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That dark matter has never been found is no deterrent to the physicists who are looking for it.
"Even if we don't know what dark matter is, we know how it must act," said Eduardo Abancens, a physicist at the University of Zaragoza in Spain and the designer of a prototype dark matter detector.
According to physicists, o... | <urn:uuid:d9aadd22-3749-42e1-bfee-6f6161236376> | 3.53125 | 171 | Truncated | Science & Tech. | 38.871551 |
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2006 December 31
Explanation: The past year was extraordinary for the discovery of extraterrestrial fountains and flows -- some offering new potenti... | <urn:uuid:ba0e06c7-0cc5-4941-b35a-b3e9b339732a> | 3.234375 | 235 | Knowledge Article | Science & Tech. | 38.031541 |
The Met Office is hot out of the blocks on the climate front this year, issuing the first "climate disaster" story of the year via the BBC's Roger Harrabin.
The frequency of extreme rainfall in the UK may be increasing, according to analysis by the Met Office.
Statistics show that days of particularly heavy rainfall ha... | <urn:uuid:5a46ab38-3c0c-46b9-ae7a-9545b0ad4401> | 3.046875 | 254 | Personal Blog | Science & Tech. | 52.05 |
The Science of Hob, Kind Of
Ever wonder why extremely advanced machines in science fiction often have an organic look and are sometimes able to morph in decidedly unmechanical ways? The term nanotechnology is tossed around a lot as an explanation, but that covers a very wide range of technologies and can have a lot of ... | <urn:uuid:36a3d30b-837b-48cc-b16d-eddbce5a7f30> | 2.84375 | 479 | Personal Blog | Science & Tech. | 24.439901 |
Graphics For Media Use
This page gives you access to the original graphics files used to produce the USGS Summary on the new San Francisco Bay Region Earthquake Probability Study. The graphics are available in either Adobe Acrobat .pdf or .tif formats.
Please credit the USGS as the source of these graphics.
Probabiliti... | <urn:uuid:4dc187d8-944f-41eb-aaf4-009ed5a02453> | 3.078125 | 410 | Knowledge Article | Science & Tech. | 56.711364 |
Helmholtz resonance is the phenomenon of air resonance in a cavity, such as when one blows across the top of an empty bottle. The name comes from a device created in the 1850s by Hermann von Helmholtz, the "Helmholtz resonator", which he, the author of the classic study of acoustic science, used to identify the various... | <urn:uuid:ab349c5c-ca5b-4457-afff-8bcf0307b7de> | 4.1875 | 1,318 | Knowledge Article | Science & Tech. | 42.089506 |
|Part of a series on|
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (March 2010)|
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a resu... | <urn:uuid:23cb9c85-818d-47b0-aecd-653dd07775ba> | 4.09375 | 3,013 | Knowledge Article | Science & Tech. | 49.259416 |
|Science Applications and Data Distribution with International Partners
Once of the major purpose of NASA's support of collaboration in coral reef mapping is to find ways to get remote sensing data and derived maps into the hands of the managers that are making decisions about coral reef ecosystems. NASA has supported ... | <urn:uuid:02f31eda-5ca2-4286-881a-b4303e140645> | 3.515625 | 1,524 | Knowledge Article | Science & Tech. | 35.937571 |
An experiment was conducted to compare the strength of welds produced by four different welding techniques. Each technique was used to weld five pairs of metal plates. The average strengths for the five welds for each technique were:
Technique: A B C D
69 83 75 71
The estimate of experimental error variance was MSE = 1... | <urn:uuid:9bcbdd7d-bdf1-43dc-afb8-4efabcd563f4> | 3.34375 | 109 | Tutorial | Science & Tech. | 60.357317 |
|Annu. Rev. Astron. Astrophys. 1997. 35:
Copyright © 1997 by . All rights reserved
1.2. Distances and Hubble Law
The Hubble law between distance and cosmological redshift is a blessing for the cosmographer. A great motivation for investigation of the distance scale, it is also helpful for tackling the problems mentione... | <urn:uuid:8bd21e13-bfaf-44c1-ad58-90dfa92ef14b> | 3.109375 | 526 | Academic Writing | Science & Tech. | 31.386482 |
Two trees 20 metres and 30 metres long, lean across a passageway between two vertical walls. They cross at a point 8 metres above the ground. What is the distance between the foot of the trees?
