbalances
Ordinarily, chemical and physiological buffer systems maintain the hydrogen ion concentration of body fluids within very narrow pH ranges. Abnormal conditions may disturb the acid-base balance. For example, the pH of arterial blood is normally 7.35-7.45. A value below 7.35 produces acidosis. A pH above 7.45 produces alkalosis. Such shifts in the pH of body fluids may be life threatening. In fact, a person usually cannot survive if the pH drops to 6.8 or rises to 8.0 for more than a few hours.
Acidosis results from an accumulation of acids or a loss of bases, both of which cause abnormal increases in the hydrogen ion concentrations of body fluids. Conversely, alkalosis results from a loss of acids or an accumulation of bases accompanied by a decrease in hydrogen ion concentrations.
The two major types of acidosis are respiratory acidosis and metabolic acidosis. Factors that increase carbon dioxide, also increasing the concentration of carbonic acid (the respiratory acid), cause respiratory acidosis. Metabolic acidosis is due to an abnormal accumulation of any other acids in the body fluids or to a loss of bases, including bicarbonate ions.
Similarly, the two major types of alkalosis are respiratory alkalosis and metabolic alkalosis. Excessive loss of carbon dioxide and consequent loss of carbonic acid cause respiratory alkalosis. Metabolic alkalosis is due to excess loss of hydrogen ions or gain of bases.
Since in respiratory acidosis carbon dioxide accumulates, it can result from factors that hinder pulmonary ventilation. These include the following:
Diseases that decrease gas exchanges, such as pneumonia, or those that reduce surface area of the respiratory membrane, such as emphysema.
Any of these conditions can increase the level of carbonic acid and hydrogen ions in body fluids, lowering pH. Chemical buffers, such as hemoglobin, may resist this shift in pH. At the same time, increasing concentrations of carbon dioxide and hydrogen ions stimulate the respiratory center, increasing breathing rate and depth and thereby lowering carbon dioxide concentration. Also, the kidneys may begin to excrete more hydrogen ions.
Eventually, thanks to these chemical and physiological buffers, the pH of the body fluids may return to normal. When this happens, the acidosis is said to be compensated.
The symptoms of respiratory acidosis result from depression of central nervous system function, and include drowsiness, disorientation, and stupor. Evidence of respiratory insufficiency, such as labored breathing and cyanosis, is usually also evident. In uncompensated acidosis, the person may become comatose and die.
Metabolic acidosis is due to either accumulation of nonrespiratory acids or loss of bases. Factors that may lead to this condition include:
Prolonged vomiting that loses the alkaline contents of the upper intestine and stomach contents. (Losing only the stomach contents produces metabolic alkalosis.)
Prolonged diarrhea in which excess alkaline intestinal secretions are lost (especially in infants).
Diabetes mellitus, in which some fatty acids are converted into ketone bodies. These ketone bodies include acetoacetic acid, betahydroxybutyric acid, and acetone.
Normally these molecules are produced in relatively small quantities, and cells oxidize them as energy sources. However, if fats are being utilized at an abnormally high rate, as may occur in diabetes mellitus, ketone bodies may accumulate faster than they can be oxidized. At such times, these compounds may be excreted in the urine (ketonuria); in addition, acetone, which is volatile, may be excreted by the lungs and impart a fruity odor to the breath. More seriously, the accumulation of acetoacetic acid and betahydroxybutyric acid may lower pH (ketonemic acidosis).
These acids may also combine with bicarbonate ions in the urine. As a result, excess bicarbonate ions are excreted, interfering with the function of the bicarbonate acid-base buffer system.
In each case, the pH tends to shift toward lower values. However, the following factors resist this shift: chemical buffer systems, which accept excess hydrogen ions; the respiratory center, which increases the breathing rate and depth; and the kidneys, which excrete more hydrogen ions.
Respiratory alkalosis develops as a result of hyperventilation. Hyperventilation is accompanied by too great a loss of carbon dioxide and consequent decreases in carbonic acid and hydrogen ion concentrations.
Hyperventilation may occur during periods of anxiety, although it may also accompany fever or poisoning from salicylates, such as aspirin. At high altitudes, hyperventilation may be a response to low oxygen pressure. Also, musicians, such as bass tuba players, who must provide a large volume of air when playing sustained passages, sometimes hyperventilate. In each case, rapid, deep breathing depletes carbon dioxide and the pH of body fluids increases.
Chemical buffers, such as hemoglobin, that release hydrogen ions resist this pH change. Also, the lower concentrations of carbon dioxide and hydrogen ions stimulate the respiratory center to a lesser degree. This inhibits hyperventilation, thus reducing further carbon dioxide loss. At the same time, the kidneys decrease their secretion of hydrogen ions, and the urine becomes alkaline as bases are excreted.
The symptoms of respiratory alkalosis include lightheadedness, agitation, dizziness, and tingling sensations. In severe cases, impulses may be triggered spontaneously on peripheral nerves, and muscles may respond with tetanic contractions.
Metabolic alkalosis results from a great loss of hydrogen ions or from a gain in bases, both of which are accompanied by a rise in the pH of the blood (alkalemia).
This condition may occur following gastric drainage (lavage), prolonged vomiting in which only the stomach contents are lost, or the use of certain diuretic drugs. Because gastric juice is very acidic, its loss leaves the body fluids with a net increase of basic substances and a pH shift toward alkaline values. Metabolic alkalosis may also develop as a result of ingesting too much antacid, such as sodium bicarbonate, medication to relieve the symptoms of indigestion. The symptoms of metabolic alkalosis include a decrease in the breathing rate and depth, which, in turn, results in an increased concentration of carbon dioxide in the blood.
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A demand for scarce skills can be quickly filled even if there are only small numbers of people to demonstrate them; but such people must be easily available. During the Forties, radio repairmen, most of them with no schooling in their work, were no more than two years behind radios in penetrating the interior of Latin America. There they stayed until transistor radios, which are cheap to purchase and impossible to repair, put them out of business. Technical schools now fail to accomplish what repairmen of equally useful, more durable radios could do as a matter of course.
Converging self-interests now conspire to stop a man from sharing his skill. The man who has the skill profits from its scarcity and not from its reproduction. The teacher who specializes in transmitting the skill profits from the artisan’s unwillingness to launch his own apprentice into the field. The public is indoctrinated to believe that skills are valuable and reliable only if they are the result of formal schooling. The job market depends on making skills scarce and on keeping them scarce, either by proscribing their unauthorized use and transmission or by making things which can be operated and repaired only by those who have access to tools or information which are kept scarce.
Schools thus produce shortages of skilled persons. A good example is the diminishing number of nurses in the United States, owing to the rapid increase of four-year B.S. programs in nursing. Women from poorer families, who would formerly have enrolled in a two- or three-year program, now stay out of the nursing profession altogether.
Insisting on the certification of teachers is another way of keeping skills scarce. If nurses were encouraged to train nurses, and if nurses were employed on the basis of their proven skill at giving injections, filling out charts, and giving medicine, there would soon be no lack of trained nurses. Certification now tends to abridge the freedom of education by converting the civil right to share one’s knowledge into the privilege of academic freedom, now conferred only on the employees of a school. To guarantee access to an effective exchange of skills, we need legislation which generalizes academic freedom. The right to teach any skill should come under the protection of freedom of speech. Once restrictions on teaching are removed, they will quickly be removed from learning as well.
The teacher of skills needs some inducement to grant his services to a pupil. There are at least two simple ways to begin to channel public funds to non-certified teachers. One way would be to institutionalize the skill exchange by creating free skill centers open to the public. Such centers could and should be established in industrialized areas, at least for those skills which are fundamental prerequisites for entering certain apprenticeships—such skills as reading, typing, keeping accounts, foreign languages, computer programming and number manipulation, reading special languages such as that of electrical circuits, manipulation of certain machinery, etc. Another approach would be to give certain groups within the population educational currency good for attendance at skill centers where other clients would have to pay commercial rates.
A much more radical approach would be to create a “bank” for skill exchange. Each citizen would be given a basic credit with which to acquire fundamental skills. Beyond that minimum, further credits would go to those who earn them by teaching, whether they serve as models in organized skill centers or do so privately at home or on the playground. Only those who have taught others for an equivalent amount of time would have a claim on the time of more advanced teachers. An entirely new elite would be promoted, an elite of those who earn their education by sharing it.
Should parents have the right to earn skill-credit for their children? Since such an arrangement would give further advantage to the privileged classes, it might be offset by granting a larger credit to the underprivileged. The operation of a skill exchange would depend on the existence of agencies which would facilitate the development of directory information and assure its free and inexpensive use. Such an agency might also provide supplementary services of testing and certification and might help to enforce the legislation required to break up and prevent monopolistic practices.
Fundamentally, the freedom of a universal skill exchange must be guaranteed by laws which prevent discrimination only on the basis of tested skills and not on the basis of educational pedigree. Such a guarantee inevitably requires public control over tests which may be used to qualify persons for the job market. Otherwise, it would be possible to surreptitiously reintroduce complex batteries of tests at the work place itself which would serve for social selection. Much could be done to make skill testing objective, e.g., allowing only the operation of specific machines or systems to be tested. Tests of typing (measured according to speed, number of errors, and whether or not the typist can work from dictation), operation of an accounting system or of a hydraulic crane, driving, coding into COBOL, etc., can easily be made objective.
In fact, many of the true skills which are of practical importance can be so tested. And for the purposes of manpower-management a test of a current skill level is much more useful than the information that a person—twenty years ago—satisfied his teacher in a curriculum where typing, stenography, and accounting were taught. The very need for official skill testing can, of course, be questioned: I personally believe that freedom from undue hurt to a man’s reputation through labeling is better guaranteed by restricting than by forbidding tests of competence.
Peer Matching
At their worst, schools gather classmates into the same room and subject them to the same sequence of treatment in math, citizenship, and spelling. At their best, they permit each student to choose one of a limited number of courses. In any case, groups of peers form around the goals of teachers. A desirable educational system would let each person specify the activity for which he seeks a peer.
School does offer children an opportunity to escape their homes and meet new friends. But, at the same time, this process indoctrinates children with the idea that they should select their friends from among those with whom they are put together. Providing the young from their earliest age with invitations to meet, evaluate, and seek out others would prepare them for a lifelong interest in seeking new partners for new endeavors.
A good chess player is always glad to find a close match, and one novice to find another. Clubs serve their purpose. People who want to discuss specific books or articles would probably pay to find discussion partners. People who want to play games, go on excursions, build fish tanks, or motorize bicycles will go to considerable lengths to find peers. The reward for their efforts is finding those peers. Good schools try to bring out the common interests of their students registered in the same program. The inverse of school would be an institution which increases the chances that persons who at a given moment share the same specific interest could meet—no matter what else they have in common.
Skill teaching does not provide equal benefits for both parties, as does the matching of peers. The teacher of skills, as I have pointed out, must usually be offered some incentive beyond the rewards of teaching. Skill teaching is a matter of repeating drills over and is, in fact, all the more dreary for those pupils who need it most. A skill exchange needs currency or credits or other tangible incentives in order to operate, even if the exchange itself were to generate a currency of its own. A peer-matching system requires no such incentives, but only a communications network.
Tapes, retrieval-systems, programmed instruction, and reproduction of shapes and sounds tend to reduce the need for recourse to human teachers of many skills; they increase the efficiency of teachers and the number of skills one can pick up in a lifetime. Parallel to this runs an increased need to meet people interested in enjoying the newly acquired skill. A student who has picked up Greek before her vacation would like to discuss in Greek Cretan politics when she returns. A Mexican in New York wants to find other readers of the paper Siempre—or of “Los Asachados,” the most popular political cartoons. Somebody else wants to meet peers who—like himself—would like to increase interest in the work of James Baldwin or of Bolivar.
The operation of a peer-matching network would be simple. The user would identify himself by name and address and describe the activity for which he seeks a peer. A computer would send him back the names and addresses of all those who have inserted the same description. It is amazing that such a simple utility has never been used on a broad scale for publicly valued activity.
In its most rudimentary form, communication between client and computer could be done by return mail. In big cities, typewriter terminals could provide instantaneous responses. The only way to retrieve a name and address from the computer would be to list an activity for which a peer is sought. People using the system would become known only to their potential peers.
A complement to the computer could be a network of bulletin boards and classified newspaper ads, listing the activities for which the computer could not produce a match. No names would have to be given. Interested readers would then introduce their names into the system. A publicly supported peer-match network might be the only way to guarantee the right of free assembly and to train people in the exercise of this most fundamental civic activity.
The right of free assembly has been politically recognized and culturally accepted. We should now understand that this right is curtailed by laws that make some forms of assembly obligatory. This is especially the case with institutions which conscript according to age-group, class, or sex, and which are very time-consuming. The army is one example. School is an even more outrageous one.
To de-school means to abolish the power of one person to oblige another person to attend a meeting. It also means recognizing the right of any person, of any age or sex, to call a meeting. This right has been drastically diminished by the institutionalization of meetings. “Meeting” originally referred to the result of an individual’s act of gathering. Now it refers to the institutional product of some agency.
The ability of service institutions to acquire clients has far outgrown the ability of individuals to be heard independently of institutional media, which respond to individuals only if they are salable news. Peer-matching facilities should be available for individuals who want to bring people together as easily as the village bell called the villagers to council. School buildings—of doubtful value for conversion to other uses—could often serve this purpose.
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Word of the Day |
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Bisexuality refers to sexual behavior with or attraction to people of both sexes, or to a bisexual orientation. People who have a bisexual orientation "can experience sexual, emotional, and affectional attraction to both their own sex and the opposite sex"; "it also refers to an individual’s sense of personal and social identity based on those attractions, behaviors expressing them, and membership in a community of others who share them. It is one of the three main classifications of sexual orientation, along with a heterosexual and a homosexual orientation. Individuals who do not experience sexual attraction to either sex are known as asexual.
According to Alfred Kinsey's research into human sexuality in the mid-20th century, many humans do not fall exclusively into heterosexual or homosexual classifications but somewhere between. The Kinsey scale measures sexual attraction and behavior on a seven-point scale ranging from 0 (exclusively heterosexual) to 6 (exclusively homosexual). According to Kinsey's study, a substantial number of people fall within the range of 1 to 5 (between heterosexual and homosexual). Although Kinsey's methodology has been criticized, the scale is still widely used in describing the continuum of human sexuality.
Despite common misconceptions, bisexuality does not require that a person be attracted equally to both sexes. In fact, people who have a distinct but not exclusive preference for one sex over the other may still identify themselves as bisexual. A recent study by researchers Gerulf Rieger, Meredith L. Chivers, and J. Michael Bailey, which attracted media attention in 2005, purported to find that bisexuality is extremely rare, and perhaps nonexistent, in men. This was based on results of controversial penile plethysmograph testing when viewing pornographic material involving only men and pornography involving only women. Critics state that this study works from the assumption that a person is only truly bisexual if he or she exhibits virtually equal arousal responses to both opposite-sex and same-sex stimuli, and have consequently dismissed the self-identification of people whose arousal patterns showed even a mild preference for one sex. Some researchers say that the technique used in the study to measure genital arousal is too crude to capture the richness (erotic sensations, affection, admiration) that constitutes sexual attraction. The study, and The New York Times article which reported it, were subsequently criticized as flawed and biphobic. FAIR also criticised the study.
Because bisexuality is often an ambiguous position between homosexuality and heterosexuality, bisexuals form a heterogeneous group and the relations between their behaviors, feelings, and identities are not always consistent. Some who might be classified by others as bisexual on the basis of their sexual behavior self-identify primarily as homosexual. Equally, otherwise heterosexual people who engage in occasional homosexual behavior could be considered bisexual, but may not identify as such. For people who believe that sexuality is a distinctly defined aspect of the character, this ambiguity is problematic. On the other hand, some believe that the majority of people contain aspects of homosexuality and heterosexuality, but that the intensities of these can vary from person to person. Some people who engage in bisexual behavior may be supportive of homosexual people, but still self-identify as heterosexual; others may consider any labels irrelevant to their positions and situations. In 1995, Harvard Shakespeare professor Marjorie Garber made the academic case for bisexuality with her 600 page, Vice Versa: Bisexuality and the Eroticism of Everyday Life in which she argued that most people would be bisexual if not for "repression, religion, repugnance, denial" and "premature specialization.
Bisexuality is often misunderstood as a form of adultery or polyamory, and a popular misconception is that bisexuals must always be in relationships with men and women simultaneously. Rather, individuals attracted to both males and females, like people of any other orientation, may live a variety of sexual lifestyles. These include lifelong monogamy, serial monogamy, polyamory, polyfidelity, promiscuity, group sex, and celibacy. For those with more than one sexual partner, these may, or may not, all be of the same gender.
A 2002 survey in the United States by National Center for Health Statistics found that 1.8 percent of men ages 18–44 considered themselves bisexual, 2.3 percent homosexual, and 3.9 percent as "something else". The same study found that 2.8 percent of women ages 18–44 considered themselves bisexual, 1.3 percent homosexual, and 3.8 percent as "something else". The Janus Report on Sexual Behavior, published in 1993, showed that 5 percent of men and 3 percent of women consider themselves bisexual and 4 percent of men and 2 percent of women considered themselves homosexual. The 'Health' section of The New York Times has stated that "1.5 percent of American women identify themselves [as] bisexual."
Dr. Alfred Kinsey's 1948 work Sexual Behavior in the Human Male found that "46% of the male population had engaged in both heterosexual and homosexual activities, or "reacted to" persons of both sexes, in the course of their adult lives". The Kinsey Institute has stated that "Kinsey said in both the Male and Female volumes that it was impossible to determine the number of persons who are "homosexual" or "heterosexual". It was only possible to determine behavior at any given time". Kinsey's book, and its companion Sexual Behavior in the Human Female, have received vocal criticism for their findings and methodology. The New York Times called his research "conscientious and comprehensive and Professor Martin Duberman called it "skillful" and "a monumental endeavor".
Dr. Fritz Klein believed that social and emotional attraction are very important elements in bisexual attraction. For example, a bisexual might be attracted to both feminine women and feminine men, but have little interest in masculine individuals. This individual, while they might be highly attracted to certain members of both sexes, would be unlikely to be attracted to most males in modern western society (who tend to be masculine). As this study employed 2-minute clips of standard heterosexual and homosexual pornography, the study would be blind to the this type of bisexual. One third of the men in each group showed no significant arousal. The study did not claim them to be asexual, and Rieger stated that their lack of response did not change the overall findings.
Sigmund Freud theorized that every person has the ability to become bisexual at some time in his or her life. He based this on the idea that enjoyable experiences of sexuality with the same sex, whether sought or unsought, acting on it or being fantasized, become an attachment to his or her needs and desires in social upbringing. Prominent psychoanalyst Dr. Joseph Merlino, Senior Editor of the book, Freud at 150: 21st Century Essays on a Man of Genius stated in an interview:
Human bisexuality has mainly been studied alongside with homosexuality. Van Wyk & Geist (1995) argue that this is a problem for sexuality research because the few studies that have observed bisexuals separately have found that bisexuals are often different from both heterosexuals and homosexuals. Furthermore, bisexuality does not always represent a halfway between the dichotomy. Research indicates that bisexuality is influenced by biological, cognitive and cultural variables in interaction, and this leads to different types of bisexuality.
There is currently a debate on the importance of biological influences on sexual orientation. Biological explanations have been put to question by social scientists, particularly by feminists who encourage women to make conscious decisions about their life and sexuality. A difference in attitude between homosexual men and women has also been reported as men are more likely to regard their sexuality as biological, "reflecting the universal male experience in this culture, not the complexities of the lesbian world." There is also evidence that women's sexuality may be more strongly affected by cultural and contextual factors.
