text large_stringlengths 148 17k | id large_stringlengths 47 47 | score float64 2.69 5.31 | tokens int64 36 7.79k | format large_stringclasses 13
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Find the exact values of x, y and a satisfying the following system
of equations: 1/(a+1) = a - 1 x + y = 2a x = ay
Find the sum of the series.
Photocopiers can reduce from A3 to A4 without distorting the image.
Explore the relationships between different paper sizes that make | <urn:uuid:ba840440-e053-47a1-9eb8-a49bd446ce69> | 2.765625 | 74 | Content Listing | Science & Tech. | 54.881912 |
A cool early Earth
John W Valley, William H Peck, Elizabeth M King, Simon A Wilde April 2002 Geology v. 30; no. 4; p. 351-354
This landmark paper describes the analysis of the oldest-known earth materials, 4.4 billion year old zircon grains. Studies of these zircons suggest that some continental crust formed as early a... | <urn:uuid:8e049746-9094-4b80-988b-a51e7451851d> | 3.34375 | 158 | Academic Writing | Science & Tech. | 68.888945 |
Density Altitude Calculator
2. Relative humidity in percent.
3. Corrected barometric pressure in inches of Mercury. This is the barometric pressure as reported by most local radio and TV stations. It is corrected to sea level.
4. Your location altitude in feet.
Then click the calculate button.
2. Density Altitude in fe... | <urn:uuid:af85c7f1-2145-49f0-8f9c-03d3fc125d01> | 3.265625 | 106 | Tutorial | Science & Tech. | 37.841657 |
HOW DO BABY TURTLES SURVIVE WINTERS?
Questions about how various animals survive winter come across my desk (or rather my computer screen) rather frequently. Every species living in the temperate zone has to cope in some way with winter cold. Birds fly south as winter approaches. Mammals add a layer of body fat when co... | <urn:uuid:8b40ae6a-d8c2-47bb-b90c-e01934332e12> | 3.8125 | 749 | Nonfiction Writing | Science & Tech. | 44.418401 |
YELLOWSTONE VOLCANO OBSERVATORY MONTHLY UPDATE
Monday, March 1, 2010 2:47 PM MST (Monday, March 1, 2010 21:47 UTC)
YELLOWSTONE VOLCANO (CAVW #1205-01-)
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
February 2010 Yellowstone Seismicity ... | <urn:uuid:9e157381-beb4-4b52-8eb5-7c40abdda23b> | 2.75 | 713 | Knowledge Article | Science & Tech. | 53.558212 |
Joined: May 2002
Here's that 100,000 rpm flagellum:
Polar Flagellar Motility of the Vibrionaceae
Linda L. McCarter*
Interestingly, this one has more flagellin genes than usual, and no single one is crucial:
Flagellar filaments, which act as propellers, consist of self-assembling protein subunits (flagellin) arranged in... | <urn:uuid:f5f4d1ae-2b49-4f04-8521-dd8f7e48c171> | 2.765625 | 2,996 | Academic Writing | Science & Tech. | 35.202205 |
Why does this galaxy emit such spectacular jets?
No one is sure, but it is likely related to an active supermassive black hole at its center.
The galaxy at the
Hercules A, appears to be a relatively normal
elliptical galaxy in visible light.
When imaged in
radio waves, however, tremendous
jets over one million light ye... | <urn:uuid:dac49a60-1eac-4f73-8830-6623dbcf73f0> | 3.59375 | 238 | Knowledge Article | Science & Tech. | 35.379118 |
I am really confused with tostring........ Why does this program give an output of 10. There is no way in the program that I am refering to the method tostring, still why does it executes the tostring method.. Mysterious strings.........
Take a look at <code>java.io.PrintStream</code> class which is contained in the th... | <urn:uuid:f255b082-0179-4e5b-a2d0-7acaab183de3> | 3.125 | 602 | Q&A Forum | Software Dev. | 59.218573 |
Marine geologists studying ocean temperatures at the 2500 meter deep spreading center of the Galapagos Rift acquired their first definitive evidence for the existence of hydrothermal vents in May, 1976. A deep-tow vehicle deployed less than 40 meters above the volcanic ridge detected a buoyant plume of vent discharge. ... | <urn:uuid:19698438-0c42-4ce2-814a-5eed1a89c020> | 4.3125 | 899 | Knowledge Article | Science & Tech. | 25.817926 |
Niels Bohr was a Danish scientist who won the Nobel Prize for physics
in 1922 for his work in regards to understanding the structure
of atoms. Bohr introduced the theory that electrons travel in
an orbital path around the atom's nucleus. He also theorized that
light could have properties of both a wave and a particle a... | <urn:uuid:2153b87e-cb4b-452b-a6fc-90ae54f4ca4d> | 3.5625 | 399 | Knowledge Article | Science & Tech. | 43.753245 |
Suppose a square is inside a right triangle as shown in the picture.
If the square is 1 inch on each side and the hypotenuse is
inches long, find the length of the
vertical (longer) leg of the triangle.
[Problem submitted by Robert Hart, LACC Associate Professor of Computer Science.] | <urn:uuid:36da62a9-5b37-495d-8050-29cd01b1a4b5> | 3.296875 | 68 | Tutorial | Science & Tech. | 54.558333 |
You have said that you use THIOSULPHATE as a reducing agent.
What does a reducing agent do? And what are the properties of it?
Basically im asking for as much information as possible about the chemical.
A reducing agent is a substance that's works together with an oxidizing
agent. The type of reaction is an oxidation r... | <urn:uuid:3cd1a1e3-5280-48ed-af32-c1a113ecb517> | 3.40625 | 235 | Q&A Forum | Science & Tech. | 44.78623 |
Light Speed and Theories
Name: James L.
