1

To all the cosmologists and black hole experts out there: What would happen to a large object (very fast moving asteroid, planetoid, etc.) that was on a trajectory to tangentially intersect an event horizon, in a manner such that a portion of the object remained outside the event horizon and the rest entered inside the event horizon as the object passed by. Assume the black hole is very large and the tidal forces near the event horizon are not particularly large. Nothing should be able to escape from within the horizon, even in this contrived thought experiment. And yet I can't think of any physics that would require that the whole object enters the black hole, but the tidal forces would be unable to pull the object apart. What happens to the object? Anybody have any potential answers?

engineer64
  • 11
  • Related, possible duplicate: https://physics.stackexchange.com/q/526806/123208 The answers there cover both powered and unpowered trajectories. – PM 2Ring Aug 10 '22 at 01:20
  • For unpowered trajectories, not even light can escape once it crosses the photon sphere at 1.5× the Schwarzschild radius. I have some diagrams here: https://physics.stackexchange.com/a/680961/123208 – PM 2Ring Aug 10 '22 at 01:23
  • Also see https://physics.stackexchange.com/a/688602/123208 which discusses a flywheel crossing the event horizon. – PM 2Ring Aug 10 '22 at 01:32
  • 1
    The point of my question is to get clarification on whether a macroscopic object can be on a trajectory that would cause part of the object to enter beyond the point of no return, and the rest of the object to not do so. I assume this is a possible scenario. The problem then becomes what tears the object apart? if the trajectory does not pass through a gravitational gradient large enough to tear the object apart by tidal forces, what is the mechanism that does? – engineer64 Aug 11 '22 at 21:03

0 Answers0