Most of the few available scientific studies on bisexuality date from before the 1990s. Interest in bisexuality has generally grown, but research focus has lately been on sociology and gender studies as well as on bisexuals with HIV and AIDS.
Social factors
There is a consensus among scholars of different faculties that cultural and social factors have an effect on human sexual behaviour. As bisexual people come from all social classes and familial backgrounds, such factors cannot independently explain why some people are bisexual.
Krafft-Ebing was the first to suggest that bisexuality is the original state of human sexuality. Freud has famously summarized on the basis of clinical observations: "[W]e have come to know that all human beings are bisexual - - and that their libido is distributed between objects of both sexes, either in a manifest or a latent form." According to Freud, people remain bisexual all their lives in a repression to monosexuality of fantasy and behaviour. This idea was taken up in the 1940s by the zoologist Alfred Kinsey who was the first to create a scale to measure the continuum of sexual orientation from hetero to homosexuality. Kinsey studied human sexuality and argued that people have the capability of being hetero or homosexual even if this trait does not present itself in the current circumstances.
From an anthropolocial perspective, there is large variation in the prevalence of bisexuality between different cultures. Among some tribes it appears to be non-existent while in others a universal, including the Sambia of New Guinea and other similar Melanesian cultures.
Even though only a small percentage of people have bisexual traits, this does not outrule the possibility of bisexual behaviour of the majority in different circumstances. Similarly, although evolutionary psychologists consider most males as promiscuous by nature, the majority of American men are faithful to their wives, appearing essentially monogamous. These traits can be explained as the result of culture constraints on evolutionary predispositions.
Sex drive
Several studies comparing bisexuals with hetero or homosexuals have indicated that bisexuals have higher rates of sexual activity, fantasy or erotic interest. Van Wyk and Geist (1984) found that male and female bisexuals had more heterosexual fantasy than heterosexuals. Dixon (1985) found that bisexual men had more sexual activities with women than did heterosexual men. Bisexual men masturbated more but had less happy marriages than heterosexuals. Bressler and Lavender (1986) found that bisexual women had more orgasms per week and they described them as stronger than did hetero or homosexual women. Goode and Haber (1977) found bisexual women to sexually mature earlier, masturbate and enjoy masturbation more and to be more experienced in different types of heterosexual contact.
More recent research, however, associates high sex drive and increased attraction to both sexes only in women. Bisexual men's pattern has been more similar to heterosexuals with a stronger correlation with high sex drive and other-sex attraction.
Masculinization of women and hypermasculinization of men has been a central theme in sexual orientation research. There are several studies suggesting that bisexuals have a high degree of masculinization. LaTorre and Wendenberg (1983) found differing personality characteristics for bisexual, heterosexual and lesbian women. Bisexuals were consistently more masculine than other subjects.
Women usually have a better hearing sensitivity than males, but homosexual and bisexual women have been found to have weaker sensitivity than heterosexual women while homosexual and bisexual men have hypermasculinized hearing.
Prenatal hormones
The prenatal hormonal theory of sexual orientation suggests that people who are exposed to excess levels of sex hormones have masculinized brains and show increased homosexuality. Studies to provide evidence for the masculinization of the brain have however not been conducted to date. Research on special conditions such as Homosexuality and Christianity and DES indicate that prenatal exposure to, respectively, excess testosterone and estrogens are associated with female–female sex fantasies in adults. Both effects are associated with bisexuality rather than homosexuality.
There is research evidence that the ratio of the length of the 2nd and 4th digits (index finger and ring finger) is somewhat negatively related to prenatal testosterone and positively to oestrogen. Studies measuring the fingers found a statistically significant skew in the 2D:4D ratio (long ring finger) towards homosexuality with an even lower ratio in bisexuals. It is suggested that exposure to high prenatal testosterone and low prenatal oestrogen concentrations is one cause of homosexuality whereas exposure to very high testosterone levels may be associated with bisexuality. Because testosterone in genereal is important for sexual differentiation, this view offers an alternative to the suggestion that male homosexuality is genetic.
Brain structure
There is some evidence to support the concept of biological precursors of bisexual orientation in genetic males. According to Money (1988), men with an extra Y chromosome are more likely to be bisexual, paraphilic and impulsive.
Evolutionary theory
People may not express their sexual orientation in their sexual behavior. People with a bisexual orientation may be celibate, have sexual relationships with the same sex, the opposite sex, or both. In some places, same-sex relationships may be illegal, while other places officially recognize these relationships. Bisexual people may also enter into a mixed-orientation marriage with a member of the opposite sex.
Bisexuality in History
In some cultures, historical and literary records from most literate societies indicate that male bisexuality was common and indeed expected. These relationships were generally age-structured as in pederasty or shudo. or gender-structured as in the Two-Spirit or bacchá practices. Most of the commonly cited examples of male "homosexuality" in previous cultures would more properly be categorized as bisexuality. Determining the history of female bisexuality is more problematic, in that women in most of the studied societies were under the domination of the males, and on one hand had less self-determination and freedom of movement and expression, and on the other were not the ones writing or keeping the literary record. Sappho, however, is a notable exception.
In 124 CE the bisexual Roman emperor Hadrian met Antinous, a 13- or 14-year-old boy from Bithynia, and they began their pederastic relationship. Antinous was deified by Hadrian when he died six years later. Many statues, busts, coins and reliefs display Hadrian's deep affections for him. Ancient Rome, Arab countries up to and including the present, China, and Japan, all exhibit patterns of analogous bisexual behavior. In Japan in particular, due to its practice of shudo and the extensive art and literature associated with it, the record of a primarily bisexual lifestyle is both detailed and quite recent, dating back as recently as the 19th century. Bisexual behavior was also common among Roman and Chinese emperors, the shoguns of Japan, and others.
Ancient Greece
Ancestral law in ancient Sparta mandated same-sex relationships with youths who were coming of age for all adult men, so long as the men eventually took wives and produced children. The Spartans thought that love and erotic relationships between experienced and novice soldiers would solidify combat loyalty and encourage heroic tactics as men vied to impress their lovers. Once the younger soldiers reached maturity, the relationship was supposed to become non-sexual, but it is not clear how strictly this was followed. There was some stigma attached to young men who continued their relationships with their mentors into adulthood. For example, Aristophanes calls them euryprôktoi, meaning "wide arses", and depicts them like women.
In Ancient Greece it is believed that males generally went through a homosexual stage in adolescence, followed by a bisexual stage characterized by pederastic relationships in young adulthood, followed by a (mostly) heterosexual stage later in life, when they married and had children. Alexander the Great, the Macedonian king, is thought to have been bisexual, and to have had a male lover named Hephaestion.
Social status
Historically, bisexuality has largely been free of the social stigma associated with homosexuality, prevalent even where bisexuality was the norm. In Ancient Greece pederasty was not problematic as long as the men involved eventually married and had children. In many world cultures, homosexual affairs have been quietly accepted among upper-class men of good social standing (particularly if married), and heterosexual marriage has often been used successfully as a defense against accusations of homosexuality. On the other hand, there are bisexuals who marry or live with a heterosexual partner because they prefer the complementarity of different sexes in cohabiting and co-parenting but have felt greatly enriched by homosexual relationships alongside the marriage in both monogamous and "open" relationships.
Since the 1970s, there have been waves of bisexual chic, in which celebrities and other persons of some notoriety have embraced and advocated bisexuality. This has led to more acceptance of bisexuals in some regards; however, some have latched onto bisexual chic for publicity's sake, with varying degrees of sincerity and permanency. Such celebrities as David Bowie, Dave Navarro, Anne Heche and others have claimed bisexuality only to later renounce the idea (although Bowie has since retreated some on renunciation).
The term "flex sex" developed in the late 2000s, regarding women that generally regard themselves as heterosexual, but who occasionally have sex with other women.
Some in the homosexual community accuse those who self-identify as bisexual of duplicity, believing they are really homosexuals who engage in heterosexual activity merely to remain socially acceptable. They may be accused of "not doing their part" in gaining acceptance of "true" homosexuality. Some homosexual people may also suspect that a self-described bisexual is merely a homosexual in the initial stage of questioning their presumed heterosexuality, and will eventually accept that they are homosexual; this is expressed by a glib saying in gay culture: "Bi now, gay later." These situations can and do take place, but do not appear to be true of the majority of self-described bisexuals. Nonetheless, bisexuals do sometimes experience lesser acceptance from homosexual people, because of their declared orientation. Biphobia can sometimes be the results of repressed bisexual desire in homosexual people.
Bisexuals are often associated with men who engage in same-sex activity while closeted or heterosexually married. The majority of such men—said to be living on the down-low—do not self-identify as bisexual.
Because some bisexual people do not feel that they fit into either the homosexual or the heterosexual world, and because they have a tendency to be "invisible" in public, some bisexual persons are committed to forming their own communities, culture, and political movements. However, since "Bisexual orientation can fall anywhere between the two extremes of homosexuality and heterosexuality", some who identify as bisexual may merge themselves into either homosexual or heterosexual society. Still other bisexual people see this merging as enforced rather than voluntary; bisexual people can face exclusion from both homosexual and heterosexual society on coming out. Psychologist Beth Firestein states that bisexuals also tend to internalize social tensions related to their choice of partners. Firestein suggests bisexuals may feel pressured to label themselves as homosexuals instead of occupying a difficult middle ground in a culture that has it that if bisexuals are attracted to people of both sexes, they must have more than one partner, thus defying society's value on monogamy. These social tensions and pressure may and do affect bisexuals' mental health. Specific therapy methods have been developed for bisexuals to address this concern.
Relatively few supportive bisexual communities exist, therefore there is not as much support from people who have gone through similar experiences. This effectively can make it more difficult for bisexuals to "come out" as such.
Pride symbols
Another symbol that uses the color scheme of the bisexual pride flag is a pair of overlapping pink and blue triangles, the pink triangle being a well-known symbol for the homosexual community, forming purple where they intersect.
Many homosexual and bisexual individuals have a problem with the use of the pink triangle symbol as it was the symbol that Hitler's regime used to tag homosexuals (similar to the yellow Star of David that is constituted of two opposed, overlapping triangles). Because pink triangles were used in the persecution of homosexuals in the Nazi regime, a double moon symbol was devised specifically to avoid the use of triangles. This bisexual symbol is a double moon that is formed when the sex-specific attributes of the astrological symbol of Mars & Venus (representing heterosexual union) are reduced to the two circles open on both ends, thus symbolizing that bisexuals are open to either-sex unions. The color of the bisexual double moon symbol varies. The symbol is most often displayed with rainbow colors, signifying that bisexuals belong to the gay community. It also may appear with the pink-purple-blue colors of the bisexual pride flag. The double moon symbol is common in Germany and surrounding countries. Another symbol used for bisexuality is a purple diamond. From an upside down triangle and a right way up one, pink and blue, placed overlapping.
Bisexuality in animals
Many non-human animal species also exhibit bisexual behavior. This is, of course, common in hermaphroditic animals, but is also known in many other species. Examples of mammals include the bonobo (formerly known as the pygmy chimpanzee), orca, and bottlenose dolphin. Examples of avians include some species of gulls and Humboldt Penguins. Other examples occur among fish, flatworms, and crustaceans.
Many species of animals are involved in the act of forming sexual and relationship bonds between the same sex; even when offered the opportunity to breed with members of the opposite sex, they picked the same sex. Some of these species are gazelles, antelope, bison, and sage grouse.
In some cases animals will choose intercourse with different sexes at different times in their life, and sometimes will perform intercourse with different sexes at random. Homosexual intercourse can also be seasonal in some animals like male walruses, who often engage in homosexual intercourse with each other outside of the breeding season and will revert to heterosexual intercourse during breeding season.
In some cases bisexuality is actually a form of fitness favored by evolution. For example, in the absence of male whiptail lizards (Cnemidophorus), females reproduce by pairing up with each other. During the breeding season females will take turns switching between "male" and "female" roles as their hormones fluctuate. Estrogen levels are high during ovulation ("female" role) and much lower after laying eggs ("male" role). While in the "male" role, a female lizard will mount another in the "female" role and go through the motions of sex to stimulate egg-laying. The hatchlings produced are all female. This all-female species has evolved from lizards with two sexes, but their eggs develop without fertilization (parthenogenesis). Female whiptail lizards can lay eggs without sex, but they lay far fewer eggs than if they engage in sexual stimulation by another female.
Bisexuality in culture
Comparatively positive and notable portrayals of bisexuality can be found throughout mainstream media.
In movies such as: The Pillow Book (film); Alexander (film); The Rocky Horror Picture Show; Henry and June; Chasing Amy; Kissing Jessica Stein, The Fourth Man, Basic Instinct and Brokeback Mountain.
Especially noteworthy are the bisexual themes in the films of Federico Fellini. While individual films are rarely "bisexual" themselves, he has made films that both employ prominent heterosexual characters and themes La Strada, La Dolce Vita, 8 1/2, and Amarcord and also made blatantly homosexual themed films such as Satyricon and involving homosexual themes and characters in many of his less famous films. Fellini was suspected of being bisexual in real life, though the extent to which he had many sexual relationships at all, much less of both sexes, is unclear.
In popular music, many of the songs of The Smiths are commonly cited as classic examples. In the songs and stage presentation of Suzie Quatro and Joan Jett, there have been additional examples. In 1995, Jill Sobule sung about bi-curiosity in her song "I Kissed a Girl". The video for the song was slightly less subtle alternating images of Jill Sobule and her boyrfriend (played by Fabio) with images of her with her girlfriend. the song appeared on Beavis and Butt-head. The recently popular song "I Kissed a Girl" by Katy Perry also hints at bisexuality, or at least bi-curiosity, with lyrics such as "I kissed a girl just to try it/I hope my boyfriend don't mind it" and "You're my experimental game/Just human nature".
In notable graphic novels, Love and Rockets (1981 to 1996) subtly portrays bisexuality; Krazy Kat (1913 to 1944) is a comic-strip character whose love is not limited by sex; Alan Moore's Lost Girls (1991 to 2006) portrays bisexual versions of three famous literary characters; Terry Moore's Strangers in Paradise (1993 to 2007) includes several bisexual characters.
Notable novels containing significant bisexual characters are:
Non-fiction scholarship, such as Marjorie Garber's Vice Versa: Bisexuality and the Eroticism of Everyday Life (1995), and Camille Paglia's Sexual Personae (1990), has uncovered previously hidden histories of bisexuality.
On the TV sitcom Will & Grace, the character of Karen Walker appears to be bisexual and—although married to a man—often kisses Grace and seems to have had many female lovers throughout her life. The character Jack Harkness of Doctor Who and Torchwood is from 51st century, in which mankind has become more open minded sexually since it's integration with alien cultures. He is often described as "omnisexual" by his fans, remarking on the question of sexual orientation "You people and your quaint little categories." Harkness is the first openly non-heterosexual character depicted in the long-running Doctor Who. Torchwood also features bisexual characters Toshiko Sato, and Ianto Jones. Rebecca Romijn portrayed a bisexual con artist in the film Femme Fatale.
In the sci-fi television series Babylon 5, characters including Susan Ivanova and Talia Winters are portrayed as bisexual or pansexual. There seems to be a general feeling in the show that it is accepted and common for people to follow their hearts wherever they may take them, ignoring sex. Other examples include the characters Marcus Cole and Stephen Franklin posing as a married couple, and series creator J. Michael Straczynski indicating that the station commander John Sheridan would have been propositioned by the male Lumati ambassador if Susan Ivanova had not been handling those negotiations.
In the 1996 Broadway musical turned movie Rent, Idina Menzel plays Maureen Johnson, a character who has a relationship with both Mark Cohen (Anthony Rapp [who is openly bisexual in real life]), and Joanne Jefferson (Tracie Thoms/Fredi Walker). In the musical, Menzel's character sings the following lines in the song "Take Me or Leave Me":
Ever since puberty, everybody stares at me,
Boys, girls—I can't help it, baby
In the television program "Bottom", Richie is shown consistently throughout the series to be trying to get a girlfriend but to be either secretly attracted to men or accidentally finding more luck with men. He maintains a facade of heterosexuality throughout this, although in the stage adaptations he is shown to be far more attracted to men but still also to women.
In the video game series Metal Gear Solid, the villain Vamp is known to be bisexual, as reported by Hideo Kojima. In the Fox television series, The O.C., Marissa Cooper (played by Mischa Barton ) has a same-sex fling with the character Alex Kelly, played by Olivia Wilde.
The high rated MTV series, A Shot At Love With Tila Tequila, is a bisexual reality show. Tila Tequila or Tila Nguyen, is the bisexual bachelorette, trying to find love from 16 straight males and 16 lesbians.
The tv series Buffy the Vampire Slayer the character Willow Rosenberg, while identifying as a lesbian, is hinted to have a bisexual side to her. She forms strong heterosexual relationships across the first 3 seasons and her vampire alter ego displays overt bisexuality.
In the medical comedy Scrubs the surgeon Todd is a misogynist who makes sex jokes at any opportunity. In the earlier seasons he is hinted at having gay tendencies and in the season five episode My Lunch he is seen looking at pictures of topless men. Elliott and Carla convince him to come out but at the end of the episode he is revealed to be bisexual and walks down the hallway, hitting on a male and female nurse. The janitor asks him "What the hell are you?" to which he replies "I'm the Todd".
Media stereotypes
There are also negative media portrayals—references sometimes made to stereotypes or mental disorders.
In an article about Brokeback Mountain, sex educator Amy Andre argued that in films, bisexuals are always depicted negatively:
Using a content analysis of more than 170 articles written between 2001 and 2006, sociologist Richard N. Pitt, Jr. concluded that the media pathologized black bisexual men’s behavior while either ignoring or sympathizing with white bisexual men’s similar actions. He argued that the "Down Low" black bisexual is often described negatively as a duplicitous heterosexual man whose behaviors threaten the black community. Alternately, the "Brokeback" white bisexual (when seen as bisexual at all) is often described in pitying language as a victimized homosexual man who is forced into the closet by the heterosexist society around him.
On the HBO drama Oz, Christopher Meloni played Chris Keller, a bisexual sociopath who tortured, raped, and had numerous sexual encounters with various men and women whom he met. Desperate Housewives features Andrew Van De Kamp.
A Saturday Night Live joke ran thus:
"A bisexual is a person who reaches down the front of somebody's pants and is satisfied with whatever they find." -- Dana Carvey as The Church Lady, Saturday Night Live.
Movies in which the bisexual characters conceal murderous neuroses include Basic Instinct, Black Widow, Blue Velvet, Cruising, and Girl, Interrupted.
In one of his comedy routines, George Carlin admits to thinking about what a curse bisexuality must be: "Could you imagine wanting to fuck everybody you meet? Think of all the phone numbers you'd accumulate! You might as well just walk around with the White Pages under your arms."