I recently read an article (The article can be found
at http://www.nature.com/nsu/000601/000601-5.html) which stated that by
using evanescent waves people were able to transmit a wave faster then c for
very short distances. c of course being the speed of light in a
vacuum. How do... | <urn:uuid:adfd69ec-d547-41e8-8cb4-4bafd2886b46> | 3.4375 | 306 | Comment Section | Science & Tech. | 59.125036 |
Superman relies on the same illusion to protect his identity: thanks to a pair of glasses, a change of clothes and a different hairstyle, nobody in Metropolis realizes that he and Clark Kent are the same person.
Gaze at the angry face (left) for about 30 seconds while looking around the face from the eyes to the mouth,... | <urn:uuid:dac05d35-b7cc-4235-ab0d-2ff98cfa528c> | 3.59375 | 248 | Knowledge Article | Science & Tech. | 52.998413 |
Polar Bear Births Could Plummet With Climate Change
Edmonton, Canada (SPX) Feb 16, 2011
University of Alberta researchers Peter Molnar, Andrew Derocher and Mark Lewis studied the reproductive ecology of polar bears in Hudson Bay and have linked declining litter sizes with loss of sea ice.
The researchers say projected ... | <urn:uuid:cca4cba1-896a-4d6d-a45f-8dc80606ba8b> | 3 | 691 | Truncated | Science & Tech. | 34.049925 |
Boffins get black hole double-vision
Messier 22 springs astro-physics surprise
The Messier 22 globular star cluster has yielded a messier-than-expected observation: instead of the black hole astronomers expected to find in its centre, there are two.
Conducted by the University of Southampton’s Dr Tom Maccarone, Michiga... | <urn:uuid:eeba46e4-c6dd-4fc6-9e16-3133bdbe3726> | 2.859375 | 570 | Comment Section | Science & Tech. | 54.499527 |
| A solar array is made up of many individual solar cells that generate a low current. Each individual cell is made up of two layers of different semiconductor materials: a p-type layer (containing free holes) overlain by an n-type layer (containing free electrons). Where the two layers are joined the free electrons in... | <urn:uuid:4246aea3-3097-458f-8898-891cc7a5cb93> | 4.28125 | 257 | Knowledge Article | Science & Tech. | 42.061295 |
cean The children learned about earthquakes that happen under the ocean but not the old story about California falling into the ocean! In fact, our earthquakes are proof in and of themselves that we cannot fall into the ocean. Read the description under Epicenter of how an earthquake happens. Earthquakes only happen wh... | <urn:uuid:0cff79ab-1910-4687-8ac6-7ac47ee1fe7f> | 3.53125 | 203 | Knowledge Article | Science & Tech. | 47.602533 |
What Is the Difference Between Weather and Climate?
It’s a sweltering midsummer day. “It must be global warming,” mutters someone. But is it the Earth’s changing climate that has made the day so warm? Or, is it just the weather that is so unbearable?
Weather is the mix of events that happen each day in our atmosphere i... | <urn:uuid:68cc0d5b-57b9-4412-bf5c-46b0755daedc> | 3.421875 | 318 | Knowledge Article | Science & Tech. | 45.733485 |
Paleobiology of Marine Benthic Communities
History of Regional Outbreaks of Coral Disease on Caribbean
The staghorn coral Acropora cervicornis was a dominant
space-occupier and an important framework constructor of
Caribbean coral reefs during the Pleistocene and Holocene.
Populations of Acropora were killed throughout... | <urn:uuid:ccde4f82-0c8b-49c8-8278-8ab16170ba61> | 3.59375 | 3,327 | Academic Writing | Science & Tech. | 46.543571 |
Snow and Ice
Climate Change Opinion
Book and Movie Reviews
A study released by NASA confirmed that 2005 was the warmest year on record, narrowly beating out 1998. That year a strong El Niño--a warm water event in the eastern Pacific Ocean--added significant warmth to global temperatures. The new record was set without ... | <urn:uuid:a8795493-ce0c-4d4f-8b0e-655190c0ee3f> | 3.9375 | 420 | Knowledge Article | Science & Tech. | 54.514521 |
The principle of mathematical induction is based on the fifth Peano Postulate, which states that:
If a statement holds for the positive integer 1, and if, whenever it holds for a positive integer, it also holds for that integer's successor, then the statement holds for all positive integers.
This property is quite fund... | <urn:uuid:c744011f-2623-4636-b965-05549cd69548> | 3.953125 | 255 | Knowledge Article | Science & Tech. | 66.777208 |
universe is a system with broken symmetries.
In the very early universe, the strong, weak, and electromagnetic
forces were indistinguishable. At
some point as things cooled off, the symmetry between these forces broke and
the three forces went their separate ways to become the three very different
forces that, along wi... | <urn:uuid:9b38ccdb-4f34-4778-bb8b-623177196425> | 3.21875 | 2,515 | Academic Writing | Science & Tech. | 34.638 |
By Sarah Wagner, Institute for Collaborative Education (I.C.E.)
Quick! Run! The zombie apocalypse is finally upon us. But it’s much less scary when it’s ants being zombified.
In Brazil, four new types of fungi were found that take over ants’ brains, turning them into zombies. The fungi, each of which attacks a specific... | <urn:uuid:9f628977-519d-40e3-add3-aac409cf5e93> | 3.171875 | 514 | Personal Blog | Science & Tech. | 67.532219 |
|Chandra X-Ray Observatory|
|The third of NASA's Great Observatories for Space Astrophysics|
The electromagnetic spectrum, extends from radio waves to gamma waves, from very low frequencies to extremely high frequencies. Our ability to tune in the more exotic radio waves has grown in recent decades.
