Light Around Black Holes: Can It Orbit?

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SUMMARY

Light can indeed orbit a black hole, specifically at the photon sphere, which is defined for a Schwarzschild black hole at the radius r_{ps} = 3GM/c². However, this orbit is unstable, meaning that while light can exist at this distance from the event horizon, it cannot maintain this position indefinitely without external influence. This conclusion confirms the theoretical understanding of light behavior in the vicinity of black holes.

PREREQUISITES
  • Understanding of Schwarzschild black holes
  • Familiarity with general relativity concepts
  • Knowledge of photon spheres and their properties
  • Basic grasp of gravitational physics
NEXT STEPS
  • Research the implications of unstable orbits in gravitational fields
  • Study the mathematical derivation of the photon sphere radius
  • Explore the effects of black hole rotation on light paths
  • Investigate observational evidence of light behavior around black holes
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Astronomers, physicists, and students of astrophysics interested in the behavior of light in extreme gravitational fields and the dynamics of black holes.

turin
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I just wanted a quick affirmation. Can light orbit a black hole? That is, can light remain between two well-defined distances from the event horizon (or at a single well-defined distance, which I am leaning towards) indefinitely?
 
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For a Schwarzschild hole it can orbit at the photon sphere [tex]r_{ps}[/tex] which is at
[tex]r_{ps} = \frac{3GM}{c^{2}}[/tex].
It is an unstable orbit though.
 
Thanks, DW. That's exactly what I was looking for.
 

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