Conservapedia - User contributions [en]

Mango

2011-12-05T17:49:15Z

RedStateRefugee: Mango health info

[[Image:Mangos.jpg|thumb|right|300px]]
The '''mango''' is the edible fruit of the mango tree, which is native to southern [[Asia]]. The fruit has a smooth outer rind, sweet juicy flesh that is somewhat fibrous, and a single seed in the middle of the fruit. Mango trees can grow 30 to 100 feet tall and are best grown in a warm climate, as they do not tolerate cold, and require warm, dry weather to bear fruit.

An average size mango has about 135 calories, 1 gram of fat and 4
grams of fiber. The fruit is high in [[vitamin|Vitamin A]] and [[Vitamin C]]. <ref> http://www.bellybytes.com/articles/29foods.shtml </ref>

Mangos are a great source of vitamins and antioxidants but glutinous consumption of the fruit can cause certain skin conditions.

The original wild mangos were small fruits with scant, fibrous flesh, but through many centuries of commercial propagation and cultivation there are now over 500 different varieties of mango. Domestication of the mango appears to have emerged in Southeast Asia in about 200 BC.

There are two distinct varieties of mango, the original variety which is native to [[India]]; and a second type that is grown in Southeast Asia and the [[Philippines]]. The trees have differing requirements: The Indian mango tree is intolerant of [[humidity]], and is susceptible to mildew, while the the mango tree grown in the Philippines withstands excess moisture, and resists mildew. <ref>
http://www.crfg.org/pubs/ff/mango.html </ref>

[[India]] produces 65% of the world's mango crop, and is one of the main exporters of the fruit. Other large explorters include the Philippines, [[Thailand]], Indonesia, [[Mexico]], and [[South Africa]]. Mangos were introduced to [[California]] around 1880, and are today grown in the Western United States, particularly California and [[Hawaii]], and are also grown in [[South America]]. <ref>
http://www.hort.purdue.edu/newcrop/morton/mango_ars.html </ref>

==References==

<references/>

[[Category: Fruits]]

Silk

2011-12-03T18:08:12Z

RedStateRefugee: History of silk

'''Silk''' is a soft cloth woven from the thread of the [[silkworm]]. Silk was so highly revered in China that it was called imperial cloth and bureaucrats from Bejing controlled every aspect of its production. Silk worms were often thought to contain a piece of the ancestors soul that would be transmitted into the silk.

[[Category:Textiles]]

Mars

2011-12-03T02:49:47Z

RedStateRefugee: added some facts

''For the [[Roman]] god of war, see [[Mars (god)]]''

{{Planet|image=Mars Viking.jpg
|caption=Mars photographed by [[Viking Orbiter]]s
|symbol=Mars symbol.svg
|discname=Known to ancients
|origname=Roman god of war
|order=4
|primary=Sun
|periapsis=206,620,000 km<ref name=marsfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html Mars Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 29, 2007. Accessed May 27, 2008.</ref>
|apoapsis=249,230,000 km<ref name=marsfact/>
|semimajor=227,920,000 km<ref name=marsfact/>
|bode=1.6 AU
|circumference=1,429,033,627 km
|eccentricity=0.0935<ref name=marsfact/>
|sidereal=686.980 da<ref name=marsfact/>
|synodic=779.94 da<ref name=marsfact/>
|orbitspeed=24.077 km/s
|inclination=1.850°<ref name=marsfact/>
|reference=the ecliptic
|siderealday=24.6229 h<ref name=marsfact/>
|solarday=24.6597 h<ref name=marsfact/>
|rotatespeed=465.11 m/s
|axialtilt=25.19°<ref name=marsfact/>
|mass=6.4185 * 1023 kg<ref name=marsfact/>
|density=3,933 kg/m³<ref name=marsfact/>
|surfacegrav=3.71 m/s²<ref name=marsfact/>
|escapespeed=5.03 km/s<ref name=marsfact/>
|meanradius=3389.5 km<ref name=marsfact/>
|equatorradius =3396.2 km<ref name=marsfact/>
|polarradius=3376.2 km<ref name=marsfact/>
|surfacearea=144,800,000 km²
|mintemp=140 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/mars.html Entry for Mars]." ''The <s>Nine</s> 8 Planets'', September 26, 2006. Accessed May 27, 2008.</ref>
|meantemp=218 K<ref name=Arnett/>
|maxtemp=300 K<ref name=Arnett/>
|moons=2
|composition=Rock
|color=Red
|albedo=0.15<ref name=marsfact/>
|pmdm=2.1 * 1018 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.51 * 1023 N-m/T<ref name=Humphreys/>
|mdt=535 a<ref name=Humphreys/>
|mhl=370.83 a<ref name=calc>Calculated</ref>
}}
'''Mars''' is the fourth planet from the [[Sun]], after [[Mercury]], [[Venus]], and [[Earth]]. It is called "The Red Planet" on account of the iron oxide that covers much of its suface.