In fact, it's only ... | <urn:uuid:61fcbd63-300e-448e-b300-fb8dd79284c7> | 3.796875 | 642 | Knowledge Article | Science & Tech. | 48.508578 |
Ask a question about 'Newton disc'
Start a new discussion about 'Newton disc'
Answer questions from other users
A Newton disc
is a disc with segments in rainbow
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in th... | <urn:uuid:f8e00b7b-b041-4996-8e87-8223a844440a> | 3.46875 | 278 | Q&A Forum | Science & Tech. | 54.6515 |
August 20, 2009
Just about every two years, the planet
Mars makes its closest approach to Earth... around 36 million miles.
That's when we pack our robotic emissaries off to
timing their launches to spend the least effort to get there.
Some fly around it... snapping pictures...
Others land... to sample its surface...a ... | <urn:uuid:2fa5b583-24ef-4f43-8028-b9b21b7cd59d> | 3.484375 | 847 | Nonfiction Writing | Science & Tech. | 69.440484 |
Based on their distinguished achievements in original research, three Caltech professors—Mike Brown, Ken Farley, and John Seinfeld—are among the 84 members and 21 foreign associates newly elected to the National Academy of Sciences.
In 1969, an exploding fireball tore through the sky over Mexico, scattering thousands o... | <urn:uuid:8e2bbc80-4984-4518-99aa-e7b7906fae85> | 3.4375 | 636 | Content Listing | Science & Tech. | 30.152758 |
molecules have nonsuperimposable mirror images. And as a general
rule of thumb, chiral molecules must have one or more chiral
centers -- that is, carbons that have four non-identical
substituents around it. (There are, of course, exceptions
to this rule). A classic case of a simple chiral molecule
is the following halo... | <urn:uuid:3a6d6276-ee28-4806-915b-5fcab1a033e6> | 3.5625 | 1,107 | Tutorial | Science & Tech. | 38.862325 |
|All materials consist of many small particles, the molecules. Air, the earth - everything which surrounds us. The aggregation state of a material - solid, liquid or gaseous - depends upon how closely these molecules are bound together. Take the example water. Water freezes below 0°C, thus becomes solid. The molecules ... | <urn:uuid:b38ce935-aa0e-4696-bc71-b58cc4b07725> | 4.28125 | 863 | Knowledge Article | Science & Tech. | 53.495872 |
| Many shrews have such uniformly grayish coats that separate species cannot easily be distinguished, but both the summer and winter coats of the Tundra Shrew are highly distinctive. Its summer pelage is tricolored, dark brown on the back, pale gray on the underparts, and brownish-gray or pale brown in between. Its lon... | <urn:uuid:4bbf31c4-ce2c-4e7c-9a49-d2ec167d5e3b> | 3.453125 | 209 | Knowledge Article | Science & Tech. | 56.06374 |
Report an inappropriate comment
Sat Sep 13 10:38:03 BST 2008 by Pat Donnelly
A distant cluster of galaxies is said to confirm the existence of undetectable energy. Not a single reference is made to the most powerful known force in the cosmos: electricity. Because the speed of light is used as a benchmark for defining c... | <urn:uuid:de1cdca0-2f77-40af-9ad3-9fa96c501015> | 3.078125 | 1,032 | Comment Section | Science & Tech. | 35.252083 |
Is Antarctica losing or gaining ice?
What the science says...
|Select a level...||Basic||Intermediate|
Satellites measure Antarctica is gaining sea ice but losing land ice at an accelerating rate which has implications for sea level rise.
Skeptic arguments that Antarctica is gaining ice frequently hinge on an error of ... | <urn:uuid:ccf1e401-2006-4aa4-a201-af4d3ebb4886> | 3.625 | 768 | Knowledge Article | Science & Tech. | 45.58612 |
The Dark Ages Lunar Interferometer (DALI)
Kurt Weiler (NRL)
The Dark Ages Lunar Interferometer (DALI) is a Moon-based radio telescope concept aimed at imaging highly-redshifted neutral hydrogen signals from the first large scale structures forming during the Universe’s “Dark Ages” and “Epoch of Reionization.” The Unive... | <urn:uuid:641ad975-09e6-4244-9c09-75f2e1aee56a> | 3.171875 | 557 | Academic Writing | Science & Tech. | 23.383896 |
Alternate Entry Name: _EPOST
B: .epost( errnum, format, arg1, arg2, ... );
C: void _epost(int errnum, const char *format, ...);
.EPOST "posts" an error message. This means that the message is formatted using the "format" string and arguments, then is saved in memory for later retrieval.
For example, suppose that a prog... | <urn:uuid:8fdd4c35-11b6-4cdb-8a83-73cf09da4e8d> | 2.765625 | 369 | Documentation | Software Dev. | 57.346164 |
Narrator: This is Science Today. Earlier this year, an international team of astrophysicists discovered a distant, icy planet five times the size of Earth. The smallest extrasolar planet revealed outside of our solar system was found using a technique called microlensing that is based on an idea Albert Einstein came up... | <urn:uuid:2af12d66-b487-4614-aeba-dc97f8a1663b> | 4.0625 | 257 | Audio Transcript | Science & Tech. | 58.911275 |
Naturally occurring uranium contains more than 99% 23892U, an isotopeOne of two or more samples of an element whose atoms differ in the number of neutrons found in the nucleus. which decays to 23490Th by α emission, as shown in Eq. (1) from Naturally Occurring Radioactivity. The productA substance produced by a chemica... | <urn:uuid:3a4b3e2d-8c51-4c49-b695-424e316378a2> | 3.90625 | 629 | Tutorial | Science & Tech. | 51.408347 |
This video is called Australian Antarctic season 2012-13.
