Do photons gain mass in the presense of a black hole?

In summary, there are no theories that predict a photon acquiring mass in the presence of a singularity, such as a black hole. Although black holes have extreme gravity, they do not change the properties of photons. Instead, they drastically deform the shape of space-time, making it impossible for anything to escape once it crosses the event horizon. This means that light waves, or photons, cannot leave a black hole's event horizon, but this does not affect the photons themselves.
  • #1
kjamha
98
1
I understand how gravity can affect photons or light waves (Einstein's equivalence principle). But I was wondering if there are any theories that predict that a photon might somehow acquire mass in the presence of a singularity.
 
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  • #2
I'm going to assume that you mean black-hole, when you say singularity. The central point of the BH should have no relevance---unless I misunderstand you.

Note that there isn't anything special about the gravity of a BH. If a BH's gravity somehow gave light mass, then a star, or even a planet would also.

Nothing, however, can give a photon rest-mass. In general relativity, 'mass' (in-general) is not always well-defined. A photon will (presumably) exert a gravitational force on other-particles, regardless of the local gravity (e.g. a black-hole).
 
  • #3
My understanding is that light waves flatline when trying to leave a BH - they can not escape. I was not sure if this had an effect on the photons. - Thank you for your answer.
 
  • #4
kjamha said:
My understanding is that light waves flatline when trying to leave a BH - they can not escape. I was not sure if this had an effect on the photons. - Thank you for your answer.
Black-holes don't change anything about the photons themselves; instead they're drastically deforming the shape of space-time itself. At (and within) the event horizon, the photons are exactly the same, but spacetime is bent so much that nothing can move outward.
 
  • #5
I was not sure if this had an effect on the photons. http://www.bosin.info/g.gif
 
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FAQ: Do photons gain mass in the presense of a black hole?

How does a black hole affect the mass of photons?

In the presence of a black hole, photons do not gain mass. However, they can be affected by the intense gravitational pull of a black hole, which can alter their trajectory.

Can photons have mass?

According to the current understanding of physics, photons are considered to be massless particles. They do not have a rest mass, but they do have energy and momentum.

What is the relationship between photons and gravity in the presence of a black hole?

The presence of a black hole does not change the fundamental relationship between photons and gravity. Photons still follow the curvature of spacetime caused by the black hole's intense gravitational pull.

Do photons behave differently near a black hole compared to other objects?

Yes, photons can behave differently near a black hole compared to other objects due to the extreme gravitational forces. They can be affected by gravitational lensing, where their path is bent due to the curvature of spacetime.

Can photons escape a black hole's event horizon?

No, photons cannot escape a black hole's event horizon. Once they cross this point of no return, their path is redirected towards the singularity at the center of the black hole and they cannot escape.

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