Wikipedia:Main Page history/2012 April 19

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Today's featured article
General relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics. General relativity generalises special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time. In particular, the curvature of spacetime is directly related to the four-momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations. Some predictions of general relativity differ significantly from those of classical physics. Examples of such differences include gravitational time dilation, gravitational lensing, the gravitational redshift of light, and the gravitational time delay. General relativity's predictions have been confirmed in all observations and experiments to date. Although general relativity is not the only relativistic theory of gravity, it is the simplest theory that is consistent with experimental data. However, unanswered questions remain, the most fundamental being how general relativity can be reconciled with the laws of quantum physics to produce a complete and self-consistent theory of quantum gravity. (more...) Recently featured: Nigel Kneale – St Cuthbert Gospel – Lycoperdon echinatum Archive – By email – More featured articles...
Did you know...
From Wikipedia's newest content: ... that the Easter egg tree (pictured) in Saalfeld, Thuringia, was decorated with 10,000 Easter eggs in 2012? ... that Anthony Alexander Forrest played two senior games of Australian rules football for the Perth Football Club before dying at age 16 in the Second Boer War? ... that the center of Santa Barbara, California, is built in a homogeneous style because of a 1925 earthquake? ... that two guide dogs, Salty and Roselle, were awarded the Dickin Medal for gallantry after leading their blind owners out of the World Trade Center during the September 11 attacks? ... that, as of 2010, 85 percent of the readers of the Indonesian daily Bernas are male? ... that Bach created an "operatic scene" in his cantata Halt im Gedächtnis Jesum Christ, BWV 67, with Jesus serenely repeating "Peace be with you" against the raging of the enemies? ... that John Merton Aldrich donated 45,000 flies to the United States National Museum? Archive – Start a new article – Nominate an article

In the news
India successfully test launches the Agni-V intercontinental ballistic missile. Jim Yong Kim (pictured) is elected President of the World Bank. Amid a dispute with Repsol and the government of Spain, Argentina announces re-nationalisation of the oil company YPF. Taur Matan Ruak is elected President of East Timor. In Afghanistan, Taliban insurgents launch coordinated attacks on NATO's headquarters, foreign embassies, military bases and the country's parliament. In the United Kingdom, Neptune Collonges wins the Grand National horse race. Wikinews – Recent deaths – More current events...
On this day...
April 19: Feast of Saint Alphege (Western Christianity); Yom HaShoah (Israel, 2012); 100th anniversary of the birth of Glenn T. Seaborg, discoverer of ten atomic elements 1713 – With no living male heirs, Holy Roman Emperor Charles VI (pictured) issued the Pragmatic Sanction to ensure one of his daughters would inherit the Habsburg lands. 1810 – An expanded municipal government of Caracas deposed Captain General Vicente Emparán and established the First Republic of Venezuela. 1861 – American Civil War: The first bloodshed of the war took place when Confederate sympathizers in Baltimore, Maryland, attacked members of the Massachusetts militia en route to Washington, D.C. 1971 – The first space station, Salyut 1, was launched from the Baikonur Cosmodrome near Tyuratam, Kazakh SSR, USSR. 1984 – Scottish-born composer Peter Dodds McCormick's "Advance Australia Fair", a patriotic song that was first performed in 1878, officially replaced "God Save the Queen" as Australia's national anthem. More anniversaries: April 18 – April 19 – April 20 Archive – By email – List of historical anniversaries It is now April 19, 2012 (UTC) – Refresh this page

Today's featured picture

A view of Black Tusk in Garibaldi Provincial Park, British Columbia, Canada. It is the core of an extinct stratovolcano, formed about 1.2 million years ago when the loose cinder around it eroded, leaving only the hard lava core. At 2,319 m (7,608 ft) above sea level, it is particularly noticeable from the Sea-to-Sky Highway just south of Whistler, B.C.

Photo: Andysonic777

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