From Wildlife Extra:
New acoustic devices to track and count Blue whales
Eavesdropping on the elusive blue whale
October 2012: Australian Antarctic scientists have successfully tested new acoustic technology to track and locate scores of blue whales hundreds of ... | <urn:uuid:b48cf28f-e867-416f-b268-c1e0f6fd77b1> | 3.53125 | 635 | Personal Blog | Science & Tech. | 36.313957 |
Protons are positively electric; electrons negative. This is an attractive situation. Where do the shells come from that keep electrons from falling into the protons under attraction?
The answer can be addressed by many ways. Here is some, which follows from AWT
: the rotating electron makes the vacuum foam near proton... | <urn:uuid:ce104a14-3361-4b14-862a-d1e98679bd7a> | 3.5 | 320 | Comment Section | Science & Tech. | 27.906165 |
Fossils and Living Species
Fossils raised many questions about the origin of species--and not just for Darwin. Discoveries in geology had already challenged the idea that the world and all its species had been created at the same time a few thousand years ago. Fossils clearly showed that in past ages, the world had bee... | <urn:uuid:f6f8d765-d8b1-4278-935c-0122c1bd7736> | 3.875 | 186 | Knowledge Article | Science & Tech. | 42.21913 |
FORUM ON EDUCATION
Energy - a Basic Physics Concept and a Social Value
John L. Roeder
Thirty years ago I began teaching at The Calhoun School in New York City. Soon after I arrived, the Arab Oil Embargo meant that the availability of gasoline at the corner service station could no longer be taken for granted, and befor... | <urn:uuid:ce08ddda-2638-411a-a67d-a1783618f5d8> | 2.6875 | 2,003 | Nonfiction Writing | Science & Tech. | 51.859446 |
The kinetic model of matter is an important idea that can be tackled at a variety of levels.
To link the animation to NC 'Scientific Enquiry' it would be useful to emphasise that the animation is trying to model how matter behaves and as a model it will have flaws. As part of this discussion the pupils' attention could... | <urn:uuid:4b3392ea-54d9-45cc-819f-5c35503c3150> | 4.53125 | 351 | Tutorial | Science & Tech. | 43.552873 |
Predicting the consequences of global warming is one of the most difficult tasks for the world’s climate researchers. This is because the natural processes that cause rain, hail and snow storms, increases in sea level and other expected effects of global warming are dependent on many different factors. It is also diffi... | <urn:uuid:37952460-92ae-46f5-8081-5d1eafb510ee> | 3.96875 | 519 | Knowledge Article | Science & Tech. | 38.677273 |
Zelia developed from a convective cloud cluster in the near equatorial trough to the southwest of Sumatra. Intensifying and moving to the southeast on the southern side of the middle level ridge it soon encountered low-level southeasterly flow following the passage of a cold front to the south. This weakened the system... | <urn:uuid:7b578f77-0193-4dd5-b3af-22b33c9d77d0> | 2.859375 | 134 | Knowledge Article | Science & Tech. | 46.445302 |
One of the delights of wandering around an undergraduate chemistry laboratory is discussing the unexpected, if not the outright impossible, with students. The >100% yield in a reaction is an example. This is sometimes encountered (albeit only briefly) when students attempt to recrystallise a product from cyclohexane, a... | <urn:uuid:447f442b-9d5b-4fc0-9c83-ef3acd6ff5d7> | 3.046875 | 483 | Personal Blog | Science & Tech. | 47.211602 |
The Unusual Properties of Water Molecules
Water molecules have unusual chemical and physical properties. Water can exist in all three states of matter at the same time: liquid, gas, and solid.
Imagine that you’re sitting in your hot tub (filled with liquid water) watching the steam (gas) rise from the surface as you en... | <urn:uuid:d9e5600c-955f-419a-bc33-6f44ca608ddd> | 3.71875 | 868 | Knowledge Article | Science & Tech. | 38.904832 |
Contact: Christine Pulliam
Harvard-Smithsonian Center for Astrophysics
Caption: A giant gamma-ray structure was discovered by processing Fermi all-sky data at energies from 1 to 10 billion electron volts, shown here. The dumbbell-shaped feature (center) emerges from the galactic center and extends 50 degrees north and ... | <urn:uuid:31110fa4-e149-4e5c-aa7e-3c4ac1a0671f> | 3.46875 | 137 | Truncated | Science & Tech. | 34.520435 |
In any geometric solid that is composed of flat surfaces, each flat surface is called a face.
The line where two faces meet is called an
For example, the cube above has six faces, each of which is a
Where two squares meet, a
is formed, which is called an
In the case of a
cube, it has 12 such edges.
(C) 2009 Copyright M... | <urn:uuid:07d85d21-f77f-4def-bde5-4bc53c4ec931> | 3.765625 | 88 | Knowledge Article | Science & Tech. | 57.460238 |
A loop statement specifies the repeated execution of a statement sequence. It is terminated by the execution of any exit statement within that sequence.
LoopStatement = LOOP StatementSequence END.
