# Four black hole questions

What would happen if two Schwarzschild black holes were near each other? If I am understanding right, a black hole should not be able to move since its singularity is actually a point in which space has been pierced or broken through. Let’s say that two binary stars became black holes at the same time. Yes I know they would have probably merged together during the red giant stage, and the odds of both doing this at the same time are nill, but lets assume. They are now stationary (correct?) and have gravitational pull (correct?). So the first question is: do they collide or not?

Second… Can a Schwarzschild black hole really exist? Seems we would know the position of the hole at all times (if it doesn’t move) and due to the uncertanty principle this would be impossible. Its position could be measured, and its velocity is always 0. A ring singularity would be rotating rapidly, and the position of the matter in the ring could never be measured due to the event horizon. This would not violate the uncertanty principle.

Third, in a Kerr type black hole, the ring needs to actually exist and be physical matter (i.e. the thickness of the ring can be close to but not zero). Why does the ring not collapse on itself?

Lastly, if time slows down for an object going into the hole, and this makes objects going into a black hole appear in limbo, then why do we not see any black holes? Seems we should see all of them as we should actually see all of the matter that the hole will consume just outside its event horizon. All light will be red shifted extremely due to the gravitational pull, but it will still leave the hole since the event horizon isnt crossed yet. Could this be quasars?

You wouldn’t be able to see anything at the event horizon, because of the infinite red shift.

spectrum. Zero cycles per unit of time.

Answer to #1: Oh yes, black holes move. No one has any idea what happens at the singularity, but they do move and can collide. The collision of two massive black holes is expected to be one event that will make detectable gravity waves. This really answers #2 too. I don’t know what a Kerr type black hole is.

Aha… Yes if they can move, then #1 and #2 are answered.

As for the answer to #4, infinite red shift occurs at the event horizon. Time slows long before this. A traveller who bids adeau to his pals on his ship, and then travels towards a black hole to be sucked in would approach it faster and faster, then cross the event horizon and travel into the singularity. If he looked behind him, he would witness everything on fast forward so to speak, going faster and faster as he neared the event horizon. He may see millions or even billions of years pass in a few seconds. The people in hte ship however would see him go slower and slower and eventually appear to stop outside the black hole. If they could wait forever, they would see him eventually cross the event horizon, but this would take billions of their years. He isn’t really stuck, time is just different. Assuming I have this concept correct (a large assumption indeed) then we should see all the matter that has gone into black holes in the last few billion years clumped outside the event horizon. As it hits this, then the infinite red shift would occur, after it passes, then we see nothing.