See also
Further reading
• Sigmund Freud. Three Contributions to the Theory of Sex. ISBN 0486416038
Ancient Greece
By country
• Stephen O. Murray and Will Roscoe, et al. Islamic Homosexualities: Culture, History, and Literature, New York: New York University Press, 1997. ISBN 0-8147-7468-7
• J. Wright & Everett Rowson. Homoeroticism in Classical Arabic Literature. 1998. ISBN 023110507X (pbbk)/ ISBN 0231105061 (hdbk)
• Gary Leupp. Male Colors: The Construction of Homosexuality in Tokugawa Japan, Berkeley, University of California Press, 1995. ISBN 0-520-20900-1
• Tsuneo Watanabe & Jun'ichi Iwata. The Love of the Samurai. A Thousand Years of Japanese Homosexuality, London: GMP Publishers, 1987. ISBN 0-85449-115-5
Modern Western
• Bi Any Other Name : Bisexual People Speak Out by Loraine Hutchins, Editor & Lani Ka'ahumanu, Editor ISBN 1-55583-174-5
• Getting Bi : Voices of Bisexuals Around the World by Robyn Ochs, Editor & Sarah Rowley, Editor ISBN 0-9653881-4-X
• The Bisexual Option by Fritz Klein, MD ISBN 1-56023-033-9
• Bi Men : Coming Out Every Which Way by Ron Suresha and Pete Chvany, Editors ISBN 978-1-56023-615-9
• Bi America : Myths, Truths, And Struggles Of An Invisible Community by William E. Burleson ISBN 978-1-56023-478-4
• Bisexuality in the United States : A Social Science Reader by Paula C. Rodriguez Rust, Editor ISBN 0-231-10226-7
• Bisexuality : The Psychology and Politics of an Invisible Minority by Beth A. Firestein, Editor ISBN 0-8039-7274-1
• Current Research on Bisexuality by Ronald C. Fox PhD, Editor ISBN 978-1-56023-288-5
• Exploring Biphobia (144 KB PDF). Report on the problems caused by stereotyping of bisexuals.
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Human–machine interface
From Wikipedia, the free encyclopedia
(Redirected from Human-machine interface)
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A human–machine interface usually involves peripheral hardware for the INPUT and for the OUTPUT. Often there is an additional component implemented in software, like e.g. a graphical user interface.
Human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of that part of the Human Machine Interface which we can see and touch.
The engineering of the human–machine interfaces is by considering ergonomics (Human Factors). The corresponding disciplines are Human Factors Engineering (HFE) and Usability Engineering (UE), which is part of Systems Engineering.
Tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the expression Graphical User Interface for human–machine interface on computers, as nearly all of them are now using graphics.
Primary methods used in the interface design include prototyping and simulation.
Interface design[edit]
See also[edit] |
Shyama Sangeet
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Shyama Sangeet (Bengali: শ্যামা সঙ্গীত ) is a genre of Bengali devotional songs dedicated to the Hindu goddess Shyama or Kali which is a form of supreme universal mother-goddess Durga or parvati. It is also known as Shaktagiti or Durgastuti.[1]
During the 12th-13th centuries when Shaktism grew in Bengal, it inspired a number of poets to compose poems on Kali. Mukundarāma, known as Kavikaṅkaṇ or 'gem of poets, ' wrote his chief poem, the epic Chaṇḍī, in 1589. Towards the middle of the 18th century, the poet Ramprasad Sen instilled new life into it and turned it into a distinct genre of Bengali songs.
Ramprasad was succeeded by number of composers like Kamlakanta Bhattacharya (1772–1821), Rasikchandra Ray (1820–1893), Ramchandra Datta (1861–1899), and Nilakantha Mukhopadhyaya. In modern times both Rabindranath Tagore and Kazi Nazrul Islam have composed poems of Shyama Sangeet genre.
The term 'Shyama' refers to the skin color of Kali (usually depicted in black or deep blue.) Literally, it means dusky.
Shyamasangeet can be divided into two streams: devotional or metaphysical and Durgastuti, Umasangit, Agamani or Vijaya songs. The first category of songs is inspired by devotion and spiritual thoughts. The second category which is based on themes of daily family matters or social events, is known as Padavali, Umasangit, Agamani or Vijaya songs.
Shyama Sangeet conceptualizes Goddess Kali as a loving human mother and the singer is longing for The Mother’s love. The songs have become popular not only for its devotional side, but also for its human appeal.
The theme and occasion of Āgāmanī and Vijayā songs are as follows. Parvati (Umā or Gaurī), daughter of Himālaya and Menakā, was married to Śiva, the Lord of Kailāsa. Parvati as the form of Goddess Durga (the supreme universal mother-goddess) comes to see her parents from her in laws every year. The goddess is portrayed here as an ordinary girl living far away from her mother and feels joyous to come back home after a long stay at her in laws’ place. These songs too are highly popular because of their human appeal and as they are easily identifiable with any married girl living far away from their parents.
What Edward Thompson wrote in 1923 is true even today.
But the Śākta poems are a different matter. These have gone to the heart of a people as few poets' work has done. Such songs as the exquisite 'This day will surely pass, Mother, this day will pass,' I have heard from coolies on the road or workers in the paddy fields; I have heard it by broad rivers at sunset, when the parrots were flying to roost and the village folk thronging from marketing to the ferry. Once I asked the top class in a mofussil high school to write out a song of Rabindranath Tagore's; two boys out of forty succeeded, a result which I consider showed the very real diffusion of his songs. But, when I asked for a song of Rāmprasād's, every boy except two responded. Truly, a poet who is known both by work and name to boys between fourteen and eighteen, is a national poet. Tagore's songs are heard in Calcutta streets, and have been widely spread by the student community and the Brahmo Samaj; but in the villages of Bengal they are unknown, while Rāmprasād's are heard everywhere. 'The peasants and the paṇḍits enjoy his songs equally. They draw solace from them in the hour of despair and even at the moment of death. The dying man brought to the banks of the Ganges asks his companions to sing Rāmprasādī songs.[2]
Shayama sangeet become more popular at the time of Sri Ramkrishna Paramahansa, who was an ardent Kali bhakta/devotee. Ramprasad Sen, Rabindranath Thakur/Tagore, Girishchandra Ghosh, and Swami Vivekananda, among others, composed numerous Shyama Sangeet. India's national song, 'Vande Maataram'/'Hail to the Mother', whose lyrics were written by Bankimchandra Chatterjee/Chattopadhyay and whose music was composed by Thakur/Tagpre, is first and foremost a hymn to Ma Durga which hails the Indian motherland, "Bharat Mata", as being a form of the supreme goddess Durga. Rabindranath Thakur/Tagore's 'Jana Gana Mana', the Indian national anthem, contains a line, "Snehamayee tumi mata", which literally means India is a loving mother ("Bharat mata")... Rabindranath Thakur/Tagore also composed a song which was later picked to be the national anthem of Bangladesh ('Amar Sonar Bangla'/'My golden Bengal') in which he refers to the entirety of Bengal (undivided Bengal; the song was written before the split of West Bengal and Bangladesh) as being a segment of the body of the supreme mother.
1. ^ "Shyamasangit". Banglapedia. Retrieved 25 February 2012.
2. ^ Thompson, Edward. J. and Spencer, Arthur Marshman, Bengali Religious Lyrics, Śākta, Oxford University Press, London, 1923. p 19
• Thompson, Edward. J. and Spencer, Arthur Marshman, Bengali Religious Lyrics, Śākta, Oxford University Press, London, 1923. [1] |
Take the 2-minute tour ×
• How should a two year post high school curriculum focusing on
statistics instead of on calculus be designed to accomplish the
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The phrase "day to day life" seems odd to me here. Obviously you can buy groceries and balance your checkbook without knowing calculus or statistics. If you're talking about people's professional life, then it depends completely on their profession. Engineering majors are the single largest group of students who take calculus. They need to understand calculus in order to do engineering. – Ben Crowell Dec 16 at 2:00
3 Answers 3
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Introduction to Simple Linear Regression (SLR) & R
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For high school math students, there are two basic "tracks." One leads to pre-calculus and calculus, etc. The other is called "general math."
Statistics makes a good "general math" study for students who don't want to pursue calculus. That is because it deals with things that are found in everyday life, such as the "averages" and "dispersions" of things like height, weight, grades,and other key attributes for high school students.
Calculus-bound students could also benefit from the study of statistics (and probability), but they can wait to take the calculus first, and then learn about integrating conditional density functions in probability, or differentiating normal equations in statistics.
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If you have ever looked at the end of a crane, or if you have ever used an engine hoist or a come-along, or if you have ever looked at the rigging on a sailboat, then you have seen a block and tackle at work. A block and tackle is an arrangement of rope and pulleys that allows you to trade force for distance. In this edition of How Stuff Works we will look at how a block and tackle works, and also examine several other force-multiplying devices!
Understanding the Block and Tackle
Imagine that you have the arrangement of a 100 pound (45.4 kilogram) weight suspended from a rope, as shown here.
In this figure, if you are going to suspend the weight in the air then you have to apply an upward force of 100 pounds to the rope. If the rope is 100 feet (30.5 meters) long and you want to lift the weight up 100 feet, you have to pull in 100 feet of rope to do it. This is simple and obvious.
Now imagine that you add a pulley to the mix.
Does this change anything? Not really. The only thing that changes is the direction of the force you have to apply to lift the weight. You still have to apply 100 pounds of force to keep the weight suspended, and you still have to reel in 100 feet of rope in order to lift the weight 100 feet.
The following figure shows the arrangement after adding a second pulley:
This arrangement actually does change things in an important way. You can see that the weight is now suspended by two pulleys rather than one. That means the weight is split equally between the two pulleys, so each one holds only half the weight, or 50 pounds (22.7 kilograms). That means that if you want to hold the weight suspended in the air, you only have to apply 50 pounds of force (the ceiling exerts the other 50 pounds of force on the other end of the rope). If you want to lift the weight 100 feet higher, then you have to reel in twice as much rope 0- 200 feet of rope must be pulled in. This demonstrates a force-distance tradeoff. The force has been cut in half but the distance the rope must be pulled has doubled.
The following diagram adds a third and fourth pulley to the arrangement:
In this diagram, the pulley attached to the weight actually consists of two separate pulleys on the same shaft, as shown on the right. This arrangement cuts the force in half and doubles the distance again. To hold the weight in the air you must apply only 25 pounds of force, but to lift the weight 100 feet higher in the air you must now reel in 400 feet of rope.
A block and tackle can contain as many pulleys as you like, although at some point the amount of friction in the pulley shafts begins to become a significant source of resistance. |
Inner transition metal
From Wikipedia, the free encyclopedia
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An inner transition metal is one of a group of chemical elements on the periodic table. They are normally below all of the other elements. They include elements 57-71 (lanthanides) and 89-103 (actinides). The lanthanides are very similar, and the actinides are all radioactive. They have three incomplete outermost shells and are all metals. They can be in some cases quite malleable and ductile. They do not occur in nature (except for uranium) and are highly unstable. |
What is a maternal name?
A person's maternal name is the family name, or surname, from the mother's side of the family. The maternal name remains the same even if the mother legally changes her name after marriage and never uses the maternal name.
In many countries, babies are traditionally given the father's last name or paternal name. However, other options are available. Sometimes couples create a new last name by combining parts of their surnames to give to their child. In other cases, when both partners in a marriage keep their original last name, they select the mother's surname to pass on to their offspring. Certain couples decide to give their children the hyphenated version of both the parental surnames.
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Alternative Flours
Did you know that ALL Flours are a processed food and can cause a spike in your blood sugar. If you chose to eat any flour it should only be eaten in moderation as part of clean eating meal plan. Your best option when eating bread from wheat is to eat bread made from sprouted wheat.
If your goal is to lose weight, you should avoid eating any wheat, barley or rye, including any bread made with the flour from these three grains.
• Wheat, barley and rye are high on the glycemic index chart making them “bad” carbohydrates. They can rapidly raise your blood sugar, trigger insulin and raise your blood fats (triglycerides) causing your body to go into fat storing mode.
• Wheat, barley and rye contain a protein called gluten. This protein is sometimes hard for our bodies to digest even if you are not gluten-sensitive.
If you suspect you’re gluten-sensitive or want to see if you, give up gluten for two weeks, then reintroduce it and see how you react. Your body will let you know. It’s a very powerful way to find out if gluten affects you.
Be careful when purchasing and using “Gluten Free” pre-mixed flour mixes. Most can contain a man made product called Xanthan Gum that is used to replace the gluten in wheat, barley and rye flours. Xanthum Gum was developed by the United States Department of Agriculture while it was doing experiments involving bacteria and various sugars to develop a new thickening agent similar to corn starch. Xanthan gum is used as a stabilizer or thickener and can be found in salad dressing and sauces, frozen foods and beverages.
There are alternative flours that will benefit you, even if you don’t have a gluten or wheat allergy. Here are a few healthier options for you to try:
Alternative Flours
Quinoa flour A high protein flour that has vitamins A, C, D, B1, B2, E, folic acid, niacin, calcium, iron, phosphorus, 20 amino acids(including the “10 essential amino acids) This flour has a light pleasant taste and combines well with other flours, making it my favorite flour to use.
Brown Rice Flour Milled from unpolished brown rice this flour has more nutrients than white rice flour. It has more oils than wheat flour but has a shorter shelf life.
Sorghum Flour High in soluble fiber with a taste very similar to wheat. It works best if combined with a starch, such as potato or corn starch.
Almond Meal Flour Made from blanched almonds. Great source of protein, fiber, vitamin E and Magnesium |
East African trypanosomiasis
caption Female Tsetse fly. (Source: USDA)
East African trypanosomiasis is a disease caused by a protozoan parasite that is carried by the tsetse fly. The Centers for Disease Control and Prevention (CDC) has provided the following answers to questions about the organism and the disease:
What is East African trypanosomiasis?
There are two types of African trypanosomiasis (also called sleeping sickness); each is named for the region of Africa in which they were found historically. East African trypanosomiasis is caused by the parasite Trypanosoma brucei rhodesiense (tri-PAN-o-SO-ma BREW-see-eye rho-DEE-see-ense), which is carried by the tsetse fly. Each year, 500 to 1,000 cases of East African trypanosomiasis are reported to the World Health Organization. However, many cases are not recognized or reported due to a lack of infrastructure and the true number of new cases is higher. Since 1967, thirty-seven cases of East African trypanosomiasis have been diagnosed in the United States, all among individuals who had traveled to eastern Africa. (See also West African trypanosomiasis.)
caption Blood smear showing Trypanosomes. (Source: CDC; Credit: Mae Melvin)
How is East African trypanosomiasis spread?
caption African Trypanosomiasis Life Cycle. (Source: CDC)
Is East African trypanosomiasis a serious illness?
Where can you become infected with East African trypanosomiasis?
What are the symptoms of East African trypanosomiasis?
A bite by the tsetse fly is often painful and can develop into a red sore, also called a chancre (SHAN-ker). Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness. Some people develop a skin rash. Progressive confusion, personality changes, and other neurologic problems occur after infection has invaded the central nervous system. If left untreated, infection becomes worse and death will occur within months.
Symptoms usually within 1 to 3 weeks after an infective bite.
What is the treatment for East African trypanosomiasis?
Once infected, am I immune to East African trypanosomiasis?
Who is at risk for contracting East African trypanosomiasis?
Can I take a medication to prevent East African trypanosomiasis?
How can I prevent African trypanosomiasis and prevent other insect bites?
See also West African trypanosomiasis, and American trypanosomiasis (also known as Chagas disease).
CDC Disclaimer
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Centers for Disease Control and Prevention (CDC). Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Centers for Disease Control and Prevention (CDC) should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.
(2008). East African trypanosomiasis. Retrieved from http://www.eoearth.org/view/article/51cbed737896bb431f692408
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Use of Stinging Nettles for School Corporal Punishment
August 15 2006 at 5:01 PM
I have recently read an article on the net about the use of stinging nettles in an S&M context.
This has made me think about the possibility of the use of nettles as a form of school corporal punishment. From what I have read, I think they could be the perfect method of corporal punishment for children and adolescents. There are many advantages that the use of nettles would have over the more traditional forms of punishment such as caning/paddling/slippering etc, and also many of the disadvantages are avoided. I will look as these later in this post. First, let me describe how nettles would be used as a method of punishment.
Like other forms of punishment, the nettles can be applied to the skin of the buttocks and upper thighs. They can also be applied quite safely to the immediately neighbouring and more sensitive areas without any risk of injury or damage. The buttocks must obviously be naked for the punishment to be effective. The child or adolescent to be punished would be made to bend over and lower trousers and underpants (boys) or lift skirt and lower knickers (girls) to fully display his or her bottom, whilst an appointed staff member (of the same gender for obvious reasons) would apply several freshly pulled stems or sprigs of stinging nettles all over the exposed region. The most effective method of application is simply to brush the nettle sprigs over the skin so that the stinging parts of the leaves (being the serrated edges) brush over the skin. The punished child should have their feet (or knees if in a kneeling position) well spread to allow the nettles full access to every part of the bottom. The effect of nettles is first to create a stinging sensation, but this gradually develops within an hour or so into an extremely intense fiery tingling burning and throbbing, which can last for up to 24 hours. This period is the most intense and effective part of the punishment, and a child or adolescent so punished would find it nearly impossible to either sit, or stand still during this time, or to think about anything else other than the burning tingling throbbing sensation in his or her buttocks and adjacent parts. After this intense period has faded, the skin will feel slightly sensitive and sore for a few days, after which it will be completely back to normal again.
This method of punishment would have all of the advantages of more traditional forms of punishment, and would also avoid the disadvantages for the following reasons:-
1. It creates a similar (or even greater) intensity and type of sensation in the childs buttocks as does traditional caning/slippering/paddling or birching, but avoids the injury, bruising and tissue damage that these other methods that involve beating invariably cause. In fact, nettling, as we shall call it, is completely harmless and causes virtually no physical injury or tissue damage whatsoever. The natural chemicals in nettles which cause the stinging are completely safe and harmless, and remain localised to the area of skin to which they are applied. Although the initial pain of the nettle stings is not as intense as a cane or paddle blow, the intensity and duration of the aftermath of a severe nettling is much longer lasting, with a burning throbbing and tingling sensation in the affected area which is virtually unbearable for several hours, but then fades completely, leaving absolutely no tissue damage or internal scar tissue, as can be the case with caning or paddling.
2. As nettling does not involve hitting or blows of any kind, but the simple brushing of nettles against the skin, the anti-corporal punishment do gooders would be silenced. The never hit a child campaign would have to rethink their name. As nettling is totally safe, and causes no physical injury or tissue damage at all, it would be far more difficult for the anti-punishment people to oppose on those grounds, as they oppose beating forms of punishment.
3. As with beating forms of punishment, the severity of a nettling can be varied to suit the offence for which the child/adolescent is being punished. This is simply achieved by increasing or decreasing the time of the actual nettling, and the number of nettle sprigs used. A sprig of nettles will lose some of its effectiveness after being brushed against the skin for about 20 seconds, as the stings are used up. Nettlings could therefore be classified by the number of sprigs/stems used, similar to how the number strokes used in conventional corporal punishment determines the severity. A mild nettling may therefore use say, 3 sprigs/stems and take one minute, whereas a severe one might use 15 sprigs/stems, and take five minutes to administer, with 20 seconds of brushing with each sprig of nettle leaves before it is discarded.
4. As nettlings have to be applied bare bottom, the avoidance techniques used by schoolchildren to lessen the effect of traditional forms of punishment (e.g. extra padding underneath pants/knickers) would not be possible. However, I would add the following note of caution. There is, in fact, an natural antidote to the effect of stinging nettles, which considerably counteracts and lessens the intensity of the burning/throbbing and tingling. That natural antidote is urine. Therefore, if nettling became established as a method of corporal punishment in schools, and this antidote becomes generally known amongst children/adolescents, which inevitably it will, it doesnt take a brain surgeon to work out what will happen. Very soon all schoolchildren/adolescents/teenagers, (especially girls), will soon discover that by discreetly wetting their knickers after a severe nettling, they can lessen the burning, throbbing and tingling in their bottoms. Girls would be at a distinct advantage over boys in this respect for the following two reasons:
(i) When a girl wets herself, the urine naturally tends to spread from the gusset of her knickers rearwards to the seat area, providing soothing exactly where the girl needs it. This is not the case for boys.
