Thread: Black Hole Collisions

OK ... when black holes collide ... do they keep the shape that they were in at the point of collision ( from the stand point of the external observer )?

Baiscally if time stops at the EH ... then at the point of impact of 2 black holes the EH WOULD NOT be spherical. But the moment they get close enough to form a bonding EH between them then I dont see how the shape of that EH could morph further, from the point of view of the external observer, since time has stopped, relatively.


So based on this could I predict that there are unique shaped BHs in the universe?

So you think they'd look like strings of beads?

If I may interject an only slightly related thought, I am wondering, if the event horizons touch, does that mean, that's it, they're glued together forever?

If two black holes do not collide, but pass by quite closely, would they flatten a bit? Seems like there should be something akin to a Lagrange point between them. But that's using Newtonian reasoning; maybe it doesn't work in GR.

The collided black holes might be a bit like this - MVI_0102.AVI - YouTube
and the space/time curvature that defines the EH would be thrashing around faster than the matter/energy could keep up with.

Stuff that was beyond the EH would suddenly find itself back on this side of it (and vice-versa)
the observer might see a sparkly black hole - like when you strike flint into fire - but with sparkles as bright as whole galaxies.

If you listened to it on a radio it would sound like a drum roll followed by BADOOM - KSSSHH

Don't BHs have different masses? So why wouldn't the larger draw the smaller in and the volumes of the EH's combine to create a "new" BH and larger EH?

I wonder however if this would appear violent or deathly black.

But this is at the heart of my question time is STOPPED ... so how could it thrash around ( at least from the viewpoint of the external observer ).

Originally Posted by TaoZero5

The collided black holes might be a bit like this - MVI_0102.AVI - YouTube
and the space/time curvature that defines the EH would be thrashing around faster than the matter/energy could keep up with.

Stuff that was beyond the EH would suddenly find itself back on this side of it (and vice-versa)
the observer might see a sparkly black hole - like when you strike flint into fire - but with sparkles as bright as whole galaxies.

If you listened to it on a radio it would sound like a drum roll followed by BADOOM - KSSSHH

This was another one of my questions ... and I believe the answer is yes ... but ... it gets complicated. If someone could clarify this it would be great.

Once EH are merged they are linked until evaportation ( well depending on how this thread is answered ) . My question that I post regarding this was if two black holes travelled towards each other at near the speed of light and barely touched EH ( well where the EH merged ) Could the Blackholes escape ...

But the thing is that space time is SOOOO curved in that region then even travelling with the speed and momentum that they have they could not escape.

The net momentum would be conserved.

Originally Posted by Coelacanth

If I may interject an only slightly related thought, I am wondering, if the event horizons touch, does that mean, that's it, they're glued together forever?

If two black holes do not collide, but pass by quite closely, would they flatten a bit? Seems like there should be something akin to a Lagrange point between them. But that's using Newtonian reasoning; maybe it doesn't work in GR.

what happens is the EH expands and reaches out between the two ... Because the potential gravity of the 2 black holesystem would be great in the area between the two closely passing BHs.

Originally Posted by JFalz1024

Don't BHs have different masses? So why wouldn't the larger draw the smaller in and the volumes of the EH's combine to create a "new" BH and larger EH?

Originally Posted by tom

what happens is the EH expands and reaches out between the two ... Because the potential gravity of the 2 black holesystem would be great in the area between the two closely passing BHs.

I feel like the "centers" of the BH's would be pulled toward eachother and "collide" where the EH's stretch and meet eachother.