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How does a Cameleon change color base on its environment? | So the video you are talking about is fake. Chameleons don't actually change their skin to blend in with their environment, the pigments in their skin expand or contract based off of how warm or cold they are.
As silly as it is, [this video has good information.](_URL_0_) | [
"Spots and broad vertical bands on the chameleon's flanks range in color from brown, dark green, yellow or even black. The basic coloration of the creature is a deep forest green with white stripes, but like many chameleons it can change its color depending on various circumstances. If being fed or handled they mig... |
When a thyroid disorder is suspected, are the TSH and T4 blood tests sufficient to confidently confirm or disprove the diagnosis? | In addition, one could use:
1. [Thyroid ultrasound](_URL_2_): ?cystic/nodular, size of cysts/nodules, no information on function of nodule (?toxic/non-toxic)
2. [Nuclear thyroid uptake scan](_URL_1_) using technetium pertechnetate: function of nodules (?hot/"warm"/cold)
3. [Fine needle aspiration](_URL_0_): microscopy... | [
"Diagnosis starts with a history and physical examination. Screening for thyroid disease in patients without symptoms is a debated topic although commonly practiced in the United States. If dysfunction of the thyroid is suspected, laboratory tests can help support or rule out thyroid disease. Initial blood tests of... |
why are there fake/bad ads on sites like "putlocker" and other various sketchier websites. | Imagine that out of the people who visit websites with those ads, 50% of them see the ads. Now imagine out of those who see them, 1% click on them by accident and 0.5% click on them on purpose (e.g. they are computer illiterate, don't realize what they're doing, think they're legitimate, etc.). In reality those numbers... | [
"A CNN investigation examined exactly how fake news can start to trend. There are \"bots\" used by fake news publishers that make their articles appear more popular than they are. This makes it more likely for people to discover them. \"Bots are fake social media accounts that are programmed to automatically 'like'... |
how can the voyager and other craft go to such extreme distance? how does it have enough fuel? why can't we send humans like that instead? | Nobody mentioned this, but the Voyager missions were created to take advantage of an unusual planetary alignment. They gravity whipped around several planets as they went outward, both saving on fuel, and getting great close-ups of them.
Normally a mission like that would only fly by one, maybe two, and never have en... | [
"After further studies, it became possible to gain the space of one propulsion compartment, which is now used for cargo and personnel. The ships can ferry 20 people, and up to 60 for short travel with a calm sea.\n",
"Though having developed interstellar travel, spaceships can still only travel at the speed of li... |
why does sound need a medium to travel through and exist upon? | Sound is movement of particles. If there is no particle there is no movement and therefore there is no sound.
When we hear things what we are hearing is the movement in the air. That hits the eardrum is converted into an electrochemical signal in the brain and then we hear it. I.e., sound is a way for us to sense mov... | [
"Sound typically travels fastest and farthest through solids, then liquids, then gases such as the atmosphere. Sound is affected during fog conditions due to the small distances between water droplets, and air temperature differences.\n",
"The mechanical vibrations that can be interpreted as sound can travel thro... |
how are nuts so high in calories, yet so healthy and good for weight loss? | They're healthy but not "eat all you can" healthy. They are nutrient rich, and the fat in them will help curb your appetite making it easier to make it to your next meal time without snacking. The energy you get from eating them will last a good long while with no crash. That being said you must still limit the amount ... | [
"Nuts are an important source of nutrients for both humans and wildlife. Because nuts generally have a high oil content, they are a highly prized food and energy source. A large number of seeds are edible by humans and used in cooking, eaten raw, sprouted, or roasted as a snack food, or pressed for oil that is used... |
Could you completely sound proof a room from sounds outside of it by creating a thin vacuum layer around the room? | In principle yes, but how would you keep the two domes from touching? | [
"An acoustic anechoic chamber is a room designed to absorb as much sound as possible. The walls consist of a number of baffles with highly absorptive material arranged in such a way that the fraction of sound they do reflect is directed towards another baffle instead of back into the room. This makes the chamber al... |
If a nipple is removed, by any means, does it grow back as a nipple or just regular skin? | The nipple-areolar complex cannot grow back - after [mastectomies in which the NAC is not spared](_URL_1_), surgeons will often create an artificial nipple and then [tattoo in a surrounding areola](_URL_0_) for cosmesis. | [
"Another method of protracting inverted nipples is to have the nipple pierced. This method will only be effective if the nipple can be temporarily protracted. If pierced when protracted, the jewellery may prevent the nipple from returning to its inverted state. The success of both of these methods, from a cosmetic ... |
why isn't australia cold and snowy like north america and europe? | [Have a look at this map](_URL_0_).
What it shows is the antipodes for every bit of land on earth. It shows you quite neatly that Australia is about as far south as the northern parts of Africa, Spain, Mexico, the southern US are north.
In other words... a polar region it ain't. | [
"Because Australia is a medium sized continent, separated from polar regions by the Southern Ocean, it is not subject to movements of frigid polar air during winter, of the type that sweep over the continents in the northern hemisphere during their winter. Consequently, Australia's winter is relatively mild, with l... |
Why does my Hand Sanitizer expire? | I really hate that the top two responses link to a shitty 'explanation' for why hand sanitizer 'doesn't really' expire.
[doctoreldritch](_URL_0_) is correct in his/her explanation for how hand sanitizer works, with the key line in his/her link being "Their cidal activity drops sharply when diluted below 50% concentrat... | [
"Hand sanitizer is a liquid generally used to decrease infectious agents on the hands. Formulations of the alcohol-based type are preferable to hand washing with soap and water in most situations in the healthcare setting. It is generally more effective at killing microorganisms and better tolerated than soap and w... |
Monday Mish-Mash | History on Television | Any Pole interested in modern history will tell you that Bogusław Wołoszański was one of the best "TV historians" (he still publishes books and makes historical movies but major works are from nineties and early 2000s) and he is one of the most famous Polish "major propagator of history". He produced "Sensacje XX wiek... | [
"Considered by TV historians as a classic of the medium, with Ronald C. Simon, television curator of The Paley Center for Media calling it \"a pinnacle of television history\", the series presented 90 minutes of comedy live each week for 39 weeks a year, for a total of 160 shows airing February 25, 1950, to June 5,... |
How does our brain turn the sound waves it hears into a something understandable and something we can take information from? | The inner ear is quite fascinating. To understand this, you have to know what hair cells are.
Hair cells are a very special type of cell which gets depolarized (activated) by tilting the stereocilla. Once the stereocilla gets tilted, the "top opens" allowing sodium to come in and depolarize the hair cell.
Now, back t... | [
"When sound waves reach the ears, the energy they contain is converted into electrical signals, which are sent via the auditory nerves to the brain. Sound processing begins when these electrical signals reach the primary auditory receiving area in the core part of the temporal lobe. Signals then travel to the area ... |
how do those heart rate monitors on phones that don't have built in sensors work by using only flash and the camera? | The flash lights up your finger, the camera detects any changes to how brightly lit your finger is. During a beat there’s a little more blood in the vessels of the finger, so it blocks a little more light. The camera can see these small variations in brightness.
