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Black holes dilemas

  1. Jan 14, 2008 #1
    My question is related to blackholes, well there are many books and writings that explain what a black hole is and all AFTER collapse but i have seen few that explains the BEFORE collapse; exactly how is that matter can be squeezed to an infintesimal point, ¿what effects could one expect to see before the collapse?
    ¿why are astrophysicists so sure that if a star has the critical mass , then it would inexorably colapse to a black hole, why cant be that could exist other types of star collapses apart of white dwars and neutron stars?
    ¿if black holes really exists , doesnt this imply that electrons and all elemental particles can be splittered infinitely ? so they are not elemental
  2. jcsd
  3. Jan 15, 2008 #2


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    The question of what happens to matter inside a black hole is still open. Collapsing to a point is preducted by genral relativity theory, but quantum theory which also has to hold is in conflict.

    The densist form of matter outside black holes is that of a neutron star (no electrons). If a neutron star is big enough, its Schwarzschild radius will be greater than the radius of the star. This is the point where current theory breaks down.
  4. Feb 11, 2008 #3
    My understanding is that current theory implies that time would be distorted to such an extent that any collapse that has been initiated could not have proceeded to a singularity relative to us. Collapsing matter would be frozen at the event horizon, from our point of view.
  5. Feb 16, 2008 #4
    They believe this because a stars mass (in general) will tell us what a star is composed of - and when it runs out of elements to fuse it will collapse under gravity to form an extremely dense object.
  6. Feb 16, 2008 #5
    If the mass is small enough when the star begins to 'collapse' electrons in the star will get 'claustraphobic' and start vibrating very rapidly, which is known as electron degeneracy, therefore it exerts a pressure pushing outwards, if there is not enough mass (gravity) to counter this, then they live in a cute little equilibrium as a white dwarf or neutron star.

    If the star is too massive, then the gravity is too strong and will overcome the pressure of the degeneracy (i think the is neutron degeneracy too) and it will collapse into a black hole.

    It's been years since I've read an astrophysics book though, but I am sure that is fairly accurate.
  7. Feb 16, 2008 #6
    That sounds very familiar from some thermal physics lecture last year Riogho!

    I think you're correct :)
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