Wikipedia:Picture of the day/April 2006

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Indigenous languages of the Americas (or Amerindian Languages) are spoken by indigenous peoples from the southern tip of South America to Alaska and Greenland, encompassing the land masses which constitute the Americas. These indigenous languages consist of dozens of distinct language families as well as many language isolates and unclassified languages.

Map credit: Ish ishwar
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A waterfall is usually a geological formation resulting from water, often in the form of a stream flowing over an erosion-resistant rock formation that forms a sudden break in elevation. Waterfalls may also be artificial, and they are sometimes used for garden and landscape ornaments. Some waterfalls form in mountain environments where erosion is rapid and stream courses may be subject to sudden and catastrophic change.

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The Buddhabrot is a special rendering of the Mandelbrot set, which resembles, to some extent, certain depictions of the Buddha. Mathematically, the set consists of the set of points c in the complex number plane for which the iteratively defined sequence

with z₀ = 0 does not tend to infinity.

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A gamelan is a kind of musical ensemble of Indonesian origin typically featuring metallophones, xylophones, drums, and gongs. The term can be used to refer either to the set of instruments or the players of those instruments. Traditionally, "gamelan" comes from the Javanese word "gamel", meaning hammer.

Photo credit: Fir0002
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Oil-on-panel portrait of Sir Thomas More
by Hans Holbein the Younger (1527)
Thomas More was a lawyer and political figure in 16th century England, best remembered as Henry VIII's Lord Chancellor. St. Thomas More was an influential shaper of modern thought, introducing the term Utopia with his novel by the same name, and at the same time a devout Catholic, even embracing ascetical practices such as the use of a hair shirt. He became increasingly firm in his Catholic religious convictions and fell into disfavour with Henry VIII over his refusal to accept Henry as the head of the Church of England. This in turn lead to More's execution at the Tower of London in 1535. On the 400th anniversary of his execution, More was declared a Saint.

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Apollo 17 was the eleventh manned space mission in the NASA Apollo program and was the sixth and last mission to date to land on the Moon. It was the first night launch, and the final mission, of the Apollo program.

Photo credit: NASA
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Polydactyly is the anatomical abnormality of having more than the usual number of digits on the hands or feet. It is a congenital abnormality, usually genetically inherited as an autosomal dominant trait. There are several varieties of polydactyly; this X-ray photograph shows a left hand with middle ray duplication. In Western societies, the additional digits are usually surgically removed during early life.

Photo credit: Drgnu23 and Grendelkhan
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The Pleiades (also known as M45 or the Seven Sisters) is an open cluster in the constellation of Taurus. It is among the nearest to the Earth of all open clusters, probably the best known and certainly the most striking to the naked eye.

Photo credit: NASA
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The Plumed Basilisk (Basiliscus plumifrons) is a species of lizard native to Latin America. Its natural range covers a swath from Mexico to Ecuador.

Plumed basilisks are omnivorous and will eat insects, small mammals (such as rodents), smaller species of lizards, fruits and flowers. Its predators include raptors, opossums and snakes.

Plumed Basilisks are noted for a remarkable ability to, in an attempt to evade possible threats, run across bodies of water using their extremely fast-moving, large, webbed feet.

Photo credit: Marcel Burkhard (cele4)
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A TRACE image of sunspots on the surface, or photosphere, of the sun from September 2002, is taken in the far ultraviolet on a relatively quiet day for solar activity. However, the image still shows a large sunspot group visible as a bright area near the horizon. Although sunspots are relatively cool regions on the surface of the sun, the bright glowing gas flowing around the sunspots have a temperature of over one million °C (1.8 million °F). The high temperatures are thought to be related to the rapidly changing magnetic field loops that channel solar plasma.

Photo credit: NASA/TRACE
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Geisha ("person of the arts") are traditional Japanese artist-entertainers. Geisha were very common in the 18th and 19th centuries, and are still in existence today, although their numbers are dwindling. Geisha take lessons in several arts forms for most of their lives, not for just entertaining customers but for a lifetime of learning.

Photo credit: ToddLara
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Pu'u 'O'o is a classic cinder-and-spatter volcanic cone on Kilauea, Hawaii. Expanding gases in the lava fountain tears the liquid rock into irregular globs that fall back to earth, forming a heap around the vent. The still partly liquid rock splashing down and over the sides of the developing mound is called spatter.

Photo credit: G.E. Ulrich of the United States Geological Survey
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The activation energy in chemistry and biology is the threshold energy, or the energy that must be overcome in order for a chemical reaction to occur. Activation energy may otherwise be denoted as the minimum energy necessary for a specific chemical reaction to occur. The sparks generated by striking steel against flint provide the activation energy to initiate combustion in this bunsen burner. The blue flame will sustain itself after the sparks are extinguished because the continued combustion of the flame is now energetically favorable.

Photo credit: Debivort
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The Emperor Gum Moth caterpillar feeding on a eucalyptus leaf. Caterpillars of the Emperor Gum Moth pass through five stages, shedding their skin and changing their appearance at each stage of development, before spinning a dark brown silken cocoon and metamorphosing into the adult moth.

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Monarch butterflies are especially noted for their massive southward migrations from August through October. Female Monarch butterflies deposit eggs for the next generation during these migrations. The population east of the Rocky Mountains overwinters in Michoacán, Mexico, and the western population overwinters in various sites in central coastal California. The length of these journeys far exceeds the lifetime of any given butterfly. How the species manages to return to the same overwintering spots over a gap of several generations is still subject of research.

