Basically, my question is the title. If a black hole crosses the Roche limit of another black hole, what happens?
For a hypothetical example, let’s say you have a two black holes: one at 5 solar masses and one at 300 solar masses. If the smaller black hole crosses the Roche limit of the larger what happens? Does they simply merge? Would the event horizon of one or both black hole’s be geometrically distorted in some way or retain their spherical shape?
I asked this some months ago. The consensus seemed to be the they merge and become one. But I can’t get passed the feeling that the two centres of mass becoming one and the same gives us some sort of info about what happens behind the combined event horizon, which seems wrong. So if that’s not what happens then perhaps the two black holes only appear merged, but actually they’re just very close, and from our view they’re perpetually falling toward each other slowed by relativistic effects?
I’d love to watch an actual scientist tackle this question. Without an answer from a professional there isn’t an answer.
FWIW the Wikipedia page on the first detection a few times quotes the research papers that they do “merge”. A process whose completeness seems emphasised by the subsequently detected ripples that decay to nothing which they call the “ringdown”.
But yes, explanation by a professional would be fantastic
That’s pretty cool.
Supposedly tomorrow all the planets are going to line up at night. If you enjoy science and stuff look up for that.
Very good. The problem is that singularities are quantum objects. Quantum physics works nothing like classical physics.
For example, in the case of perpetually falling singularities, would they just quantum tunnel into each other? Or would singularities even exist? According to general relativity, singularities are a sphere that never stops being compressed due to its own gravity. What happens when this sphere hits a diameter smaller than Plank’s length? Does the universe take a screenshot? The point is, we have absolutely no clue about what’s happening here.
To understand the above, we would first need to understand how gravity works at the quantum level, which we don’t. Why? Gravity is incredibly weak. Studying it is thus, very hard.
I was wondering today if singularities might actually be the purest form of “nothing” and the mass of a blackhole around that void is what is keeping that void from collapsing, kind of like a massive traffic jam. The space would have to be perfectly empty: No vacuum energy, no gravity, no fields of any kind.
Yes, this is a silly idea and just a weird thought experiment, TBH.
However, it’s much more easy to visualize than a traditional infinite singularity since it can be rationalized in a simple 3D space… It’s just a ball of nothing.
Hell, even if the void was the size of a pinhead, the entire force of the universe would be “squeezing it”, trying to move energy into a space that contained none.
Ok, that probably broke a few hundred thousand universal rules of physics, but it’s easy to speculate about something we can’t see or study.
One could say the same for the mass of each of the black holes as well from the start of their collapse, and anything else they’ve ingested. They are still falling into their singularity point, forever.