Wristwatches with pulse meters do the same thing, just ... | [
"Instant Heart Rate, released in October 2010, is a mobile Heart Rate Monitor app. With advancements in mobile phone camera resolution, most smart phones can accurately measure heart rate by analyzing minute color changes of the skin. The application, illuminates a user's finger with a phone's flashlight feature an... |
Copper jewelry | Copper jewelry exists as far back as the Badarian Period in Egypt (pre-Dynastic circa 4400BC). Copper jewelry is found all over the ANE going as far back as the Chalcolithic period (c 6000BC). Copper jewelry runs from prehistoric Britain all the way through the Anglo-Saxon period (2000BC-1066AD). That pretty much cov... | [
"In heraldry, copper is the tincture of metallic copper. Copper has been introduced in Canadian heraldry. It is considered a metal along with Argent (silver) and Or (gold) and should be depicted as bright, new copper metal.\n",
"Copper is a chemical element with the symbol Cu (from ) and atomic number 29. It is a... |
Can someone tell me about the 17th-19th C History of Lower Silesia, Poland? | /u/Premislaus, I hope you don't mind me tagging you, you're just the only flaired user with Polish history in your flair :) | [
"The history of the region dates back over a thousand years and Lower Silesia was once part of Medieval Poland, Bohemia, Austria, Prussia, Germany and modern Poland after 1945. At its foundation the territory was under the rule of the Piast dynasty and became a duchy. It was divided into small realms reigned by Pia... |
How were WW2/WW1 ships repaired? | Repairs could be made in a number of ways, depending on the extent of the damage, the time pressure on the repair and the facilities available. Generally speaking, prefabricated parts were rare. Instead, repair crews would fabricate new pieces, or patch damaged plates.
The first, and most immediate, set of repairs tha... | [
"Ships in continuous use during war need repair both from wear and from war damage such as naval mines, kamikaze attacks, dive bombs and torpedoes. Rudders and propellers are best serviced on dry docks. Without remote on location dry docks, months could be lost in a ship returning to a home port for repair.\n",
"... |
where does all the internet comes from and why the speed isn't the same everywhere? | The Internet is just a bunch of servers and networks that are connected to each other, think of old school telephone operators, you pick up the phone, tell them who you want to talk to, and they connect you to them. This is basically what happens when you are connecting to a website.
The speeds aren't the same for... | [
"The Internet carries many network services, most prominently the World Wide Web, including social media, electronic mail, mobile applications, multiplayer online games, Internet telephony, file sharing, and streaming media services.\n",
"The internet service covers most of the continental U.S., Alaska, and Hawai... |
darren aronofsky's "the fountain" | There are three plot lines going on throughout the movie:
1. In 1500, Queen **Isabella** of Spain wants to find the Fountain of Youth / Tree of Life in the Yucatan, and is threatened by the head of the Spanish Inquisition because of this. She sends her lover, the conquistador **Tomas** in search of it. With the help o... | [
"The Fountainhead is a play written in 2014 by Belgian theatre director Ivo van Hove. It is an adaptation of the 1943 novel of the same name by American author Ayn Rand. The story focuses on Howard Roark, an individualistic architect who designs modernist buildings and refuses to compromise with an architectural es... |
Why do a large amount of Renaissance paintings have either bad or inaccurate anatomy in regards to humans? | Hi there -- you may be interested in [this section of our FAQ](_URL_0_) which covers art in the Renaissance and touches on "realism" in painting. | [
"Art critics debate whether his paintings were whimsical or the product of a deranged mind. A majority of scholars hold to the view, however, that given the Renaissance fascination with riddles, puzzles, and the bizarre (see, for example, the grotesque heads of Leonardo da Vinci), Arcimboldo, far from being mentall... |
why do some of my beard hairs grow in insanely thick while the rest are pretty normal? | I, too, would like to know why this happens. Mine seem to be sort of brittle as well, and I generally can't stop myself from fiddling with them until they just sort of break off at the root, only to grow back in in a day or two. | [
"A relatively small number of women are able to grow enough facial hair to have a distinct beard. It is usually the result of a fairly common condition: polycystic ovary syndrome, which causes excess testosterone, and also an over-sensitivity to testosterone, and thus (to a greater or lesser extent) results in male... |
why is china lowering the yuan to a decade year low a big deal? | Does your country trade with China? If yes, the exchange rate is important.
If the Chinese Yuan (CNY) devalues, it means you can buy Chinese-made stuff cheaper. You are discouraged from buying local-made stuff since the price is higher.
Even if you personally don’t buy Chinese goods, manufacturers will still buy Chin... | [
"Since 2014, the situation changed dramatically, as China stopped artificially deflating its currency, as the growth in the Chinese economy slowed and Chinese investors made more investments outside the country, leading to a drop in the yuan's value in relation to the dollar, as well as a decline in China's reserve... |
Can more than two stars orbit each other, and is there a limit to how many stars there can be in the same multiple star system? | More than two stars can orbit each other: in fact the closest extrasolar star system, Alpha Centauri, consists of two sunlike stars circling one another with a smaller red dwarf companion orbiting them at a great distance.
More is possible as well: the current record is [seven](_URL_0_), and it's at least theoreticall... | [
"A multiple star system consists of three or more stars that appear from Earth to be close to one another in the sky. This may result from the stars actually being physically close and gravitationally bound to each other, in which case it is a \"physical\" multiple star, or this closeness may be merely apparent, in... |
what exactly is blood pressure | Blood runs in tubes around your body. These tubes are called blood vessels, and to drive the blood around the heart pumps all the time throughout our lives (the heart is pretty much a glorified muscle).
Where does pressure come into it? If a tube (or a balloon, or anything else, really) is chock full of fluid, it migh... | [
"Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels. Most of this pressure is due to work done by the heart by pumping blood through the circulatory system. Used without further specification, \"blood pressure\" usually refers to the pressure in large arteries of the systemic cir... |
what is the difference between a web designer, a web developer, and a web programmer? | From my limited experience as a network admin
I'd say...
Web Designer: This guy has an art background
and knows CSS and HTML.
Web Dev: This guy manages a little more than
programs. Although he is fluent in just about
everything, just not great at it.
Web Programmer: This is your javascript guru.
The web guys usual... | [
"Content designers who specialize in programming might deliberate the role of a \"web developer\" versus \"web designer.\" Web developers deal with the non-design aspect of building websites, which includes coding and writing markup and site hierarchy, including: client-side coding, server-side coding, and database... |
what exactly causes our skin to "crawl" when we see something disturbing or unexpected? | That's your hair standing on end. Its caused by a hormone released in response to certain stresses. Its the same thing that makes a cats fur puff out when scared, and done for the same reason. Of course in cats and animals this makes them look bigger, to scare away threats.
