A 1971 prediction by Stephen Hawking just came true with a cosmic collision 1.3 billion light-years away: Now scientists are trying to understand how

Key Points:

• Scientists have confirmed Stephen Hawking's 1971 black hole area law prediction through the observation of a collision between two black holes 1.3 billion light-years away, named GW250114, detected by LIGO in January 2025.
• The merger resulted in a black hole with an event horizon area larger than the sum of the original black holes' areas, supporting Hawking's theory that the total area cannot decrease in classical processes, with a confidence level of 99.999%.
• This observation marks the most precise test of Hawking's prediction to date, surpassing previous accuracy limited by noisier signals, and was made possible by significant improvements in gravitational wave detector sensitivity.
• The study, published in Physical Review Letters, involved collaboration among LIGO, Virgo, and KAGRA scientists, and highlights the connection between black hole area, entropy, and fundamental laws of physics.
• Since the first gravitational wave detection, upgrades have increased detection rates to about one black hole merger every three days, enabling more detailed tests of fundamental physics theories like those proposed by Hawking.