== Ancient knowledge and naming ==
Mars has the [[Rome|Roman]] name of the classical god of war. This name in turn derives from the [[Greece|Greek]] name ''Ares'' for this god. (The traditional symbol of Mars is his shield and spear.) The ancient [[Egypt]]ians simply called Mars ''Her Descher'', or "the red one."<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/mars.htm Entry for Mars]." ''Views on the Solar System'', 2008. Accessed May 27, 2008.</ref> The [[Hindu]]s call Mars Mangala, one of the Navagraha.<ref name=ucar>"[http://www.windows.ucar.edu/tour/link=/mythology/mangala.html&edu=high Mangala]." ''Windows to the Universe'', University Corporation for Atmospheric Research, University of Michigan, September, 2000. Accessed May 27, 2008.</ref> The [[Maya]] people also tracked Mars regularly. Pacific islanders regarded Mars as a representation of the god of death.

== Orbital characteristics ==
Mars is in a highly elliptical orbit around the Sun and maintains an average distance slightly more than 1.5 AU. The synodic period of Mars is roughly 26 months. This fact makes Mars a particularly difficult object to explore, because opportunities to launch a rocket probe to Mars occur so far apart in time.

== Rotational characteristics ==
Mars' sidereal and solar days are only slightly longer than the days of earth. This fact has led long-term Mars mission planners to adopt a permanent system for keeping time "local" to Mars. The first mission to use this "Mars solar clock" was [[Viking 1]] in 1976.<ref name=Allison>Allison, Michael, and Schmunk, Robert. "[http://www.giss.nasa.gov/tools/mars24/help/notes.html Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock]." Goddard Institute for Space Studies, [[National Aeronautics and Space Administration|NASA]], May 20, 2008. Accessed May 27, 2008.</ref>

== Physical characteristics ==
Mars is half the size of Earth and has about 11% of earth's mass. The large proportion of [[iron]] in Mars' clay-like topsoil gives Mars its distinctive color.

The weather on Mars is seasonal, on account of Mars's axial inclination. Yet because Mars's orbit is so eccentric, "summer" and "winter" on the northern and southern hemispheres can vary greatly. Temperatures vary from 140 K to 300 K, with an average temperature of 210 K. (The freezing point of [[water]] is 273.15 K.)

=== Atmosphere ===
Mars' atmosphere is quite thin and has an average pressure of 6.36 mb or 0.636% of that of earth. Its chief components are 95.32% [[carbon dioxide]], 2.7% [[nitrogen]], 1.6% [[argon]], 0.13% [[oxygen]], and 0.08% [[carbon monoxide]]. In addition it has trace amounts of [[water]] (210 ppm), [[nitrogen oxide]] (100 ppm), [[neon]] (2.5 ppm), hydrogen-deuterium oxide (HDO) (0.85 ppm), [[krypton]] (0.3 ppm), and [[xenon]] (0.08 ppm). Winds on Mars vary in speed from 2-7 m/s in summer to 5-10 m/s in fall, though the [[Project Viking]] landers have recorded winds varying from 17-30 m/s during dust storms that have swept past the landing sites.<ref name=marsfact/>

Recent warming trends on Mars, including an apparent partial melt of the polar ice caps, have led at least one scientist to question the widely circulating theories of [[global warming]] on earth. Specifically, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, asserts that the sun, and not any activity specific to the earth, must be responsible for any warming observed on either planet.<ref name=ngs>Ravilious, Kate. "[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says]." ''National Geographic News'', National Geographic Society, February 28, 2007. Accessed May 27, 2008.</ref>