The equation a^x + b^x = 1 can be solved algebraically in special
cases but in general it can only be solved by numerical meth... | <urn:uuid:6b05a558-b4a4-4330-a2f1-b4f94b3e8f9e> | 2.8125 | 101 | Q&A Forum | Science & Tech. | 69.711301 |
04 November 2010
Posted in Crosby Observatory
Measuring and evaluating the brightness of stars can be traced back to the Greek astronomer and mathematician Hipparchus during 190 - 120 BC. He is responsible for producing a catalogue of comparative brightness and positioning of over 850 stars. Hipparchus formed the appar... | <urn:uuid:8eef1c84-d41d-411a-8aac-3ec9942cf9f6> | 4.09375 | 216 | Knowledge Article | Science & Tech. | 46.545957 |
USGS/Cascades Volcano Observatory, Vancouver, Washington
RSAM - Real-Time Seismic-Amplitude Measurement System
SSAM - Seismic Spectral-Amplitude Measurement System
Ewert, J.W.; Murray, T.L.; Lockhart, A.B.; and Miller, C.D., 1993,
Preventing Volcanic Catastrophe:
The U.S. International Volcano Disaster Assistance Progr... | <urn:uuid:ad621322-8668-4e68-9477-c6704a8434e4> | 3.375 | 2,054 | Knowledge Article | Science & Tech. | 33.842113 |
Liquid Fiber Optics by Benjamin Freeberg
Honorable - Contrived Category
School: The Wheatley School
Teacher: Mr. Adam Plana
This photo exemplifies total internal reflection. Water was poured into a bucket with a hole in one side. A laser beam was then aimed through that hole, where the water poured out. Since the index... | <urn:uuid:666da5b5-42d4-4b5b-8e0f-4b8a4e0262d8> | 2.9375 | 137 | Knowledge Article | Science & Tech. | 57.179937 |
Science Fair Project Encyclopedia
In astronomy, the termination shock is theorised to be a boundary marking one of the outer limits of the sun's influence. It is where the bubble of solar wind particles slows down to below supersonic speed and heats up due to collisions with the galactic interstellar medium. It is beli... | <urn:uuid:3d2bd064-6309-43c5-8aa6-461658368888> | 3.6875 | 143 | Knowledge Article | Science & Tech. | 49.576362 |
© Frans Lanting / Minden Pictures
As the human population increases, so does our need for materials and space. Non-human primates are just one of the many creatures that are threatened by human sprawl and resource exploitation. The following are examples of a few typical ways humans are causing the loss of crucial habi... | <urn:uuid:ab85bdf3-a552-49c2-af44-aed585c07574> | 3.65625 | 232 | Knowledge Article | Science & Tech. | 25.941313 |
So, what is this chemical? It’s a liquid found in almost every food item available at your local supermarket, is found in nearly every stream, lake, ocean and reservoir on the planet, and a large quantity is currently in your bloodstream. It is also eroding many of the world’s natural landscapes, is the main component ... | <urn:uuid:e16e9c07-48f2-4009-b089-a23eb9ae5b21> | 3.078125 | 305 | Personal Blog | Science & Tech. | 51.755213 |
Bringing Life to Mars; The Future of Space Exploration; Scientific American Presents; by McKay; 6 Page(s)
Four billion years ago Mars was a warm and wet planet, possibly teeming with life. Spacecraft orbiting Mars have returned images of canyons and flood valleys-features that suggest that liquid water once flowed on t... | <urn:uuid:73293c6c-0082-4661-bf99-47bfc49abcc6> | 4.25 | 281 | Truncated | Science & Tech. | 32.664142 |
IN TRYING TO DEVELOP a unified theory, Einstein worked closely with Peter Bergmann (left) and Valentine Bargmann (right), two young German-born physicists who also had fled the Nazis and who went on to become renowned scientists in their own right. Bargmann's wife, Sonja, was the one who translated Einstein's Scientifi... | <urn:uuid:5098fdaa-1603-4046-8ceb-b108ea279b60> | 3.765625 | 292 | Truncated | Science & Tech. | 39.349401 |
This drawing shows the 4 Galilean satellites and the path of the Galileo spacecraft.
Click on image for full size
This drawing shows the positions of the four Galilean satellites relative to each other, and the path of the Galileo spacecraft on one of its flyby's past Jupiter.
Of the four Galilean satellites, Io is the... | <urn:uuid:66d14941-7ef7-4300-9c75-4bd4c618818b> | 3.796875 | 493 | Content Listing | Science & Tech. | 55.545341 |
Although the Red Bull Stratos jump is over, the physics goes on. In case you missed it (I don’t know how), let me recap:
Felix Baumgartner rides a balloon up to 128,000 feet altitude – of course he has to wear a space suit.
He jumps (falls) out.
During the fall, he goes faster than the speed of sound.
Although he made ... | <urn:uuid:d8917478-644b-4d02-93a5-a098140f4bd2> | 2.78125 | 2,659 | Personal Blog | Science & Tech. | 67.758371 |
The Tree of Life has three great branches: the eukaryotes, including all plants, animals, fungi, and single-celled creatures like malaria parasites and amoebae. There are the prokaryotes, or bacteria. And there are the Archaea, a group of single-celled organisms divergent from both the other groups.
Life on this planet... | <urn:uuid:0c74a315-e88f-4d8c-97fc-261c0a9a03a6> | 3.171875 | 610 | Personal Blog | Science & Tech. | 47.957491 |
A winning proposal for the Innovative Research Program, 2009:
Can sea-ice extent from the 1960s be determined from reprocessed Nimbus data?
Investigators: Walter N. Meier (CIRES/NSIDC), Dennis Wingo (NASA Ames Research Center), Mary J. Brodzik (CIRES/NSIDC)
Old satellite data can now be reprocessed using modern algorit... | <urn:uuid:f30d68de-424e-43bf-9166-58d3cc2621f5> | 2.90625 | 1,383 | Academic Writing | Science & Tech. | 39.664388 |
Date of this Version
The recent comprehensive review of Maccoa Duck Oxyura maccoa biology by Clark (1964) has provlded the first detailed summary of the species' reproductive behaviour patterns and other aspects of breeding in this little-studied stiff-tail. It has been evident that the evolutionary relationships of th... | <urn:uuid:27541f87-c253-4ab5-ae37-39ddb05ccdb1> | 3.09375 | 365 | Knowledge Article | Science & Tech. | 31.967622 |
Gadagkar, Raghavendra and Kolatkar, Milind (1996) Evidence for Bird Mafia! Threat Pays. In: Resonance, 1 (5). pp. 82-84.