(ii) It is much easier for a girl to wet herself discreetly, where the school uniform requires a skirt or dress, so that the wet area of her knickers will not normally directly contact her outer clothing and therefore show a visible wet patch. Again, for boys wearing trousers, this will not be the case.
Therefore, school authorities would need to have policies in place, with particular attention to girls, to prevent such avoidance tricks
However, this is a small problem which could easily be resolved with suitable deterrents. I would recommend that any girl (or boy) found with wet knickers or pants within 24 hours of being nettled would have their nettling repeated with double the dose the next day.
So, what do you think?
Out of interest, does anyone know of nettles being used for school/institutional punishment in history?
Respond to this message
A further point
August 15 2006, 5:13 PM
I must just add a point about what I mean by child/adolescent etc. in respect of the ages for which nettling punishment in schools would be appropriate. As far as I am concerned, it is suitable for all children of UK secondary school age and above, that is both boys and girls in the age range from 11 up to 18. Obviously the severity should increase proportionally with the age of the child. Therefore, for a sixteen year old, say, a 5 minute, 15 sprig nettling would be appropriate, with this severity decreased or increased for adolescents/teens below or above that age accordingly.
Wembley Man
Re: A further point
August 15 2006, 5:38 PM
Im very much in favour of this, but getting fresh nettles would be a problem. Schools are unable to grow their own nowadays, having sold off every last bit of land to the likes of Burger King and Spud-U-Like.
Therefore, as an alternative to nettling, I suggest sandpapering.
Bob T
Re: A further point
August 15 2006, 5:55 PM
This just proves there are more horses asses in this world than there are horses.
Steve M
Re: A further point
August 15 2006, 6:00 PM
There was a reference in Under Milk Wood to rhubarb sticks being used.
Having had the fortune to use one on a compliant 16 yr old(and I was 16,then,too!!), it was "enjoyed" by sticker & stickee!
Nettles would need a serious supply of garden gloves,fairly heavy duty ones too, to the nettler. This might be a cost factor-the other is the destruction of a VERY significant source of food for butterflies. That might surprise you from a man with 12 cats,but the more that breed in my garden, the more the cats get just bored with the plethora of easy kills & let sunning butterflies sun.
I'd have to say there would also be a case for using the nettle to beat the victim-after all, if the stem is thick enough to simulate a cane, the merest contact with those leaves would be sufficient stingies for most miscreants.
Whatever, it would bring a new meaning to getting nettled!
Lotta Nonsense
Re: A further point
August 15 2006, 6:19 PM
Disciplinarian, please get therapy!
Ants in their Pants
August 16 2006, 4:02 PM
What an excellent idea Disciplinarian. As an alternative we should also explore the use of ants. Certain species of ants can deliver a sting that is quite painful. If the headmaster or headmistress of the school kept a suitable supply of stinging ants in an ant farm in his or her study they could be used in a similar way to the nettles.
The miscreant would be required to lower their trousers and underpants in the case of boys, lift up their skirts and lower their knickers in the case of girls, and then bend over a chair or desk. The head teacher would then place a number of stinging ants appropriate to the punishment on the bare bottom of the pupil. Ten ants might be suitable for a minor offence such as talking back to a teacher. Forty ants could be used for more serious offences such as smoking dope or cheating on an exam. The head teacher would use tweezers to pick the ants out of the ant farm and spread them evenly over the bare bottom.
Once all the stinging ants are in position, the pupil would be required to pull up their knickers or pants therby trapping the ants inside their pants and then return to class.
Ants in their pants
August 16 2006, 6:17 PM
An interesting idea Dave, but I think that certainly in the UK anyway, the availability and, if necessary the cultivation, of nettles would be more practical for schools to administer. Most schools have some areas of free land, e.g. around the borders of the playing fields, and around the school campus itself which would easily be sufficient area to maintain a plentiful supply. A heated greenhouse may, however, be required to maintain the supply though the winter months.
Bob T
Re: Ants in their pants
August 16 2006, 7:40 PM
Finally, a solution to the discipline problem in schools! Just look what can be accomplished when people of your ilk put their heads together. I reccomend this ant > http://en.wikipedia.org/wiki/Paraponera . Of course you wouldn't want any of them getting loose.
more nettling
September 23 2006, 2:33 AM
I agree with the use of nettles on both schoolboys and girls of all ages 11 - 16. A slight change to your method would be to make the pupils change into gym kit i.e tight fitting pants and shorts for the boys and p.e knickers for the girls. What you do is put the nettles down the back and front of there pants and make them keep them in for a set amout of time i.e 5 - 15 mins. You make them walk of run or do other excercise till the pain builds up beyond belive. then you pull the nettles out.
I can asure you this is a very painfull punishment and very affective.
Steve M
Re: more nettling
September 23 2006, 1:41 PM
Just a thought, but are there any species of ants known for their nettle-harvesting tendencies?
We could then combine the "best" of both worlds. Might also save a heap of money re juvenile offenders-all the probation officers could start as nettle harvesters or ant trainers,too.
After use, the nettles could also be boiled down to provide excellent soup for Jamie Oliver's new school dinners!
Isn't it wonderful how we think outside the box on here?
Bob T
Re: more nettling
September 23 2006, 5:20 PM
I suggest we do a full round of testing first. I'm sure Steve, nettles, and Disciplinarian will be happy to volunteer. We can start with some Fire Ants and work our way up to the Bullet Ants.
Stinging nettles
September 24 2006, 9:54 AM
A good idea of punishing without the hassle of caning or spanking!!
But I have a few doubts:
1. How does one ensure that there's no bleeding?
2. Can nettling cause damage if applied to testicles for boys/vagina for girls?
I am sure that the knowledgeable Mr. Disciplinarian will have a answer to these questions!
This subject...
April 28 2008, 11:31 PM
Well, I must admit, I had never heard of "nettles punishment" until I read this. But then, being American, I suppose that's not too surprising...
I know that in the Victorian era, as a way to prevent masturbation & "impure thoughts" in boys, it was a practice to fit a locking cage-like device with barbs inside over around the genitals (such "chastity" appliances are employed in the BDSM scene today) but the notion of something like "nettles" I find curious; and, yes, kinky... And unduly sadistic, likely harmful, and most probably illegal...
Indulge me to aver here the way used to tame & discipline boys at the school I attended as a youth as an alternative in this regard, as it worked amazingly well:
Simply, you'd be made to spend several days going in a pair of inordinately brief & snug short pants-- during which time you were subject to (often) having your naked thighs whacked with a ruler (whenever a teacher deemed you'd "earned" it). The pain of being swatted on one's inner-thighs is quite more "impressive" than even a bare-bottom spanking; likewise, the humiliation of being exhibited so barelegged total. It was a dreaded punishment only more awful to endure, which is why it "worked" so well as a deterrent to bad behavior & to instilling good...
Anyway, thanks for your interest...
April 29 2008, 11:17 AM
Flagellation upon the bare posterior is very theraputic and was practised in medieval times by religious penitants without pants.
nowadays it can be indulged in by health crazy women if desired as a tonic and invigorating toner.!
i would be glad to offer an introductory course at £15 a lesson.
Tight lycra bottoms are not advised as afterwards sitting will be extremly painful.
the nettles (stingius bumus)are organically grown in woods around the land and near fairy groves.
a big bunch is required for the fatter arse.
it has the merits of being a particularly quiet form of flagellation avoiding the loud cracks and yells of a bull whip that so alarm pikknikers and local livestock.
all that is heard is the rustle and swish swish swish sound.
after 10 minutes of the nettle cure a state of nirvana is achieved or ought to be
the arse comes over in a red tingling glow and exitation may result.
however it can be a bit sore sitting all the way back on the 408 from Banstead Woods.
mandatory chatting about your experince with the girls later is reccomended.
please ignore any sour comments like "'e did wot?filthy perv"
they are most probably just jealous
Re: Use of Stinging Nettles for School Corporal Punishment
April 30 2008, 9:08 AM
Brilliant Bozo.
Thanks for the cheer up this morning.
June 8 2012, 10:27 PM
Nettles are perfect for discipline!! A guy who deals with me on a regular basis loves to have a fresh bundle of nettles ready (when available) to rub my back with - man does that hurt! But it's perfect - you can have your bare back punished without the risks involved with whipping and hardly any marks either - all gone the next day. So I highly recommend the method.
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The Black Cat
The Black Cat
by Edgar Allan Poe
Violence Theme
In "The Black Cat" the unnamed narrator offers us a parade of violent acts. Eye gouging, hanging, axing – these are the gruesome highlights. Until the end of the story, when somebody is killed, the detailed accounts of violence are focused on Pluto, the black cat who moves from pampered pet to persecuted beast. The violence the unnamed narrator practices against his wife and the other pets is rather vague. Yet, we get a pretty clear picture of what is happening. And by the end of the story the narrator has completely destroyed his family, and perhaps, completely destroyed himself in the process. In this horror classic, violence is an insidious beast that creeps, spreads, and grows uncontrollably, destroying all the bodies and minds it touches.
Questions About Violence
1. How did you react to the violence in the story? Was there a particular act of violence that struck you? If so, which one?
2. What do you think made the man turn violent? Do you believe him when he implies he wasn't violent before he got married and started drinking? Try to use the text to support your answer.
3. Does the man do violence to himself? If so, how? If not, why not?
4. Is there psychological abuse in the story? If so, where do you see it? Does the narrator state it explicitly, or is it only implied? Pick a passage to show what you mean.
Chew on This
Even though the man's says he loved his wife, he becomes violent because he isn't happy in his married life.
By focusing attention on helpless pets "The Black Cat" is an example of how art and activism can work hand in hand.
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The Mathematical Formula That Proves Cow-Tipping Is a Myth
Can you tip a car over? No? Then you probably can't tip over a cow.
Shutterstock/Andreas Gradin
Cow-tipping: the ultimate urban rural legend.
In an article for Modern Farmer, Jake Swearingen explains why the activity -- a pastime that has inspired so many drunken teenagers across so many stretches of pasture -- is one that exists, in the end, only in our minds.
Reason number one: The phenomenon is not documented anywhere on YouTube. Like, anywhere. And if there's one place where cow-tipping would be documented, it would be YouTube.
Reason number two: Actual farmers don't think cow-tipping is real. "There’s more cows that have been tipped in people’s imaginations,” Nate Wilson, a veteran dairy farmer, tells Swearingen, “than in the real world.”
Reason number three: Cows don't actually sleep standing up. Horses do; cows tend to rest on their stomachs. So the core logic of cow-tipping -- taking advantage of a slumbering beast while it's doing its slumbering -- is based on a lie.
The big reason, though -- reason number four -- is simpler. And also more complicated. Physically, mathematically, scientifically ... cow-tipping is simply not feasible. As Swearingen explains,
Swearingen is basing that analysis on a 2005 study conducted by University of British Columbia researchers Margo Lillie and Tracy Boechler -- and on an equation the pair created to determine the force required to, yep, tip a cow. (You have to factor in not just the animal's mass, but also its ability to brace itself against would-be tippers.) As Boechler explained of the equation, "a cow of 1.45 meters in height pushed at an angle of 23.4 degrees relative to the ground would require 2,910 Newtons of force, equivalent to 4.43 people."
In other words:
In other words: Tipping a cow -- toppling a beast that weighs nearly a ton -- would require a coordinated effort among four-or-maybe-five (and-maybe-even-more) people. And those people, if humanity's previous attempts at cow-tipping are any guide, would probably be drunk as they make that effort. "It just makes the physics of it all, in my opinion," Lillie tells Swearingen, "impossible." Not to mention extremely uncool to the cow.
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Megan Garber is a staff writer at The Atlantic.
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Chapter 1 - The Republic
Government Country Info Symbols Constitution Holidays Map
Article 1 [Establishment of the Republic of Namibia and Identification of its Territory]
3. The main organs of the State shall be the Executive, the Legislature and the Judiciary.
4. The national territory of Namibia shall consist of the whole of the territory recognized by the international community through the organs of the United Nations as Namibia, including the enclave, harbour and port of Walvis Bay, as well as the off-shore islands of Namibia, and its southern boundary shall extend to the middle of the Orange River.
5. Windhoek shall be the seat of central Government.
6. This Constitution shall be the Supreme Law of Namibia.
Article 2 [National Symbols]
1. Namibia shall have a National Flag, the description of which is set out in Schedule 6.
3. (a) The National Seal of the Republic of Namibia shall show the Coat of Arms circumscribed with the word ’NAMIBIA’ and the motto of the country, which shall be determined by Act of Parliament as aforesaid.
Article 3 [Language]
1. The official language of Namibia shall be English.
3. Nothing contained in Paragraph (1) shall preclude legislation by Parliament which permits the use of a language other than English for legislative, administrative and judicial purposes in regions or areas where such other language or languages are spoken by a substantial component of the population. |
• n. A word, such as a noun, verb, or adjective, that has a statable lexical meaning, rather than indicating a syntactic function, as a function word does.
from Wiktionary, Creative Commons Attribution/Share-Alike License
• n. A word that is not a function word, including nouns, verbs, adjectives, and most adverbs with the exception of the likes of "then" and "why".
• n. a word to which an independent meaning can be assigned
Sorry, no etymologies found.
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Amazing Data
Dogs and Cats
Category: Amazing pictures
Pets have always played an important role in human kind history and have followed us from the down of civilization. But none are more preferred than dogs and cats. But first let us ask ourselves…
Why do we keep pets:
Adopting a pet can be a great way to reduce our every day stresses .In addition, there are many other reasons why adopting a dog or cat can be important in anyone’s life.
Presenting first contestant, DOG:
The dog (Canis lupus familiaris) is a domesticated subspecies of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history.
Dog humans best friend:
Domestic dogs inherited a complex social hierarchy and behaviors from their ancestor, the wolf. Dogs are pack animals with a complex set of behaviors related to determining each dog’s position in the social hierarchy, and they exhibit various postures and other means of nonverbal communication that reveal their states of mind. These sophisticated forms of social cognition and communication may account for their trainability, playfulness, and ability to fit into human households and social situations, and these attributes have earned dogs a unique relationship with humans despite being potentially dangerous apex predators.
Although experts largely disagree over the details of dog domestication, it is agreed that human interaction played a significant role in shaping the subspecies. Shortly after domestication, dogs became ubiquitous in human populations, and spread throughout the world. Emigrants from Siberia likely crossed the Bering Strait with dogs in their company, and some experts suggest that use of sled dogs may have been critical to the success of the waves that entered North America roughly 12,000 years ago. Dogs were an important part of life for the Athabascan population in North America, and were their only domesticated animal. Dogs also carried much of the load in the migration of the Apache and Navajo tribes 1,400 years ago. Use of dogs as pack animals in these cultures often persisted after the introduction of the horse to North America.
Presenting second contestant, CAT:
Cats and humans:
Human attitudes toward cats vary widely. Some people keep cats for casual companionship as pets. Cats are also bred and shown as registered pedigree pets, in a hobby known as the cat fancy.
Because of their small size, domesticated house cats pose almost no major danger to adult humans — the main hazard is the possibility of infection (e.g., cat scratch disease, or, rarely, rabies) from a cat bite or scratch. Cats can also potentially inflict severe scratches or puncture an eye, though this is quite rare (although dogs have been known to be blinded by cats in fights, where the cat specifically and accurately targeted the eyes of the larger animal).
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From Wikipedia, the free encyclopedia - View original article
Great creator god in Inca mythology
Offspring(according to some legends) Inti, Killa, Pachamama
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Great creator god in Inca mythology
Offspring(according to some legends) Inti, Killa, Pachamama
This article is about the Andean deity. For other uses, see Wiraqucha (disambiguation).
Viracocha is the great creator god in the pre-Inca and Inca mythology in the Andes region of South America. Full name and some spelling alternatives are Wiracocha,[1] Apu Qun Tiqsi Wiraqutra, and Con-Tici (also spelled Kon-Tiki) Viracocha. Viracocha was one of the most important deities in the Inca pantheon and seen as the creator of all things, or the substance from which all things are created, and intimately associated with the sea.[2] Viracocha created the universe, sun, moon, and stars, time (by commanding the sun to move over the sky)[3] and civilization itself. Viracocha was worshipped as god of the sun and of storms. He was represented as wearing the sun for a crown, with thunderbolts in his hands, and tears descending from his eyes as rain.
Cosmogony according to Spanish accounts[edit]
According to a myth recorded by Juan de Betanzos,[4] Viracocha rose from Lake Titicaca (or sometimes the cave of Paqariq Tampu) during the time of darkness to bring forth light.[5] He made the sun, moon, and the stars. He made mankind by breathing into stones, but his first creation were brainless giants that displeased him. So he destroyed it with a flood and made a new, better one from smaller stones.[6] Viracocha eventually disappeared across the Pacific Ocean (by walking on the water), and never returned. He wandered the earth disguised as a beggar, teaching his new creations the basics of civilization, as well as working numerous miracles. He wept when he saw the plight of the creatures he had created.[citation needed] It was thought that Viracocha would re-appear in times of trouble. Pedro Sarmiento de Gamboa noted that Viracocha was described as "a man of medium height, white and dressed in a white robe like an alb secured round the waist, and that he carried a staff and a book in his hands."[7]
In one legend he had one son, Inti, and two daughters, Mama Killa and Pachamama. In this legend, he destroyed the people around Lake Titicaca with a Great Flood called Unu Pachakuti, saving two to bring civilization to the rest of the world, these two beings are Manco Cápac, the son of Inti (sometimes taken as the son of Viracocha), which name means "splendid foundation", and Mama Uqllu, which means "mother fertility". These two founded the Inca civilization carrying a golden staff, called 'tapac-yauri'. In another legend, he fathered the first eight civilized human beings. In some stories, he has a wife called Mama Qucha.
