Stephen Hawking's black hole theorem proved right after 50 years In 1971, Hawking proposed the area theorem, which set off a series of fundamental insights about black hole mechanics. The theorem predicts that the total area of a black hole's event horizon -- and all black holes in the universe, for that matter -- should never decrease. New York: Fifty years after physicist Stephen Hawking derived the black hole theorem, physicists at Massachusetts Institute of Technology have confirmed it for the first time, using observations of gravitational waves. In 1971, Hawking proposed the area theorem, which set off a series of fundamental insights about black hole mechanics. The theorem predicts that the total area of a black hole's event horizon -- and all black holes in the universe, for that matter -- should never decrease. The statement was a curious parallel of the second law of thermodynamics, which states that the entropy, or degree of disorder within an object, should also never decrease.