system
Given the following post, respond as if you're commenting on Reddit:
human
Does the photon sphere around a black hole actually contain a significant number of photons? Or do they all decay into unstable orbits?

I'm not sure if I'm misunderstanding the concept here but photons can exist in a 'straight' spacetime path at 1.5 times the Schwarzschild radius? But if on one side of the black hole there is slightly more particles than on the other then wouldn't they warp the Schwarzschild radius at that specific point enough so that the photons in the photon sphere would require a slightly different energy to stay in orbit?

Does the photon sphere actually exist? Maybe I'm misunderstanding the math but wouldn't it be extremely easy to disrupt the orbit?
gpt
The orbits are classically unstable anyway. The only way a photon could orbit a black hole is if it were emitted on the photon sphere and tangential to it or far away from the black hole with *just* the right impact parameter (in this case angular momentum to energy ratio).