But we don't have nearly as much hair, havi... | [
"There are a few spiders that can bite human skin and cause a skin reaction, but spiders are blamed for many more reactions. In particular the misdiagnosis of infections and other skin ailments are commonly attributed to brown recluses.\n",
"In rare cases, individuals become convinced that the sensation is due to... |
why did 20th century bombs dropped from aircraft usually made high-pitched, loud whistle-like sounds while falling? | The whistles were purposefully attached to the bombs. Their purpose was to weaken enemy morale and to enhance the intimidation of dive-bombing. Look at the Stuka dive-bomber, a similar case. What other purpose did it's sirens have? As far as warning the target, it's too late to get to safety once you hear the whistle i... | [
"Shock waves develop around aircraft as they near Mach 1 (1225.0 km/h). At ground level, these are perceived as a loud double boom or bang. Their intensity varies due to factors such as weather, refraction from different layers of atmospheric density, and size of the aircraft, but in general, from a supersonic airc... |
why does romaine seem to be recalled so frequently, but other lettuces not so often? is there something about romaine that doesn't occur with green leaf, spinach, etc..? | I'm not sure if the premise is necessarily true: that Romaine is recalled more often. There is an outbreak E. Coli outbreak going on with Romaine this year, so it may seem that way. However, I certainly remember bagged lettuce being massively recalled a few years ago. Green leaf lettuce recalls have happened as wel... | [
"On 6 December 2008, as a precautionary measure, the Food Safety Authority initiated a product recall of all Irish pork and bacon products which had been produced since 1 September 2008. This was due to the presence of dioxin in a small sample of Irish pork and bacon products which was confirmed on Saturday, 6 Dece... |
Is arctic methane sequestered carbon? | Yes. The carbon in permafrost comes from organic matter that was originally in the soil before it froze (as is the case for essentially all soils on Earth). | [
"The release of methane from the Arctic is in itself a major contributor to global warming as a result of polar amplification. Recent observations in the Siberian arctic show increased rates of methane release from the Arctic seabed. Land-based permafrost, also in the Siberian arctic, was estimated in 2013 to relea... |
Would you say America wanted the Cold War more than the Soviets? In other words, did the U.S. "start" it? | It's simplistic to attempt to attribute the Cold War to one side or the other. Here's the best (and so well written I'm just going to quote it) 'back of the envelope'analysis I've read. From Postwar, by Tony Judt.
"In Europe the Cold War began not after the Second World War but following the end of the First... .Th... | [
"The Cold War was a state of political and military tension after World War II led by the United States (and the Western Bloc) and the Soviet Union (and the Eastern Bloc). After World War II, the victory of the Soviet Union over Germany granted them considerable territorial spoils; the Soviet Union banded together ... |
what is the difference between a home and a pro version of windows? | You won't probably feel the differences at home.
The main difference is the Pro editions can be joined to an Active Directory domain. The second is the built-in encryption system (BitLocker).
| [
"Windows 10 is available in five main editions for personal computing devices, of which the Home and Pro versions are sold at retail in most countries, and as pre-loaded software on new computers. Home is aimed at home users, while Pro is aimed at small businesses. Each edition of Windows10 includes all of the capa... |
do governments have plans set in the event of a contact with extra-terrestrial beings? | Yes, it is called a post-detection policy (PDP)
United Nations Office for Outer Space Affairs (UNOOSA) and the International Academy of Astronautics (IAA) have them. [Here](_URL_0_)
Private companies like the IAU, have their [official protocol] (_URL_1_) for an ET signal.(You tell IAU. IAU contacts the world leader... | [
"Aliens might, for example, choose to allow contact once the human species has passed certain technological, political, or ethical standards. They might withhold contact until humans force contact upon them, possibly by sending a spacecraft to planets they inhabit. Alternatively, a reluctance to initiate contact co... |
what is meritorious consideration in contract law? | In order for a contract to be valid, both parties have to get some sort of benefit from it. I give you $20, you mow my lawn, we are both getting something out of it. The legal term for this is a *consideration*, and a valid consideration is regarded as being meritorious.
Let's say I trick you into signing a contract... | [
"When a contract is formed, good consideration is needed, and so a gratuitous promise is not binding. That said, while consideration must be of sufficient value in the law's eyes, it need not reflect an adequate price. Proverbially, one may sell a house for as little as a peppercorn, even if the seller \"does not l... |
What were Teddy Roosevelt's views and political stance on race and equal rights? | Roosevelt's views on race were complicated but on the whole they were progressive for the period (haha). He did support black civil rights. However he spent a good bit of time in North Dakota, and while he was there he became convinced that the local Native Americans were as a group worthless. He went so far as to clai... | [
"Roosevelt made the case for what he called \"the New Nationalism\" in a speech in Osawatomie, Kansas, on September 1, 1910. The central issue he argued was government protection of human welfare and property rights, but he also argued that human welfare was more important than property rights. He insisted that onl... |
What happens to the oil that we apply on our skin? | Massage therapists use water-based lubricant, so the majority of the "oil" that they applied has simply evaporated. Only a small amount of non-water material remains.
If you were to try rubbing actual oil on your body, you would find that it does not absorb or evaporate. It just...soaks into everything you touch, le... | [
"In this beauty treatment, the oil is rubbed into skin for approximately two minutes. Next, a warm, damp microfiber wash cloth is used to wipe off the excess oil. Applied sparingly, oil may be used to moisturize the skin after the cleansing oil has been removed from the face.\n",
"There is some evidence that the ... |
During WW2, how were the Soviets able to so out-produce Germany? |
The USSR had a much more intense wartime mobilization of their workforce. When it mattered.
The key area is in war-related industry, where from the start of the war until 1943 Germany only increased the workforce in miniscule ( < 1%) proportions (of overall available workers), where the Soviets increased theirs drama... | [
"During the rapid German advances in the early months of the war, nearly reaching the cities of Moscow and Leningrad, the bulk of Soviet industry which could not be evacuated was either destroyed or lost due to German occupation. Agricultural production was interrupted, with grain harvests left standing in the fiel... |
Why does music/sounds make me think of either shapes or a specific color pattern? | You could have 'synesthesia' which is where the stimulation of one sense triggers another. There are various different types of synesthesia as we have many senses, but sound and vision seems to be the most common (of those who have synesthesia, which is pretty rare itself).
_URL_0_ | [
"Most cultures which compose music in this way organize the patterns into distinct melody types. These are often compared to modern Western scales, but they in fact represent much more information than a sequence of permissible pitches, since they include how those pitches should function in the music, and indicate... |
if nazi war criminals were given (somewhat) fair trials at nuremberg then why wasn't osama bin laden given one? | Because he shot at the people trying to capture him, and was killed in the firefight. There's no reason to believe he wouldn't have been given a trial had this not happened. | [
"Former Nuremberg prosecutor Benjamin B. Ferencz stated it was unclear if bin Laden's killing was justified self-defense or premeditated illegal assassination, and that \"killing a captive who poses no immediate threat is a crime under military law as well as all other law,\" a view also held by legal scholar Phili... |
What is the difference between Roman concrete and modern concrete? Also have we "rediscovered" how Roman concrete was made? | First off there's a wide variety of modern concrete. The portland cement part of concrete is the same but what you add to it and the water/cement ratio can vary quite a bit depending on what properties you want out of your concrete.