LOOP IF t1^.key > x THEN t2 := t1^.left; p:= TRUE ELSE t2 := t1^.right; p:= FALSE END; IF t2 = NIL THEN EXIT END; t1=t2 END... | <urn:uuid:fae096dc-a42a-4c60-a594-bb7438c851b9> | 3.234375 | 213 | Documentation | Software Dev. | 38.257468 |
NGC 1961 is a problematic galaxy. Its highly disturbed and asymmetric
spiral arms would normally indicate an interaction or merger with
another galaxy. However, no culprit is found to be the source of
NGC 1961's angst. This galaxy is part of a group (of about 10 other smaller
galaxies) around 171 million light years aw... | <urn:uuid:91c3c5be-d1bf-4538-a563-f6fd1d670385> | 2.9375 | 246 | Knowledge Article | Science & Tech. | 56.004978 |
I’ve been trying to find out how many taste buds pigeons have after reading somewhere that they haven’t got many compared to humans. Well, after a lot of searching I found the original paper (Pigeon Pages by Pigeon Recovery) I had read which states that feral pigeons have only 57 taste buds compared to the 9000 humans ... | <urn:uuid:8da3eaa1-cd01-4d8a-8a85-d583670f1e3b> | 3.125 | 1,049 | Personal Blog | Science & Tech. | 50.898363 |
Dec. 19, 2011 A new German-based project is setting out to rescue biodiversity data at risk of being lost, because they are not integrated in institutional databases, are kept in outdated digital storage systems, or are not properly documented.
The project, run by the Botanic Garden and Botanical Museum Berlin-Dahlem, ... | <urn:uuid:427ccd40-74a8-4196-aafb-0571242124fe> | 3.0625 | 683 | Knowledge Article | Science & Tech. | 31.661747 |
The preservation of living cells for transport and storage has become increasingly important as cell based treatments and living products have been developed for medical care. To treat a patient using living cells that can assist in wound repair or synthesize important chemicals in the body has tremendous medical poten... | <urn:uuid:b72bfc20-197b-4310-92df-581589455698> | 3.640625 | 268 | Academic Writing | Science & Tech. | 38.415833 |
Let us now see how the Maxwell equations (17.2)–(17.5) predict the existence of electromagnetic waves. For simplicity we will consider a region of space and time in which there are no sources (i.e., we consider the propagation of electromagnetic waves in vacuum). Thus we set p = 0 = j in our space-time region of intere... | <urn:uuid:54324a60-a77d-45dd-abec-3afe6467175f> | 2.84375 | 129 | Academic Writing | Science & Tech. | 53.871128 |
Many soils of the arid west have a rich active azofying flora. This is due in no small measure to their composition. They are high in calcium and magnesium carbonate and contain a good supply of available phosphorus and potassium but have a low nitrogen content. They are poor in organic carbon; hence, their native supp... | <urn:uuid:4caaa164-cea4-4378-b851-d3b4bd5b0bc7> | 2.953125 | 202 | Academic Writing | Science & Tech. | 59.738457 |
In our last session we learnt about header, footer, hgroup, figure and figure caption tags.One thing you can notice is that these tags are replacement of our traditional div tag in HTML 4 and rather more specific and categorized.There are a few more tags before we move into our next topic.
- <time>-Time tag is used to ... | <urn:uuid:f651c6da-477e-4032-b48c-205f738e186d> | 3.296875 | 283 | Tutorial | Software Dev. | 56.75035 |
1. Click on the five different buttons in the applet (F=4, F=6, F=8, F=12, F=20). Can you name the five regular polyhedra?
2. Look at the top of the chart. How many faces does each polyhedron have? How many vertices?
3. Stop the rotation. Look at each of the polyhedra. What polygon do you see on the faces of the
4. Ins... | <urn:uuid:eab74388-2650-4417-9513-1e6fbb034c78> | 3.234375 | 186 | Tutorial | Science & Tech. | 82.575072 |
Assume you have a rigid body falling into the ocean at terminal velocity. Also assume that the rigid body does not break on impact. How could you figure out how much kinetic energy would be lost in the resulting splash? I promise this isn't a homework question, but an engineering thought experiment. I began to reason t... | <urn:uuid:8e50de63-f627-4f1b-b46f-414ae3bc396f> | 2.75 | 211 | Q&A Forum | Science & Tech. | 53.592316 |
The way we control machines has changed dramatically over time. We have gone a long way from manual handles, knobs, strings and buttons to a great invention like the mind control head sets, seen in sci-fi movies only not long ago. Well, it is no longer science fiction. The possibility to control things with the power o... | <urn:uuid:6bc0cd73-c891-4521-b2a2-f87cf62382ec> | 2.71875 | 800 | Truncated | Science & Tech. | 51.583392 |
My hero helping to beat back the tide of stupidity and hysteria?
Climate change theories face being debunked by Captain Cook and Darwin
Weather reports made by famous explorers such as Captain James Cook and Charles Darwin are helping scientists to study climate change.
Although there are numerous weather reports from ... | <urn:uuid:66c8ccc8-cf0c-411d-8a05-5a197bd8edba> | 2.765625 | 252 | Personal Blog | Science & Tech. | 35.983442 |
In a first for interplanetary exploration, NASA engineers said Wednesday that the $2.5 billion Curiosity robot rover successfully mined material from inside a rock on Mars, advancing the agency's search for conditions once favorable for microbial life.