In another legend,[8] Viracocha had two sons, Imahmana Viracocha and Tocapo Viracocha. After the Great Flood and the Creation, Viracocha sent his sons to visit the tribes to the northeast and northwest to determine if they still obeyed his commandments. Viracocha himself traveled North. During their journey, Imaymana and Tocapo gave names to all the trees, flowers, fruits, and herbs. They also taught the tribes which of these were edible, which had medicinal properties, and which were poisonous. Eventually, Viracocha, Tocapo and Imahmana arrived at Cusco (in modern-day Peru) and the Pacific seacoast where they walked across the water until they disappeared. The word "Viracocha" literally means "Sea Foam."[8]
Tiqsi Huiracocha may have several meanings. In the Quechua language tiqsi means foundation or base, wira means fat, and qucha means lake, sea, or reservoir.[9] Viracocha's many epithets include great, all knowing, powerful, etc. Wiraqucha could mean "Fat (or foam) of the sea".[2][10]
The name is also interpreted as a celebration of body fat (Sea of fat), which has a long pre-Hispanic tradition in the Andes region as it is natural for the peasant rural poor to view fleshiness and excess body fat as the very sign of life, good health, strength, and beauty.[11]
Controversy over "White God"[edit]
Spanish chroniclers from the 16th century claimed that when the conquistadors led by Francisco Pizarro first encountered the Incas they were greeted as gods, "Viracochas", because their lighter skin resembled their god Viracocha.[12] This story was first reported by Pedro Cieza de León (1553) and later by Pedro Sarmiento de Gamboa. Similar accounts by Spanish chroniclers (e.g. Juan de Betanzos) describe Viracocha as a "White God", often with a beard.[13] The whiteness of Viracocha is however not mentioned in the native authentic legends of the Incas and most modern scholars therefore consider the "White God" story to be post-conquest Spanish invention.[14][15]
Moche ceramic vessels depicting bearded men
Similarly to the Incan god Viracocha, the Aztec god Quetzalcoatl and several other deities from Central and South American pantheons, Bochica is described in legends as being bearded. The beard, once believed to be a mark of a prehistoric European influence and quickly fueled and embellished by spirits of the colonial era, had its single significance in the continentally insular culture of Mesoamerica. The Anales de Cuauhtitlan is a very important early source which is particularly valuable for having been originally written in Nahuatl. The Anales de Cuauhtitlan describes the attire of Quetzalcoatl at Tula:
"Immediately he made him his green mask; he took red color with which he made the lips russet; he took yellow to make the facade; and he made the fangs; continuing, he made his beard of feathers..."[16]
In this quote the beard is represented as a dressing of feathers, fitting comfortably with academic impressions of Mesoamerican art. The story, however, does not mention whether Viracocha had facial hair or not with the point of outfitting him with a mask and symbolic feathered beard being to cover his unsightly appearance because as Viracocha said "If ever my subjects were to see me, they would run away!"[17] While descriptions of Viracocha's physical appearance are open to interpretation, it should be noted that men with beards were frequently depicted by the Peruvian Moche culture in its famous pottery, long before the arrival of the Spanish.[18] Modern advocates of fringe theories however such as a pre-Columbian European migration to Peru continue to cite these bearded ceramics and Viracocha's beard as being evidence for an early presence of a non-Amerindian race in Peru.[19][20] Although most Indians do not have heavy beards, there are groups who do, such as the Aché of Paraguay who also have light skin but who show no evidence of admixture with Europeans and Africans.[21] When the Southern Paiutes were first contacted by Europeans in 1776, the report by fathers Silvestre Vélez de Escalante and Francisco Atanasio Domínguez noted that "Some of the men had thick beards and were thought to look more in appearance like Spanish men than native Americans".[22]
Representation of Wiracochan or Tunupa at Ollantaytambo[edit]
Face in stone of Wiracochan or Tunupa at Ollantaytambo
According to local myth, a representation of the messenger of Viracocha ('The Creator of Civilization') named Wiracochan or Tunupa is shown in the small village of Ollantaytambo, southern Peru. Ollantaytambo located in the department of Cusco makes up a chain of small villages along the Urubamba Valley. Also known as the Sacred Valley of the Incas, it was an important stronghold of the Incan Empire. Facing the ancient Inca ruins of Ollantaytambo in the rock face of Cerro Pinkuylluna is the 140 metre high figure of Wiracochan. The angry-looking formation of his face is made up of indentations that form the eyes and mouth, whilst a protruding carved rock denotes the nose. Inca ruins built on top of the face are also considered to represent a crown on his head. Artists' impressions of the rock face also include a heavy beard and a large sack upon his shoulders.
The face of Viracocha at Ollantaytambo can be captured as noted by Fernando and Edgar Elorrieta Salazar.[1] Wiracochan, the pilgrim preacher of knowledge, the master knower of time, is described as a person with superhuman power, a tall man, with short hair, dressed like a priest or an astronomer with tunic and a bonnet with four pointed corners.
According to travel writer Paul Jones,[23] "This incredible myth of a Viracocha spreads throughout South America and beyond. This ancient mystical God, who by local legend rose from the middle of Lake Titicaca to create mankind was and is still today truly respected. The rock carving at Ollantaytambo is a striking reminder of the spiritual connections the Incas had with the Andes."
See also[edit]
1. ^ a b Fernando E. Elorrieta Salazar & Edgar Elorrieta Salazar (2005) Cusco and the Sacred Valley of the Incas, pages 83-91 ISBN 978-603-45-0911-5
2. ^ a b Dover, Robert V. H.; Katharine E. Seibold; John Holmes McDowell (1992). Andean cosmologies through time: persistence and emergence. Caribbean and Latin American studies. Indiana University Press. p. 274. ISBN 0-253-31815-7. Retrieved 22 November 2009. :56
3. ^ Young-Sánchez, Margaret (2009). Tiwanaku: Papers from the 2005 Mayer Center Symposium at the Denver Art Museum. Denver Art Museum. ISBN 0-8061-9972-5. Retrieved 22 November 2009.
4. ^ Alan Kolata's Valley of the Spirits: a Journey into the Lost Realm of the Aymara (1996), pages 65-72
5. ^ Andrews, Tamra (2000). Dictionary of Nature Myths. Oxford University Press. p. 216. ISBN 0-19-513677-2.
6. ^ "Viracocha". Bloomsbury Dictionary of Myth. Bloomsbury Publishing Ltd., London. 1996. Retrieved 2009-02-10.
7. ^ Viracocha and the Coming of the Incas from "History of the Incas" by Pedro Sarmiento De Gamboa, translated by Clements Markham, Cambridge: The Hakluyt Society 1907, pp. 28-58.
8. ^ a b "Glossary, Inca Gods". First People of America and Canada - Turtle Island. Retrieved 2009-02-10.
10. ^ Damian, Carol; Steve Stein; Nicario Jiménez Quispe (2004). Popular art and social change in the retablos of Nicario Jiménez Quispe. Edwin Mellen Press. ISBN 0-7734-6217-1. Retrieved 22 November 2009.
11. ^ Weismantel, Mary J. (2001). Cholas and pishtacos: stories of race and sex in the Andes. University of Chicago Press. ISBN 0-226-89154-2.
12. ^ Colonial Spanish America: a documentary history, Kenneth R. Mills, Rowman & Littlefield, 1998, p. 39.
13. ^ Pre-Columbian America: Myths and Legends, Donald. A. Mackenzie, Senate, 1996, p.268-270
14. ^ The Skeptic: encyclopedia of Pseudoscience, "white god legends", Michael Shermer, ABC-CLIO, 2002, p. 578.
15. ^ Mills, 1998, p. 40.
16. ^ Anales de Cuauhtitlan., 1975, 9.)
17. ^
18. ^ Portrait Vase of Bearded Figure, Brooklyn Museum
19. ^ Fingerprints of the Gods, Graham Hancock, Mandarin, 1996, pp.50-51
20. ^ In Quest of the Great White Gods, Robert F. Marx, Crown Publishers, 1992 pp. 7-15.
21. ^ Hill, Kim; A. Magdalena Hurtado (1996). Aché life history: the ecology and demography of a foraging people. Aldine Transaction. p. 58. ISBN 978-0-202-02036-5. Retrieved 31 May 2011.
23. ^ Jones, Paul J (2009) author and travel writer, Peru Guide (the only), the online guide to Peru. |
bold behavior definition, bold behavior meaning | English dictionary
1 courageous, confident, and fearless; ready to take risks
2 showing or requiring courage
a bold plan
3 immodest or impudent
she gave him a bold look
4 standing out distinctly; conspicuous
a figure carved in bold relief
5 very steep
the bold face of the cliff
6 imaginative in thought or expression
the novel's bold plot
7 (Printing) set in bold face
8 (Printing) short for bold face
boldly adv
boldness n
bold face
1 (Printing) a weight of type characterized by thick heavy lines, as the entry words in this dictionary
Compare light face
2 (of type) having this weight
Philip the Bold
n 1342--1404, duke of Burgundy (1363--1404), noted for his courage at Poitiers (1356) in the Hundred Years' War: regent of France for his nephew Charles VI (1368--88, 1392--1404)
English Collins Dictionary - English Definition & Thesaurus
Collaborative Dictionary English Definition
young woman who adopts a unconventional behavior and look
term largely used in the 20's to describe women who acted contrary to what was commonly expected by going out, drinking, smoking, dancing, wearing make-up etc.
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Provided by: util-linux_2.19.1-2ubuntu3_i386 bug
mkfs - build a Linux file system
disk partition. filesys is either the device name (e.g. /dev/hda1,
/dev/sdb2), or a regular file that shall contain the file system.
the directories listed in the PATH environment variable. Please see
the file system-specific builder manual pages for further details.
-V Produce verbose output, including all file system-specific
commands that are executed. Specifying this option more than
once inhibits execution of any file system-specific commands.
This is really only useful for testing.
-t fstype
Specifies the type of file system to be built. If not
specified, the default file system type (currently ext2) is
File system-specific options to be passed to the real file
system builder. Although not guaranteed, the following options
are supported by most file system builders.
-l filename
Read the bad blocks list from filename
-v Produce verbose output.
specific options. Some file system-specific programs do not support
file system-specific programs do not automatically detect the device
size and require the blocks parameter to be specified.
David Engel (
Fred N. van Kempen (
Ron Sommeling (
The manual page was shamelessly adapted from Remy Card's version for
the ext2 file system.
fs(5), badblocks(8), fsck(8), mkdosfs(8), mke2fs(8), mkfs.bfs(8),
mkfs.ext2(8), mkfs.ext3(8), mkfs.ext4(8), mkfs.minix(8), mkfs.msdos(8),
mkfs.vfat(8), mkfs.xfs(8), mkfs.xiafs(8)
The mkfs command is part of the util-linux package and is available |
Psychology Wiki
George Lakoff
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Professional Psychology: Debating Chamber · Psychology Journals · Psychologists
"Lakoff" redirects here. For other uses, see Lakoff (disambiguation).
George P. Lakoff (/ˈleɪˌkɔf/, born 1941) is a professor of linguistics (in particular, cognitive linguistics) at the University of California, Berkeley, where he has taught since 1972. Although some of his research involves questions traditionally pursued by linguists, such as the conditions under which a certain linguistic construction is grammatically viable, he is most famous for his ideas about the centrality of metaphor to human thinking, political behavior and society. He is particularly famous for his concept of the "embodied mind" which he has written about in relation to mathematics. In recent years he has applied his work to the realm of politics, and founded a progressive think tank, the Rockridge Institute.
The reappraisal of metaphor
Lakoff began his career as a student and later a teacher of the theory of transformational grammar developed by Massachusetts Institute of Technology professor Noam Chomsky. In the late 1960s, however, he joined with other former students to promote generative semantics as an alternative to Chomsky's generative syntax. In an interview he stated:
"During that period, I was attempting to unify Chomsky's transformational grammar with formal logic. I had helped work out a lot of the early details of Chomsky's theory of grammar. Noam claimed then — and still does, so far as I can tell — that syntax is independent of meaning, context, background knowledge, memory, cognitive processing, communicative intent, and every aspect of the body...In working through the details of his early theory, I found quite a few cases where semantics, context, and other such factors entered into rules governing the syntactic occurrences of phrases and morphemes. I came up with the beginnings of an alternative theory in 1963 and, along with wonderful collaborators like Haj Ross and Jim McCawley, developed it through the sixties."
His differences with Chomsky contributed to fierce, acrimonious debates among linguists that have come to be known as the "linguistics wars."
Lakoff's original thesis on conceptual metaphor was expressed in his book with Mark Johnson entitled Metaphors We Live By in 1980.
Metaphor has been seen within the Western scientific tradition as purely a linguistic construction. The essential thrust of Lakoff's work has been the argument that metaphors are primarily a conceptual construction, and indeed are central to the development of thought. He says "Our ordinary conceptual system, in terms of which we both think and act, is fundamentally metaphorical in nature." Non-metaphorical thought is for Lakoff only possible when we talk about purely physical reality. For Lakoff the greater the level of abstraction the more layers of metaphor are required to express it. People do not notice these metaphors for various reasons. One reason is that some metaphors become 'dead' and we no longer recognise their origin. Another reason is that we just don't see what is going on.
For instance, in intellectual debate the underlying metaphor is usually that argument is war:
• He won the argument
• Your claims are indefensible
• He shot down all my arguments
• His criticisms were right on target
• If you use that strategy, he'll wipe you out
Lakoff's theory has major consequences if correct. It points to the complete re-evaluation of the entire Western philosophical and scientific traditions. It has applications throughout all academic disciplines and much of human social interaction. Lakoff has explored some of the implications of the embodied mind thesis in a number of books, most written with coauthors.
Scott Adams' book God's Debris is influenced by Lakoff's idea that metaphors are central to the human thought process.
(Further reading: Milton Erickson, the so-called "father of modern hypnotherapy", who was also a strong advocate of metaphor as a means for communication)
About the embodied mind
Finally, based on research in cognitive psychology and some investigations in the philosophy of language, he argues that very few of the categories used by humans are actually of the black and white type amenable to analysis in terms of necessary and sufficient conditions. On the contrary, most categories are supposed to be much more complicated and messy, just like our bodies.
Many scientists share the belief that there are problems with falsifiability and foundation ontologies purporting to describe "what exists", to a sufficient degree of rigor to establish a reasonable method of empirical validation. But Lakoff seems to discard both claims entirely. In particular, in an idiosyncratic claim extending those published in "The Embodied Mind", he asserts that falsifiability itself can never be established by any reasonable method that would not rely ultimately on a shared human bias.
Lakoff is, with coauthors Mark Johnson and Rafael E. Núñez, the primary proponent of the embodied mind thesis. Others who have written about the embodied mind include the physicist David Bohm (see his Thought As A System), John Grinder and Richard Bandler in their neuro-linguistic programming, and Julian Jaynes.
The embodied mind and mathematics
According to Lakoff, even mathematics itself is subjective to the human species and its cultures: thus "any question of math's being inherent in physical reality is moot, since there is no way to know whether or not it is." Lakoff and Rafael E. Núñez (2000) argue at length that mathematical and philosophical ideas are best understood in light of the embodied mind. The philosophy of mathematics ought therefore to look to the current scientific understanding of the human body as a foundation ontology, and abandon self-referential attempts to ground the operational components of mathematics in anything other than "meat".
Mathematical reviewers have generally been critical of Lakoff and Núñez, pointing to mathematical errors. (Lakoff claims that these errors have been corrected in subsequent printings.) Their book has yet to elicit much of a reaction from philosophers of mathematics, although the book can be read as making strong claims about how that philosophy should proceed. The small community specializing in the psychology of mathematical learning, to which Núñez belongs, is paying attention.
Lakoff has also claimed that we should remain agnostic about whether math is somehow wrapped up with the very nature of the universe. Early in 2001 Lakoff told the AAAS, "Mathematics may or may not be out there in the world, but there's no way that we scientifically could possibly tell." This claim bothers those who believe there really is a way we could "tell." The falsifiability of this claim is perhaps the central question in the cognitive science of mathematics, a field which attempts to establish a foundation ontology based on the human cognitive and scientific process.
Political significance and involvement
Lakoff's "application of cognitive linguistics to politics, literature, philosophy and mathematics" has led him into territory normally considered basic to political science.
Lakoff has publicly expressed both ideas about the conceptual structures that he views as central to understanding the political process, and some of his particular political views. He almost always discusses the latter in terms of the former.
Moral Politics gives book-length consideration to the conceptual metaphors that Lakoff sees as present in the minds of American "liberals" and "conservatives". The book is a blend of cognitive science and political analysis. Lakoff makes an attempt to keep his personal views confined to one particular section near the book's close.
Lakoff argues that the differences in opinions between progressives and conservatives follow from the fact that they subscribe with different strength to two different metaphors about the relationship of the state to its citizens. Both, he claims, see governance through metaphors of the family. Conservatives would subscribe more strongly and more often to a model which he calls the "strict father model" and has a family structured around a strong, dominant "father" (government), and assumes that the "children" (citizens) need to be disciplined to be made into responsible "adults" (financially and morally responsible beings). However, the "children" are "adults", and so the "father" should not interfere with their lives: the government should stay out of the business of those in society who have proved their responsibility. In contrast, Lakoff argues that progressives place more support in a model of the family, which he calls the "nurturant parent model," based on "nurturant values", where both "mothers" and "fathers" work to keep the essentially good "children" away from "corrupting influences" (pollution, social injustice, poverty, etc.). Lakoff says that most people have a blend of both metaphors applied at different times, and that political speech works primarily by invoking these metaphors and urging the subscription of one over the other.
Lakoff further argues that one of the reasons progressives have had difficulty since the 1980s is that they have not been as aware of their own guiding metaphors, and have too often accepted conservative terminology framed in a way to promote the strict father metaphor. Lakoff insists that progressives must cease using terms like "partial birth abortion" and "tax relief" because they are manufactured specifically to allow the possibilities of only certain types of opinions. "Tax relief," for example, implies explicitly that taxes are an unpleasant thing, something someone would want "relief" from. To use the terms of another metaphoric worldview, Lakoff insists, is to unconsciously support it. Progressives must support linguistic think tanks in the same way that conservatives do if they are going to succeed in appealing to those in the country who share their metaphors.
Lakoff has distributed some much briefer political analyses via the Internet. One article distributed this way is "Metaphor and War: The Metaphor System Used to Justify War in the Gulf", in which Lakoff argues that the particular conceptual metaphors used by the first Bush administration to justify American involvement in the Gulf ended up either obscuring reality, or putting a spin on the facts that was accomodating to the administration's case for military action.
In recent years, Lakoff has become involved with a progressive think tank, the Rockridge Institute, an involvement which follows in part from his recommendations in Moral Politics. Among his activities with the Institute, which concentrates in part on helping liberal candidates and politicians with re-framing political metaphors, Lakoff has given numerous public lectures and written accounts of his message from Moral Politics. His latest political work, Don't Think of an Elephant! Know Your Values and Frame the Debate, self-labeled as "the Essential Guide for Progressives," was published in September 2004 and features a foreword by former Democratic presidential candidate Howard Dean.
Partial bibliography
• How Democrats and Progressives Can Win: Solutions from George Lakoff DVD format
Books that discuss Lakoff
• Harris, Randy Allen. The Linguistics Wars. Oxford University Press, 1995. ISBN 019509834X. (Focuses mostly on Lakoff's and others' disputes with Chomsky.)
• Haser, Verena, Metaphor, metonymy, and experientialist philosophy: challenging cognitive semantics. Berlin; New York: Mouton de Gruyter, 2005. (A critical look at the ideas behind embodiment and conceptual metaphor.)
• Kelleher, William J., Progressive Logic: Framing A Unified Field Theory of Values For Progressives. The Empathic Science Institute, 2005. ISBN 0-9773717-1-9
• McGlone, M.S. (2001). Concepts as metaphors. In S. Glucksberg, Understanding figurative language (pp. 90-107). New York, NY: Oxford University Press.
• Richardt, Susanne, Metaphor in languages for special purposes. The function of conceptual metaphor in written expert language and expert-lay communication in the domains of economics, medicine and computing. Peter Lang, Frankfurt am Main. 2005. ISBN 3-632-53159-1.
See also
External links
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So When, Where, Why and How Does the Technology Fit In?
I’ve read many articles and blogs and I’ve heard many discussions debating the role and place that technology has in the classroom. Some argue that classrooms should reflect the 21st century world that our students live in which means allowing them to learn with 21st century tools and media. Others argue that these 21st century tools and media serve as distractions in the classrooms and take away from the learning. I thought I would join the conversation and offer my thoughts.
I think it is important to differentiate between right drivers and wrong drivers and where that leaves technology. In Michael Fullan’s article titled, Choosing The Wrong Drivers For Whole System Reform, he states, “A ‘wrong driver’ is a deliberate policy force that has little chance of achieving the desired result, while a ‘right driver’ is one that ends up achieving better measurable results for students”. He argues that focusing on technology as a driver will not achieve the desired goal which according to Fullan is “the moral imperative of raising the bar (for all students) and closing the gap (for lower performing groups) relative to higher order skills and competencies required to be successful world citizens”. Therefore, the right driver should always be good pedagogy and in Ontario, I believe we are focusing on the right driver.