Roman concrete had volcanic ash added to it. That's similar to modern concrete that ha... | [
"Roman concrete, also called opus caementicium, was a material used in construction during the late Roman Republic until the fading of the Roman Empire. Roman concrete was based on a hydraulic-setting cement. Recently, it has been found that it materially differs in several ways from modern concrete which is based ... |
During the heyday of the Russian Empire, to what degree could Cossacks be considered state-sponsored military colonists (or a 'rank' of the Russian military), and to what degree could they be considered a cohesive ethnic group? | While I can't answer, I'm really interested in your topic, militarized agricultural japanese colonialism. Do you have any good reading on that? | [
"Cossacks were simultaneously both an ethnicity and special social estates in the Russian Empire from the 16th to the early 20th century. Because of their military tradition, Cossack forces played an important role in Russia's wars of the 17th–20th centuries such as the Crimean War, Napoleonic Wars, various Russo-T... |
how do asians differentiate amongst people based on their countries? | The same way everyone else does. You have difficulty telling Asian nationalities apart because it's not something you do on a regular basis. There are visible ways to tell, and people who are exposed to a wider diversity of Asians know. But then they might have difficulty picking up the differences between say a Englis... | [
"Although the concept of a united Asian people is not the same as that of the Asian race. It is even more debatable due to the fact that most of the world link the Asian identity to the people of South, East and Southeast Asia and exclude regions of Western Asia who do not consider themselves as part of the Eastern... |
why is it that sometimes japanese spellings of (video game, tv show, movie, etc) titles are just the sound of the english title written out, even though it comes from japan? | They are using English words, the same way English speaking media is using foreign words some times.
The difference is that the native Japanese way of writing (and with it pronouncing things) is rather different from most European languages.
They primarily use a syllabary that has very limited number of syllables.
W... | [
"The Japanese version features Japanese subtitles for the cutscenes while the characters retain the use of English, as with previous \"Biohazard\" titles. Because of the character variety, this leads to a strange continuation where the Japanese subtitles read as having all the characters saying the same thing in so... |
what happens to prisoners serving a 100+ year sentence when they start to get senile and old? do you die in prison the same way you normally would of old age? | Pretty much, yeah. If you have medical conditions that can't be properly attended to in prison you might be moved to a secure hospital, but they don't let you out. You will die in prison or some prison-like facility. | [
"Prisoners sentenced to life imprisonment serve an average of 17 years. A person with a life sentence will not be released if it is considered likely that the offender will recommit. This means that some offenders have served a considerably longer time than the average and in recent history there are four where thi... |
After reading about Julius Caesar's Legion's dedication towards him, how did they react when they heard the news of his assassination? | Well, by the time of Caesar's Assassination, the Legion had been disbanded and all the veterans had been given parcels of land to live out their days on.
When Caesar was assassinated, however, the men must have been outraged simply out of the fact that they reformed their Legion and fought for the Triumvirate right up... | [
"The assassination of Julius Caesar was a conspiracy of several Roman senators, notably led by Marcus Junius Brutus, Cassius Longinus, and Decimus Brutus, at the end of the Roman Republic. They stabbed Caesar to death in the Theatre of Pompey on the Ides of March (15 March) 44 BC.\n",
"BULLET::::- Marcus Tullius ... |
Are diabetes and cancer fairly new illnesses or are they old yet not talked so much about like acne? | On cancer, I can strongly recommend [Siddhartha Mukherjee's The Emperor of All Maladies](_URL_0_), which (among many other things) is a history of cancer and the ways we have treated it. (That is my source for the purposes of this comment, in any case - actual historians of science and medicine may be able to do better... | [
"Genes may play a role in the chances of developing acne. Comedones may be more common in some ethnic groups. People of Latino and recent African descent may experience more inflammation in comedones, more comedonal acne, and earlier onset of inflammation.\n",
"In 2015, acne was estimated to affect 633 million pe... |
When a water filter (e.g. Brita filter) is past its expiration date, is it just not filtering very well anymore, or is it actively making the water worse? | Assuming you have the same water source and it's consistent (tap water, for example), then the adsorption capacity of the filter will eventually get used up. Most filters like a Brita have adsorbents an ion exchange resin (white particles) for capturing metals (lead and copper) and activated carbon (charcoal) for captu... | [
"A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents for purposes such as providing agricultural irrigation, accessible drinking water, public and private aquariums, and the safe u... |
Is it true that Manuel I Komnenos aided the Turks/worked against the crusaders, during the Second Crusade? | Not really. It certainly seems that Manuel I was not particularly inclined to help the Crusaders and didn't go out of his way to make things easier for them but actually going so far as to ally himself with the Turks would be too far. It's worth remembering that the Crusaders didn't exactly make themselves out to be gr... | [
"On 28 June 1098, the crusaders defeated Kerbogha in a pitched battle outside the city, a victory caused by Kerbogha's inability to organize the different factions in his army. While the crusaders were marching towards the Muslims, the Fatimid section of the army deserted the Turkish contingent, as they feared Kerb... |
how did congress set their salaries? | Congress is in charge of the government's money, so they set their own salaries by passing the appropriate bill. The president still has veto power, of course, and any salary changes won't take place until after the next Congressional election. In terms of benefits and such, they're just like any other Federal Employee... | [
"This chart shows historical information on the salaries that members of the United States Congress have been paid. The Government Ethics Reform Act of 1989 provides for an automatic increase in salary each year as a cost of living adjustment that reflects the employment cost index. Since 2010 Congress has annually... |
Is there an historical reason Turkey is considered part of Europe/Asia but Egypt is not considered Africa/Asia? | One thing worth considering is that, since relative land area isn't a number most people have to hand, and it's not a very intuitive way of thinking about geography, relative land area just isn't an important factor in deciding which continent we think a country is part of.
Turkey has at least two major cities in Euro... | [
"The European section of Turkey, eastern Thrace () is located at the easternmost edge the Balkan peninsula). It forms the border between Turkey and its neighbors Greece and Bulgaria. The Asian part of the country is comprised mostly by the peninsula of Anatolia, which consists of a high central plateau with narrow ... |
Where do the particles to be fired in the Large Hadron Collider come from? | The protons come from a bottle of hydrogen at LINAC 2. The gas is ionised in a device called a duoplasmatron (effectively a gas-filled discharge tube with a hole in the anode).
For the lead ions, an isotopically pure sample of ^(208)Pb is heated up until it's vaporised, then ionised into a plasma and accelerated in LI... | [
"particle collider was ADONE, which began operations in 1968. This device accelerated electrons and positrons in opposite directions, effectively doubling the energy of their collision when compared to striking a static target with an electron. The Large Electron–Positron Collider (LEP) at CERN, which was operation... |
Does the human inclination to eat things with a certain taste reflect deficiencies of certain nutrients in the body? | this was discussed a few weeks back with some good answers here:
_URL_0_ | [
"Very few specific appetites for particular nutrients have been identified in humans. The most robustly identified are salt appetite/sodium appetite. The problem with many other nutrients is that they do not have distinctly identifiable tastes, and only two other specific appetites, for iron and calcium, have been ... |
what happened to aol, man? | They're still around, mostly as a branding/media company. They own the Huffington Post, for example. (They own a lot of other properties and have an extensive online advertising arm, but HuffPo is the most notable.)