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The Harbor seal or Common seal (Phoca vitulina) is a true seal of the Northern Hemisphere. Having the widest range of all pinnipeds, Harbor seals are found in coastal waters of the northern Atlantic and Pacific Oceans as well as those of the Baltic and North Seas.

Photo credit: Marcel Burkhard (cele4)
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The Eiffel Tower in Paris is one of the world's most recognizable buildings and a symbol of France. The 300 m (986 ft) high tower was designed by Gustave Eiffel as a gateway to the Exposition Universelle of 1889. It was the world's tallest structure for forty years. Eiffel used his experience in building railway bridges when designing the tower, prefabricating the 18,038 wrought iron pieces off site then assembling the pieces with the help of 300 workers.

Photo credit: Tristan Nitot
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Crepuscular rays is a term used in atmospheric optics for rays of sunlight that appear to radiate from a single point in the sky. The name comes from their frequent occurrences during twilight, where the contrasts between light and dark are the most obvious. Crepuscular rays are parallel, but appear to diverge because of linear perspective. They are often seen through sunlight shining through holes or breaks in cloud cover.

Photo credit: Fir0002
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The Australian War Memorial is Australia's national memorial to the members of all its armed forces and supporting organizations who have died in the wars of the Commonwealth of Australia. The Memorial is located in Australia's capital, Canberra. It is the northern terminus of the city's ceremonial land axis, which stretches from Parliament House on Capital Hill along a line passing through the summit of the cone-shaped Mt Ainslie to the northeast.

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The Three Sisters is a famous rock formation in the Blue Mountains of New South Wales, Australia. They are close to the town of Katoomba and are one of the Blue Mountains' most famous sights, towering 900m (≈2953 ft) above the Jamison Valley. Their names are Wimlah, Meehni and Gunnedoo.
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Photo credit: Diliff
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At the U.S. Naval Academy in Annapolis, Maryland, newly commissioned officers celebrate their new positions by throwing their midshipmen covers into the air as part of the graduation and commissioning ceremony. The "hat toss" has been a traditional ending to the ceremony at the Academy since 1912.

Photo credit: Photographer's Mate 2nd Class Daniel J. McLain, USN
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The Superb Fairy-wren (Malurus cyaneus) is the best-known of all fairy-wrens, and in south-eastern Australia is frequently known simply as the blue wren. It is common throughout most of the relatively wet and fertile south-eastern corner of the continent, from the south-east of South Australia, through all of Victoria, coastal and sub-coastal New South Wales, and Queensland as far north as the Brisbane area, and also in Tasmania. Superb Fairy-wrens occupy wide range of habitat types, and are found in almost any area that has at least a little dense undergrowth for them to shelter in. Photo credit: LiquidGhoul
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The Lorenz attractor, introduced by Edward Lorenz in 1963, is a non-linear three-dimensional deterministic dynamical system derived from the simplified equations of convection rolls arising in the dynamical equations of the atmosphere. For a certain set of parameters the system exhibits chaotic behavior and displays what is today called a strange attractor; this was proven by W. Tucker in 2001. The strange attractor in this case is a fractal of Hausdorff dimension between 2 and 3. Grassberger (1983) has estimated the Hausdorff dimension to be 2.06 ± 0.01 and the correlation dimension to be 2.05 ± 0.01.
Photo credit: Wikimol
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The Hubble Ultra Deep Field or HUDF is an image of a small region of space composited from Hubble Space Telescope data accumulated over a period from September 3, 2003 through January 16, 2004. It is the deepest image of the universe ever taken in visible light, looking back in time more than 13 billion years. The HUDF contains an estimated 10,000 galaxies. The patch of sky in which the galaxies reside (just one-tenth the diameter of the full moon) was chosen because of the low density of bright stars. Although most of the targets visible in the Hubble image can also be seen at infrared wavelengths by ground-based telescopes, Hubble is the only instrument which can make observations of these distant targets at visible wavelengths.
Photo credit: NASA
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Zion National Park is a United States National Park located near Springdale, Utah in the southwestern United States. The principal feature in the 229 square mile (593 km²) park is the 15 mile (24 km) long and up to half a mile (1 km) deep Zion Canyon, which was cut through the reddish and tan-colored Navajo Sandstone by the North Fork of the Virgin River. The geology of the Zion and Kolob canyons area includes nine formations that together represent 150 million years of mostly Mesozoic-aged sedimentation. At various periods in that time, warm, shallow seas, streams, ponds and lakes, vast deserts and dry near-shore environments covered the area.
Photo credit: Diliff
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A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. A transformer comprises two or more coupled windings, or a single tapped winding and, in most cases, a magnetic core to concentrate the flux. An alternating current in one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings. Transformers are used to convert between high and low voltages, to change impedance, and to provide electrical isolation between circuits.
Photo credit: BillC
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Deep Impact is a NASA space probe designed to study the composition of the interior of comet Tempel 1. At 5:52 UTC on July 4, 2005, one section of the Deep Impact probe successfully impacted the comet's nucleus, excavating debris from the interior of the nucleus. Photographs of the impact showed the comet to be more dusty and less icy than expected. The impact generated a large, bright dust cloud that obscured the hoped-for view of the impact crater.

Photo credit: NASA
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Six F-16 Fighting Falcons with the U.S. Air Force Thunderbirds aerial demonstration team fly in delta formation in front of the Empire State Building during an air show. The F-16 Fighting Falcon is a modern multi-role jet fighter aircraft built in the United States. Designed as a lightweight fighter, it evolved into a successful multi-role aircraft, and is serving 24 countries.

Photo credit: Tech. Sgt. Sean Mateo White, USAF
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