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tiny-tim
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May24-08, 06:50 PM
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Quote Quote by Jorrie View Post
For non-rotating (Schwarzschild) black holes, free-falling objects cannot pass closer then 1.5 times the event horizon radius without spiraling into the hole.
Hi Jorrie!

I don't think that's right.

1.5 is the distance at which light orbits a blac k hole.

So if light has "horizontal" velocity closer than 1.5, then is must crash into the black hole.

And even light in orbit at exactly 1.5 will be in unstable orbit, and so will either spiral in or spiral out.

But give it a kick radially inwards, from 1.5, and I think it just reaches the opposite point of the orbit with the same kick outwards, and then escapes.