As far as their online services went...they had specialized in the "walled garden" approach, which work... | [
"On March 13, 2008, AOL purchased the social networking site Bebo for $850m (£417m). On July 25, AOL announced it was shedding Xdrive, AOL Pictures, and BlueString to save on costs and focus on its core advertising business. AOL Pictures was terminated on December 31. On October 31, AOL Hometown (a web hosting serv... |
How did Nomads survive in Siberia? | [Nomads still survive in siberia](_URL_0_). The nenet tribe follows herd of reindeer. They eat reindeer meat, wear reindeer fur, make tents from reindeer pelts, etc etc, and presumably have been doing so for a very long time.
as for pre-historic peoples in the area that came to be england and ireland, [here](_URL_1_) ... | [
"[T]he term 'nomad', if it denotes a wandering group of people with no clear sense of territory, cannot be applied wholesale to the Huns. All the so-called 'nomads' of Eurasian steppe history were peoples whose territory/territories were usually clearly defined, who as pastoralists moved about in search of pasture,... |
Why do dogs know our emotions and we know theirs? | from what I remember from Nat Geo's [Science of Dogs](_URL_0_) (but it very well might have been Nova's [Dogs Decoded](_URL_1_)) humans and dogs evolved together in a kind of symbiotic relationship. We innately know about each other. For example, we know a dog's emotional state just by listening to the noises they make... | [
"There is some evidence that humans can determine the suspected emotions of dogs while listening to barks emitted during specific situations. Humans scored the emotions of dogs performing these barks very similarly and in ways that made sense according to the situation at hand. In one example, when subjects were pl... |
why does eating a pound of food (or any amount) not cause you to weigh + that amount immediately after when stepping on a scale? | It does, but typical hooman scales are horribly innacurate. Just ask any pugilist how much an average poo weighs before weigh-in. | [
"A commonly asserted \"rule\" for weight gain or loss is based on the assumption that one pound of human fat tissue contains about 3,500 kilocalories (often simply called \"calories\" in the field of nutrition). Thus, eating 500 fewer calories than one needs per day should result in a loss of about a pound per week... |
Was the split of Germany the main cause of the Cold War? | The split of Germany was an early effect of the Cold War, more than a cause. Initially, all Germany was under the ultimate sovereignty of the Allied Control Council, where all four powers sat together and decisions were to be made by unanimous vote. For practical convenience, though, Germany was divided into four occ... | [
"Both Germany and the RSFSR were left vulnerable in the period following the end of World War I. Germany had lost the war, leaving it diplomatically isolated, and the Treaty of Versailles after the war led to German disarmament and the cession of German territories, including all her colonies. The Soviet Union had ... |
What are some good science books for lay folks? | Any particular field? I've recommended "The Emotional Brain" by Joseph LeDoux as a pretty good book on how we came to really understand the role of the amygdala in fear processing... if you're interested in neuroscience. | [
"The Let's-Read-and-Find-Out Science Books series, originally published by Crowell, now HarperCollins, is an American children's book series designed to educate preschoolers and young elementary school students about basic science concepts.\n",
"Jennifer Cameron-Smith at: \"This is a delightful book and would mak... |
Who is more genetically similar to
you, your sibling or offspring? | Neither one is inherently/absolutely more genetically similar or dissimilar to you.
As someone else said, the average shared DNA is the same, 50%.
However, siblings can vary somewhat substantially from this percentage. **Your sibling might share more than 50%, or less than 50% with you.** Others have mentioned that... | [
"\"Full siblings\" (full brothers or full sisters; or brother and sister) have the same biological parents and are 50% related (full siblings share 50% of their genes out of those that vary among humans). Identical twins by definition are 100% related. Full siblings are also the most common type of siblings.\n",
... |
What did the armies of The Battle of Tours consist of? | The Muslim forces would have been almost exclusively armored cavalry with lances and long swords. They would have planned to simply charge and disperse the Frankish infantry. In the Middle Ages, infantry could usually not stand up to armored cavalry.
The Frankish infantry were arranged in a tight square and would have... | [
"The Battle of Tours (10 October 732) – also called the Battle of Poitiers and, by Arab sources, the Battle of the Highway of the Martyrs () – was an important victory of the Frankish and Burgundian forces under Charles Martel over the raiding parties of the Umayyad Caliphate led by Abdul Rahman Al Ghafiqi, Governo... |
Is it inherently easier to see something small and nearby than something big and far away? | `YouHaveShitTaste` seems to be trolling in that thread.
For someone who's young enough, and with good eyes, you're right: both drawings will occupy the same size on the retina, and thus, they'll be able to see them just as well.
Older people (after, say, 40) tend to be far-sighted: their aging crystalline lens have ... | [
"This part of optics, when well understood, shows us how we may make things a very long distance off appear as if placed very close, and large near things appear very small, and how we may make small things placed at a distance appear any size we want, so that it may be possible for us to read the smallest letters ... |
why do all uk plugs have three prongs/ always have an 'earth' whilst most other counties only have two prongs? (or no earth?) | In short, because UK Plugs are by far the most safe, most reliable, best designed plugs in the entire world and the rest of the world would be smart if they were to all adopt our standards.
/Brit.
;)
| [
"The plug consists of two vertical and one horizontal flat pin, arranged like 3 sides (left, right and top) of a rectangle. The two vertical pins carry the same tip and ring signals used in other countries. The third pin (top, horizontal) used to be connected to ground and was occasionally used with switchboards, b... |
how can 2 switches wired to the same light be able to turn it on and off no matter the state of the other switch? | In household electric wiring, a three-way switch setup (common term) often involves wiring two double-pole switches a line, with the power source connected to one and the lamp connected to each other. In this case, each switch has two positions, and the circuit can be completed [or broken] by moving by moving either ... | [
"Using three switches, there are eight possible permutations of switch positions: four with the light on and four with the light off. Note that these diagrams also use the American electrical wiring names.\n",
"Electrically, a typical \"3-way\" switch is a single pole, double throw (SPDT) switch. By correctly con... |
why does youtube's copyright law about songs not affect lyric videos? | If you make content or a music mix, you are to put the titles of songs used in your video description. Else they will will remove your video.
Making a lyric video counts as user made content (I guess). So as long you put credits in your description it should be fine. | [
"An independent test in 2009 uploaded multiple versions of the same song to YouTube, and concluded that while the system was \"surprisingly resilient\" in finding copyright violations in the audio tracks of videos, it was not infallible. The use of Content ID to remove material automatically has led to controversy ... |
what does it mean for austrailia now that abbot is the pm? | Tying to be as non-bias as possible. Your day to day life will not be affect aside from the fact that you might pay slightly higher taxes / you might receive slightly less services. A lot of people were against abbott on the internet because people who are technologically advanced are often Labor supporters; they proba... | [
"The Honourable Sir Dominic Anthony Gerard Asquith (born 7 February 1957) is a British career diplomat and former Ambassador to Iraq, Egypt, and Libya. He is currently the British High Commissioner to the Republic of India.\n",
"George Antonysamy (born 15 February 1952), is an Indian prelate of the Catholic Churc... |
How does time near the speed of light work for two different frames of reference? | Ah this is the classic [twin paradox](_URL_0_).