The School Effectiveness Framework (SEF) is a K-12 support document that is aimed to help Ontario educators with school improvement planning with the focus on students achieving success. The SEF highlights six components of effective schools with indicators and evidence that help schools build coherence in their improvement plans. On page 9 of the SEF document, there is a diagram that explains how the province, district, and school support the instructional core. At the classroom level, the instructional core is represented by the triangle in the diagram below. This idea of the instructional core originates from a book titled, Instructional Rounds in Education by Elizabeth A. City, Richard F. Elmore, Sarah E. Fiarman, and Lee Teitel where the instructional core is described as the important relationship that exists between the teacher, the student and the content. The instructional core allows educators to focus on improving student learning by creating rich instructional tasks. However, in order to create rich learning tasks that foster higher order thinking and student engagement, all three vertices of the instructional core (teacher knowledge and skills, the role of the student in the learning, and the curriculum) must be considered. The instructional core is the focus in many schools and classrooms (as it should be) but what is often left out are the conditions that can enable this learning to occur and this is ultimately where technology is often left out of the learning conversation.
So when, where, why and how does technology fit in? Many educators view technology as a great option for the end product, the culminating task that provides students with new and engaging media to create and showcase their learning. However, solely focusing on using technology for culminating tasks is a very narrow application of it and therefore technology is only used and viewed as another medium for assessment of student learning. Technology is bey0nd just a medium for culminating tasks. Technology is part of the conditions for learning in a classroom and a great option for developing 21st century learning skills. Educators need to start thinking about how technology can be effectively blended to the classroom to enhance the learning conditions for students in the following ways:
• make thinking visible
• increase reflection and metacognition
• allow for synchronous and asynchronous participation anytime and anywhere
• increase collaboration and co-learning
• differentiate the communication of ideas
• provide descriptive feedback
• promote on-going learning
If technology is focused on developing 21st century learning skills and the process of learning then it becomes more than just another medium, it becomes an important part of the learning conditions needed for students in today’s classroom. The diagram below illustrates some key components that make up the learning conditions (blended learning, 21st century learning skills, and technology). However, there is often a disconnection between the instructional core/rich learning tasks and technology.
As I stated earlier, technology is often viewed as a distraction to schools focusing on the instructional core and that a rich learning task is engaging enough for students but in my opinion, technology as a learning condition cannot and should not be ignored. Michael Fullan best explains the relationship that should exist between technology and pedagogy, “The essential idea is to get the right learning embedded in the technology”. I made an addition to Elmore’s instructional core diagram below to illustrate that when you combine the learning conditions of technology, 21st century skills, and blended learning with the instructional core, you can increase, enhance, and bump UP any rich learning task.
City, E. A., Elmore, R. F., Fiarman, S. E., & Teitel, L. (2009). Instructional rounds in education: A network approach to improving teaching and learning. Cambridge: Harvard Education Press.
Education, Ontario. Ministry of. School Effectiveness Framework K-12: A support for school improvement and student success. 2010. (
Fullan, M. (2011). Choosing the wrong drivers for whole system reform. Centre for strategic education, Retrieved from
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One thought on “So When, Where, Why and How Does the Technology Fit In?
1. Excellent synthesis accompanied by great visual. A perfect example of enhanced learning and understanding through the use of technology! ;-)
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Good Math, Bad Math
rates in the world.
There’s an idea in economics about taxes called the Laffer curve, which is based on the
extreme value theorem. What the Laffer curve describes is the relationship between tax
revenues taken in by the government and take rates. Naively, you might assume a linear
relationship between taxes and revenues: raise the tax rate, and the amount of money that
the government brings in increases.
But reality isn’t so simple. When you increase tax rates, you reduce the amount of money
available to people and businesses for investment. So it’s not a simple linear thing; the
size of the pool of taxable profits can be altered by changing the tax rate, because a higher tax rate reduces the amount of money that can be invested in growing a business,
which can slow the growth of the business, which reduces its taxable profits.
The Laffer curve is a model for the relationship between tax rates and tax revenues. It starts off roughly linear, and then the revenue growth rate starts to slow, until it reaches an inflection point, and revenues start to *decrease* as tax rates increase. The figure to the right is a drawing of the standard Laffer curve borrowed from Wikipedia.
What people like the WSJ editorial page like about the Laffer curve is that one of the
implications of it is that if your tax rate is *past* the inflection point, then you can
*increase* tax revenue by *decreasing* the tax rate. So they constantly argue that our tax
rates area on the downward-trending side of the curve – and that therefore, lowering takes
isn’t just good because it means that people get to keep more of their money, but it’s in
some sense free, or even *better than* free, because it will have either no impact or a
positive impact on government revenue.
The catch, of course, is that for that to be true, you need to be on the far side of the
curve, where revenues are dropping because the rate is so high that it’s stifling investment. The WSJ editorial board constantly argues that we’re on that side. And they
argue it in stupid, sloppy ways.
Which brings us to the subject at hand: the WSJ’s latest effort to support their argument that we’re on the wrong side of the Laffer curve. They take a scatter plot of tax revenues as a percentage of GDP against take rates for a selection of countries, and then argue that it’s an illustration of the Laffer curve. The thing is, it’s more of a laughable curve than a Laffer curve. If you look at the data, what you see is a scatter that looks an awful lot like a typical noisy linear curve. It’s got one extreme outlier, which the WSJ chooses as
an inflection point, and then they curve fit on either side. The resulting curve is blatantly ridiculous – the tax rate smoothly increases in an almost linear way up to almost 25%; slows to crest over about 3%, and then falls into an almost perfectly vertical line over the next 4%. It’s a terrible curve fit, which is just simple foolishly wrong.
In fact, it’s an example of the same kind of nonsense that I wrote about in the very first
post on the original GM/BM back at blogger, where the Geiers were analyzing autism rates, and *wanted* to show an inflection point, so they inspected the data, picked an
outlier, split the data around it, and then argued for an increasing slope on one side, and a decreasing slope on the other, even though a single linear regression with a shallow increasing slope matched the data better than the double-curve with their chosen inflection point.
That’s exactly what’s going on here. For *some* reason, Norway is an extreme outlier in
this data. Eliminate Norway, and you’ve got data that looks awfully close to either a nice linear slope, or to a very shallow Laffer curve. But drawing the curve not as any
reasonable mathematical curve fit, but instead building it specifically to pivot on the
outlying point, they’ve created an artificial and ridiculous curve. Sure, it supports what they’re arguing for: it was artificially and dishonestly created to do exactly that.
Here’s an interesting fact, which the WSJ folks certainly know about. In mathematical curve fitting, where you try to use some kind of regression method *honestly* fit the curve to data, you *never* wind up with a curve that intersects the most extreme outlier. The fact that this curve does just demonstrates its dishonesty.
The data underlying this is also definitely not honest. Calling the US corporate tax rate
34% without any qualification isn’t honest at all; it neglects to mention the fact that
the US has one of the most ridiculously loophole-ridden tax codes in the world, and that the actual average rate actually paid by American corporations is dramatically lower. (Just for example, the WSJ cites the average state tax rate at 4%; actually statistics show that the state rates really paid were under 2.5%, and the larger the business, the lower the rate they paid. In 2003, for example, Boeing and ATT paid *no* state taxes *at all*.)
I don’t know where we fit on the Laffer curve. Frankly, I think our tax code is so distorted by random loopholes that it’s probably impossible to make a blanket statement; for some businesses, we’re probably taxing them enough effectively reduce the tax
revenues received from them; for many others (can you say oil company?), we’re clearly
But the idea that this curve produced by the WSJ folks has *any* meaning at all is simply laughable.
1. #1 Michael R. Head
July 14, 2007
Ugh… Since when is the AEI considered a reliable source of data anyway?
2. #2 Walker
July 14, 2007
The economics blogs suggest that Norway is an outlier because of oil revenues. Other oil rich countries either have low tax rates or are not very dilligent at corporate tax collection.
3. #3 Anthony Mills
July 14, 2007
Not to mention Norway’s huge ($300 billion +) investment stash ( which might throw things off a bit.
4. #4 Jonathan Lubin
July 14, 2007
umm – do a global search and replace: replace “inflection point” by “extremum”. The curve as drawn has no inflection point.
5. #5 Gork
July 14, 2007
Give them credit for being clever.
When I first heard of the Laffer curve in the news decades ago, the news coverage never explained what it was.
Your article is the first description of what the curve is.
Thanks much. Now I know what all that blather was about a quarter century ago.
6. #6 A. Mused
July 14, 2007
until it reaches an inflection point
You mean a maximum, right?
7. #7 Isabel
July 14, 2007
I wouldn’t quite say that it’s linear when you leave out Norway. There seems to be a maximum at somewhere around (30%, 4%) — I think that for tax rates between 30 and 35% I see the points tending downwards. (And I am sufficiently ignorant of economics that I assure you I am not grinding any sort of ideological axe.)
Of course, trying to fit a curve mathematically to this plot can’t be done unless you know ahead of time that the curve should be, say, quadratic — and we don’t know what shape it should have a priori.
8. #8 Aaron F.
July 14, 2007
Isabel — I noticed the same hint of a turnover, but I think it’s probably just a mirage. Jiggle all the data points half a tick in a random direction, and that peak would disappear!
Incidentally, curve fitting is something that’s been on my mind lately. A few days ago at work, I made a plot that looked *very* much like a power law with an exponential cutoff, but a power law without a cutoff fit it just as well. I’m beginning to suspect that without an a priori model, fitting isn’t any use at all… :P
9. #9 David Brabant
July 14, 2007
Pardon me if my question sounds extremely naïve, but can’t that be simulated? Isn’t it possible to build a reasonable model illustrating the Laffer effect, and helping to determine where the inflexion point is, according to a few key parameters?
I guess my question could be rephrased as: in these days where we attempt to model cimate change, building a model showing that the Laffer curve is for real, shouldn’t be that difficult, should it?
By the way, hello from … Norway, the country of the tax optimum (uh?).
10. #10 Tyler DiPietro
July 14, 2007
“You mean a maximum, right?”
No, I suspect he means a point where a curve alternates concavity (upward/downward), i.e., a point of inflection.
11. #11 Bob O'H
July 14, 2007
Correction: even with Norway you’ve got data that looks awfully close to either a nice linear slope. It might be slightly heteroscedastic, but it still looks linear (and adding the quadratic term in the regression increases the R2 by less than 0.2%).
12. #12 Ryan D
July 14, 2007
If they placed the inflection point around, say, Australia, it might look half-reasonable and BS’able.
13. #13 SLC
July 14, 2007
I think the point is being missed here. The WSJ should be challenged to provide the R^2 values for their curve and a linear regression curve. I will bet the ranch that their curve will have a significantly lower value then a linear regression.
14. #14 Paul Butler
July 14, 2007
You mean a maximum, right?
I thought the same thing when I read it.
But the function doesn’t change concavity; It’s derivative is always decreasing.
15. #15 El Cid
July 14, 2007
The WSJ and other “supply side” minions would use graphs in the shape of Sesame Street’s “Cookie Monster” if they thought it would help cut taxes on their corporate buddies and the super-ultra-mega wealthy.
The theoretical maximum of the beloved Laffer curve is, I would hypothesize, very, very simple to determine: it is far closer to zero (or negative taxation, why not?) of whatever tax rate corporations and the super-rich find themselves at present.
So if today’s tax rate were 10%, that maxima would be at, who knows, 2%, and if today’s tax rate were 2%, then that maximum would be at 0.05%, and if today’s rate of taxation of corporations and the super-wealthy were at 0.05%, then the WSJ editorialists and pals would argue that ideally their tax rate should be at -2%, where the rest of us pay them dividends simply for being so wealthy.
16. #16 Emory K.
July 14, 2007
And don’t forget Martin Gardner’s Neo-Laffer curve, from his Scientific American column many years ago. Martin accepted the two endpoints of the curve, where zero or 100% taxation will obviously drive revenue to zero. But anywhere in between, any real economy will be so complicated, non-linear, and chaotic that it is absurd to draw _any_ simple-looking curve. The real curve, says Mr. Gardner, would have quite a collection of valleys and peaks of varying sizes – and good luck predicting where the myriad rises and falls will be. Here’s Martin G.’s Neo-Laffer curve:
17. #17 mj
July 14, 2007
Seeing where the US and France are according to the WSJ “Laffer curve” it seem like an infinitisimal tax decrease would give a fantastic increase in revenue. However, I suspect that the authors argue for a somewhat larger reduction than that. So, their ridiculous curve doesn’t even work very well for their arguments’ sake.
18. #18 Caledonian
July 14, 2007
Isn’t it also possible that the curve isn’t being derived from the data, that the shape of the Laffer curve is being asserted on some other grounds and the points are just to show where various nations are in relation to it?
19. #19 Zarquon
July 14, 2007
And yet by some coincidence that theory which dare not speak its name produces a point exactly on Norway?
20. #20 Reinier Post
July 14, 2007
As always, Mark hits the nail on the head: someone *wanted* to see a Laffer curve, looking at data points that, in essence, look like a bowl of tea leaves. But the textbook predicts a curve, so a curve it shall be. This is the kind of situation statistics thrives on. And whenever statistics is involved, I’m never sure if the lying is deliberate.
21. #21 Anonymous
July 14, 2007
I wonder what function they used to give that steep drop-off? Of course, if you look at the data, you end up concluding that any functional relationship between the tax rate and revenue only explains a tiny part of the variance, so you might as well forget about the Laffer curve as a guide to tax policy.
22. #22 Tyler DiPietro
July 14, 2007
“But the function doesn’t change concavity; It’s derivative is always decreasing.”
I don’t see how the derivative can always be decreasing, the tangent line on the curve would have to alternate direction at some point. But as the above poster noted, it’s difficult to even discern the function they’re using by simply looking at the graph.
23. #23 Paul Butler
July 14, 2007
Although the tangent (and hence the derivative) goes from positive to negative, there is no point where it is not decreasing.
An easy way to prove that the Laffer curve has no points of inflection is to notice that the tangent line never crosses the curve.
24. #24 Tyler DiPietro
July 14, 2007
You’re right, I accept the correction. I was thinking in terms of relative extrema and overlooked a simpler indication.
25. #25 gah
July 14, 2007
“I don’t see how the derivative can always be decreasing.”
Draw a line tangent to the curve. The derivative at that point is the slope (steepness) of the line. At the left the line is very steep and becomes less so as you move to the right. Since the line rises to the right the slope is positve at the left. At the peak the slope is zero. To the right of the peak the slope is *negative*. Positive to zero to negative– always decreasing.
26. #26 Tyler DiPietro
July 14, 2007
As I mentioned the tangent line in my post, it should be obvious I already know this. I overlooked a more important detail.
27. #27 Ian Gould
July 14, 2007
Point 1: The graph is comparing total tax revenue to corporate tax rates. A more useful comparison would be to compare corporate tax revenue with corporate tax rates. Total tax revenue in France isn’t higher than in the US because the nominal corporate tax rate is slightty lower – it’s higher because personal income tax and value-added taxes in France are much higher.
Point 2: Nominal corporate tax rates are deeply misleading in any case because there are huge differences between nominal and effective tax rates depending on deductions and other aspects of the tax system. For example, in most developed countries, workers pay taxes to fund universal heath care. In the US, employers are given tax incentives to buy private health insurance fro their workers. Those tax concessions reduce the effective tax rate below the nominal tax rate.
Point 3: Virtually the only unambiguous evidence of a positive revenue effect from cuts in nominal tax rates comes from countries where the nominal rates were at 80% or greater. Claims that US tax cuts produced higher government revnue are based on conflating several different logical fallacies.
For example, we’re told that tax receipts in 1987, after the Reagan tax cuts, were higher than in 1980. This is true in nominal terms – i.e. if you ignore the high inflation of the intervening period. Hell, if we lower taxes to 1% and just print a few hundred trillion dollars in fiat money, we can probably produce an even higher increase in nominal tax revenue.
28. #28 Ian Gould
July 14, 2007
Australia and Luxembourg are also anomalous outliers.
Here in Australia we’ve been incredibly fortunate over the last years in that the commodities boom has delivered a massive profit boost to our mining companies.
Luxembourg is a relatively low tax country within the EU and attracts large investment inflows from Germany and other countries. The country is also an attractive legal residence for European companies (American readers should be familiar with te expression “A Delaware company”.)
I find it interesting too that the CEI and WSJ are apparently claiming that Canada and France are more business-friendly and entrepeneurial than the US. I doubt that’s an argument they’d be making in any other circumstances.
29. #29 archgoon
July 15, 2007
Wait wait wait…. Taxes are higher in the US than in France or Germany? That doesn’t sound quite right…
30. #30 Bob O'H
July 15, 2007
Ooh, as a professional statistician, do you mind if I fume at that for a moment?
The imposed Laffer curve is awful statistically: we have a huge suite of techniques for fitting curves to data like this: least squares, non-linear least squares, splines etc. etc. None of them would produce a curve like that with the data.
Most problems commonly associated with statistics are due to the people who are mis-using them. A lot of attention is paid to trying to prevent this sort of abuse: through statistical training, education of the public and other efforts (e.g. the Royal Statistical Society made a public statement on the Sally Clark case, because the evidence presented was so bad). We dislike things like this as much as everyone else does, and it doesn’t help that we get the blame.
In reality, it’s the economists who are the evil-doers. We’re pure as the driven snow, and standing up for all that is good and can be counted! :-)
31. #31 daenku32
July 15, 2007
I have always wondered about corporate taxes. Corporations have so many write-offs that I’m not sure on what money they are even required to pay taxes off of. Aren’t investments tax write-offs anyways? If a corporation has a huge operating margin but reinvests a large portion of it, doesn’t that mean they only have to pay very little tax?
32. #32 Caledonian
July 15, 2007
First of all, the x-axis shows corporate taxation. Secondly, the point for France is approximately on the same spot as the US on that axis.
33. #33 Paul Carpenter
July 15, 2007
Lies, damned lies and statistics, this looks like to me. Perhaps an article on how curves should really be drawn is in order?
34. #34 Jonathan Vos Post
July 15, 2007
I have worked as employee, contractor, or consultant for many corporations, often in the Software Engineering department, and on special projects for the very top executives, including:
Boeing, Burroughs, EarthLink, Ford, General Motors, Hughes, Lear Astronics, Systems Development Corporation, Yamaha.
There was enormous diversity in the politico-economic beliefs of the managers and executives that I worked with, as well as among the engineers and secretaries and others. But there is no question that the Wall Street Journal was as universally respected as Aviation Week and Space Technology (in the aerospace companies), and IEEE Computer or Communications of the ACM at the computer/software companies.
The management clustered around reverence for Capitalism in an unrestrained form (such as Taiwan has more than the USA). They appreciated the vast amounts of money that they were able to pry away from U.S. Army, U.S. Navy, U.S. Air Force, Federal Aviation Administration, and NASA, by means of Proposals that ran to 1,000,000 pages in length (and in which I was often deeply involved as writer, editor, or management Gold Team reviwer, or the like).
Once your tax dollars were in corporate hands, they were systematically plundered in what I best describe as ongoing criminal enterprises. The “Laffer Curve” invented during a 3-martini lunch at WSJ is benign compared to the frauds that I saw (and officially audited!) at these large corporations.
The corporations made routine use of the Revolving Door. They hired former government officials who used to shovel money to them, and used them to help get more. They sent former executives of the corporation to the government, to improve the efficiency ofd the shoveling. Once in a long while, someone was caught, and their hands were slapped. Sometimes the slap was more substantial, as with Boeing’s multibillion dollar Air Force Tanker scam, or Rockwell’s Rocky Flats dumping of plutonium in the Denver water supply, which got the installation shut down, and the employees not laid off with benefits, but somehow out the door with no benefits.
