Photon Sphere and time travel around a Black Hole?

In summary: No, the sphere would be much larger for larger black holes, right? The light leaves your spaceship and then you see the back of your spaceship. You are in the present and the light you see is from your past.
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infinitebubble
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Reading the post below on event horizon of a black hole (BH) got me thinking about the photon sphere of the BH. We all know light will travel around this photon sphere and how light from a source would completely travel back to it's source if one could see it real time, we all know this from relativity.

Now I postulate if a vehicle could theoretically be at this photon sphere and travel around it, we know it would see itself from the light traveling back and they would eventually see themselves... would TIME be the same or would as I suspect they would see themselves in the future?
 
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You can reproduce all effects of the photon sphere with mirrors at home (although things like time delays will be too short to notice without sensitive equipment, of course). No time travel involved, and everything you see happened in the past.
 
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infinitebubble said:
OK... perhaps I was seeing some time dilation as the light/vehicle traveled around the BH. But if you see your past then you would be in the future would it?

No, you would be here now in the present.
 
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jedishrfu said:
No, you would be here now in the present.

Would this be the same for supermassive BH's on the order of millions of Suns?
 
  • #7
infinitebubble said:
Would this be the same for supermassive BH's on the order of millions of Suns?

The photon sphere would just be larger for larger black holes, right? The light leaves your spaceship and then you see the back of your spaceship. You are in the present and the light you see is from your past.
 
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1. What is a photon sphere and how does it relate to a black hole?

The photon sphere is the region around a black hole where photons (particles of light) can orbit in a circular path. This is possible because the intense gravitational pull of the black hole causes light to curve, allowing it to orbit instead of escaping. It is the closest stable orbit possible around a black hole.

2. How does time travel work around a black hole's photon sphere?

Time travel around a black hole's photon sphere is possible due to the extreme gravitational time dilation. Time dilation is a phenomenon where time moves slower in areas with stronger gravitational pull. This means that an observer near the photon sphere would experience time at a slower rate than someone farther away, creating the possibility of traveling into the future.

3. Can objects or people actually travel through a black hole's photon sphere?

No, it is not possible for objects or people to physically travel through a black hole's photon sphere. The intense gravitational pull would cause them to be crushed and destroyed before reaching the photon sphere. However, the concept of time travel and observing the effects of the black hole's gravity from a safe distance is still possible.

4. Are there any risks associated with traveling near a black hole's photon sphere?

Yes, there are significant risks associated with traveling near a black hole's photon sphere. The extreme gravitational pull can cause severe gravitational time dilation, making it difficult to return to the same point in time as when the journey began. Additionally, intense radiation and tidal forces near the photon sphere can be fatal to any living organism.

5. Can we observe the effects of time travel around a black hole's photon sphere?

Yes, it is possible to observe the effects of time travel around a black hole's photon sphere. Scientists can use powerful telescopes and other instruments to study the gravitational lensing and time dilation effects near the photon sphere. Additionally, simulations and mathematical models can help us understand the potential for time travel around a black hole.

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