Can Photons Actually Orbit Massive Objects?

[sheriefer]

According to Einstein's theory of general relativity, light bends--or rather space bends--around mass. So, in theory, is it possible for a photon to orbit around a body of sufficiently large mass?

 

[ProTerran]

Well, I think that this is possible - black holes are such objects.

 

[Bill_K]

Yes, a circular photon orbit is possible at r = 3GM/c². (The Schwarzschild radius, which defines the 'surface' of the black hole is 2GM/c²) However the orbit is unstable, meaning that photons won't accumulate there, and any photon that is placed there will eventually fall into the hole or run off to infinity.