Special relativity states that reference frames that are uniform are equivalent. i.e. they are either traveling at a constant speed or stationary.
The thought experiment is: if you are on a bus that's traveling at a constant speed, it is indistinguishable from if you a... | [
"Frames of reference are especially important in special relativity, because when a frame of reference is moving at some significant fraction of the speed of light, then the flow of time in that frame does not necessarily apply in another frame. The speed of light is considered to be the only true constant between ... |
what is the physics explanation behind 3d technology? | One of the most compelling ways to convince the brain that you are seeing something that is 3D when it is actually an image on a flat surface is to feed a different image into each eye. This is how the old red/blue 3D glasses work—they project both images on the same surface but they are tinted different colors so you... | [
"3D graphics are created via the process of designing imagery from geometric shapes, polygons or NURBS curves to create three-dimensional objects and scenes for use in various media such as film, television, print, rapid prototyping, games/simulations and special visual effects.\n",
"Digital 3D is a non-specific ... |
What are the environmental benefits to bringing wolves back to most of their native habitats? | This is an important recent study that you should read about trophic cascades between wolves, elk and aspen in Yellowstone. Basically, having a top predator back in the system has effects on all trophic levels of the ecosystem: _URL_0_ | [
"In 2007, British and Norwegian researchers who included experts from the Imperial College London said that wolf reintroduction into the Scottish Highlands and English countryside would aid in the re-establishment of plants and birds currently hampered by the deer population. Their study also assessed people's atti... |
what did the idea of "Gross" look like before the development of germ theory? how quickly did germ theory change the daily habits of common people? | I"m only a dabbler in historical knowledge, but in this case I think you may be looking for more of an anthropological or sociological answer. The thing is that even with modern germ theory a lot of this comes down to culture and in my limited experience is often cast through the lens of religion - Emile Durkheim immed... | [
"Germ theory's stance that the \"germ\" was the disease's \"necessary and sufficient cause\"—the single factor both required and complete to result in the disease—proved false. Germ theory gradually evolved to include other factors, whereupon germ theory resembled miasmatic theory, which had had to recognize bacter... |
how do testicles not get wrapped around each other inside the scrotum? | Your balls are seperated by a thin wall so they cant tangle each other. However one testicle can twist around itself causing testicular torsion. | [
"A testicle cuff is a ring-shaped device around the scrotum between the body and the testicles which when closed does not allow the testicles to slide through it. A common type has two connected cuffs, one around the scrotum and the other around the base of the penis. They are just one of many devices to restrain t... |
why can’t video games make walking/running look realistic? | A lot of movement animation is captured live with peoples' actual body movements ([Example](_URL_0_)) and then these are applied to the character's animation when moving in-game.
The problem comes because many states/actions can make the player run faster/slower (such as sprinting vs. walking, as well as changing dire... | [
"In his review for AllGame, Jonathan Sutyak stated that the game can be difficult for players \"to react quickly enough when something appears on the screen\" due to its speed. Sutyak also praised the game's graphics, although he found it difficult to tell between what the player is skating on and what is the backg... |
Why was Australia not discovered by the Chinese first? | I am not an expert on China, and can't say much about Chinese sea-faring. I can however correct a few misconceptions here.
Indigenous Australians first discovered Greater Australia at least 60,000 years ago.
Visits from Austronesian seafarers in the last 1000 years are likely, evidenced by the introduction of the din... | [
"The following year. the sinologist C.P. FitzGerald mentioned the possibility of pre-European Chinese visits to Australia in an article, which conjecture a possible early Chinese presence in northern Australia, by mentioning a Chinese statue which had been dug up in 1879 near Darwin.\n",
"The Janszoon voyage of 1... |
So what would happen if you took off your helmet on mars? It has a form of an atmosphere so I wouldn't imagine it'd be the same effect as space. How long would you have to live and what's the most likely cause of death? | It does have an atmosphere, but its density is so low that for all practical purposes (at least from the point of view of human respiration) it is equivalent to a vacuum.
The effect will be exactly the same as in space: Your lungs lose oxygen instead of gathering it. After like 15 seconds this deoxygenated blood reach... | [
"If Mars' atmospheric pressure could rise above , then a pressure suit would not be required. Visitors would only need to wear a mask that supplied 100% oxygen under positive pressure. A further increase to of atmospheric pressure would allow a simple mask supplying pure oxygen. This might look similar to mountain ... |
Explain this hoverboard design and why I shouldn't get excited. | Supermagnets spinning over expensive copper slabs. Yes real. Here's my [1995 demo version](_URL_1_)
Here's a man-lifting version from [Korea] _URL_0_
Only trouble is, this is Maglev Train technology: it requires a track, and it needs about a kilowatt to lift an average person. The track gets hot from eddy curre... | [
"In 2019, hoverboards now feature a self balancing mode, in which the motors automatically engage the gyroscope in the opposite direction. This way, when the rider leans forward or backward the board is always attempting to level itself, making it easier to ride than its 2016 predecessors.\n",
"The name “Hoveroun... |
When did humans realize clouds are evaporated water? | We had a thread similar to this a few months back. From [What did people think clouds were before we could scientifically describe them?](_URL_0_), /u/RomeosDistress quotes Augustine of Hippo (354-430 CE):
> The clouds, according to the testimony of those who have walked through them in the mountains, have this vapor... | [
"Water vapor generated through surface evaporation is transported by circulatory patterns in the atmosphere. When atmospheric conditions permit an uplift of warm, humid air, this water condenses and falls to the surface as precipitation. Most of the water is then transported to lower elevations by river systems and... |
How factionalized was the German government during Nazi rule and how did factional infighting affect the war effort? | An interesting source here is Albert Speer's *Infiltration*; Speer was Hitler's Minister of Armaments after 1942, and the book is largely about the way Himmler's SS and the Ministry of Armaments kept butting heads. To hear Speer tell it, Himmler's efforts to build a postwar power base--the SS has been well described as... | [
"On 30 January 1933, the National Socialist German Workers' Party, under its leader Adolf Hitler, came to power in Germany. While the Weimar Republic had long sought to annex territories belonging to Poland, it was Hitler's own idea and not a realization of Weimar plans to invade and partition Poland, annex Bohemia... |
usage factor on electricity bill | Some electrical companies charge you based on "demand" or "peak" or "load", rather than a flat rate.
