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About white holes

  1. Jun 19, 2006 #1

    Kit

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    for black holes, we can find some evidences to prove its existence(ex. gravitational lens...etc)

    so how about while holes, can we observe anythinjg about white holes?? or it only exists mathmatically??

    thanks for answering^^

    kit
     
  2. jcsd
  3. Jun 19, 2006 #2

    George Jones

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    No accepted empirical evidence for white holes has been found.

    As you say, there exist valid mathematical white hole solutions.

    However, unlike black holes, which are sometimes the end result of stellar collapse, white roles are not the end result of any known physical process. Consequently, for white holes to exist, the universe would have to have had them as initial conditions, which seems unlikely.

    Suppose the preceding paragraph is wrong, i.e., supppose that there is a physical process that results in white holes, or that white holes were born with the universe. Theoretical arguments have been put forward which show that typical white hole are probably unstable, and that they rapidly turn into white holes.

    The case for physical white holes does not look good.
     
  4. Jun 21, 2006 #3

    Chronos

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    As George indicated, there is plenty of observational evidence favoring the existence of black holes, whereas there is none favoring the existence of white holes.
     
  5. Jun 22, 2006 #4

    wolram

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    Or to put it another way math can describe any thing, it is the models we like that are put foraward, the others are discarded, even if they are predicted. and if you want to argue the point where are white holes predicted?
     
    Last edited: Jun 22, 2006
  6. Jun 22, 2006 #5

    George Jones

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    In this case, white holes are valid mathematical solutions for Einstein's equation of general relativiy that, for all practical purposes, have been discarded because the solutions don't appear to be physical.
     
  7. Jun 24, 2006 #6
    Well, before asking whether we can observe white holes, it's probably a good idea to note that we still don't have conclusive evidence of the existence of black holes! Everybody believes that they exist because the evidence is strongly in their favour, but it's not a closed case by any means.

    The idea of a white hole is largely a mathematical construct. In particular, if one looks at the Schwarzschild solution there exists a very well-known technique called "maximal analytic extension" which you can think of as taking the implications of the Schwarzschild metric to their extreme logical conclusion. A white hole is essentially a time-reversal of a black hole. Things can escape from the white hole region of the maximal Schwarzschild spacetime into our part of the universe, but we can never put anything in to the white hole. This is the opposite of a black hole: we can put things into the black hole but once they're in there, nothing can ever come out.

    As I said, this is an interesting, but largely mathematical idea. It's primarily useful since if you want to construct a conformal, or Penrose, diagram of the spacetime, you're always interested in the *entire* spacetime, not just the part that we believe to be physical.
     
  8. Jun 25, 2006 #7

    Chronos

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    Nothing much is ever proven in cosmology, we rely upon the preponderance of evidence. The preponderance of observational evidence favors the existence of black holes, whereas there is virtually no observational evidence favoring the existence of white holes.
     
  9. Jun 25, 2006 #8
    a white hole would be kinda hard to miss
    as they are a big bright thing
    and we just donot see any such thing

    UNLESS you think the BIG BANG is one
    in that case we are in one
    or the cooling remain of one anyway
     
  10. Jun 29, 2006 #9
    White holes don't have to be bright.
    We might assume that when a beam of light goes into a blackhole it gain's so loses so much energy that when it comes out...it is super slow.
    Or its super fast so it just goes right by us.
    Or the whiteholes we have from other universes are from dead universes with no light to go through.
    In anycase their are many reasons why there might not be wormholes. Or why they exsist.
    If we get a Hubble Like Gravitational telescope anytime soon we would know. The universe would look like paper with weird folds and cones. Cones that go up- whiteholes,
    cones going up- blackholes.
     
  11. Sep 17, 2006 #10
    i was thinking the same thing sounds plausable. Has anyone looked at the simularitys between a 'white hole' and the big bang? mathmatically speaking of course
     
  12. Sep 17, 2006 #11
    that contradicts the laws of physics. you may say what you want about the ray of light while it is "inside" or near a white whole but once it is sufficiently far enough in the astronomical sense that light or to be more precise electromagnetic radiation beam follows the laws of our universe one of which that light travels at C if we are talking about a scenario that falls under the special relativity, or that its speed is very close to C as long as it is moving in a region of space that is not highly warped "which is really almost every where in the universe" that light would still have a speed very close to C. point is unless you are saying that the photon actually has been permenantly changed which i cannot think of any physical reason why it would once that photon leaves the highly wapred region close to a white whole it would become a regular photon. btw the energy of the phton does not at all affect its speed the energy affects the wave length "or frequancy if you will" of the beam meaning changing the color of the light composed of these phtons or maybe even transforming it into microwave or another type of radiation but it will always travel at C.

    i have no problem with that but remeber the rule in physics and in science is that things do not exist until we prove they do not that every possible thing exists until we prove it doesn't.
     
  13. Sep 18, 2006 #12

    Lee Smolin's Cosmic Natural Selection model is based on the idea that black holes give birth to new universes- and that Natural Selection would favor universes with more black holes and thus more offspring universes- he created the theory as a sort of example of a testable multiverse theory to argue against the Anthropic Principle and M-Theory Landscape-

    he describes it in this paper: http://www.arxiv.org/abs/hep-th/0407213

    and wrote a book on it: http://www.amazon.com/Life-Cosmos-Lee-Smolin/dp/0195126645


    I have a related idea that is a bit of a corollary to Smolin's CNS conjecture: that because Black Holes are by definition quantum computers- of VERY large numbers of qubits- that instead of a black hole generating one new cosmic region with a single history that it actually computes the ENTIRE Hilbert Space of possible quantum histories that it's trapped mass can take in superposition- thus each black hole actually computes a transfinite number of 'baby virtual universes'
     
    Last edited: Sep 18, 2006
  14. Sep 18, 2006 #13

    hellfire

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    Consider a perfect spherical universe, homogeneous and isotropic with positive curvature of space filled with dust. Put a single pointlike light-source, say, on the "north pole" - lets take the two dimensional analogy to make things more simple to figure out. The energy flow or the number of photons per area will decrease as we increase our distance from the light source until we reach the equator, because the "area" grows. However, when approaching the "south pole", the energy flow will increase again as the "area" decreases, and an observer located at the "south pole" would see the same intensity of light, temperature, etc. than one located at the north pole. Consider now a black hole instead of a light-source at the "north pole". Would a white hole form at the "south pole"? I don't know the answer, but my intuition tells me it would. This would be, however, a white hole without any "unphysical" condition.
     
  15. Sep 23, 2006 #14
    Our universe seems to have an imbalance of matter and anti-matter. Perhaps it might also have an imbalance of black holes and white holes, or perhaps white holes and black holes would not (or could not) exist in the same universe.

    A black hole is continuous in operation. It's opposite would seem likely to be a short lived entity. Instead of continuously emitting matter it might loose everything in a very short time.
     
  16. Jun 10, 2009 #15
    They only exixst mathematicly. Even if they are possible, we would not be able to see them because they would be very difficult to detect.
     
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