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The black hole isn't actually a hole

  1. Sep 16, 2010 #1
    Is this true?

    We're in computing but we have a classmate that says that when a star collapses, all the material in it fuses together under such power, that it creates one giant super stable atom, and the actual black hole isn't a hole at all.

    What do you think?
     
  2. jcsd
  3. Sep 16, 2010 #2
    That's a very simplified explanation but it is essentially correct.
     
  4. Sep 16, 2010 #3
    When a star reaches the end of its life, the energy it is producing is no longer sufficient to prevent the mass of the star from collapsing in on itself. Most starts explode but very large stars may keep collapsing until all the space between the individual particles is squeezed out and it is essentially a homogeneous ball a tiny fraction of the size of the original star. The reason it is called a black hole is because such a massive ball of matter in such a small volume has such a strong gravitational pull that anything getting too close cannot escape and that includes light. Black holes are not truly black, but they leak only a very small amount of radiation so it's close enough for jazz.
     
  5. Sep 16, 2010 #4
    When a star explodes at the end of its life, it leaves a dense, stable, "ball" (from the simultaneous implosion). Depending on density of the final "ball", it is ether a black dwarf (destiny of our sun), a neutron star, or a black hole as Rebound said.

    Light essentially curves around any very massive bodies (incl. the sun). A black hole is a mass that will have light spiral inwards.
     
  6. Sep 16, 2010 #5
    he is thinking of a neutron star as a kind of giant nucleus.
     
  7. Sep 16, 2010 #6

    George Jones

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    If you mean a ball of matter, this isn't true.
     
  8. Sep 16, 2010 #7
    Another reason it may be confused with a hole is because in many pictures its depicted bending the spacetime beneath it.
     
  9. Sep 16, 2010 #8
    To be clear, if you take GR at its "word" then there is no matter involved in a singularity; it is just gravitation, mass, spin and charge. Otherwise, I think granpa is right about the OP.
     
  10. Sep 16, 2010 #9
    Yes, I'm aware. I deliberately over-simplified. I was in a bit of a hurry.
     
  11. Sep 19, 2010 #10
    hey guys .. a black hole is nothing but a compressed mass , and a hole means absense mass of a particular area of a substances . i don't see absense off mass in a black hole
    and it is called a hole , because in a hole everything just falls and is very hard (nearly immpossible in this case) to remove it

    and rebound ...can you pls tell me that if black holes leak then do they leak the leaked matter which is at a greater velocity of light ?????
     
  12. Sep 19, 2010 #11
    Black holes do not "leak matter", but under the correct conditions it's theorized that they would emit Hawking radiation. For the rest... yeeeeaaaahhh... I think we're pretty clear on what GR says a black hole is, and what it may be in other frameworks as well. I should add that the MASS isn't compressed, it just exists within a given region as a result of matter having collapsed at a prior point in time. A black hole is a region more than anything else; a region having a specific mass within (what appears to be) a given volume that vanishes to 0 at the singularity, if that is indeed what happens.

    Finally... where do you get faster than light out of all this? Are you talking about polar jets, and relativistic beaming which makes them APPEAR to be "faster than light" to some observers... but is NOT EXCEEDING c? That radiation comes from the poles of the accretion disk OUTSIDE of the event horizon, just to be clear.
     
  13. Sep 19, 2010 #12
    i was talking about mass evaporation about a black hole not galatric jets ..... if by hawking radiation , a black holes mass is evapourated , then the mass needs to come out of it , hence it has to ecxeed the velocity of light to come out of it ......
    and decreasiing the volume of the mass , does mean that it is compressed in a tiny region ............ i thought GR always regected the very existence of a black hole , so i guess how can GR define singularity then ?
     
  14. Sep 19, 2010 #13
    No, HR doesn't exceed c at all. I don't know why you believe that it does. HR is all about quantum oddities which allow for one part of a particle pair to be created just outside the event horizon, therefore requiring no FTL travel. It's not that simple, but you can do some very basic research and that's pretty much the non-mathematical treatment.
     
  15. Sep 19, 2010 #14
    The black hole evaporates if there is a leak.........so is it due to jets or creation of particles in Quantum vaccuum??!!!:confused:
     
  16. Sep 19, 2010 #15
    OK, I can't tell if you and andya are joking around here, but I'm done with this.

    Read this: http://en.wikipedia.org/wiki/Hawking_radiation

    If you don't get it, learn some more about black holes, because they don't bloody LEAK, or eject superluminal particles. I'm happy to be part of a discussion, but not when the people involved haven't bothered with the absolute basics.
     
  17. Sep 19, 2010 #16
  18. Sep 19, 2010 #17
    First, note the "may leak" in the very url, second that is not a leak of the type you're thinking of. Please, the subject how HR is complex, and it requires understanding the best current theories of how a black hole evolves and what it is. HR is, as of this writing, still plagues by this: http://en.wikipedia.org/wiki/Black_hole_information_paradox

    There are certainly possible ways around this, but none are confirmed anymore than HR itself is confirmed.
     
  19. Sep 19, 2010 #18
    ...... our point is that , HR is caused due to evaporation of mass .... when 2 particles are created by the uncertanty principle around a black hole one is an anti particle and the other is a normal positive particle ....... iff the anti particle falls in a black hole , should'nt it annhilate with the mass of the black hole .... and those particles are just near the event horizon ...
    can you pls answer one of my question ,,..... that if black holes did not evaporate then just imagine , the amount of black hole waste in the cosmos ...............?????
    so dude you might be very intellegent , ane we might be idiots ... but here we have a point that if black holes evaporate then the particle evapourated fom the black hole shoul exceed the velocity of light ... or the gravity of the black hole on that particle should reduce only then the particle can escape to infinty
    and if you read the article which suk sci posted then a research is been done that information beyond the event hoorizon can be found ......
    then how does the information escape the escape velocity of a black hole ??????
     
    Last edited: Sep 19, 2010
  20. Sep 20, 2010 #19
    Lets start from point #1: What do you mean, "evaporation of mass"? That's an approximation of a quantum mechanical process in which one half of the pair is created WITHIN the event horizon, and the other outside of it. The EH is the point at which you would need to exceed 'c' to escape, so once again... where are you getting the notion of FTL motion? In addition, HR does not allow information about what fell IN, to get OUT, hence the paradox I linked to in my previous post.
     
  21. Sep 21, 2010 #20
    i know . that ........... but if you read the article which suk sci posted it tell s that information from a black hole can be revealed............ and hey if the HR is to reduce the energy of the black hole then some energy IS SUPOSSED TO get of that body , if it is not exceeding the velocity of light then how is it getting out of the black hole........
    ok lets assume the information is lost inside a black hole , now if i pour a bucket of hot water in a black hole , and it comes to an environment where it is cooler , it should radiate ??? !!! and now if the gravity is holding on to this radiation , and as mentioned by hawkings that this radiation will be just below the event horizon . now if entropy increses with time , here it will increase the fastest caz there are 2 constant forces acting on the radiation to be emitted .... now at some point of time t it will increase soo much that it should escape....... dude , just leave behind the basics and just think logically applying the most basic 9th grade physics to this . you'll get my question if you do that
    https://www.physicsforums.com/showthread.php?t=379883&highlight=black+holes check out this link
     
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