=== Magnetosphere ===
Mars has a very weak magnetic field. Data from various missions has established an upper limit of 2.1 * 1018 N-m/T on the [[magnetic dipole moment]] of Mars. According to [[Russell Humphreys]]'s model of the creation of magnetic fields, Mars probably had a magnetic dipole moment ''at creation'' of 1.51 * 1023 N-m/T. Thus Mars's magnetic field has been decaying very rapidly. This tremendous decay, and the presence on [[Mercury]] of a magnetic field of significant strength, baffles [[astronomy|astronomers]] who have assumed that magnetic fields form on rapidly moving planets that have conductive and liquid cores that can act as dynamos. In fact, Humphreys asserts that the characteristic that determines which of the [[Terrestrial Planet|terrestrial planets]] will have a persistent magnetic field is the core radius, and that the cores of all four of these planets have similar conductivities. Mercury and Earth have larger cores than do Mars and Venus. The lengths of the sidereal days on those worlds do not matter.<ref name=Humphreys/>

=== Geology ===
[[Image:MarsTopoMap-PIA02031 modest.jpg|left|thumb|300px|Topographic map of Mars.]]
There is a dichotomy on the surface of Mars; the northern hemisphere consists of low-lying volcanic plains, with the southern hemisphere consists of ancient, heavily-cratered highland plains. Mars also has two volcanic regions: Tharsis and Elysium. Within the Tharsis region is the largest volcano in the solar system, [[Olympus Mons]]. Olympus Mons is approximately 500 km across and is about the same size as the state of Arizona. Its peak is 24 km above the surrounding plains and it is surrounded by a vertical scarp 6 km high. A large canyon system, Valles Marineris, is located along the Martian equator east of the Tharsis region. Valles Marineris is 2-6km deep and 200-600km wide and approximately 4,500 km long (approximately the distance from San Francisco to Boston). The eastern part of Valles Marineris appears to have a tectonic origin, but the western part is characterized by features such as teardrop islands and longitudinal grooves, indicating it may have been formed by catastrophic flooding in the past. Such flooding may be possible under current climate conditions. Run-off channels in the cratered highland indicate a thicker atmosphere or warmer climate in the past that would have allowed water to be stable on the surface.

Recent satellite imagery has shown that Mars has a 3 kilometre deep ice cap around its polar regions. The northern polar region is surrounded by [[dune]] fields. During the Martian winter, a layer of carbon dioxide condenses at the poles and sublimates in the summer, leaving the water-ice and dust polar caps exposed. The ratio of dust to water-ice contained in the polar caps remains unknown.
[[Image:F035a72_processed.jpg|thumb|100px|left|Cydonia Mensae, home of the alleged "face on Mars."]]
Persistent rumors tell of a "face on Mars," allegedly located in the Cydonia Mensae region at coordinates 40.9°N and 9.45°W. This alleged "face" is located in the midst of several pyramids and other mountains. Prevailing opinion at NASA is that the "face" is a trick of the eye due to the unusual lighting conditions.<ref name=faq>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/planetaryfaq.html#Mars Frequently Asked Questions - Planetary - Mars]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], January 2, 2008. Accessed May 27, 2008.</ref>

It's believed the Mar's unique geological history resulted in the creation of many gems, including rubies, in seams just under the surface.

=== Water on Mars ===
[[Image:Weeping_100.jpg|thumb|120px|right|Multiple gullies in a south-facing wall in the Gorgonum Chaos region on Mars]]
Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]].<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref>

== Life on Mars ==
The possibility that [[extraterrestrial life]] exists, or has existed, on Mars has been the subject of persistent scientific speculation for decades. The earliest speculation concerned a possible civilization on Mars,<ref name=Hamilton/> this after Percival Lowell theorized that the straight lines that several astronomers had seen on Mars were in fact artificial constructs, and specifically canals.<ref name=canals>"[http://ssed.gsfc.nasa.gov/tharsis/canals.html The canals of Mars--historical note]." Goddard Space Flight Center, [[National Aeronautics and Space Administration|NASA]], n.d. Accessed May 27, 2008.</ref> Lovell popularized his theory as early as 1906, and for a long time the suspicion of a non-human civilization native to Mars would find repeated expression in novels and dramatic presentations. Only with the first successful explorations of Mars would the scientific community, and the public, abandon that theory.