So, basically, when you consume your kwh at night, the power plant is not busy and can easily supply it, but if you consume it during the day, they also have to supply a lot of businesses, so that means more effort o... | [
"The energy unit used for everyday electricity, particularly for utility bills, is the kilowatt-hour (kWh); one kWh is equivalent to 3.6×10 J (3600 kJ or 3.6 MJ). Electricity usage is often given in units of kilowatt-hours per year (kWh/yr). This is actually a measurement of average power consumption, i.e., the av... |
why when a drop of water lands on a piece of paper and it dries the paper is left wrinkled at that spot. | I have no evidence but my thought is that the fibers of the paper likely swell and rearrange themselves as they push outward in their swelling. Try getting a piece of paper wet and leaving something quite heavy on top of it to see if that changes the result | [
"Pressing the sheet removes the water by force; once the water is forced from the sheet, a special kind of felt, which is not to be confused with the traditional one, is used to collect the water; whereas when making paper by hand, a blotter sheet is used instead.\n",
"While the rain falls, the water collected by... |
How are underwater tunnels built? (Such as the one from Copenhagen to Malmö) Additionally, what steps and precautions are taken to ensure it will not flood both during and after construction? | This is called an *immersed tube tunnel*. The first thing to do is to cut a trench in the seafloor along the route of the tunnel. Meanwhile, prefabricated sections of the tube are built in dry docks from steel or reinforced concrete. These are then sealed at each end with temporary bulkheads and floated to the constru... | [
"Underwater tunnels are either bored or immersed: tunnel boring is common for deepwater tunnels longer than 4 or , while immersion is commonly used for tunnels which cross relatively shallow waters. Immersion involves dredging a trench across the seafloor, laying a foundation bed of sand or gravel, and then lowerin... |
Why is thunder a low-pitch rumbling instead of a high-pitch blast? | Audio engineer here, I would think it has to do with the wavelength of the different frequencies of the audible frequency band. Lower sounds (bass) have much longer wavelengths, and therefore do not produce a full wave (compression/rarefaction) until a much greater distance than high frequencies. When standing close... | [
"Thunder is the sound caused by lightning. Depending on the distance from and nature of the lightning, it can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure and temperature from lightning produces rapid expansion of the air within and surrounding the path of a light... |
how/why does it benefit the us dollar when saudi arabia uses it exclusively when selling oil? also, why do a lot of places outside of the us accept/favour the us dollar? | If the dollar weakens, a barrel of oil will still cost the same amount for American customers.
The price paid will only be based on the oil market at the time, rather than how many pounds, euros, etc the dollar is worth. | [
"Saudi Arabia has been an enticing trade partner with the United States from the early 20th century. The biggest commodity traded between the two nations is oil. The strength of the relationship is notoriously attributed to the United States' demand on oil throughout the post modern era, approximately 10,000 barrel... |
will wearing glasses daily deform your skull? | I don't have glasses but have an indent. Does this mean I will need glasses? | [
"In his 1939 book, James Grant Pattison claimed the skull was in a glass case for many years but it was damaged when one of the holder's children attempted to practice dentistry by smashing the lower jaw to obtain the teeth.\n",
"The glasses appear to be more susceptible to damage than the screwdriver; in \"The G... |
how do contactless payments through a phone work without service or wifi? | Your phone creates a "virtual card" of sorts. Your normal card is just a collection of data like serial numbers, account number etc that tells the card reader how to withdraw money. Your phone simply creates similar card, that effectively functions same way. Your card doesn't need internet access to work, and so neithe... | [
"The service works through a smartphone application, through which the user's phone number is connected to their bank account, and which makes it possible to transfer money in real time, a few seconds until confirmation is received by both parties. The user must have a second mobile application called \"Mobilt Bank... |
how do home routers work and what do the various bands do? | Quite likely you are just being defrauded by your ISP provider, Just because you are paying for it does not mean you are getting it.
Your download speed will be determined by your weakest link. Get a friend to come by with a laptop and check the download and do a ping test.
If you can hook up with a CAT 5 cable do th... | [
"BULLET::::- A router manages network layer connectivity between a WAN and the HAN. It performs the key function of network address translation enabling multiple devices to share the home's single WAN address. Most home networks feature a particular class of small, passively cooled, table-top device with an integra... |
If a huge and dense enough amount of coherent light was emitted, would it create a black hole traveling at the speed of light? | A system of photons all moving in the same direction has no invariant mass, so you can Lorentz-transform into a frame where they have arbitrarily small energy. And in such a frame, it's clear that they should not form a black hole.
And, a black hole has mass so it can never move at c.
But anyway, it's in principle po... | [
"Across the 0.2-second duration of the detectable signal, the relative tangential (orbiting) velocity of the black holes increased from 30% to 60% of the speed of light. The orbital frequency of 75 Hz (half the gravitational wave frequency) means that the objects were orbiting each other at a distance of only 350 k... |
why do animals not seem to need the vitamins that humans do? | First, you don't NEED a lot of vitamins. You benefit from their presence, but you can survive without them.
But for some of the ones you do need that animals don't seem to, it's because our bodies have evolved somewhat counterproductively to lose the ability to synthesize them ourselves. Back in the caveman days befo... | [
"Animals store vitamin B in the liver and muscles and some pass the vitamin into their eggs and milk; meat, liver, eggs and milk are therefore sources of the vitamin for other animals as well as humans. For humans, the bioavailability from eggs is less than 9%, compared to 40% to 60% from fish, fowl and meat. Insec... |
why is aids poked fun at by comedians and shows like south park while diseases like cancer aren't? | If you tell a cancer joke to an audience, you better make it the funniest joke you've ever told, because it's likely that 75% of people in the audience have some personal relationship to a cancer victim, and a notable percentage have/had cancer themselves.
That makes it a pretty tough sell. You'd be better off telling... | [
"Robert R. Reilly argued in \"Making Gay Okay\" (2014) that Kirk and Madsen's proposed strategy of portraying gay people as victims was successful. He believed that the success of this strategy was the reason why, \"AIDS gets more research money per patient than any other disease.\" The journalist Rod Dreher, writi... |
if most money is just numbers in a database, how come we don't hear of hackers who break in and just increase their account balance? | Accounting and balance sheets. Every debit has to have a credit, and every credit a debit...or it will show up as out of balance. If there were to be a balancing entry in the respective offset account, then maybe it would go undetected...but nonetheless it would still show up as an entry that someone is eventually resp... | [
"Although the functionality of a database may appear unblemished, without rigorous testing, the exiguous flaws can allow hackers to infiltrate a system's cyber security. Frequently, databases are published without stringent security controls hence the sensitive material is easily accessible.\n",
"Besides swinging... |
why news reports always use the word "allegedly" even if there is proof of something? | Legally people are innocent until proven guilty. While they have arrested someone and charged them with say thievery, until the trial convicts them they are simply a "suspect" and not a thief. News agencies therefore cannot rightly declare them thieves just because they were charged with the offense and could rightly b... | [
"The term was coined in 1973 by American writer Norman Mailer to mean a piece of information that becomes accepted as a fact even though it is not actually true, or an invented fact believed to be true because it appears in print. Since its creation in 1973, the term has evolved, now often being used to describe a ... |
how do gift cards for multiple restaurants/stores work? | It gets split up when you purchase an item.