Birds are remarkable for their extraordinary efforts at nest building and brood care. Given that so many species of birds spend so much time and effort at these activities, there is plenty of room fo... | <urn:uuid:b21f8e7e-1394-4420-8f5d-b74a76dca921> | 3.390625 | 449 | Academic Writing | Science & Tech. | 51.126325 |
Most species of ground beetles are predators so they are considered beneficial. The bombardier beetle has a dark body with reddish yellow or orange head and legs. It inhabits all continents except Antarctica. They commonly live under shoreline debris. They are parasitoids of whirligig beetle pupae so they tend to live ... | <urn:uuid:cb7e6b65-6086-4da4-bbfd-ea154f7fe2d8> | 3.59375 | 235 | Knowledge Article | Science & Tech. | 55.50109 |
For a brief instant, it appears, scientists at Brook haven National Laboratory on Long Island recently discovered a law of nature had been broken.
Action still resulted in an equal and opposite reaction, gravity kept the Earth circling the Sun, and conservation of energy remained intact. But for the tiniest fraction of... | <urn:uuid:f9b25933-43b4-4993-9b2d-e5b2e1ebcbfc> | 3.953125 | 191 | Personal Blog | Science & Tech. | 34.263226 |
>>>>> "Bob" == Bob Kline <bkline@stripped> writes:
Bob> On Thu, 14 Oct 1999, MySQL Server wrote:
>> When using certain floating point values in a column of type "float"
>> the value displayed differs from the actual value. For example, a
>> column of type "float(9,7)" with value of "0.283" will be displayed
>> as "0.28... | <urn:uuid:d656b387-06f8-4ba9-9d7c-f1bf25a5f5d6> | 2.84375 | 845 | Comment Section | Software Dev. | 73.422896 |
Lessons in Nuclear Safety from Fukushima
Technology Review has a short article on what has been learned since the meltdowns last year – What We Learned About Nuclear Safety From Fukushima:
Reactors and radioactive materials at Fukushima Daiichi were destabilized by back-to-back beyond design-basis events. First was the... | <urn:uuid:c0ceaf11-7802-4a4c-8336-d68f657fb1d6> | 2.796875 | 518 | Personal Blog | Science & Tech. | 28.581196 |
I have a question that came up in a discussion with friends. If I throw a ball straight up in an enclosed train car moving with constant velocity, I believe the basic physics books say it will land in the same spot. But will it really? I think I can say that the answer is "not in the real world".
Trivially, a train car... | <urn:uuid:7af7359d-25e5-484d-a2a8-41475621106b> | 3.09375 | 450 | Q&A Forum | Science & Tech. | 75.953921 |
"Doppler shift" refers to the stretching of waves (known as "redshifting") from a source moving away from the observer, and the compression of waves (called "blueshifting") from a source approaching the observer. Redshifted waves have a longer wavelength (or lower frequency) than they otherwise would, and blueshifted w... | <urn:uuid:d5cc37cc-d4ef-4fda-9d7d-2f852802694a> | 3.796875 | 170 | Knowledge Article | Science & Tech. | 34.171338 |
The Wimshurst Machine
Electrostatic induction refers to the principle that charges in an object (especially a conductor) redistribute themselves in the presence of nearby charges. Opposite charges are attracted to each other, while similar charges are repelled.
Larger charges can be stored by connecting the knobs to Le... | <urn:uuid:55ff2f33-fae5-4ac9-8af1-5eefb91bbdae> | 3.40625 | 200 | Truncated | Science & Tech. | 56.054738 |
Austin, Texas just hit 100 degrees today (according to weather.com).
This is our 25th day of 100 degree weather this year. That pales in comparison to 2011, where at this time last year we were counting down to breaking the previous record of 69 days of 100 degree days set back in 1925. Austin did that and more, settin... | <urn:uuid:1936fac9-946e-4d04-9fc2-f257584af777> | 2.703125 | 658 | Personal Blog | Science & Tech. | 53.589812 |
Before continuing our tale, I'm going to bluntly advertise for the next session of my Introduction to Astronomy course which starts in January.
This course is for school children ages 8 and up, and surveys the science of astronomy from the contents of our solar system, to how stars form age and die, to the farthest reg... | <urn:uuid:77660bd7-4cac-461c-9db3-19e215f1ca06> | 3.359375 | 1,773 | Personal Blog | Science & Tech. | 35.183928 |
PGC2429 is an Elliptical Galaxy and is considered part of the Andromeda Galaxy. This galaxy has turned up in many different reference guides and has many names; M110 and NGC205, to name a few. A satellite of the Andromeda Galaxy, PGC2429 is often seen as a small ball of light underneath or just outside of the larger sp... | <urn:uuid:cdec210a-44a9-4d45-8bb9-8454e979e72c> | 3.25 | 661 | Knowledge Article | Science & Tech. | 64.251765 |
Abell 644 and SDSS J1021+131: Two galaxies, 920 million and 1.1 billion light years away from Earth respectively, used in a new study of supermassive black holes.
Caption: The galaxy on the left, Abell 644, is in the center of a cluster of galaxies. The right panel contains SDSS J1021+131, a so-called field galaxy beca... | <urn:uuid:a3b57857-2983-40ac-b756-9fd5ab9d0be1> | 3.75 | 210 | Truncated | Science & Tech. | 67.993501 |
Rare Corals Breed Their Way Out Of Trouble
Source: Science Daily
October 20, 2008
Rare corals may be smarter than we thought. Faced with a dire shortage of mates of their own kind, new research suggests they may be able to cross-breed with certain other coral species to breed themselves out of a one-way trip to extinct... | <urn:uuid:0d92073d-35b5-4e70-b882-cda4f1f50b19> | 2.78125 | 83 | Truncated | Science & Tech. | 62.732273 |
bobhenstra wrote:So, where is the strength in EQ shock waves of less than one hertz? How does a frequency of less than one hertz "signal?" earthquakes in distance areas as the map above supposedly shows? It would seem to me that if the supposition is true that frequencies of a percentage of less than one would have to ... | <urn:uuid:81457fa6-5249-4afd-8ea1-2dcce375edce> | 3.703125 | 328 | Comment Section | Science & Tech. | 54.512336 |
I feel like whenever a big giant roach crosses my path, it comes right at me as if it’s being remotely controlled by someone who has learned my deepest, darkest fears and is using them to torment and ‘bug’ me. Well, it seems I may be right!