Current speculation concerns the possible finding of [[microbe]]s. These would be [[extremophile]]s, or microbes that survive and even grow in environments lethal to other forms of life. Direct attempts to find such life began in 1976 with the [[Viking 1]] and [[Viking 2]] landers. To date no positive sign of life on Mars has been found. The Viking landers found evidence of unexplained chemical activity, but no clear evidence of microbes. Whether the Viking landers would have been able to detect extremophiles, a concept unknown to the Viking mission planners, is unclear.<ref name=Hamilton/>

The [[astrobiology|astrobiologists]] involved with [[Project Viking]] suspect that Mars might be an inherently inhospitable environment for life. Ultraviolet light from the sun shines unchecked on Mars, on account of Mars' thin atmosphere and weak magnetic field. The soil of Mars is also very dry, and the soil has a high proportion of oxidizing agents.<ref name=Hamilton/>

== Problem for uniformitarian theories ==
The most formidable current problem that Mars poses for uniformitarians today is that its magnetic field is weak and inconsequential, while a planet (Mercury) of little more than half its weight does have a significant magnetic field. According to current theory, planets derive their magnetic fields by dynamo action. This requires fast rotation and liquid cores. Mars and Earth have comparable sidereal days, but Earth's magnetic field is strong enough to protect Earth from the [[solar wind]], while that of Mars is not. Mercury has a far longer sidereal day than Mars has, and yet Mercury has a significant magnetic field while Mars has none.

== Young Mars Creation model. ==
[[Image:Meridiani Planum.jpg|thumb|150px|right|Meridiani Planum region of Mars.]]

Discoveries by the [[Mars Excursion Rover]] ''Opportunity'' have led to a Young Mars Creation model of Martian geology. These discoveries combine with data from the rest of Mars to indicate a massive Martian catastrophe.

Since ''Opportunity'' landed in the Meridiani Planum region of Mars it has sent back findings showing that the area was once underwater and that the water was very acidic. This high concentration of [[sulfuric acid]] militates against this being a habitable sea. The entire Meridiani Planum region has much evidence of catastrophic flooding, including a clear inlet channel to the southeast and a splash zone in the north.

Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology.

[[Image:Mars topography.jpg|thumb|150px|right|Mars' global topography, and the relationship between the Hellas impact basin and the Tharsis volcanoes.]]Mars’ largest impact basin is called Hellas. As shown in the topography map, on exactly the other side of Mars from Hellas is Mount Alba Patera, the largest volcano by surface area. This antipodal juxtaposition suggests that the Hellas impact caused the eruptions of Alba Patera and the volcanoes of the Tharsis plateau to the south and southwest. To the east is found the gigantic rift valley called Valles Marineris.

These relationships indicate a major geologic catastrophe on Mars resulting in massive volcanic activity. The dating of this event from craters places it at about the time of the [[Great Flood]] on [[Earth]]. This volcanic activity would have increased Mars’s atmospheric pressure to allow liquid water to flow on the surface and thus allow the flooding of the Meridiani Planum region.

This shows that, like Earth, Mars has evidence that it is only a few thousands of years old and not 4.6 billion years old.<ref name=creager>Creager, Charles, Jr. "[http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]." ''Answers Research Journal'' 1 (2008): 89–93. Accessed September 23, 2008.</ref>

== Mars in popular culture ==
Mars has figured prominently in [[science fiction]] in the Western world for more than a century.

=== The War of the Worlds ===
The first novel speculating on a civilization on Mars was ''The War of the Worlds'' by [[H. G. Wells]], in 1897. Wells' Martians had a military strength that human civilization could not match, but ultimately perished after contracting various [[infectious disease]]s caused by microbes native to Earth to which the Martians effectively had no defense.

In 1938, actor/director [[Orson Welles]] and his Mercury Theater produced a [[radio]] drama based on this novel. Welles updated the novel to his own period but otherwise remained faithful to the source material. The broadcast created such a panic in the [[United States]] that Welles was compelled to order a broadcast disclaimer in mid-show and, at the end of the show, personally assure his listeners that no such thing as an extraterrestrial invasion had taken place.<ref name=Hamilton/>

H. G. Wells' novel would inspire two [[motion picture]] projects and one [[television]] series.

=== Other speculations on civilizations ===
Author [[Edgar Rice Burroughs]] published several novels speculating on an elaborate civilization on Mars to which humans traveled, but which was not bent on invading the earth. Author [[C. S. Lewis]], in his novel ''Out of the Silent Planet'', envisioned Mars as the home of three races of non-fallen beings that were instructed to regard the earth as off-limits on account of man's [[fall of man|fallen nature]].

