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Redshift occurs when the visible light from an object is shifted towards the red end of the spectrum. This increase in wavelength corresponds to a decrease in the frequency of the electromagnetic radiation. A redshift can occur when a light source moves away from an observer, corresponding to the Doppler shift that changes the frequency of sound waves. Although observing such redshifts has several terrestrial applications (e.g. Doppler radar and radar guns), spectroscopic astrophysics uses Doppler redshifts to determine the movement of distant astronomical objects. This Doppler redshift phenomenon was first predicted and observed in the nineteenth century as scientists began to consider the dynamical implications of the wave-nature of light. Another redshift mechanism accounts for the famous observation that the spectral redshifts of distant galaxies, quasars, and intergalactic gas clouds are observed to increase proportionally with their distance to the observer. This relation is accounted for by models that predict the universe is expanding, seen in, for example, the Big Bang model. Yet a third type of redshift, the gravitational redshift also known as the Einstein effect, results from the time dilation that occurs in general relativity near massive objects. (more...)

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From Wikipedia's newest articles:

...that the Armenian oil magnate Alexander Mantashev (pictured) handpicked 50 talented young Armenians and sent them to study at the best universities of continental Europe and Russia?
...that the Parliament of Malaysia made a retroactive amendment to the Constitution to prevent the case of Loh Kooi Choon v. Government of Malaysia from being subject to Article 5(4) of the Constitution?
...that the popular Soviet TV show Goluboy Ogonyok had as guests various prominent Soviet people, including Super workers, Heroes of Socialist Labor and cosmonauts?
...that the 1929 Chicago Cubs outfield comprised of Riggs Stephenson, Hack Wilson and Kiki Cuyler was the only complete outfield in Major League Baseball history to each drive in over 100 runs in the same season?

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In the news

Fighters of the Islamic Courts Union leave Mogadishu as Ethiopian military units and forces of the Transitional Federal Government surround the Somali capital.
Former U.S. President Gerald Ford (pictured) dies at age 93.
A series of earthquakes off the southern coast of Taiwan damages several undersea cables, disrupting telecommunication services in various parts of Asia.
The United Nations Security Council unanimously adopts Resolution 1737, imposing sanctions on Iran for its nuclear enrichment program.
Heavy rains lead to a series of floods in southern Peninsular Malaysia, forcing the evacuation of more than 60,000 people.
U.S. military prosecutors charge eight Marines, including four for murder, in connection with last year's Haditha killings.
In Indonesia, the conviction of Abu Bakar Bashir for his alleged role in the 2002 Bali bombing is overturned.

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On this day...

December 29:

1845 - The Republic of Texas was annexed by the United States, becoming the state of Texas.
1860 - The British Royal Navy launched the world's first iron-hulled armoured battleship, the HMS Warrior.
1890 - The United States Army killed over 400 members of the Great Sioux Nation at the Wounded Knee Massacre.
1937 - A new state called the Republic of Ireland replaced the Irish Free State when a new constitution was adopted.
1993 - The Tian Tan Buddha (pictured), the world's tallest outdoor bronze statue of the seated Buddha, was completed.

Recent days: December 28 – December 27 – December 26

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Today's featured picture

A branch from a pine tree, with both male and female pine cones. The male cones produce pollen and are orange, growing in a cluster. The female seed-producing cone, located at the end of the branch, is still immature.

Photo credit: Menchi
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