Scientists from North Carolina have developed remotely-controlled roaches, not ... | <urn:uuid:fc39882d-0aff-45d2-8918-6bac26705f69> | 2.921875 | 627 | Audio Transcript | Science & Tech. | 51.060196 |
THE CASE for life in the underworld is stronger than ever, say Swedish scientists, who have found the remains of micro-organisms that once flourished in granite more than 200 metres underground.
Earlier this decade scientists claimed to have found bacteria in a 1.8-billion-year-old granite layer nearly 200 metres below... | <urn:uuid:05c566ee-da77-42b0-89be-72c66868c067> | 3.46875 | 218 | Truncated | Science & Tech. | 50.10352 |
|Feb13-13, 11:27 AM||#1|
Resonance frequency of a matrix system
I have a 2d system of the form:
dm1/dt + A11 m1 + A12 m2 = 0
dm2/dt + A21 m2 + A22 m2 = 0
I saw that the resonance frequency of such a system is defined as:
fr = 1/(2*pi) [ (A11 + A22)/2 + sqrt( ((A11-A22)/2)^2 + A12*A21 )
if I'm not mistaking - I can't ev... | <urn:uuid:19dfdf4d-a77d-4390-b2f0-2a95e46beec8> | 2.96875 | 279 | Comment Section | Science & Tech. | 60.965 |
Alain Van Ryckegham, a professor at the School of Natural Resources at Sir Sandford Fleming College in Lindsay, Ontario, Canada, offers this explanation:
Image: Bioinfo Animal Pictures Archive
Bats are a fascinating group of animals. They are one of the few mammals that can use sound to navigate--a trick called echoloc... | <urn:uuid:e12e7f89-a44b-45f0-811f-090d0b95df2e> | 4.5 | 763 | Knowledge Article | Science & Tech. | 41.42623 |
The Scariest Monsters of the Deep Sea
We took the spook-tacular celebration to the depths of the ocean, where some of the craziest—and scariest—looking creatures lurk in the dark.
- By Emily G. Frost and Hannah Waters
- October 30, 2012, Subscribe
|Learn more about the
ocean from the
Smithsonian's Ocean Portal.
(Ocean ... | <urn:uuid:15acc594-5a66-485c-b6a1-55262c6b5dc9> | 2.828125 | 215 | Listicle | Science & Tech. | 67.771108 |
A strange 525 million-year-old fossil creature is baffling scientists because it does not fit neatly into any existing animal groups.
The animal, from the early Cambrian Period, might have belonged to a now extinct mollusc-like phylum, academics from America and China say.
Other researchers have suggested the creature ... | <urn:uuid:aad5e940-5608-4d6c-9d1f-63db621b49a6> | 3.671875 | 1,171 | Comment Section | Science & Tech. | 51.746431 |
The colorsys module defines bidirectional conversions of color values between colors expressed in the RGB (Red Green Blue) color space used in computer monitors and three other coordinate systems: YIQ, HLS (Hue Lightness Saturation) and HSV (Hue Saturation Value). Coordinates in all of these color spaces are floating p... | <urn:uuid:bd4f9230-0d40-4a16-9e92-177231154384> | 2.6875 | 246 | Documentation | Software Dev. | 76.791438 |
Humans have been using wind power for more than 5500 years to propel all manner of boats, and to create some natural ventilation inside of many buildings. Its mechanical use came much latter in history however. The first historic mention of a windmill occurred in the 1rst century AD. The first modern wind turbines were... | <urn:uuid:0e493e1b-f8ac-4319-bf86-fca862205a22> | 3.140625 | 156 | Knowledge Article | Science & Tech. | 46.438043 |
Mass m is connected to the end of a cord at length R above its rotational axis (the axis is parallel to the horizon, the position of the mass is perpendicular to the horizon). It is given an initial velocity, V0, at a direction parallel to the horizon. The initial state is depicted at position A in the image.
The force... | <urn:uuid:84d75004-70c0-42fd-a80d-f8a16032f7dc> | 3.34375 | 251 | Q&A Forum | Science & Tech. | 64.442746 |
astroengine writes "What if the Martian terrain is too rugged for a rover to traverse? How do we study surface features that are too small for an orbiter to resolve? If selected by NASA, the Aerial Regional-Scale Environment Surveyor (ARES) could soar high above the Martian landscape, getting a unique birds-eye view of... | <urn:uuid:f0d17b2e-d3f8-459d-b049-5a5c753d2982> | 3.234375 | 138 | Comment Section | Science & Tech. | 34.161487 |
This simulation illustrates the electric field generated
by a line of charge, and shows how, by the principle
of superposition, a continuous charge distribution can
be thought of as the sum of many discrete charge elements.
Each element generates its own field, described by Coulomb's
Law (and represented here by the sm... | <urn:uuid:e0e3b870-19c8-422e-b6d0-8b846798e58d> | 3.703125 | 206 | Documentation | Science & Tech. | 28.420847 |
M theory is a name for a more unified theory that has the different string theories, as we know them, as limits, and which also can reduce, under appropriate conditions, to eleven-dimensional supergravity. There's this picture that we all have to draw where different string theories are limits of this M theory, where M... | <urn:uuid:41e58dc5-b0cf-414e-8b67-e2fd3e4c5e53> | 2.875 | 554 | Comment Section | Science & Tech. | 39.659683 |
Vapor Pressure: Using Barometers
The measurement of pressure exerted by a vapor is demonstrated using barometers. The vapor pressures of water and ethanol are compared. The 28 thumbnail images summarize the content of the video. Click an image to see the image gallery.
