Tagged Questions
0
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0answers
23 views
Black hole and photons [duplicate]
I've read in a book that even light can't escape the gravitational pull of a black hole after a certain distance. But this seemed impossible to me.
Imagine a photon, moving directly in the opposite ...
0
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0answers
69 views
Is there any proof that the speed of gravity is limited? [duplicate]
I must warn that though I'm argumenting with black holes I'm not asking how does gravity escape the black hole!. I want to know if the absolute speed of gravity waves were proven bu an experiment.
We ...
2
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3answers
124 views
Why are black holes special?
A black hole is where it's mass is great enough that light can't escape at a radius above the surface of the mass?
I've been told that strange things happen inside the event horizon such as ...
0
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0answers
24 views
Why photons can't escape black hole? [duplicate]
Photons do not have (rest) mass. Then why are they attracted by the black hole? And is it possible that a photon crossing a black hole from a little distance could get accelerated due to the force?
0
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2answers
561 views
If nothing in the universe can travel faster than light, how come light can't escape a black hole? [duplicate]
Possible Duplicate:
How does gravity escape a black hole?
If nothing in the universe can travel faster than light, how come light can't escape a black hole? I mean, Einstein's relativity ...
1
vote
1answer
194 views
What is the speed for an object that travel close to the speed of light?
I have some questions regarding Einsteins theory of Relativity that should be fairly easy to answer. Lets say we make an experiment where we have a rocket (with an astronaut inside) that travels very ...
7
votes
1answer
331 views
Can a black hole form due to Lorentz contraction? [duplicate]
Possible Duplicate:
If a 1kg mass was accelerated close to the speed of light would it turn into a black hole?
Imagine, a rod of length L is moving with velocity approaching the speed of ...
7
votes
3answers
547 views
Why is a black hole black?
In general relativity (ignoring Hawking radiation), why is a black hole black? Why nothing, not even light, can escape from inside a black hole? To make the question simpler, say, why is a ...
1
vote
3answers
479 views
will free-fall object into black hole exceed speed of light before hitting blackhole surface?
imagine if we throw an object in against direction of gravity with speed v and it achieve max. height of h. now if we allow object to fall from that height h, it will eventually attain speed v when it ...
9
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5answers
3k views
Why can't light escape from a black hole?
Photons do not have mass (that's why they can move at speed of "light").
So, my question is how the gravity of black hole can stop light from escaping?
7
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4answers
1k views
If a 1kg mass was accelerated close to the speed of light would it turn into a black hole?
I'm a big fan of the podcast Astronomy Cast and a while back I was listening to a Q&A episode they did. A listener sent in a question that I found fascinating and have been wondering about ever ...
92
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13answers
5k views
How does gravity escape a black hole?
My understanding is that light can not escape from within a black hole (within the event horizon). I've also heard that information cannot propagate faster than the speed of light. It would seem to ...