I have never seen any of the fraud perpetrators go to jail. I am still furious that nobody went to jail for the Challenger and Columbia tragdies, for instance, on Manslaughter.
Google “Mens Rea” for the reason embedded in US law as to why Corporations cannot be guilty of most crimes.
The Wall Street Journal was the bible of my grandfather, who worked his way up from floor sweeper at a haberdashery to founder of a stock brokerage and owner of a seat on the New York Stock Exchange. he was opposed to Unions, Taxes, and FDR for good reasons. But I think he’d be uncomfortable with such a blatant lie as the WSJ has printed here.
I’m not so much offended as a Mathematician, as I am offended as a Capitalist and a taxpayer and a former card-holding journalist.
Good thing that Rupert Murdoch doesn’t own the WSJ. Why, he’d bias their news writing to achieve political ends and to line his and his friends’ pockets with gold. Oh, just a second…
35. #35 Anon
July 15, 2007
Speaking as a card-carrying PhD-emburdened computer scientist, I can say with absolute conviction that Communications of the ACM is the most useless, mind-numbing mixture of utter bullshit and meaningless corporate buzzworrhea ever produced outside the DC Beltway, with occasional homeopathic quantities of actual information to cut the stench.
So when you write that WSJ was as universally respected as CACM, I know exactly what you mean.
36. #36 Science Avenger
July 15, 2007
Bob O’H said: Ooh, as a professional statistician, do you mind if I fume at that for a moment? … The imposed Laffer curve is awful statistically…Most problems commonly associated with statistics are due to the people who are mis-using them…We dislike things like this as much as everyone else does, and it doesn’t help that we get the blame.
Indeed, whenever someone tells me that people lie with statistics, I remind them they lie with words too. Does that mean we dismiss the English language? To take what some say seriously, one would think in statistics classes the instructors told us to do whatever we wanted.
More to the point, I think it worth noting that while dittoheads chant like a mantra that Reagan’s Laffer-inspired supply-side tax cuts “doubled revenues”, I’ve never seen a rigorous demonstration of this. My own attempts failed, the claim only holding up prior to adjusting for inflation, after which the Reagan years were indistinguishable from the Carter years prior or the Bush 41 years to follow.
And now Republicans areo continue to make this claim, sans evidence, that Bush 43’s tax cuts have done the same. Prove it I say.
37. #37 SWT
July 15, 2007
While I agree that the “curve fit” is howlingly, atrociously bad, there is another significant problem with the WSJ chart — it does not in fact present data by which one might evaluate a supply-side claim. Not even with a better model. Not even after excluding “outliers.” The data just are not in the figure.
Mark’s graph shows the Laffer curve as supply-side theory is typically portrayed: there is some optimal tax rate at which government revenue is maximized.
The horizontal axis on the WSJ chart is the top marginal tax rate on corporate profits, so it is not necessarily an accurate measure of the actual rate at which corporations’ incomes are taxed. It’s better than nothing, I suppose, but since these taxes are levied on profits, not on income, a country-to-country comparison is meaningful only if taxable profits are calculated the same way from country to country (which I strongly doubt).
Note further that the vertical axis on the WSJ chart is the tax revenue from corporate taxes as a fraction of GDP. (In 2004, total federal tax receipts were 16.3% of GDP, so the data presented for the USA in the graph cannot represent total federal tax revenues.) However, US government statistics for 2004 show that corporate income taxes were 1.6% of GDP, so there are other contributors to the numbers for the vertical axis. This again muddies the meaning of the plot.
But neither of these are, in my thinking, the biggest non-regression-related problem with the chart. They serve to make the meanings of the points fuzzy, but one might be sorta kinda able to spot trends if there are trends to be spotted.
The killer problen is that the vertical scale is tax revenue as a fraction of GDP; it says nothing about the size of the GDP or the amount of tax revenue received.
Thus, the relationship between the ordinate and abscissa values on the WSJ chart might tell us something about the relationship between taxable corporate income and GDP, but it tells us nothing about the relationship between government tax revenue and corporate taxation. It does, IMO, tell us something about the state of critical thinking skills at the WSJ.
38. #38 Torbjörn Larsson, OM
July 15, 2007
A paper that Cosma Shalizi coauthored has a test that can distinguish between different alternatives here.
And no, curve fitting is of no use for these types of problems:
In particular, if you’re looking at the goodness of fit of a distribution, use a statistic meant for distributions, not one for regression curves. This means forgetting about R^2, the fraction of variance accounted for by the curve, and using the Kolmogorov-Smirnov statistic, the maximum discrepancy between the empirical distribution and the theoretical one.
There is a brilliantly simple solution to this problem (at least for cases like this) which was first devised by Quang Vuong in a 1989 Econometrica paper: use the log-likelihood ratio, normalized by an estimate of the magnitude of the fluctuations in that ratio. Vuong showed that this test statistic asymptotically has a standard Gaussian distribution when the competing models are equally good; otherwise it will almost surely converge on picking out the better model. This is extremely clever and deserves to be much better known. And, unlike things like the fit to a log-log regression line, it actually has the power to discriminate among the alternatives.
I would dearly like to take this method out for a test ride next time I have to navigate these types of problems.
39. #39 Torbjörn Larsson, OM
July 15, 2007
curve fitting is of no use
On second thought, that was too harsh. Curve fitting should show you when a power law wouldn’t fit at all.
40. #40 elspi
July 15, 2007
Why would anyone believe that the Tax revenues were a function of a single variable?
(Tax rates). It seems ridiculous on the face of it.
Much more important than the rate is the how the taxes are spent: are they being used to improve the infrastructure, or are they being used to reward corruption?
The data points that we see would seem to indicate that if the tax revenue function were a function of one variable then it would not be continuous.
What it looks like is the graph of a function of several variables which some moron projected onto a plane spanned by one variable axis and the graphing axis.
41. #41 stewart
July 15, 2007
An economic take on this is posted by Brad DeLong. Basically, Norway’s revenues are not solely from corporate taxes, but from excise taxes on oil.Omitting these details misplaces them on this graph (and the curve cannot be charitably interpreted as anything other than a fraud).
42. #42 Anonymous
July 16, 2007
There’s the more important question of whether the tax rate paid by corporations is anything other than zero.
Corporations don’t pay tax because corporations don’t really exist. To the extent corporations pass the tax on to stockholders, those stockholders are being taxed twice.
43. #43 Ian Gould
July 16, 2007
Anonymous, this is not true in most developed countries since shareholders are credited for the corporations tax paid. It was true in the US until Bush did away with the double-taxation of dividends.
This is pretty much the only aspect of Bush’s tax cuts which you’ll find are broadly suppotted by economists of all political bents.
44. #44 spudbeach
July 16, 2007
Just a few comments on the “maximum / inflection point” issue:
On the Laffer Curve from Wikipedia, that is in fact a maximum, not an inflection point. For a differentiable function, a local maximum is at a point where the first derivative is zero. For a tax rate close to 0, the function has a positive derivative, and for a tax rate close to 100%, the function has a negative derivative. If the function has a continuous second derivative, then there must be a maximum somewhere between 0% and 100%. (Note the Martin Gardner Laffer curve that does _not_ have continous second derivatives.)
There is indeed no inflection point in the Laffer curve shown. An inflection point occurs when the second derivative is zero, and it may indicate a point where the concavity changes from up to down or vice-versa. As pointed out above, one way to test for a change in concavity is to see if a tangent line crosses the function.
A key point to bring out is the one implied in comments 22 and 24. The function is increasing and then decreasing, and hence the derivative is positive and then negative. However, the derivative is always decreasing, which is perhaps better stated as the second derivative is always negative. Since the second derivattive is always negative, there is not inflection point.
Sorry to be so long winded, but I taught calculus last year, and I went on and on about that stuff to my HS AP class. Everybody who knows math knows this stuff, but it can be tricky to people who haven’t had to explain it to beginners recently. I’m sure that Mark CC just slipped when he said “inflection point” instead of “maximum”.
45. #45 DrEye
July 16, 2007
It would be interesting to fit those data with a second or third degree polynomial. My guess from just eyeballing (sorry to be so technical…) is that the coefficients of the second and third order terms would be negligible. If one removed the U.A.E. point, the first order term would probably also be very small. So, it would seem there is very little correlation between the
tax rate (as stated in this plot) and the revenue (as % of GDP) collected. Does this imply that Laffer was simply wrong, or that the data are not what they purport to be (as mentioned by several posts above)?
46. #46 Antendren
July 16, 2007
Spudbeach, you don’t need a continuous second derivative, or even first for that matter. So long as the function is continuous, it will have a max on the interval.
47. #47 Mark C. Chu-Carroll
July 16, 2007
Corporations pay takes because they *do* exist.
Incorporating a business is a tradeoff. By incorporating, the business becomes an independent legal entity, with a set of legal rights, like the right to own property, to
borrow money, etc. These rights are *independent* of the rights of the owners of the corporation; so if the corporation goes bankrupt, it forfeits *its* property, but not the property of the owners. The owners are shielded from risks by creating the corporate entity: they aren’t liable for the corporation’s debt, for legal liabilities of the corporations activities, etc. The assets of the corporation belong *to the corporation*; the profits of the corporation belong *to the corporation*. The corporation as an entity can decide to keep the profits within the corporation, or it can decide to pay them out to its owners. When it pays them to its owners, it is a *transfer* of assets from one entity to another.
In exchange for that separation of the corporation from the owners, making the corporation its own entity, the corporation becomes liable for taxes *as an independent entity*.
As a business owner, you *can* decide not to incorporate. If you do that, then your business isn’t liable for any taxes on its own; the profits of the business belong to you, and you alone; and the only tax you’ll pay on its profits are *your* taxes. But if the business fails, *you* are liable for its debts.
It’s a tradeoff; you can separate the business assets and liabilities, making it a legal entity that needs to pay taxes; or you can take the risk yourself.
Seems perfectly fair to me.
48. #48 Reinier Post
July 16, 2007
To Bob O’H: I agree. Statistics are a very powerful tool when applied correctly, but as far as my (layman’s) experience goes, but a tool that is particularly prone to misapplication and worse forms of abuse (e.g. just hinting at its application, as happened in this case).
49. #49 Ben
July 16, 2007
Ceteris Paribus I guess. How else is an economist to earn a living?
50. #50 Barry
July 16, 2007
As another professional statistician, I’d like to point out that this is not a case of bad curve fitting. I can’t think of any way to fit a curve ‘through’ the data which results in what they’ve got, which is a curve which totally ignores all but two points in the left-hand portion of the data.
51. #51 gg
July 16, 2007
“Why would anyone believe that the Tax revenues were a function of a single variable?”
The Laffer curve is so fundamentally dishonest it shouldn’t even be printed in plot form: the most one should ever be able to say is that tax revenue goes to zero at 0% and 100% taxation, and that implies that there must be a turning point somewhere in the middle. This is a complicated situation, though, and there may be more than one turning point. Furthermore, there isn’t any good evidence of where those turning points should be, and it is almost certainly a dynamic function of societal conditions. Martin Gardiner’s neo-Laffer curve on the Wikipedia page sums it up nicely.
I tend to look at anyone who actually prints a Laffer curve as a serious argument as being fundamentally dishonest, or incurably stupid.
52. #52 gg
July 16, 2007
Here’s something else that ticks me off about the Laffer curve: I would strongly suspect that it is also dependent on the rate at which taxes are changed, and the direction . In a sense I would consider it a system which would probably exhibit hysteresis; if you lower taxes from some high value, you’ll probably find a different ‘peak’ to tax revenue than if you raise taxes from some low value, if for no other reason than the psychological impact on investors and businesses.
53. #53 Mike Johnson
July 16, 2007
I created a dataset based on the values in the chart, and ran a couple of regression equations to see what the data actually say. I thought it would confirm Mark’s point, but there is a somewhat curvilinear relationship here. The bivariate correlation is .32, (p = .09), largely supporting Mark’s linear interpretation. I then entered the squared term for tax rate to test the curvilinear relationship in the next step of the equation, and it had a beta weight of -1.16 (p = .11), suggesting that a quadratic curve (inverted U-shaped) also somewhat fits the data. With Norway excluded as an outlier, the linear relationship gets stronger (.41, p = .03), but so does the quadratic relationship (-1.27, p = .07).
54. #54 Sam the Centipede
July 16, 2007
Exclude the UAE (a special case because 0% tax forces 0% return regardless of all other factors), and exclude Norway too (just because that outlier looks suspicious and as though other factors might be in play — and, yes, I know that’s really dodgy reasoning!!), and what do you see? Pretty much a cloud of points, that simply suggests that the expected take from corporate taxation is about 3.5% of GDP regardless of the nominal rate. What does that suggest? This could occur if nominal rates of taxation are not actually well correlated with actual rates of taxation, due to the formulation of tax codes (with loopholes) and accounting practices.
Yup, the WSJ stuff is complete b*****ks (apologies to non-UKers who might not know what the *s stand for).
55. #55 gg
July 16, 2007
#54: “apologies to non-UKers who might not know what the *s stand for”
“Bricks”? “Books”? “Bjorks”? I’m TOTALLY lost! :)
56. #56 Mike Johnson
July 16, 2007
Your math reasoning may be dodgy but your conclusion is correct. Norway is an extreme statistical outlier on tax revenue. The mean tax revenue is 3.3%, with a standard deviation of 1.8. So Norway lies 3.7 standard deviations away from the mean– an extreme outlier.
57. #57 _Arthur
July 16, 2007
gg, nevermind the b0ll0cks
58. #58 Stephen Wells
July 16, 2007
Isn’t it slightly problematic that if you extrapolate their “fit” it actually goes negative before you reach the US/France corporate tax rates?
59. #59 vhurtig
July 16, 2007
If WSJ wanted to be honest, the data for corporate income taxes paid as a percent of corporate income for the various countries are most likely available. They certainly realize that for most countries tax loopholes and surtaxes exist which skew the actual tax revenue from the stated tax rate. As Mark points out, this is simply a case of editorial dishonesty intended to suppport a prior bias.
60. #60 Mark C. Chu-Carroll
July 17, 2007
If you read the article, they clearly say that what they’re talking about is that curve derived from that data.
61. #61 Calvert
July 17, 2007
When discussing the various tax burdens on corporations or individuals, I have not once seen any attempt to calculate a “total tax burden”, or the percentage of one’s income that one pays in taxes of all sorts. In this country there is a multitude of taxes from a wide variety of sources. There are not only federal taxes but state taxes, property taxes, school taxes, fuel taxes, sales taxes, inheritance taxes, service fees and the myriads of other ways various organs of government has to raise revenue. Focusing on one specific portion of tax at the exclusion of all others is deliberately misleading. Without knowing what the entire tax burden is on various corporations and how that differs depending on type of business, location and other circumstances, any analysis of the issue is going to be flawed from inception and more subject to the political biases of the people presenting the data.
62. #62 threetorches
July 18, 2007
Attempting to describe (or even postulate)a well-fit Laffer for an entire macro-economic world map is worthless and somewhat intentionally deceptive.
Caution: Laffer theory-work ahead–
It is easy to imagine how it might work for an individual actor: You have the opportunity to work overtime this week, or stay at home and watch football. Your decision will be based on the actual amount of money that you bring home, AFTER TAX.
So as the Gov raises your rate, your take-home on the overtime drops, and your marginal benefit becomes increasingly smaller.
At a certain point, it isn’t worth it to you anymore, and you stay home.
When you give up the overtime altogether, the Gov loses ALL tax revenue on the overtime.
Ergo, by lowering the rate and putting more of the benefit of the extra work back in your pocket, the Gov encourages you to do the extra work. Lower rate, but more income to tax for the Gov. They “make it up on volume.”
Of course, if they get the mix wrong, and lower it too much, you don’t necessarily work more than you planned in the first place, so they are foregoing revenue needlessly. Find the “tipping point,” as they say. The “point of diminishing return at the margin,” as the economists would say.
Simple, right?
Well, not if you try to extend the theoretical construct from individual actors to the entire macroeconomic structure of the world!
Especially when the countries you “randomly” select to draw your bogus curve don’t have the same (or in some cases even similar) tax structures or public policy goals, and are different in size, culture, climate, resource distribution and quantity, and type of government!
I mean seriously, what the heck were they thinking with this? It makes, like, no sense at all. Sigh. A little knowledge is a dangerous thing, I guess.
(But anyone with enough knowledge to get what they are saying or implying ought to see it for what it is…so who are they trying to BS?)
63. #63 Jonathan Vos Post
July 19, 2007
An easiler type of tax curve to graph:
Cato Policy Report, July/August 2007
The Global Flat Tax Revolution
By Daniel J. Mitchell
[Daniel J. Mitchell is a senior fellow at the Cato Institute and is currently writing a book on international tax competition.]
In the early 1990s, Rep. Dick Armey (RTX) proposed a flat tax. He would have junked the Internal Revenue Code and replaced it with a system designed to raise revenue in a much less destructive fashion. The core principles were to tax income at one low rate, to eliminate double taxation of saving and investment, and to wipe out the special preferences, credits, exemptions, deductions, and other loopholes that caused complexity, distortions, and corruption.
The flat tax never made it through Congress, but it’s been adopted by more than a dozen other countries since 1994.
As seen in Table 1 {follow hotlink to see it; I’m unable to cut and paste it here as text}, most of the new flat tax nations are former Soviet republics or former Soviet bloc nations, perhaps because people who suffered under communism are less susceptible to class-warfare rhetoric about “taxing the rich.”
64. #64 Henry
July 19, 2007
Stipulated: The graph is stupid, and the Laffer curve is unemployable in anything but econ papers for academia.
I just think people are not quite clear on the corporate tax issue.
There is a really fine point to be made about the taxation of an entity that is essentially a conglomeration of shareholders. While, as Mark says, a corporation has some presence separate from its owners, there is more at play. The “legal” existence of a firm isn’t quite the same as an extant taxable person. For instance, you can’t put a firm in jail for accounting malfeasance. Taxes, fines, and profits all devolve to the people who own shares, including profits (if any) from the sale of assets once the operation of the firm is paid for. When tax is levied, it’s levied on the activity the firm undertakes, and then on the transfer of profits (if any) to the shareholders. Increasing taxes means that either the shareholders make less, the firm gets rid of people/capital, or the company raises prices to compensate. The _elasticity_ of each is uncertain and highly variable. So not much may happen if taxes change some. If they change a lot, some combination of everything may occur. But it cannot be avoided that taxation of a corporation impacts not some independent legal entity only, but the people who constitute that entity’s owners, workers, etc.
Also, while it’s the kickbacks and backscratching loopholes that make the news, the biggest contributors to huge firms not paying taxes are the totally legal allowances for things like debt. The funny-biz comes from what firms group under the legal label as deductable. Items that are considered expenses help deduct from the amount that is taxed. But a lot of those expense are legitimate: there is no “loophole”, there’s just a distorted view on what should or shouldn’t count towards expenses. Debt interest can be written off, for example, as is clearly expressed, no loophole required. But capital assets get financed through debt, and so on. The crying shame is the complexity of the tax code; to really figure out where companies hide things takes so much time and effort (and companies hire the people who would be good at finding it to actually DO it at much higher salaries), that we have a huge circular waste of time and money as people try to avoid taxes and the government hunts down illegal evasion. It’s a tax that lots of firms avoid exceedingly well, and by doing so the firm deprives the government of revenue and the owners of value. So even if you really like having it, the country gets incredibly little from it.
65. #65 averros
July 20, 2007
Laffer curve is totally meaningless because it aggregates _present_ collections with potential collections in the _future_.