The measurement of pressure exerted by a vapor is ... | <urn:uuid:847d8a24-b744-49a8-ae7e-ee37a6afbbab> | 3.78125 | 1,267 | Truncated | Science & Tech. | 38.365447 |
find_path : (term -> bool) -> term -> string
Returns a path to some subterm satisfying a predicate.
The call find_path p t traverses the term t top-down until it finds a
subterm satisfying the predicate p. It then returns a path indicating how to
reach it; this is just a string with each character interpreted as:
- "b"... | <urn:uuid:469400a7-6002-42f0-9c84-fd51facec4c0> | 3.84375 | 192 | Documentation | Software Dev. | 67.509835 |
As was mentioned earlier, a Tkinter application spends most of its time inside an event loop (entered via the mainloop method). Events can come from various sources, including key presses and mouse operations by the user, and redraw events from the window manager (indirectly caused by the user, in many cases).
Tkinter ... | <urn:uuid:e020d3ad-cf86-4ba5-9ba3-921c2b0d3b74> | 3.59375 | 2,646 | Documentation | Software Dev. | 58.774521 |
STRANGE parents should have unusual offspring. Sure enough, when two carbon "onions" collide, a nanodiamond is born. It's an insight into the weird chemistry that arises in outer space.
Meteorites are home to diamonds a few nanometres wide but how these tiny crystals form is a mystery. A precursor could be the equally ... | <urn:uuid:40f54be9-970e-4c5c-97c8-80ab51aefdc1> | 3.4375 | 395 | Truncated | Science & Tech. | 49.598374 |
American physicist whose experiments using laser light to cool and
trap atoms earned him the Nobel Prize for Physics in 1997. He shared
the award with Steven Chu and Claude Cohen-Tannoudji, who also developed
methods of laser cooling and atom trapping.
One result of the development of laser-cooling techniques was the f... | <urn:uuid:4668ba9a-e0ac-4a03-9f40-c9d3c803eb53> | 3.421875 | 211 | Knowledge Article | Science & Tech. | 42.050503 |
Learn It: Sources of Energy
It is estimated that at current levels of usage, there is sufficient coal to last for about 300 years – but the world’s gas and oil supplies will run out around the middle of the 21st century. Hence there is a growing urgency in seeking new sources of energy, preferably renewable ones, and i... | <urn:uuid:ae6456d4-5cd4-446c-97d0-e3fb89beefbf> | 3.59375 | 372 | Tutorial | Science & Tech. | 29.262053 |
I've been doing some writing about warp drive physics, and what the hardware will look like. It all starts with having opto-electronics that can induce acceleration fields. I don't think it will be possible to curve space-time because the energy requirements are unreasonably large (e.g., the Alcubierre drive requires t... | <urn:uuid:e6d27ecb-54a0-40f9-a4e6-86a688bfb831> | 2.875 | 285 | Comment Section | Science & Tech. | 48.257422 |
"Taking fast action to reduce short-lived climate pollutants (SLCPs) including black carbon, methane, tropospheric ozone and hydrofluorocarbons (HFCs), is a critical climate strategy which can reduce the possibility that severe storms will inject more water vapor into the stratosphere, (causing accelerated ozone deplet... | <urn:uuid:d4a03229-9dbe-482c-94b7-3a1580d54b77> | 3.390625 | 740 | Comment Section | Science & Tech. | 23.622686 |
Tautomers are organic compounds that are interconvertible by a chemical reaction called tautomerization. As most commonly encountered, this reaction results in the formal migration of a hydrogen atom or proton, accompanied by a switch of a single bond and adjacent double bond. In solutions where tautomerization is poss... | <urn:uuid:67fa25b2-317c-4f60-963a-504352c99ad6> | 3.921875 | 752 | Knowledge Article | Science & Tech. | 25.672694 |
Structure and Bonding: Dueling Mechanisms - SN1 verses SN2
You may want to review the two activities that introduce the two different substitution reactions Reaction Rates and Molecular Crowding (SN2)and Consecutive Reactions (SN1). Explain the product(s) of the reaction of 2-bromobutane with the nucleophile, OH-:
C4H9... | <urn:uuid:21b453b7-1a32-4757-8347-e4c08b7b3f32> | 3.078125 | 901 | Tutorial | Science & Tech. | 53.593405 |
Understanding Evolution: Theory, Prediction and Converging Lines of Evidence, Part 1
One of the challenges for discussing evolution within evangelical Christian circles is that there is widespread confusion about how evolution actually works. In this (intermittent) series, I discuss aspects of evolution that are common... | <urn:uuid:d214eaf7-df3c-4b25-9507-fcea60168079> | 2.78125 | 1,947 | Personal Blog | Science & Tech. | 38.643649 |
There have been whole books written about the history and development of the Periodic Table of the Elements, and how that shaped what we know about chemistry now, how great it is, blah, blah, blah. And the Periodic Table is a great and useful tool, but today I’m sticking to some basic fun stuff, like this crocheted per... | <urn:uuid:08289795-d1ef-423b-8c2b-63cb5cf66133> | 3.328125 | 865 | Personal Blog | Science & Tech. | 41.659974 |
Panels are windows with the added feature of depth, so they can be stacked on top of each other, and only the visible portions of each window will be displayed. Panels can be added, moved up or down in the stack, and removed.