Latest Photos from NASA's Mars Rover
Held in a scoop on the rover's... | <urn:uuid:d6b6d764-68bb-425b-9ffb-4691c94aaf05> | 3.1875 | 443 | Truncated | Science & Tech. | 48.62063 |
Coastal & Marine Geology InfoBank
Our Mapping Systems
The USGS and Science Education
USGS Fact Sheets
ground penetrating radar
Comment: 17:47 - 19:12 (01:25)
Source: Annenberg/CPB Resources - Earth Revealed - 21. Groundwater
Keywords: pollution, groundwater, landfill, rainfall, "saturated zone", clay, leachate
Our tran... | <urn:uuid:21de66b7-e175-4e3e-82f6-242f18a62b03> | 3.859375 | 321 | Knowledge Article | Science & Tech. | 34.375169 |
Over the past few years, we have made considerable progress in understanding the genetics of flowering time in maize. As a part of our studies, we have determined the knob composition of a number of inbred lines. These include some of the currently used inbreds, or those which have been used extensively in the present ... | <urn:uuid:3f0b43ee-bff1-4344-a179-f01cbc59a635> | 3.015625 | 553 | Academic Writing | Science & Tech. | 42.13809 |
Science Fair Project Encyclopedia
An anti-radiation missile is a missile which is designed to detect and home in on the emissions of an enemy radar installation. Commonly carried by specialist "Wild Weasel" aircraft in the SEAD role, the primary purpose of this type of missile is to degrade enemy air defences in the fi... | <urn:uuid:d718d62f-9f12-4d6a-ae50-ddf5b30ed608> | 2.984375 | 607 | Knowledge Article | Science & Tech. | 47.218551 |
Science Scoops: And…Reflections of Earth's Climate
by Stephen James O'Meara
Wondering how Earth's climate may be changing over the years? Well, how about keeping an eye on the Moon? Yup. That's what researchers did in the late 1920s, and that's what Philip R. Goode (New Jersey Institute of Technology) and his colleague... | <urn:uuid:f82ffa84-c59b-4eaa-ad7d-096d5300f804> | 3.953125 | 515 | Truncated | Science & Tech. | 66.282231 |
What will happen when an F5 tornado hits a nuclear power plant?
The most violent tornadoes, F5 category, have winds in excess of 300 MPH and can pick up automobiles and hurl them like missiles at speeds of over 100 MPH. Strong frame homes are ripped off their foundations and carried through the air like toys. The winds... | <urn:uuid:6b0630e8-2fae-41d0-91e3-a0ec24e075e0> | 3.15625 | 138 | Q&A Forum | Science & Tech. | 64.96375 |
Next: Getting a string of characters and attributes from a window, Previous: Cursor location and window coordinates, Up: The basic curses library [Contents][Index]
These functions examine a character on the screen and return it, along
with its rendition.
These routines return the rendered complex character at the curre... | <urn:uuid:665d6ba6-f277-443d-a8fb-02901a372372> | 2.9375 | 70 | Documentation | Software Dev. | 22.763333 |
The coupling laser is tuned to the energy difference between states 2 and 3, so it doesn't interact at all with the electrons in the ground state. Nothing happens. Then a second laser, called the "probe laser" that contains the information they want to capture is sent into the condensate. The probe laser is tuned to th... | <urn:uuid:231ceb7b-7bf2-4a4c-8333-aab3595ae126> | 3.390625 | 199 | Knowledge Article | Science & Tech. | 51.164209 |
Antimatter is real stuff, not just science fiction. Antimatter is firmly in the realm of science with some aspects even entering the technology realm. There is also a lot of speculation about what one might do with antimatter.
What is Antimatter?
Antimatter is matter with its electrical charge reversed. Anti-electrons,... | <urn:uuid:21c5bd62-fbb0-4b38-a256-5ff21da6eccd> | 3.65625 | 411 | Knowledge Article | Science & Tech. | 33.651456 |
A North Atlantic Ocean circulation system weakened considerably in the late 1990s, compared to the 1970s and 1980s, according to a NASA study.
Sirpa Hakkinen, lead author and researcher at NASA's Goddard Space Flight Center, Greenbelt, Md. and co-author Peter Rhines, an oceanographer at the University of Washington, Se... | <urn:uuid:f27ba744-6b04-4f4a-b0ea-20760fad38e5> | 3.515625 | 860 | Knowledge Article | Science & Tech. | 37.902931 |
I would like some input into learning x86 assembly language on a PC. My question is - How do you write beginning assembly language programs without having to navigate the Windows OS? (a.k.a. Win32...
just a minor word of caution - depending on what OS you're loading after your module has finished up, you will likely ne... | <urn:uuid:b51aafe8-9319-4484-b4c7-c47bb667d470> | 2.734375 | 770 | Comment Section | Software Dev. | 77.052919 |
Context. Dwarf spheroidal (dSph) galaxies are the least luminous, least massive galaxies known. Recently, the number of observed galaxies in this class has greatly increased thanks to large surveys. Determining their properties, such as mass, luminosity and metallicity, provides key information in our understanding of ... | <urn:uuid:e527a706-e965-475b-b5b5-73c0ea84001e> | 2.734375 | 610 | Academic Writing | Science & Tech. | 55.647352 |
This image shows a cross section through the earthís crust and upper mantle showing lithosphere plates (made of the crust layer and the top part of the mantle) moving over the asthenosphere (upper mantle).
Click on image for full size
Old Rocks Give New Clues about Ancient Earth!
News story originally written on July 1... | <urn:uuid:484343c2-d3c5-47d7-a3f7-f0489fa88c89> | 4.125 | 768 | Content Listing | Science & Tech. | 63.830631 |
This is a drawing of the evolution of the interior of a giant planet.
Click on image for full size
Image from: The New Solar System
How the Interior of Uranus Formed
The drawing shows a possible history of the inside of giant planets.
