> What specific properties has LIGO confirmed about the event horizon? Hawking's area theorem is one: https://news.cornell.edu/stories/2021/07/hawkings-black-h

> What specific properties has LIGO confirmed about the event horizon? Hawking's area theorem is one: https://news.cornell.edu/stories/2021/07/hawkings-black-hole-theorem-observationally-confirmed https://news.cornell.edu/stories/2021/07/hawkings-black-hole... > It is not quite clear to me how the gravitational waves of two merging bodies would be different between a merger of normal stellar objects and black holes. I'm not sure one can be so loose here. LIGO uses detailed models of black hole and neutron star mergers to match the signals against. What are "normal stellar objects" that would yield the same magnitude of gravitational waves emitted during a merge as black holes and neutron stars? > The EHT image is mostly an accretion disk. I think accretion disks can also form around things that are not black holes. There's also a huge hole in the middle of the accretion disk. What other object, other than a black hole, has such a large accretion disk but yet no emitted radiation?