With the abandonment of the Lowell canal theory, science fiction authors and dramatists envisioned Mars as home to a human colony, such as the situation in the television series ''[[Terrahawks]]''. But at least one motion-picture producer saw Mars as a place that very ancient [[astronaut]]s had once visited. These astronauts, according to this scenario, left behind some advanced equipment that a human rebel was subsequently able to use to give Mars a breathable atmosphere and thus facilitate the Martian colony's liberation from the civilization of earth, which in the story had become venal and tyrannical.

=== Speculation on microbes ===
Authors [[John B. Olson]] and [[Randall S. Ingermanson]] have recently speculated (''[[Oxygen (novel)|Oxygen]]'' and ''[[The Fifth Man]]'') about the finding of microbes on Mars, and the implications that such a discovery would hold for the [[Christianity|Christian]] faith and the possible "back-contamination" of the earth when the crew that found the microbes returned to earth.

== Observation and exploration ==
Observation of Mars has been ongoing since the ancients noted its existence and its movements. The invention of the telescope provoked the first serious study of Mars as a celestial object, and not a prophetic sign. Yet not all of this observation led to proper inferences. Percival Lowell's canal theory would lead to more than half a century of vain speculation on extraterrestrial civilization before the first successful exploratory missions would return evidence forcing the abandonment of that theory.

Mars has been the subject of more attempts to explore it, and more failures, than any other planet. Of approximately 37 separate missions to Mars, only 13 have had any success. The planetary scientists of the [[Union of Soviet Socialist Republics]], so successful in exploring [[Venus]], experienced ten mission failures before achieving their first success, seven years after the [[United States]] achieved success with its [[Mariner 4]] mission. That Soviet mission, [[Mars 3]] in 1971, succeeded in placing a lander on Mars, but the lander's system transmitted for only 20 seconds before failing.

In 1975, [[Project Viking]] achieved the most notable success by placing two orbiters and two landers on Mars. Neither nation would attempt any further missions to Mars until 1988, when the Soviets lost one craft en route and lost contact with the other ([[Phobos 2]] seconds after its rendezvous with Mars's inner [[moon]] [[Phobos]]. Nor was the United States' program immune to failure; its ''Mars Observer'' vessel was lost prior to arrival after some propulsion systems failed.<ref name=faq/>

In 1996 the [[Mars Global Surveyor]] enjoyed the most success to date, returning more images than all previous missions combined. In that same year, the United States landed the first mobile explorer, or "rover," called the [[Mars Pathfinder]].

The United States would, unfortunately, lose the next two successive craft that it sent to Mars. But its [[Mars Odyssey]] would arrive intact in 2001 and send back the first high-resolution images. Two years later the [[European Space Agency]] would successfully place its [[Mars Express]] orbiter in the Martian system; sadly, its associated landing craft would crash-land. The Mars Express orbiter continues in orbit around Mars.<ref name=esa>"[http://www.esa.int/SPECIALS/Mars_Express/ Mars Express home page]." European Space Agency. Accessed May 27, 2008.</ref>

[[Image:Mcmurdopan_spirit_big.jpg|thumb|left|150px||360 degree panorama from mars rover ''Spirit''.]]
The most successful missions to date have been the Mars Excursion Rover missions. Two of these sophisticated mobile robots, named ''Spirit'' and ''Opportunity'', launched in 2003 and arrived safely on Mars about six months later, on opposite sides of the planet. They have been running for four years now, at least fifteen times longer than they were warranted to run. The Opportunity rover has been taking pictures of the Victoria Crater, and Spirit has been photographing the Esperanza formation which contains "vesicular" basalt (characterized by multiple cavities representing dissolved gas escaping from solution during a volcanic eruption).<ref name=David>David, Leonard. "[http://www.space.com/missionlaunches/061228_rovers_update.html Mars Rovers: On the Roll to New Targets]." ''Space.com'' December 28, 2006. Accessed May 27, 2008.</ref>

On May 26, 2008, NASA placed a polar lander on Mars for the first time: the [[Phoenix lander]]. As of June 28, 2008, the Phoenix lander is functioning well and has already discovered water ice where it landed. Contrary to prior understandings, the Phoenix lander has found an alkaline soil that might be suitable for growing Earth vegetables.

At least one non-governmental group, calling itself the Mars Society, has been actively studying technologies appropriate to send a crew of from four to six astronauts to Mars for a roughly two-year stay.<ref name=marssoc>[http://www.marssociety.org/portal The Mars Society] global and USA portal. Accessed May 27, 2008.</ref>

==Satellites==
Mars has two moons: [[Phobos]] and [[Deimos]] (which respectively mean "Fear and "Panic" in [[Greek]]). Russian scientists in the 1950s posited that Phobos might be hollow, but these claims were discredited in the late 1960s.