When you purchase a gift card at Swiss Chalet, you're really purchasing fake-money only usable at Cara Operations' stores. I'm sure in Cara's accounting books they have a big bucket for all the giftcard money. Once it is used at Swiss Chalet goes out of the Cara account and ... | [
"GiftCards.com offers gift cards from around 500,000 different large and small businesses throughout the United States. Major gift card providers include Best Buy, Sephora, Yankee Candle, Amazon.com, Pottery Barn, Starbucks, The Cheesecake Factory, Gap, Macy's, and Bloomingdale's among many others. The company also... |
why do black americans seem to be affected by slavery more so than people of other ethnicities are affected by the generational atrocities committed against their people? | The real answer is that wasn't just slavery. There was overt institutional oppression of blacks until very recently. When you're talking about, for example, Jim Crow laws that were in place until the mid 60s, they affected people who are now as young as in their 50s. That means people in their 20s might have parents th... | [
"With the long history of slavery in the United States, racism has always been an issue. The enslavement of millions of Africans along with the huge influx of immigrants throughout its history has allowed great diversity, but has created racial segregation. With the abolition of slavery, different forms of segregat... |
What the heck is with Switzerland? How have they avoided almost every single major European war or conflict for the past 600 years or so? Is it due to their geographical location, their banks, or a third factor? | First to just clarify, Switzerland has participated in some large conflicts during the last 600 years, most recently the Napoleonic wars, though they have been neutral since. I will mostly touch on the world wars but most of the points apply to almost any period since 1880.
Switzerland as a country is located high wi... | [
"During the Thirty Years' War, Switzerland was a relative \"oasis of peace and prosperity\" (Grimmelshausen) in war-torn Europe, mostly because all major powers in Europe depended on Swiss mercenaries, and would not let Switzerland fall into the hands of one of their rivals. Politically, they all tried to take infl... |
why is the death rate for alzheimer's so incredibly low in japan? | This is all supposition on my part, but here it goes...
- Society. Asian cultures are far more likely to have younger generations care for their elders. As such, they spend a lot less time isolated and maintain active participation in everyday life. Maintaining this level of brain activity and socialization can onl... | [
"According to CDC, Alzheimer is the 6th leading cause of death in U.S adults and 5th leading cause of death in adults over the age of 65. In 2014, 5 million Americans above the age of 65 were diagnosed with Alzheimer. This number is predicted to triple by the year 2060 and reach up to 14 million. Dementia and Alzhe... |
What would a nuclear detonation on the surface of the Earth look like from the ISS or similar orbiting platform? | Okay. The ISS orbits between 200 and 250 miles high. A 20 megaton bomb will produce a fireball [about 2 miles in diameter](_URL_1_). It will cause a "conflagration" [40 miles in diameter](_URL_0_).
What would this look like from 200 miles away? Here's a place to start: imagine driving down the interstate and passing a... | [
"Carolyn Porco of NASA was consulted on the planetary science and imagery. The animators realistically recreated what an explosion would look like in space: short blasts, which suck inward and leave debris from a ship floating. For shots of an imploding planet, the same explosion program was used to simulate it bre... |
Why don't microorganisms die from cold temperatures? | Microorganisms have adapted to a range of extreme environments, including extreme cold. Every microorganism will have an ideal temperature range for growth and a temperature range at which they survive, and most microorganisms cannot grow at low/near-freezing temperatures.
Microorganisms that can are called psychrophi... | [
"Microplasma that is sustained near room temperature can destroy bacteria, viruses, and fungi deposited on the surfaces of surgical instruments and medical devices. Researchers discovered that bacteria cannot survive in the harsh environment created by microplasmas. They consist of chemically reactive species such ... |
how a country like venezuela in such financial and institutional chaos can ever recover. | Define "recover". The government may be deposed violently, a bunch of people may starve or flee the country, but they aren't entirely without resources so a smaller population could be supported. Alternatively the current government may see the opposition coming and institute a civil war / purge to reduce the populatio... | [
"Since 2013, Venezuela has been suffering an economic crisis. It's the worst in Venezuelan history, caused by the economic policies of the president, Nicolás Maduro the successor of Hugo Chávez, the fall in oil prices and internal and external factors. Since 2014, Venezuela's GDP has been in recession, falling more... |
If I go headlong toward a black hole, accelerating to near the speed of light, will time dilate so I never actually get there? | > The faster you go, according to relativity, the more time slows down.
This is what other people, who aren't moving with you, see happen to your clock. You, on the other hand, experience time passing perfectly normal while observing those other clocks to be running slow.
> If I travel directly toward a black hole,... | [
"To a distant observer, clocks near a black hole would appear to tick more slowly than those further away from the black hole. Due to this effect, known as gravitational time dilation, an object falling into a black hole appears to slow as it approaches the event horizon, taking an infinite time to reach it. At the... |
In the USA before soft drinks were invented, what were the recreational drink of choice for non-alcohol drinkers? | As you hinted at, early America's drinks of choice were ale/porter/beer, cider, wine, brandy, rum, and whiskey. But other non-alcoholic drinks were readily available. They had to be. One of America's early sizable communities were the Quakers, who were teetotalers.
All the links below link back to the letters, receipt... | [
"Soft drinks soon outgrew their origins in the medical world and became a widely consumed product, available cheaply for the masses. By the 1840s there were more than fifty soft drink manufacturers – an increase from just ten in the previous decade. Carbonated lemonade was widely available in British refreshment st... |
In the study of epigenetics, how do we know a given gene is being expressed? | It depends what you mean by "expressed". Also the following techniques have nothing specifically to do with epigenetics, they're just how you can see if a given gene is being expressed:
If you mean "currently being transcribed" then you can do a [nuclear run-on assay](_URL_3_). Most other techniques (northern blot, ... | [
"Epigenetics is the study of heritable changes in gene function that cannot be explained by changes in the underlying DNA sequence but cause the organism's genes to behave (or \"express themselves\") differently. One example of epigenetic change is the marking of the genes by DNA methylation which determines whethe... |
why haven't we invented a better way to clean teeth than brushing/flossing? | We haven't really come up with a better alternative to water and a brush for any sort of cleaning at all. It's an intrinsically mechanical (as opposed to chemical) process so you need mechanical solutions. | [
"The modern manual tooth brush is a dental tool which consists of a head of nylon bristles attached to a long handle to help facilitate the manual action of tooth brushing. Furthermore, the handle aids in reaching as far back as teeth erupt in the oral cavity. The tooth brush is arguably a person's best tool for re... |
When/Why did it stop being acceptable for Western aristocrats/noblemen to take mistresses? How was this practice reconciled with Christian doctrine forbidding adultery? | This has not disappeared, but depends on the country. Mistresses are common in France - for instance [François Mitterand](_URL_0_) was well known to have a mistress. | [
"In Christian Europe, the Catholic Church originally had a monopoly on the authority to sanction marriage. It forbade polygamy and taught that divorce was an impossibility \"per se\", as it still does. Consequently, in Europe, it was very difficult to ensure succession solely by direct male descendants or even dire... |
Is it true that all ocean dwelling mammals have a terrestrial ancestor? | Yes it is accurate. You can see in the physiology of the mammals why this is the case. If you look at the tail fluke, you'll see that marine mammals have a [horizontal](_URL_0_) fluke whereas fish like sharks have a [vertical](_URL_1_) fluke. This is because when the ancestors of marine mammals were on land, their legs... | [
"Today, the 5,500 species of living synapsids, known as the mammals, include both aquatic (whales) and flying (bats) species, and the largest animal ever known to have existed (the blue whale). Humans are synapsids, as well. Most mammals are viviparous and give birth to live young rather than laying eggs with the e... |
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