Gravitational difference between a black hole and a star

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SUMMARY

The discussion centers on the gravitational differences between black holes and stars, emphasizing that a black hole is an 'immaterial' spacetime object, while stars are material objects. Key points include that gravity is solely dependent on mass and rotation, with no other characteristics influencing gravitational effects. The dynamics of various binary systems—star-star, star-black hole, and black hole-black hole—were analyzed, revealing that tidal forces differ due to the unique properties of black holes, such as their lack of deformation and friction. The conversation also touched on gravitational waves and their role in the mass reduction of black holes during collisions.

PREREQUISITES
  • Understanding of general relativity and spacetime concepts
  • Knowledge of gravitational waves and their implications
  • Familiarity with binary star systems and their dynamics
  • Basic principles of mass-energy equivalence (E=mc²)
NEXT STEPS
  • Research the effects of rotation on gravitational fields in black holes
  • Explore the dynamics of tidal forces in binary systems
  • Study the properties and implications of gravitational waves
  • Investigate the differences between material and immaterial objects in physics
USEFUL FOR

Astronomers, physicists, and students interested in gravitational theory, black hole dynamics, and the fundamental differences between material and immaterial objects in the universe.

  • #31
Generally, stars are sufficiently extended that, even when touching, their centers are not close enough, so their orbits are not fast enough, for these waves to carry any significant energy away: When/if they merge, it is because of classical physics, especially friction.

The exception is neutron stars. But even there, a very close pair can take 100 MYr or more for the gravitational waves to carry away enough orbital energy for a merger.
 

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