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kurious
Jun30-04, 02:55 PM
Two black holes of equal mass move together so their event horizons meet.
How would a photon initially going around one horizon in a circle,know which horizon to go around when it comes to the place where the horizons meet?
And if there were thousands of small black holes filling a large area of space, all with touching event horizons, how would the photon behave?

DW
Jun30-04, 06:40 PM
Two black holes of equal mass move together so their event horizons meet.
How would a photon initially going around one horizon in a circle,know which horizon to go around when it comes to the place where the horizons meet?
And if there were thousands of small black holes filling a large area of space, all with touching event horizons, how would the photon behave?

Photons don't orbit at the event horizon. They unstably orbit at the Photon sphere.

mathman
Jun30-04, 06:58 PM
When two black holes meet, they would most likely collapse into one. Similarly with lots of black holes touching.

jcsd
Jun30-04, 07:18 PM
Photons don't orbit at the event horizon. They unstably orbit at the Photon sphere.

Can the orbit be stable in an idealized Schwarzchild black hole?

DW
Jun30-04, 11:26 PM
Can the orbit be stable in an idealized Schwarzchild black hole?

No, thats actually the kind of hole I was referring to. For the ideal Schwarzschild hole the photon sphere is at
r_{ps} = \frac{3GM}{c^2}.