== References ==
{{reflist|2}}

== Related Links ==
* [http://mars.jpl.nasa.gov/missions/log/ NASA Historical Log: Missions to Mars]
* [http://www.space.com/mars/ Space.com] All About Mars
* [http://www.google.com/mars/ Google Mars], an interactive topographical map
* [http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/mars.html Mars: the Red Planet] by Starchild, an educational service of NASA.
* [http://www.war-of-the-worlds.org/ War of the Worlds] commemorative site.
* [http://www.solarviews.com/eng/terms.htm Glossary]
* [http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]
* [http://www.youtube.com/watch?v=BnOhFXamYOc Catastrophic Model of Martian Geology I] Video
* [http://www.youtube.com/watch?v=6HwZ22eYhAg Catastrophic Model of Martian Geology II]Video
*[http://genesismission.4t.com/Video/Mars1.html Catastrophic Model of Martian Geology] With Video

{{solarsystem}}
[[Category:Mars]]

Transistor

2011-12-01T05:04:34Z

RedStateRefugee: importance of Transistors

The '''transistor''' is a device used to switch electrical signals on and off, or to amplify them (make them larger). It was invented at Bell Labs in Murray Hill, [[New Jersey]], by scientists William Shockley, Walter Brattain, and John Bardeen from the University of Minnesota. All modern technology is based on transistors they have been called, "the wheat to technologies bread".

==Function==

Modern transistors are so small that designers make heavy use of [[quantum theory]]. However, this isn't important for everyday use of the devices and a simple explanation of transistors is given below. There are two basic types of transistor: field-effect transistors (FETs) and bipolar junction transistors (BJTs).

=== Field-effect transistors ===

A field effect transistor contains a thin strip of [[semiconductor]] called the "channel". A pair of metal contacts are put at either end of the channel, allowing it to be connected into a [[circuit]]. These contacts are called the "source" and the "drain". The rest of the channel is coated with an [[insulator]] to stop any unwanted currents from entering or leaving.

Finally, a third metal contact called the "gate" is placed on top of the insulator. When a battery is connected between the gate and source, the insulator stops current getting through. Instead, the electrons in the channel are all pushed away from the gate. In other words, they can only move through a very thin part of the channel, making it difficult for current to flow between the source and drain. The [[resistance]] of the channel therefore depends on the [[voltage]] at the gate. If a big enough voltage is placed on the gate, the electrons can be pushed completely out of the channel and no current can flow at all.

The first transistors were made of [[germanium]], but more modern devices are made of [[silicon]]. Some modern devices use [[silicon-germanium]] alloys or [[gallium arsenide]].

==History==

Brattain and Bardeen usually worked without much supervision, as Shockley worked mostly from home. Their mission was to create the first amplifier using semiconductors.

Bardeen and Brattain were a perfect partnership, as Bardeen was a brilliant theoretician and Brattain a genius at experiments.

In December 1947, Bardeen had the insight that electrons formed a barrier on the surface, and Brattain worked that insight into a point-contact transistor. It used strips of gold foil on a plastic triangle, held in contact by a slab of germanium.

Shockley improved it to become the junction (sandwich) transistor. He mostly built it in a hotel room in Chicago. Once perfected, this was more durable than the point-contact transistor, and far easier to make. Upon this the semiconductor industry was built.

Bell Labs announced the invention to the public on June 30, 1948. Bell Labs engineer John Pierce gave it the name "transistor", a combination of "trans-resistance" with the names like thermistors.

Bardeen, Brattain, and Shockley made very little money from their invention. Others, like Gordon Moore and Robert Noyce in founding Intel, made a fortune. This was true even though Shockley himself saw the potential and started the company upon which Silicon Valley was based.

Japanese engineers like Masaru Ibuka and Akio Morita, who founded Sony Link title, were successful in improving the manufacturing of transistors.

==Significance==
Transistors created a revolution in [[electronics]].

Prior to the transistor, electronics relied on vacuum tubes. Vacuum tubes made possible very sophisticated electronics, including broadcast radio and television as we know them, radar, and the first electronic computers.

But vacuum tubes are large, expensive, power-hungry, and unreliable. Vacuum tubes use filaments like light bulbs. A typical tube consumes as much power as a ten or twenty-watt bulb. When turned on, tubes need many minutes to "warm up" and stabilize. During this time, radios do not hold their tuning and "drift" away from stations.

