Ten years after scientists observed gravitational waves for the first time, confirming Albert Einstein’s then century-old prediction, new data confirmed another renowned physicist’s seminal hypothesis.
Stephen Hawking’s “area theorem” posited that the event horizon of a black hole, from which not even light can escape, can only grow, and never shrink.
The perfect way to test that is to use gravitational waves to measure the surface of two colliding black holes and the resulting, unified black hole.
And so physicists did just that: An analysis of a black hole collision detected in January conformed to Hawking’s predictions perfectly, with the surface area of the merged black hole slightly larger than the sum of the two originals.