As the planets drew material from the solar cloud, bits of heavy rock collected insid... | <urn:uuid:1111c550-c642-45b6-baf0-5613fd140661> | 3.96875 | 619 | Knowledge Article | Science & Tech. | 57.809759 |
Wednesday, October 03, 2012
One of the most fascinating and beautiful sites on the internet is the Astronomy Picture of the Day
. It has been online almost since the beginning of the World Wide Web, and is still breathtaking in beauty and simplicity. Each day features a fabulous photograph and sometimes a video, along ... | <urn:uuid:e51dfe33-35b3-46c2-9309-23e65f62b606> | 2.875 | 2,260 | Personal Blog | Science & Tech. | 54.38894 |
This paper presents the results of hydroacoustic noise research in three large European rivers: the Danube, the Sava, and the Tisa. Noise in these rivers was observed during a period of ten years, which includes all annual variation in hydrological and meteorological conditions (flow rate, speed of flow, wind speed, et... | <urn:uuid:041ecb79-b51a-459c-8d57-0186de43a4fb> | 3.015625 | 186 | Academic Writing | Science & Tech. | 40.775092 |
Climate Change: News and Comments
Full steam ahead for the real story of 20th Century warming
Although It seems a strange thing to celebrate, the Titanic Festival in Belfast, where the ship was built, will very soon mark the 100th anniversary of the liner’s foundering on 15 April 1912 after hitting a south-wandering ic... | <urn:uuid:fb9d6543-3353-46e5-96f4-334f39bddc69> | 3.40625 | 821 | Personal Blog | Science & Tech. | 53.075293 |
A biosignature is any substance – such as an element, isotope, molecule, or phenomenon – that provides scientific evidence of past or present life. Measurable attributes of life include its complex physical and chemical structures and also its utilization of free energy and the production of biomass and wastes. Due to ... | <urn:uuid:e769a3b3-609f-4d96-9f35-9c2658e32784> | 3.8125 | 2,702 | Knowledge Article | Science & Tech. | 42.406782 |
In the years after Columbus' voyage, burning of New World forests and fields diminished significantly – a phenomenon some have attributed to decimation of native populations by European diseases. But a new University of Utah-led study suggests global cooling resulted in fewer fires because both preceded Columbus in man... | <urn:uuid:523e9443-bdad-4dd9-bf91-f36847b3ceac> | 3.265625 | 816 | Content Listing | Science & Tech. | 36.347674 |
2.2. How much dark matter?
An important recent development is that DM can now be constrained to a value around 0.25 by several independent lines of evidence:
(i) One of the most ingenious and convincing arguments comes from noting that baryonic matter in clusters - in galaxies, and in intracluster gas - amounts to 0.15... | <urn:uuid:08bdc5f7-30be-4cc5-b79d-a811d8384609> | 2.90625 | 428 | Academic Writing | Science & Tech. | 39.265928 |
Dip your toe into the fascinating topic of genetics. From Mendel's
theories to some cutting edge experimental techniques, this article
gives an insight into some of the processes underlying. . . .
Explore the properties of this different sort of differential
Get further into power series using the fascinating Bessel's ... | <urn:uuid:91fc959a-eeba-41d2-84be-2ffa4721cc34> | 3.546875 | 1,053 | Content Listing | Science & Tech. | 51.400163 |
Thunder is the crash and rumble associated with lightning. It is caused by the explosive expansion and contraction of air heated by the stroke of lightning. This results in sound waves that can be heard easily six to seven miles (9.7 to 11.3 kilometers) away. Occasionally such rumbles can be heard as far away as 20 mil... | <urn:uuid:f40fd636-a780-448b-8bb7-1adb95eed8ba> | 3.375 | 145 | Truncated | Science & Tech. | 72.621883 |
Symbols in Ocamlyacc grammars represent the grammatical classifications of the language.
A terminal symbol (also known as a token type) represents a class of syntactically equivalent tokens. You use the symbol in grammar rules to mean that a token in that class is allowed. The symbol is represented in the Ocamlyacc par... | <urn:uuid:47745ff6-4ed8-4103-9308-14bf67ecd56e> | 3.09375 | 337 | Documentation | Software Dev. | 43.232198 |
Specify a warp factor and the form will then calculate the speed in multiples
of the speed of light and the time to travel the specified distances. You may
also specify your own distance in light years. The velocity values of warp factors
are calculated for standard conditions found within the Milky Way galaxy. Actual
... | <urn:uuid:286bca6c-22a7-4b32-be29-91633176ba07> | 2.703125 | 98 | Documentation | Science & Tech. | 35.88125 |
Published by the American Geological Institute
of the Earth Sciences
A Galapágos tortoise observes Jim Stimac backpacking to the rim of Alcedo caldera. All photos courtesy of Fraser Goff.
|In early 1995, colleagues and I ventured to the Galápagos for
six weeks in search of magmatic tritium. Extensive analysis on gases ... | <urn:uuid:684454e2-4191-4559-8995-3005e2dea3d4> | 3.4375 | 1,870 | Knowledge Article | Science & Tech. | 44.27925 |
You would be forgiven for thinking that shrinking space budgets are a total disaster. Certainly, they're not good news but the irony is that having less money may force us into missions that might previously have been overlooked, yet still have the potential to revolutionise our understanding of the universe.
In March ... | <urn:uuid:09ac3c09-76d6-4481-9001-f6df898b3f2f> | 3.375 | 834 | Nonfiction Writing | Science & Tech. | 39.422931 |
One particularly baffling aspect of planetary wanderings were the periods of retrograde motion. A planet such as Mars would spend much of the year moving slowly eastward against the background of fixed stars. Then, to everyone's surprise, it would change direction and slide westward for a couple of months or so before ... | <urn:uuid:88cedca8-89d8-49be-b7d8-a5ac1a84fc3c> | 3.875 | 320 | Knowledge Article | Science & Tech. | 45.006667 |
Web edition: June 6, 2008
Readers share their thoughts on "Down with carbon" (SN: 5/10/08, p. 18), which describes carbon dioxide sequestration:
The article repeatedly mentions liquid CO2, which has to be under high pressure to become a liquid. Has the CO2 released from burning fuel to run the necessary compressors and... | <urn:uuid:e021f92c-5163-40e3-9d2b-08f92e848cfb> | 3.203125 | 521 | Comment Section | Science & Tech. | 45.629375 |
This month’s Rakudo development work has already seen us switch to the new QRegex grammar engine for parsing Perl 6 source, unifying it with the mechanism for user-space grammars and regexes. A week and a bit on, another major improvement in this space has also landed: alternations now participate in Longest Token Matc... | <urn:uuid:e39f8a6e-912b-403f-bd9c-863403da1607> | 2.953125 | 820 | Personal Blog | Software Dev. | 48.79179 |
File this under the "Remember, it's not designed" category:
Since the best city planners around the world have not been able to end traffic jams, scientists are looking to a new group of experts: slime mold.
