All Questions
Tagged with black-holes photons
100
questions
19
votes
3
answers
2k
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How close does a photon have to get to a black hole to do a full loop?
How close does a photon have to get to a black hole to do ONE full loop? By full loop I mean it curves once around the black hole, and then it ends up on the same trajectory as it was one before it ...
- 2,908
18
votes
5
answers
5k
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Could an infinite number of photons fit into a finite space?
As photons are quantum particles and basically waves in a quantum field, could an infinite number of photons exist in a closed space described by finite numbers? Does the answer to this apply to other ...
- 401
12
votes
1
answer
327
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Can gravitational waves orbit a black hole?
Assume (for the sake of simplicity) a Schwarzschild black hole (non-rotating, non charged). This black hole has a photon sphere in $r=1.5r_s$, where photons may travel in a circular orbit.
Will a ...
- 653
10
votes
1
answer
3k
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What happens to light that falls into a black hole?
When light enters a black hole, what happens to it?
I imagine the photons will either fall into the singularity, or the light will orbit just inside the event horizon indefinitely.
(Some background ...
- 826
9
votes
2
answers
1k
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Rainbow Blackhole?
Can white light be broken into its component colors when gravitationally shifted by a black hole, in a manner similar to what a prism does?
http://www.physics.utah.edu/~bromley/blackhole/index.html
- 1
7
votes
4
answers
882
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Photon Escape Angle From Black Hole
Consider a photon source emitting photons near the surface of a Schwarzschild black hole.
What angle, as a function of the source's radius from the event horizon, must the photons be emitted at such ...
- 73
7
votes
2
answers
2k
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Computing the path of photons near a black hole
For a simulation, I want to compute the path that light follows near a black hole.
Non-relativistically, a massive point particle in a central newtonian gravitational field follows either an ellipse, ...
- 1,155
6
votes
3
answers
3k
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Does light with a wavelength on the Planck scale become a self-trapping black hole?
As the wavelength of a photon shrinks, its energy rises, and so its mass rises (using $E=hc/\lambda$ and $m=E/c^2$). On calculating the Schwarzschild radius for a photon based on its mass derived from ...
- 533
6
votes
1
answer
298
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If there is a super massive black hole at the center of our galaxy then why is the center of our galaxy so bright? [duplicate]
Below is our galaxy, if there is a such a massive black hole at the center then wouldn't it suck in any light traveling above it, or is the amount of light put out by stars near the center so great ...
- 835
6
votes
3
answers
2k
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What happens to photons that get trapped in a black holes event horizon?
So, I know that photons do not travel fast enough to escape a black hole once it passes the event horizon. Also, I know that the photons themselves aren't affected by the gravity, but rather their ...
- 565
5
votes
2
answers
2k
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Kinetic energy of a photon and Schwarzschild radius
I have read here, that $\frac{1}{2}mv^2$ must not be applied on a photon ever.
If i want to calculate escape velocity $v_e$ i need to use $\frac{1}{2}mv^2$ because we say that kinetic energy (...
- 2,585
5
votes
1
answer
1k
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Photon "stuck" on the event horizon of a black hole
According to what I've read on special relativity, $c$ is the speed limit for every object in the universe, and according to Einstein, an object's speed through the three spatial dimensions plus its ...
- 101
5
votes
1
answer
305
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Black hole wrapped in mirror (at the horizon) reflecting the present (interactive, not frozen image) or the past (frozen image)?
I have read this answer from John Rennie.
https://physics.stackexchange.com/a/39388/132371
Where he says that to a Schwarzschild observer, anything reaching the event horizon will seem to be frozen ...
- 29k
4
votes
3
answers
216
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Why energy matters for light to escape event horizon?
I like to know why photon with sufficient energy can avoid being pulled into the event horizon? Most light will get trapped and forms into photon sphere while some can escape, isn't light supposed to ...
- 13k
4
votes
3
answers
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Photons straight into black hole
What happens to a photon shot straight into a black hole? Does it gain infinite momentum before it crosses the horizon? If it has a finite momentum going in, then it would seem that a photon of the ...