The module curses.panel defines the following functions:
Returns the bottom panel in the panel... | <urn:uuid:649877e3-bcca-4380-9525-44c5a8351d1d> | 3.421875 | 364 | Documentation | Software Dev. | 58.980493 |
NOAA-10 (ATN series) was launched on September 17, 1986 and is a
third-generation operational meteorological satellite. The satellite
design provides an economical and stable sun-synchronous ... platform. This
platform enables the satellite to carry advanced operational instruments
that measure the earth's atmosphere, ... | <urn:uuid:b2fbb3e3-78f4-4cbb-96b5-13635c8f09fd> | 3.203125 | 411 | Knowledge Article | Science & Tech. | 55.538781 |
Remember how fun it was studying chemistry and physics in high school? Well we guess your recollection depends on the person who taught the class. Why not have another go at it by learning the A-to-Z of electronics from one of our favorite teachers, [Jeri Ellsworth].
You know, the person who whips up chemistry experime... | <urn:uuid:28bc8223-4dc6-4809-b75b-bda725550689> | 2.71875 | 162 | Truncated | Science & Tech. | 59.188504 |
+ Search Quest
Lunar Prospector Mission
The Lunar Prospector mission was a tremendous success. Following a nearly flawless launch, a four-day journey to the Moon, and entry into lunar orbit, the tiny spin-stabilized spacecraft successfully sent valuable data back to Earth. Carrying five scientific instruments, Lunar Pr... | <urn:uuid:c95ca802-235a-4feb-915a-fec7ce38ff5a> | 3.328125 | 345 | Knowledge Article | Science & Tech. | 22.098614 |
|Measuring Angles - Part 4|
The size of an angle will depend on the opening between the two sides of the angle (Pac Mac's mouth) and is measured in units that are referred to as degrees which is indicated by the ° symbol. To help you remember approximate sizes of angles, you will want to remember that a circle, once ar... | <urn:uuid:12c0d210-e61e-45bf-93a1-84c85217649f> | 4.375 | 305 | Tutorial | Science & Tech. | 67.408869 |
Prove analytically the the diagonals of a rectangle are equal.
I really have no idea. Please help. Thanks!
there are so many ways to prove this
Here's the easiest one
Let's say you have a rectangle ABCD. AB is parallel to CD and BC is parallel to AD. And since rectangle has right angles it would be true that AB is cong... | <urn:uuid:e3c7682f-58b1-4668-9aac-5b9fd836a4d2> | 2.921875 | 158 | Q&A Forum | Science & Tech. | 83.749381 |
Path Shape of Venus Over Time
Name: Peter C.
I was recently reading a popular fictional novel and it
said that if one were to track Venus' transit through the night sky, it
would seem as though it would form the shape of a 5 pointed star through
course of eight years. I would like to know if this is true.
Have you seen... | <urn:uuid:93ef85db-8e58-4323-8443-a19b19045589> | 2.890625 | 168 | Comment Section | Science & Tech. | 60.122916 |
Determining Stellar Ages
Name: Beth S.
How can we tell a star's age?
Estimating the age of a star depends on our understanding of the evolution
and process within a star. All stars are expected to begin their lives as a
collapsing mass of mostly hydrogen and helium with a few trace elements. When
the nuclear process be... | <urn:uuid:7c10a5ac-6420-4a36-a19b-d0100bb94fa2> | 3.65625 | 536 | Knowledge Article | Science & Tech. | 57.354812 |
Country: United States
Date: May 2007
I understand than when a
dna-polymerase is making a copy of a dna strand, it attaches nucleosides
that are present in it´s surroundings, but how
does the enzyme "picks" or "catches" the nucleosides in order to
attach them to the template strand if they are
somehow "floating around"... | <urn:uuid:11ef9d26-2fc6-4041-8caf-2ffd400e5a53> | 3.234375 | 711 | Q&A Forum | Science & Tech. | 43.983943 |
How do you tell the difference between a gamma-ray burst and a star just from a picture of a nebula, in which it cannot flash on and off here and there?
GRBs have a spectra far more Red-shifted than that of a star.. In fact, GRBs have such an unique spectra that nothing matches with it. Its profile has one or two high ... | <urn:uuid:8797338b-371e-4d80-bb4a-8bfc0b3c9ed0> | 2.984375 | 236 | Q&A Forum | Science & Tech. | 73.216193 |
I've got a rather humiliating question considering newton's third law
"If an object A exterts a force on object B, then object B exerts an equal but opposite force on object A" -> $F_1=-F_2$
Considering that, why is there motion at all? Should not all forces even themselves out, so nothing moves at all?
When I push a t... | <urn:uuid:fa33c19d-39d0-4ed9-ae10-dc69a829cdf7> | 2.703125 | 265 | Q&A Forum | Science & Tech. | 45.608486 |
We recover the energy in a maglev flywheel in the same way we almost always convert mechanical energy to electrical energy: with a 3 phase electric power generator/motor, also called an alternator, with the rotor on the same shaft or otherwise integrated with the flywheel.
In cars with a combined starter/generator, pum... | <urn:uuid:b510df96-bc32-4a7d-a376-79c4a82db681> | 3.296875 | 399 | Q&A Forum | Science & Tech. | 26.640501 |
September 8, 2009
Stemming, in the parlance of searching and information retrieval, is the operation of stripping the suffices from a word, leaving its stem. Google, for instance, uses stemming to search for web pages containing the words connected, connecting, connection and connections when you ask for a web page tha... | <urn:uuid:2255fc14-94d1-4e69-be4f-b82066e11c9a> | 3.890625 | 391 | Tutorial | Software Dev. | 40.981192 |
Spiny back orb-weaver spider. This spider (Gasteracantha arcuata) grows a pair of extremely long, curving spines from its abdomen. It is thought the long spines evolved as a deterrent against predators or to mimic spines and thorns.