Besides, given that size of tax revenues represents nothing more than amount of resources expropriated from populace under threats of violence, the very idea that this amount should be maximized is quite dubious from a moral point of view.
66. #66 Mr. Gunn
July 24, 2007
For y’all that are wondering how that curve was derived, I’ll tell you.
They didn’t use excel to make that curve. They used powerpoint.
67. #67 steve s
August 8, 2007
All this arguing about curve fitting seems to be giving them too much credit. As near as I can tell the y-axis is just a different form of tax rate. So they’ve graphed one tax rate, vs. a different tax rate. That’s not even a laffer curve. The rest of the argument is moot.
68. #68 Jared J. Myers
February 18, 2010
The Laffer Curve itself only reflects a certain part of the economy – the part run by taxable corporations. If the state doesn’t raise taxes from them at all (point 0/0), taxes would be paid only by individuals whose majority would work with corporations and thus receive higher wages (which would have the effect of a tax on revenues per employee), or cause a failure of the economy due to a decreasing demand of goods and services provided by these companies.
If taxation is at point 100/0, this means the entire economy is run by the state itself. No more corporations would be existent; a large amount of the tax sum would be necessary to invest and produce goods and services.
At any point in between, some profit stays with the private sector and will be spent, which creates demand, or saved, which creates demand later on (or devaluation or the next “financial crisis”). Some profit stays with the public sector and will be spent, which creates demand. – So, where’s the difference that could cause any change in GDP?
69. #69 detector pen
March 13, 2010
I think huge differences between nominal and effective tax rates.
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The myth of the gender wage gap
The modern feminist movement cares most about appearances, not realities. Let me endeavor to illustrate this to you.
Last week, the U.S. Senate failed to pass a bill called the Paycheck Fairness Act, which was intended to help combat wage discrimination against women based on their gender. The vote, which occurred along partisan lines, was immediately spun by the bill’s proponents (modern feminists and their political allies) as evidence that those who oppose the bill put “politics ahead of women and their families.” The bill’s proponents knew beforehand that the legislation did not have the votes to pass, and it was widely recognized (and reported) that the primary purpose of pushing the legislation to a vote was to paint the bill’s opponents as uncaring in regard to women.
The fact is, however, that the “gender wage gap” – the very problem that the Paycheck Fairness Act is meant to solve – is largely a myth: differences in pay between men and women can be explained almost entirely by behavioral differences between men and women.
In 2009, a private research firm statistically analyzed the gender wage gap for the U.S. Department of Labor. The researchers reported a difference in wages between men and women of roughly 20 percent, but found that there are “observable differences” in male and female employees that account for two-thirds to three-fourths of that 20 percent. In other words, between two-thirds and three-fourths of the 20 percent wage difference was due to observable, non-discriminatory factors, leaving the leftover portion of the difference – the portion that could possibly be due to discrimination – at a relatively small amount of five to seven percent.
Those “observable differences” were all differences in behavior among working men and women. Three behaviors primarily explained differences in wages between men and women:
1. A larger portion of women than men choose to work part-time, and part-time work “tends to pay less than full-time work”
2. A larger portion of women than men choose to interrupt their careers to care for elderly adults or children, leading to lower pay if/when they go back to work
3. Women tend to value “family friendly” workplace policies (parental leave, flexible schedule, child care, and sick leave) more than men, preferring such policies to higher pay
Further, the researchers reported that “research also suggests that differences not incorporated into the [statistical analysis] due to data limitations may account for part of the remaining gap.” This means that the part of the wage gap that could possibly be due to discrimination might actually be significantly smaller than the five to seven percent mentioned earlier. In other words, there isn’t really much of a “gender wage gap” to speak of – that idea is mostly a myth in today’s world and doesn’t require a corrective policy change.
The analysis of the “gender wage gap” supports this assertion. As the researchers conclude, “this study leads to the unambiguous conclusion that the differences in the compensation of men and women are the result of a multitude of factors and that the raw wage gap should not be used as the basis to justify corrective action.”
So if, in fact, society has basically eliminated wage discrimination based on gender, why doesn’t the modern feminist movement simply declare victory?
Well, it wouldn’t look good for the movement to admit it has basically become irrelevant when it comes to women in the workplace, would it?
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Monday, January 1, 2007
Salem Witch Trials General Info
The Salem witch trials started in 1692 when Elizabeth Parris and Abigail Williams began to exhibit strange behavior. There was no physical explanation for the girls behavior and they assumed it was the devil's work. Blame then fell on Tituba, Mr. Parris' slave, and 2 other women. These 3 people were the first accused of many in the little town of Salem between March 1692 and May 1693. Overall 20 people died in the trials, 14 women and 6 men, and at least 175 more people were imprisoned. There was also an unrecorded amount of people who died in prison because of severe torturing. The most common method to kill the accused was by hanging (19 out of the 20 people) but a less common way was by crushing them with heavy stones (1 out of the 20 people).
Torturing and Killing Devices
There were many different ways to torture the accused people untill they confessed to being an witch. Some were physical and some were mental. They usually tried to torture a person mentally first because it was easier, cleaner, and cheaper than most of the physical ways. Some examples of mental torture is starvation, extreme conditions like cold, and isolation. Sometimes just showing a person the torture devices was enough to get a confession out of somebody. When a person wouldn't give a confession then they started the physical torture. Here are a few examples of the more common torture devices. The rack: a person was tied down on a slab of wood and stretched untill he confessed. Usually dislocated the victims shoulders. Thumbscrew: a screw was slowly pressed into your finger or toe untill it broke the nail and pressed into the exposed nerves underneath. Was an easy way to inflict maximum pain with little effort. Strappado: A person was tied up with their arms behind there back and lifted up to a high point. They were then dropped and stopped a few feet from hitting the ground usually dislocating shoulders. After a witch confessed they were usually sentenced to death. The most common ways to kill someone was to hang them or burn them at the stake. Another way was by crushing them with heavy weights.
Results From The Salem Witch Trials
The Salem witch trials will always be a blemish on our countries history, but there were also other witch trials going on. Even though only 20 people died in Salem there were others that died during this time in other parts of the colonies affecting countless numbers of people. The worst thing about this is that people didn't learn from their mistakes. During the Cold War the same type of false accusations happened and no one stopped it. Just like in the Salem witch trials people were imprisoned with little evidence and had their lives ruined. The only good thing that could have came out of the Salem Witch Trials is that it turned Salem into a great tourist attraction and we got the play "The Crucible" out of it as well. |
Alternate titles: Darazi; Druse; Durūz
Druze, also spelled Druse, Arabic plural Durūz, singular Darazi, relatively small Middle Eastern religious sect characterized by an eclectic system of doctrines and by a cohesion and loyalty among its members (at times politically significant) that have enabled them to maintain for centuries of turbulent history their close-knit identity and distinctive faith. They numbered more than 250,000 in the late 20th century and live mostly in Lebanon, with smaller communities in Israel and Syria. They call themselves muwaḥḥidūn (“monotheists”).
The Druze permit no conversion, either away from or to their religion. Marriage outside the Druze faith is rare and is strongly discouraged. In those circumstances the survival of their religion and community across a millennium is the more remarkable in that their religious system is kept secret not only from the outside world but even from some of their own members; only an elite of initiates, known as ʿuqqāl (“knowers”), participate fully in their religious services and have access to the secret teachings of the ikmah, the Druze religious doctrine. In times of persecution, a Druze is allowed to deny his faith outwardly if his life is in danger. That concession, or taqiyyah, is allowed according to Al-Taʿlīm (“Instruction”), the anonymously written “catechism” of Druze faith.
It is not known to what extent this people was self-conscious and distinct before adopting their present religion. Druze religious beliefs developed out of Ismāʿīlite teachings. Various Jewish, Christian, Gnostic, Neoplatonic, and Iranian elements, however, are combined under a doctrine of strict monotheism. Propagation of the tenets of the new religion began in Cairo in 1017 ce, led by Ḥamzah ibn ʿAlī. It is from the name of Ḥamzah’s subordinate, Muḥammad al-Darazī, that the group derives its name. The eclectic belief system was organized into a doctrine of the soteriological divinity of al-Ḥākim bī-Amr Allāh (“Ruler by the Command of Allāh”), the sixth caliph (996–1021) of the Fāṭimid dynasty of Egypt, whom they call al-Ḥākim bī-Amrih (“Ruler by His Own Command”). It is believed by the Druze that al-Ḥākim did not die but vanished and will one day return in triumph to inaugurate a golden age. There is some suggestion that a number of people in widely scattered areas accepted this system, but only the Druze have survived. It is known certainly that a great many groups in the Middle East at that time, most of whom came under the various headings of the heterodox Shīʿite Muslim sects and movements, accepted similar notions and joined similar causes.
Although many Druze beliefs are kept secret from outsiders, the source materials for outsiders’ knowledge of Druze history and religion are not as scarce as might be expected. Muslim and Christian accounts of historical events, as well as comments on and assessments of the Druze religion and customs, should be treated with reserve and caution because of their polemical character. Jewish sources contemporary with the first half of the reign of al-Ḥākim present him in a favourable light.
The Druze people have figured prominently at various periods in Middle Eastern history: in the Arab stand against the Crusades; in the century following the Ottoman conquest (from 1516), prospering as powerful vassals (until their Lebanese leader and early Westernizer Fakhr al-Dīn of the house of Maʿn was driven out, to take asylum at the courts of Tuscany and Naples); in the 19th century, dominating the Lebanese aristocracy under the ruling Shihāb family (who were Sunni Muslims); and in the 20th century in many of the vicissitudes of Arab and Lebanese development.
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Adjusting of aheadset
The headset is a revolving mechanism used to connect the fork, the stem, the handlebar and the front wheel. This part must be easy to turn. Shocks from bumpy road surfaces place a lot of stress on the head set bearings. This can cause the head set to become loose and out of adjustment. The head set should not have any noticeable play.
Check bearing play
1. Check the play by wrapping your fingers around the upper bearing case and upper part of the fork as shown in the image. Picture 1
2. Pull the front brake lever with your other hand and push your Canyon to and fro.
3. If the bearings have excess play, the bearing case will move around on the head tube.
4. Another way of checking for excess play is to lift the front wheel off the ground and then gently drop it. If there really is play you’ll hear a rattling sound.
5. In order to check the smooth operation of the bearings you’ll need to lift the frame with one hand until the front wheel has no contact with the ground. Turn the handlebar from left to right. The front wheel must move smoothly from left to right without sticking. The slightest of touches should be sufficient to move the handlebar, which should then move from left to right under its own weight.
„AHEADSET” adjustment
In the case of this system a star-fangled-wedge clamps inside the fork steerer. If the wedge presses against the fork steerer tube with too much force then it will be more difficult to turn the fork. If there is too little force, the fork steerer will rattle inside the head tube. By using the adjusting bolt on the headset cap you can adjust the pressure the star-fangled-wedge exerts on the fork steerer, which also determines bearing play.
This is how you adjust the AHEADSET:
1. Slacken the stem bolts as shown in the image. Picture 2
2. Carefully tighten the counter-sunk bolt with an Allen key as shown. Picture 3
3. Straighten the stem so that the handlebar isn’t off at an angle.
4. Tighten the stem bolts to the correct torque again.
5. Now carry out the check for play already explained. The bearings should not be adjusted too tight. Position yourself in front of your Canyon and clamp the front wheel between your legs. Grip the handlebar and try to twist the handlebar. If the handlebar moves, you’ll need to tighten the stem bolts again.
i-Lock-headset adjustment
This system does not have any clamp inside the fork steerer. This saves weight and protects the material on the fork steerer.
1. Slacken the grub screw (with a 2mm Allen key, from 2011 models Torx T6) on the i-Lock headset. Then slacken the bolts on the stem. Picture 2
2. Press down on the stem. Now straighten the handlebar. Look from behind down over the stem and front wheel. Tighten the stem bolts again to the required torque. Now all you have to do is tighten the i-Lock grub screw Picture 4 until you feel a light resistance. This reduces the amount of bearing play. When you are done check for excess bearing play again.
3. When the headset is correctly adjusted, there’ll be a slight gap between the i-Lock bearing casings visible. Picture 5 When you tighten the grub screw the upper casing slides against the lower one thereby forcing it downwards and this reduces the amount of bearing play.
There should be no play around the headset, as the fork bearings could become damaged. Therefore check regularly that there is no play. Check that all screws and bolts have the correct tightening torque. You will find the correct figures on the components themselves, in the Operating Manual or here in the Tech Support Centre.
Picture 1: Check first if there is play in the aheadset
Picture 1: Check first if there is play in the aheadset
Picture 2: Losen the aheadset screws
Picture 2: Losen the aheadset screws
Picture 3: Adjust the play in the aheadset
Picture 3: Adjust the play in the aheadset
Picture 4: Adjust the play in the i-Lock aheadset
Picture 4: Adjust the play in the i-Lock aheadset
Picture 5: There needs to be a small gap in the i-Lock aheadset
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Image text transcribed for accessibility: Given: A spanner wrench is used to apply torque to circular shafts and other similar shapes. Such wrenches are routinely used in the setup of tools such as milling machines, lathes, and so on. The wrench makes contact with the shaft at point A, which may be assumed to be frictionless, and at B where a small pin fits into a hole in the shaft. If P = 80 N, L - 120 mm, r = 25 mm, and a = 120 degree. Find: The reactions at points A and B Solution: |
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Social and Behavioral Sciences Department
If you are curious about what makes people "tick" or if you want to understand why things are the way they are, then the social sciences are for you!
The Social and Behavioral Sciences (S&BS) Department offers coursework in the following disciplines:
• Anthropology
• Psychology
• Social Work
• Sociology
What are The Social Sciences?
There are a number of different disciplines that fall within the social sciences. Some are general and address broad questions about human social life. Others target only certain dimensions of the human experience.
Anthropology studies the wide variety of values, beliefs, kinship relationships, religions, and governance structures in cultures as they have evolved over time, helping us to understand similarities and differences in the human experience.
Psychology looks at the causes of individual human behavior, helping us to understand why we behave as we do by studying the brain, learning, memory, thinking, and change through the lifespan.
Social Work examines how planned change activites can impact individuals, groups, organizations, communities, and societies to improve social functioning.
Sociology looks at human behavior, focusing on how people are influenced by other people and by the social systems that we create. |
Category:Axiom of Choice
Explain xkcd: It's 'cause you're dumb.
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The Axiom of Choice is a recurring topic in xkcd. It states the product of a collection of non-empty sets is non-empty, or more simply, given any collection of bins, each containing at least one object, it is possible to make a selection of exactly one object from each bin.
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Warren Meyer Contributor
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Did CLOUD Just Rain on the Global Warming Parade?
One of the hot topics, so to speak, in the global warming debate is allocating responsibility for 20th century warming between natural and man-made effects. This is harder than one might imagine — after all, no one’s thermometer has two readings, one for “natural” and one for “man-made.” This week, from CERN in Geneva, comes an important new study in this debate.
Global warming skeptics argue that only a portion, possibly a small portion, of recent warming is due to man-made CO2 and greenhouse gasses. Climate alarmists have, in turn, argued that all of 20th century warming, and more, was due to anthropogenic effects (if the “and more” is confusing, it means that some scientists believe that certain man-made and natural cooling effects actually reduced man-made warming below what it might have been.)
It is only in this context that Michael Mann’s famous hockey stick studies make even a bit of sense. After all, what do pre-industrial world temperature trends have anything to tell us about the effect of man-made Co2 on 20th century temperatures?
But Mann’s work had a very specific purpose — to make the case that the natural variability of temperatures, at least on a millennial scale, is very small. Though considered by many to be deeply flawed, Mann’s work seemed to say that the anecdotal historical record was wrong, that there was not a Medieval warm period or very cold period during the solar minima of the 17th and 18th centuries. In his hockey stick, the only significant trend in temperatures began with the industrial age, and man’s production of CO2.
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• rogerkni rogerkni 3 years ago
“Every few months climate change skeptics come up with a new “game changing” discovery that will undo nearly 200 years of climatic science.”
It takes a lot of arrows to kill an elephant.
“climate change skeptics jump on one band-wagon after another … ”
Rather, they keep finding new chinks in the armor of the Nonsensus.
climate change skeptics … cannot even agree among themselves what the alternative is.”
And if they did, you’d be claiming it was evidence that they were reciting a script handed to them by their ologeneous overlords.
• Hello rogerkni
The basic science is settled, all of the issues that you raise do not bring into question the almost 200 years of climatic and atmospheric science on which the ACC theory is based. This is a squabbling over the details.
• economart economart 3 years ago
Hello David,
Again Arrhenius cited no cause. He said the rise in CO2 corresponds with a rise in temperatures. So stop telling us that he cited a causal effect or misrepresenting his findings. Secondly, the amount of CO2 caused by Man has been increasing for a number of centuries, yet temperatures go up at certain times and then settle. For the last 12 years they have settled. But not CO2. Finally it is well known that increases in CO2 in the atmosphere procede from increasing temperatures. They do not precede them.
You always get it backwards, or you deceive.
• skeklach skeklach 3 years ago
What’s being shown is that the IPCC’s model is heavily flawed. Mind you that it is the conclusions of the IPCC that all of these institutions are endorsing. Over the past few years, there have been many factors in their models that have been shown to be incorrect. However, instead of making adjustments accordingly to verify whether they make a difference, the claims have been met with denial where applicable and deemed irrelevant if not. They show that the science behind the IPCC’s findings are weak at worst, inconclusive at best.
Despite all of that, the IPCC has yet to acknowledge and correct it’s error in calculating the Earth’s effective temperature which led to an inaccurately low black-body temperature and thusly an overestimation of local effects upon the planet’s temperature.
In any other field of science, when confronted with an inaccuracy of the factors in your study, one would be expected to adjust accordingly and determine how it effects their results. The IPCC has yet to do this though. They have stood behind their initial results and fought tooth and nail against anything and anyone that contradicts them. They are vested in their result and that isn’t how science works. When you put your opinion before the facts, you cease to be a scientific entity and become a political one instead.
• fredlinn fredlinn 3 years ago
It seems to me that we should change what we can change.
There is no point in worrying about what we can not change.
What needs to change are things we should be doing anyway, for reasons other than climate change.
Climate change will not matter much if we have already poisoned ourselves to extinction.
• bobert bobert 3 years ago
While you tend to use middle of the road reasonable tone, your quoting of Roy Spencer, and using other refuted skeptic arguments, like the sun, and your conclusions, led me to believe your nothing more than another anti-AGW contrarian guilded by presentation.
I will quote an actual real life Climate Scientist prediction with respect to the lauded blogosphere writers would say about CERN/CLOUD:
• cincinnatus cincinnatus 3 years ago
Warren – why do you ignore the most important element of the Michael Mann Hockey Stick? The crux of Mann’s behavior is that he INTENTIONALLY OMITTED the Medieval Warming Period, AND he intentionally DID NOT DISCLOSE that fact, until he was CAUGHT with his pants down. That is when he came up with the ALIBI that he thought that it was scientifically sound to eliminate that important period as an anomaly. You also FAIL to mention that the CLOUD experiment is a higher level of investigation, precisely beause it is an EXPERIMENT, not a computer model that incorporates the biases of the pseudo AGW scammers.
• jadotch jadotch 3 years ago
I really wish it was not so politicized. It is so hard to find real answers about real concerns about global warming. I am definitely a skeptic, but I am not a denier. I have so many questions about it that neither side can give me a non-BS answer.
Also working with some one who got a government grant way back when, he talked to me at length how politics and money for science play into everything. It is frustrating.
I want real answers. Like I said, I do believe man has had an impact, but how much of one? Is it really that significant? |
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