. . . .
The scientists let the mold organize itself and spread out around these nutrients, and found that it bui... | <urn:uuid:76140525-9d00-4343-a96d-de8070125016> | 2.96875 | 273 | Personal Blog | Science & Tech. | 35.800642 |
The figure shows a right triangle ACB,
BH is the altitude drawn to the hypotenuse, HE is perpendicular
to BC, HF is perpendicular to AC, and EM and FN are
perpendicular to AB. If BC = a, AC = b,
AB = c, and CH = h, prove that
(5) HM = HN, and (6)
twice the geometric mean of AN and BM. | <urn:uuid:092a3060-91e3-4795-93cc-58b5f0319644> | 3.375 | 92 | Tutorial | Science & Tech. | 73.837931 |
By coupling a nonlinear system, such as an atom, to the electromagnetic field, it is possible to create Fock states (eigenstates of the harmonic oscillator). (Top) Brune et al. send atoms (left) into a cavity (center). The atoms are prepared with pulse to be in a superposition of states and before they enter the cavity... | <urn:uuid:1cb9b277-00ce-4a5b-9752-a42fb1826511> | 3.703125 | 153 | Knowledge Article | Science & Tech. | 35.80601 |
"Phonons -- are some sort of vibratinal lattice quarks."
Not true, phonons are not quarks but quasiparticles, more here. Phonons are also bosons.
Wikipedia misleadingly shows that phonon is not an elementary particle or a boson but my lecturer and Wikipedia article about bosons support the bosonness.
Please, note that ... | <urn:uuid:2260c8d9-9a94-459b-bbb7-0c2c775c2c47> | 2.921875 | 746 | Q&A Forum | Science & Tech. | 30.618235 |
Oh man. I don't even know where to start. That's partly because there is not one but I dunno, five or so string theories. I'll assume you know a bit about the elementary particles.
Here's what a string theory, in a nutshell is(and I like it for that).
So we built accelerators 'n stuff, and greatly expanded our horizon ... | <urn:uuid:834dea01-4bba-4e43-bc1b-e95b9e696b7b> | 3.1875 | 539 | Personal Blog | Science & Tech. | 61.355648 |
XHTML 1.0 is a reformulation of HTML 4.0. What this really means is that learning XHTML is basically the same as learning HTML. The main difference is a few simple rules - as XHTML is more strict than standard HTML.
The reality is that HTML is not going away. While there are many advantages to having a very flexible sy... | <urn:uuid:925756a8-3952-4c2d-a903-cd51e89abd56> | 3.71875 | 489 | Tutorial | Software Dev. | 68.303894 |
In an effort to stop the warming of global scale, the Framework Convention on Climate Change was concluded in 1992 at the Earth Summit held in Brazil, and it went into effect in 1994. At present, a total of 187 countries including Japan as well as the European Community have ratified the convention. In order to achieve... | <urn:uuid:03d13a74-9d69-4001-966c-65be0057eb08> | 3.375 | 464 | Knowledge Article | Science & Tech. | 23.504793 |
Notional lox/lh2 rocket engine. 101,988 kN. Study 1964. Isp=459s. Used on Rombus launch vehicle.
Thrust (sl): 79,768.100 kN (17,932,582 lbf). Thrust (sl): 8,134,205 kgf.
Status: Study 1964.
More... - Chronology...
Thrust: 101,988.00 kN (22,927,814 lbf).
Specific impulse: 459 s.
Specific impulse sea level: 359 s.
Burn t... | <urn:uuid:c5e0c2fc-20f8-4386-9d1b-145b57411e6b> | 2.796875 | 469 | Knowledge Article | Science & Tech. | 71.770254 |
Although spotted owls may be more well-known, they are not the only animals that rely on the dwindling old-growth forests of the Pacific Northwest...
Although spotted owls may be more well-known, they are not the only animals that rely on the dwindling old-growth forests of the Pacific Northwest...
By Donald W. Thomas
... | <urn:uuid:e3646955-048c-41c1-a185-e7924c142e0e> | 3.59375 | 3,230 | Academic Writing | Science & Tech. | 46.034588 |
aliphatic compoundArticle Free Pass
aliphatic compound, any chemical compound belonging to the organic class in which the atoms are not linked together to form a ring. One of the major structural groups of organic molecules, the aliphatic compounds include the alkanes, alkenes, and alkynes, and substances derived from ... | <urn:uuid:5dddc4fd-d59a-401e-b853-ed321baf98d5> | 2.875 | 111 | Knowledge Article | Science & Tech. | 33.496429 |
The self-ionization of water (also autoionization of water, and autodissociation of water) is the chemical reaction in which two water molecules react to produce a hydronium (H3O+) and a hydroxide ion (OH−):
It is an example of autoprotolysis, and relies on the amphoteric nature of water. In Computer science, ACID ( At... | <urn:uuid:a40b335c-684b-4358-8958-550904847b57> | 3.171875 | 2,081 | Knowledge Article | Science & Tech. | 29.295071 |