A frame from a computer simulation illustrating two black holes in the process of spiralling in toward each other before merging in a gravitational “space quake.” Image: SXS, the Simulating eXtreme Spacetimes (SXS) project
Physicists analysing gravity waves generated in the merger of two black hole have found “overtones” in the brief post-merger signal, allowing them to independently calculate the resulting hole’s mass and spin in agreement with the predictions of Einstein’s general theory of relativity.
The analysis also supports the “no hair” theorem, originally postulated by physicist John Archibald Wheeler, stating that a black hole’s spin, mass and electric charge are the only characteristics of the collapsed bodies that can be directly observed.
“We all expect general relativity to be correct, but this is the first time we have confirmed it in this way,” said Maximiliano Isi, a NASA Einstein Fellow in MIT’s Kavli Institute for Astrophysics and Space Research and lead author of a paper describing the analysis in Physical Review Letters.
“This is the first experimental measurement that succeeds in directly testing the no-hair theorem. It doesn’t mean black holes couldn’t have hair. It means the picture of black holes with no hair lives for one more ...