Black hole mergers lose respective rotational energy during a merger. I understand that the energy 'emitted' is scattered as gravitational 'energy' that can henceforth be detected by gravitational detectors billions of light years away. I understand that the amount of shockwave energy in stellar mass black hole mergers can be equivalent to the mass of a star such as the sun. So if two rapidly rotating SMBHs on the scale of SagA* merge, the emergy emitted is in the range of hundred thousands of solar masses...?

Either case that is a lot of energy. If a two, let's say, 10 solar mass black holes merge at 10 light years, what are the literal impact effects on a terrestrial planet in such adjacent system?

Barely sensable by its inhabitants? Significant seismic? sufficient to sharply increase volcanism? Agitating the surface to lava? Obliterate small moons or planets in to a large rapidly expanding cloud of interplanetary lahar?

Assume that every ten thousand or less years such merger occurs in the milky way galaxy? Could these mergers constitute existential risks?

  • $\begingroup$ a different but related question in Physics SE: How would a passing gravitational wave look or feel? $\endgroup$ – uhoh Sep 1 '19 at 23:59
  • $\begingroup$ I apologise if you already know this, but, as unintuitive as it is, the alleged gravitational waves are emitted whilst the bodies are still orbiting each other; not at the point of impact. $\endgroup$ – White Prime Sep 2 '19 at 17:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.