A black hole is a theoretical concentration of mass with a gravitational field so strong that its escape velocity exceeds the speed of light. This implies that nothing, not even light, can escape its gravity, hence the word "black." The term "black hole" is widespread, even though the theory does not refer to any hole in the usual sense. According to classical general relativity, no matter or information can flow from the interior of a black hole to an outside observer, although quantum mechanics may allow deviations from this strict rule. The existence of black holes in the universe is well- supported both theoretically and by astronomical observation; however, a minority of physicists dissent.

Read the rest of this article: http://en.wikipedia.org/wiki/Black_hole

Today's selected anniversaries:

1459 - The Battle of Blore Heath, the first major battle of the Wars of the Roses, was fought at Blore Heath, in Staffordshire, England. At least 3,000 men died. (http://en.wikipedia.org/wiki/Battle_of_Blore_Heath)

1846 - Neptune, the eighth planet from the sun, was discovered by French astronomer Urbain Jean Joseph Le Verrier, British astronomer John Couch Adams and German astronomer Johann Gottfried Galle. (http://en.wikipedia.org/wiki/Neptune_%28planet%29)

1932 - Hejaz and Nejd were unified and became the Kingdom of Saudi Arabia, with Abdul Aziz bin Abdul Rahman ibn Faisal Al Saud as the first monarch and Riyadh as the capital city (http://en.wikipedia.org/wiki/Saudi_Arabia)

Wikiquote of the day:

"At least two thirds of our miseries spring from human stupidity, human malice and those great motivators and justifiers of malice and stupidity, idealism, dogmatism and proselytizing zeal on behalf of religious or political idols." ~ Aldous Huxley (http://en.wikiquote.org/wiki/Aldous_Huxley)