Picture: Nicky Bay / Science Photo Library / Rex Features
“It is the first-known predom... | <urn:uuid:649691eb-098c-4c09-a08e-d64df4eb9520> | 3.125 | 135 | Personal Blog | Science & Tech. | 44.745 |
law of corresponding states
Simply begin typing or use the editing tools above to add to this article.
Once you are finished and click submit, your modifications will be sent to our editors for review.
...vary from substance to substance, the nature of the behaviour in the vicinity of the critical point is similar for ... | <urn:uuid:14ffefd4-020f-4493-9467-4d9c8d6787e9> | 3.1875 | 215 | Truncated | Science & Tech. | 52.30303 |
Simply begin typing or use the editing tools above to add to this article.
Once you are finished and click submit, your modifications will be sent to our editors for review.
Filaments of the fungi called endomycorrhizae live within the cells of the roots of certain gymnosperms, especially conifers. Endomycorrhizal fung... | <urn:uuid:cc087f6c-f0e1-4048-96b5-416c4aac84e0> | 3.6875 | 430 | Knowledge Article | Science & Tech. | 38.814437 |
The answer, as everyone knows, is a Nobel Prize. Exactly fifty years ago this month, on April 25, 1953, the molecular biologists James D. Watson and Francis H. C. Crick published their pivotal paper in Nature in which they described the geometric shape of DNA, the molecule of life. The molecule was, they said, in the f... | <urn:uuid:e903c82f-189d-4f6c-8910-0f47feaebfa4> | 3.875 | 948 | Personal Blog | Science & Tech. | 46.193688 |
Why do my fingernails grow at least three times as fast as my toenails?
Toenails are subject to less wear and tear and so do not need to grow as quickly. Hands can be used as spades, for example, and fingernails can be used to prise things open.
According to Linden Edwards and Ralph Schott, in a paper published in 1937... | <urn:uuid:d8960a68-a438-41c5-8c85-ae075d812b78> | 3.265625 | 191 | Truncated | Science & Tech. | 61.306449 |
Take a walk along the coast and help us monitor the effects of climate change and invasive species on the UK's seaweeds.
Seaweeds are easy to find and occur all around the UK coastline. There are a staggering 650 seaweed species in the UK, around 7% of the world’s species, and they play a vital role in the functioning ... | <urn:uuid:7b98e53f-1540-4afa-acfa-e2693e0d5965> | 3.5625 | 422 | Content Listing | Science & Tech. | 55.557061 |
Global Warming and Southwestern Streams
Southwestern streams originating in high mountains are fed by snowpack and often flow throughout the year because of this summertime water source. There are also an abundance of intermittent or ephemeral southwestern streams that flow only in spring or during heavy rains. At lowe... | <urn:uuid:e845d348-9799-4bd9-bc2e-92d43ef3ce0a> | 3.90625 | 723 | Knowledge Article | Science & Tech. | 23.976313 |
A nyone who has been to the beach has probably seen starfish or sand dollars. The more intrepid beachcomber may find brittle stars, sea cucumbers, or sea urchins. These and many other organisms, living and extinct, make up the Echinodermata, the largest phylum to lack any freshwater or land representatives.
Most living... | <urn:uuid:dc3daa02-52cf-44a9-9576-fdcb7ca60771> | 3.875 | 240 | Knowledge Article | Science & Tech. | 28.891798 |
Mapping land cover from multi or hyper spectral imagery can proceed only on the premise that the target cover types are spectrally different from one another. Classification is a process of grouping pixels of similar spectral properties into spectral classes in which each class is assumed to or designed to correspond t... | <urn:uuid:88ac6ed2-eba7-4aaa-a262-a871df17b9f5> | 2.96875 | 2,345 | Academic Writing | Science & Tech. | 27.028139 |
Russian Firestorm: Finding a Fire Cloud from Space
Thick, choking smoke hung over Russia on August 1, 2010, adding to the misery of a stifling summer heat wave. Thousands of people were fleeing nearly 700 fires burning in the drought-dried forests and peat bogs of western Russia, while those not directly threatened wer... | <urn:uuid:7c720e9c-7397-462e-b61a-f5727ca5ecc4> | 3.78125 | 666 | Knowledge Article | Science & Tech. | 37.821341 |
From faraway planets to the deepest depths of the ocean, 2012 has been an exciting year for scientific achievements and milestones.
Humans broke previously unimaginable barriers by detecting an elusive tiny particle and free-falling 24 miles from the edge of space. At the same time, we said goodbye to four retired NASA... | <urn:uuid:113caff8-5a14-4f0d-8fad-221600fd87fd> | 3.171875 | 375 | Listicle | Science & Tech. | 55.846981 |
I find it interesting that all life on earth use DNA. I've seen video on how helicase and ribosomes work together to copy DNA sequences (to RNA) with helicase then recreate them using ribosomes. Does this process work the same way in the simplest life forms? Bacteria and other unicellular life that reproduce through mi... | <urn:uuid:d7d777e9-6c34-4434-a399-a0888f91623e> | 3.046875 | 357 | Q&A Forum | Science & Tech. | 47.822788 |
Each week we write about the science behind environmental protection. Previous Science Wednesdays.