Like light bulbs, vacuum tubes have a short life. Eventually the filament burns out and the tube needs to be replaced.

In a home radio with six tubes, tube failure was only a nuisance. In an electronic computer—like the 17,468-tube ENIAC—it was disastrous, because with that many tubes some would always be failing.

The telephone company was concerned with tubes as well. Telephone signals cannot travel thousands of miles under the sea without amplification. Built into the cable every few miles were ''repeaters,'' electronic amplifiers to keep boosting and restoring signal strength. It is not easy to replace a tube when it fails in a cable on the sea floor.

And the military, which was starting to use electronics, was concerned because tubes are made of glass and are fragile, unable to withstand G-forces and vibration.

The transistor ushered in the "solid-state revolution," and another revolution called "miniaturization." Compared to tubes, transistors were at least a hundred times smaller, used a hundred times less power, and were extremely stable and reliable. At first, the transistor changed things in small ways. The book-sized portable radios that used small tubes were displaced by pocket-sized "transistor radios." Over time, transistors completely reshaped the way in which electronics could be used and the things that could be done with it.

A computer made out of transistors did not require continuous component replacement, and because of the stability of transistors it could be turned on and just start working properly within seconds. Transistorized circuits could withstand military conditions, in missiles for example, making electronic guidance systems much more feasible.

Originally "miniaturization" simply meant replacing light-bulb-sized tubes with jelly-bean-sized transistors. But a second breakthrough occurred in the 1960s, when engineers realized that the same technology used to create a single transistor on a semiconductor wafer could be used to create many interconnected transistors. Over time, engineers learned to put dozens, hundreds, thousand, and eventually millions of transistors onto a single chip, launching the "digital revolution."

[[Category:Technology]]

Hydrogen

2011-12-01T05:00:40Z

RedStateRefugee: /* Fuel for vehicles */

{{Element | name=Hydrogen | symbol=H | anumber=1 | amass=1.001 amu | noe=1 | class=Gas| cstructure=Unknown | color=None | }}
'''Hydrogen''' is the most abundant of all the [[element]]s,<ref>Hydrogen makes up roughly 75% of the matter in the [[universe]].</ref> and has the [[chemical symbol]] H and an [[atomic number]] of 1. Despite this abundance, naturally occurring elemental hydrogen is extremely rare on [[Earth]].

==Chemical Properties==

At normal pressures hydrogen melts at 14.01[[Kelvin]] (K) and boils at 20.28K, essentially meaning that it only exists on Earth as a gas. The near-vacuum of interstellar space means that hydrogen is also a gas under these circumstances. Astronomers and chemists hypothesise that hydrogen exists as a plasma inside stars and possibly in a metallic form in the cores of gas giant [[planets]] such as [[Jupiter]]. The most common form of hydrogen is molecular hydrogen, consisting of two atoms bonded by a single hydrogen bond. The chemical symbol for molecular hydrogen is H2.

Due to having the lowest possible atomic number hydrogen is the lightest element. As a result of this it was used in many early airships and balloons, but due to the dangers involved it has been replaced by [[helium]] in these applications.

==Isotopes==
The most common form of hydrogen is protium, although this name is rarely used and it is generally known simply as hydrogen. Protium [[atom]]s consist of a single [[proton]] orbited by a single [[electron]]. Two other hydrogen [[isotopes]] are known to exist: [[deuterium]], which has one neutron and an atomic weight of 2, and [[tritium]] with two neutrons and an atomic weight of 3. [[Tritium]] is [[radioactive]], with a [[half-life]] of 12.32 years. Naturally occurring tritium is extremely rare on Earth but has a number of valuable applications, such as light-emitting inserts for optical instruments, emergency equipment, and lubricants that do not break down break down because of high heat. As a result it is extremely expensive and very desirable especially to military purchasers.

==Compounds==
Hydrogen can be found in the vast majority of [[organic]] compounds, as well as many [[inorganic]] compounds.<ref>For example, [[hydrocarbon]]s and metal hydrides, respectively</ref> It is an important component of [[water]] and most [[acid]]s.

