G. Caneva Santoro

A clear signal from the merger of two black holes, each about 33 solar masses, confirmed Hawking's theorem: the final horizon area turned out larger than the sum of the initial ones. This strengthens the link between black hole area and entropy.

The most precise measurements of gravitational waves from a black hole collision have set a record limit on their deformability. It turns out that black holes keep their shape even under unimaginable tidal loads — just as Einstein predicted. This closes a loophole for 'soft' quantum models.

If neutron stars had tiny bumps, they would constantly hum with gravitational waves. Using LIGO, scientists searched for that hum from 34 pulsars, the largest search of its kind. No signals were found, which pushes the theoretical limits even lower. The Crab pulsar, for instance, turns less than 0.0