About the Author: Karl Berg is currently a Ph.D. student at Cornell University in Ithaca, NY, and is looking forward to a career that will combine his interests in animal behavior and conservation. His master’s research w... | <urn:uuid:772b1ae0-fb48-418c-a52b-9acbb66bee1a> | 3.765625 | 551 | Personal Blog | Science & Tech. | 34.265831 |
XDR library routines allow C programmers to describe arbitrary data structures in a machine-independent fashion. Protocols such as remote procedure calls (RPC) use these routines to describe the format of the data.
These routines deal with the creation of XDR streams. XDR streams have to be created before any data can ... | <urn:uuid:36bf5c1b-f1d2-40bb-a808-59319686e003> | 2.890625 | 704 | Documentation | Software Dev. | 55.200181 |
Tk/Tcl has long been an integral part of Python. It provides a robust and platform independent windowing toolkit, that is available to Python programmers using the Tkinter module, and its extension, the Tix module.
The Tkinter module is a thin object-oriented layer on top of Tcl/Tk. To use Tkinter, you don't need to wr... | <urn:uuid:ddd1a49f-5c32-4a94-afa6-556251e8d9ca> | 2.78125 | 241 | Documentation | Software Dev. | 54.494102 |
Try turning a growing plant on end, and a funny thing happens. It will right itself, twisting and contorting so its leaves project skyward and its roots extend down toward the center of the Earth. Logic would dictate that plants solve the problem of which way to grow by sensing gravity — but how did scientists ever pro... | <urn:uuid:b225e47d-fbe1-46f4-a54c-8724c136320f> | 4.25 | 340 | Truncated | Science & Tech. | 68.448219 |
a1 Department of Astronomy, Cornell University, 402 Space Sciences Building, Ithaca, NY 14853 USA email: firstname.lastname@example.org
The giant planets of our solar system contain a record of elemental and isotopic ratios of keen interest for what they tell us about the origin of the planets and in particular the vol... | <urn:uuid:ca958896-d8b8-4c26-b334-3348ff2050a5> | 2.859375 | 248 | Academic Writing | Science & Tech. | 32.672454 |
Earth Radiation Budget
Most input of the Earth energy is received from the Sun. The solar energy is short-wave radiation. Although the Earth also receives electromagnetic energy from the other bodies in space, it's negligible, compared with solar energy [Table 1]. The incident solar energy (shortwave) may be reflected ... | <urn:uuid:342b18ca-7052-4bf0-b02d-bf094faed82f> | 4.15625 | 757 | Academic Writing | Science & Tech. | 27.478258 |
Volume & Surface Area of a pyramid within an isohedron
Hi Maths heads
I want to find the mathmatical formula for a pyramid within a sphere.
Consider a spere of any radius R
I want to cut out a pyramid with vertex at the centre of the sphere and the cutting through the sphere at radius R
The angle between the opposite p... | <urn:uuid:b063ad1a-3d8a-49ad-952c-bcdd91d28b6d> | 3.125 | 226 | Comment Section | Science & Tech. | 34.37 |
Hydroecological factors governing surface water flow on a low-gradient floodplain
Article first published online: 28 MAR 2009
Copyright 2009 by the American Geophysical Union.
Water Resources Research
Volume 45, Issue 3, March 2009
How to Cite
2009), Hydroecological factors governing surface water flow on a low-gradien... | <urn:uuid:3c8ad5e0-5c76-40e8-9493-ff713c3c9ccc> | 2.75 | 676 | Academic Writing | Science & Tech. | 21.8344 |
Part of why you don't see colors in astronomical objects through a telescope is that your eye isn't sensitive to colors when what you are looking at is faint. Your eyes have two types of photoreceptors: rods and cones. Cones detect color, but rods are more sensitive. So, when seeing something faint, you mostly use your... | <urn:uuid:aeeede3b-bc6d-48d0-81a9-181ad4993de0> | 3.78125 | 463 | Q&A Forum | Science & Tech. | 51.907919 |
We are all familiar with the idea that there are strikingly different kinds of eyes in animals: insects have compound eyes with multiple facets, while we vertebrates have simple lens eyes. It seems like a simple evolutionary distinction, with arthropods exhibiting one pattern and vertebrates another, but the story isn’... | <urn:uuid:ea20c422-049e-48fe-9de5-008c64851f61> | 3.796875 | 2,110 | Personal Blog | Science & Tech. | 29.437934 |
In a couple of decades from now, your version of the Bible or Harry Potter (or the best-selling book of the 22nd century, whatever that might be) might just be stored in a small vial of liquid or on small chips. Harvard University researchers have just encoded a book in DNA fragments instead of on physical copy or e-co... | <urn:uuid:96fe25ef-3dbd-493d-95d2-774d48914b58> | 3.546875 | 534 | Knowledge Article | Science & Tech. | 46.808536 |
Two recent studies provide further evidence that climate change sceptics are simply burying their heads in the sand. Both studies, one in Europe the other in the US are showing that not only does increasing atmospheric CO2 lead to higher temperatures, but that higher temperatures appear to cause CO2 to increase. That’s... | <urn:uuid:47945a6b-7d1c-4fac-b424-1c06220aad47> | 3.015625 | 360 | Personal Blog | Science & Tech. | 30.094949 |
|Proofreading RNA: Structure of RNA Polymerase II's Backtracked State|
|Wednesday, 25 November 2009 00:00|
RNA polymerase II (pol II) is responsible for the production of messenger RNA, which serve as templates for the synthesis of all proteins, including key enzymes, scaffold proteins, hormones, etc. Because a low err... | <urn:uuid:58bff703-d36b-408e-82c9-6261e63b2926> | 2.765625 | 891 | Academic Writing | Science & Tech. | 43.746682 |