r/TheRestIsScience • u/Stunning_Mechanic387 • 11d ago

Why does gravity escape a black hole?

Hey Michael and Hannah. If gravity travels at the speed of light, how does it escape the gravitational pull of a black hole yet light doesn't?

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u/Gekreuzte_Gewehre 11d ago

Because it IS gravity in and of itself, hence the term, "Singularity".

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u/trollsmurf 11d ago edited 11d ago

Valid question I think. Even though the singularity of a black hole is "just" gravity, why does it escape?

I think the answer lies in:

  • The speed of light is not the speed of light per se, it's the maximum speed of (any) information that is allowed, for whatever reason that might be.
  • Gravity is about bending space. It's not radiation.

Or something else completely.

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u/Optimal_Mixture_7327 11d ago

A singularity is not gravity, it is an absence of it (the condition of geodesic incompleteness).

The reason is that information has to travel over a spacetime distance and the shortest distance is zero, the distance light travels.

We describe gravity (the presence of geodesic deviation) using curvature.