==Occurrence in Nature==

Hydrogen makes up 75% of all matter in the universe by mass. Well over 90% of all atoms in the universe are hydrogen. It is the main element found in [[stars]] and gas-giant (Jovian) planets. Huge clouds of molecular hydrogen are found in interstellar space; most astronomers believe that these clouds are associated with star formation, with the hydrogen providing the raw material and fuel for stars to form. However the timescale required for this to occur is claimed to be around 100,000 years for a star the size of the [[Sun]], which means that the process cannot be observed. For this and other reasons, this hypothesis is generally rejected by Creation scientists.

==Fuel for vehicles==
Hydrogen is one of two fuels needed for [[fuel cell]]s (the other being oxygen), which have the potential to be a major form of alternative energy in the future. Fuel cells are very clean energy sources; their only by-products are [[water]] and heat. Since no [[pollutant]]s or [[greenhouse gas]]es are produced, the use of fuel cells could provide cleaner air in larger cities

Unfortunately, hydrogen is not a viable fuel source at present. Today's average car, for example, would require an unfeasibly large fuel tank to carry enough hydrogen for practical purposes. Hydrogen is also extremely [[flammable]] and suitable safeguards are needed to reduce the chances of a fatal explosion in an accident. There is also the issue of obtaining the pure hydrogen needed. Hydrogen can be obtained from distilled water through electrolysis, but this requires the same amount of energy the Hydrogen's use in a fuel cell would yield. Fuel cells would not solve the eventual energy crisis; it would simply move the problem to the power plants providing the energy to obtain the hydrogen through electrolysis.

If hydrogen could be used in cars, it would be important in establishing the [[hydrogen economy]].

As free hydrogen does not exist on Earth, hydrogen is not actually a source of energy but rather a carrier of it: its value as a fuel is that it provides a clean and efficient way to use energy produced by some other source. Due to the Second Law of thermodynamics the energy used to produce free hydrogen must be at least equal to the energy contained within it, meaning that at present it is not a viable fuel for most applications. Potential solutions include the use of bacteria that produce hydrogen through photosynthesis, which would effectively allow solar energy to be stored in hydrogen and used as fuel.<ref>http://www.making-hydrogen.com/hydrogen-from-bacteria.html</ref>

Hydrogen is often falsely held up by enviromentalists and radical global warming advocates as some kind of cure all.

==Notes and references==
<references/>

Hydrogen

2011-12-01T04:58:45Z

RedStateRefugee: /* Isotopes */ I knew that college class would come in handy somewhere

Hijab

2011-12-01T04:51:36Z

RedStateRefugee: hijabs in the muslim world

[[Image:hajib.jpg|right|150px|thumb]]
A '''hijab''' (حجاب) is a headscarf worn by many [[Muslim]] women. The term hijab comes from the Arabic word "''hijaba''," which means to hide from view.

It not only serves to distinguishing them from non-Muslims and to conceal them from public view of males, but it is also a reminder to these women of their Islamic faith. In many of the more traditional Muslim societies, women tend to remain outside the public sphere of men, devoting themselves to child rearing and taking care of the home. Islamic dress is one of many rights granted to Islamic women. Modest clothing is worn in obedience to God and has nothing to do with submissiveness to men.

The practice of hijab among Muslim women is one based on religious doctrine, although the [[Quran]] does not mandate it. Instead, it comes from the Hadith, which reveals the teachings of the Prophet to believers. In one tradition from Hadith, the [[Prophet Muhammad]] is quoted as saying: "...If the woman reaches the age of puberty, no part of her body should be seen but this -- and he pointed to his face and hands."

Conservative Muslims wear burkas not hijabs and often look down on non-radical Muslims that only wear hijabs. In Saudi Arabia woman who wear clothing that does not cover enough have been violently attacked.

From these and other references, the vast majority of Muslim scholars and jurists, past and present, have determined that Muslim women's clothing must cover the entire body, with the exception of the face and the hands, and that the attire should not be form fitting, sheer or so eye-catching as to attract undue attention or reveal the shape of the body. There are similar, yet less obvious requirements for a Muslim male's attire. A Muslim man must always be covered from the navel to the knees, and he should similarly not wear tight, sheer, revealing, or eye-catching clothing. In addition, a Muslim man is prohibited from wearing silk clothing or gold jewelry. A Muslim woman may wear silk or gold.

In 2004, [[France]] banned the wearing of the hijab by girls in state schools. In some Muslim countries, such as [[Iran]], it is the state law that all women, even foreigners, must wear the hijab. Some view the hijab as a symbol of Islamic repression against women.

[[Category:Islam]]
[[Category:Women]]
[[Category:head covering]]