Thread: Speed of a light photon in a black hole singularity

Imagine a photon inside a black hole singularity. It's experiencing infinite space time curvature due to the black holes gravity, and (my assumption is) it has no where to go except possibly if we invoke string theory. Is the speed of the photon still c?

Best regards,

John Steele

Originally Posted by John Steele

Imagine a photon inside a black hole singularity. It's experiencing infinite space time curvature due to the black holes gravity, and (my assumption is) it has no where to go except possibly if we invoke string theory. Is the speed of the photon still c?

Best regards,

John Steele

Once a photon passes the event horizon, I can only see two possibilities.

1. It will get absorbed and that's the end of it.
2. It will go into orbit around the BH.

From our point of view, it seems kind of useless to speculate on it's final outcome.

A photon can only orbit outside of the event horizon, at a distance one and a half times the Schwarzschild radius. (Research term - photon sphere)

Once inside the event horizon, as far as we know all paths inevitably lead towards the singularity.

Originally Posted by SpeedFreek

A photon can only orbit outside of the event horizon, at a distance one and a half times the Schwarzschild radius. (Research term - photon sphere)

Once inside the event horizon, as far as we know all paths inevitably lead towards the singularity.

I'm sure that's true, however any object entering the event horizon at the speed of light could be in a decreasing orbit for a very long time. The only result we know for sure is we will never see that photon again.

Originally Posted by John Steele

Is the speed of the photon still c?

Yes, locally the speed of a photon is always c, regardless of whether it is inside or outside an event horizon. In fact, a photon crossing an event horizon would not "notice" anything special.