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black hole firewalls

Discussion in 'Electronic Design' started by Jamie M, Apr 6, 2013.

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  1. Jamie M

    Jamie M Guest

    Hi,

    Here is a new theory of a black hole's event horizon being a "fire wall"
    of high energy:

    http://www.nature.com/news/astrophysics-fire-in-the-hole-1.12726

    In the article this "fire wall" is required based on the assumption of
    entanglement, and "breaking entanglement" releases energy and creates
    the firewall. It is causing a lot of dispute though since if the
    firewall exists, then apparently it goes against Einstein's equivalence
    principle. So it sounds like it is another nail in the coffin of
    "spooky action at a distance" entanglement!

    cheers,
    Jamie
     
  2. Bill Sloman

    Bill Sloman Guest

    Jamie hasn't read this article correctly. There's nothing wrong with
    entanglement - it's an experimentally established fact - but there's a
    lot wrong with general relativity when you try to apply it at a scale
    where quantum effects become visible. the article is just talking
    about just talking about one more example of this well-known fact.

    It's odd that the article doesn't refer to

    http://en.wikipedia.org/wiki/Loop_quantum_gravity

    which seems to tackle this particular problem.
     
  3. Jamie M

    Jamie M Guest

    Hi Bill,

    I was basing my summary on this section from the article mid way down,
    which seems to indicate that if the firewall doesn't exist then
    entanglement may be flawed:

    "Yet a rigorous result of quantum mechanics dubbed ‘the monogamy of
    entanglement’ says that one quantum system cannot be fully entangled
    with two independent systems at once.

    To escape this paradox, Polchinski and his co-workers realized, one of
    the entanglement relationships had to be severed. Reluctant to abandon
    the one required to encode information in the Hawking radiation, they
    decided to snip the link binding an escaping Hawking particle to its
    infalling twin. But there was a cost. “It’s a violent process, like
    breaking the bonds of a molecule, and it releases energy,” says
    Polchinski. The energy generated by severing lots of twins would be
    enormous. “The event horizon would literally be a ring of fire that
    burns anyone falling through,” he says. And that, in turn, violates the
    equivalence principle and its assertion that free-fall should feel the
    same as floating in empty space — impossible when the former ends in
    incineration. So they posted a paper on the preprint server, arXiv,
    presenting physicists with a stark choice: either accept that firewalls
    exist and that general relativity breaks down, or accept that
    information is lost in black holes and quantum mechanics is wrong1. “For
    us, firewalls seem like the least crazy option, given that choice,” says
    Marolf."

    Would this firewall still exist with loop quantum gravity?

    cheers,
    Jamie
     
  4. YOU are FOOLY entangled.

    Think about the statement.

    'Fully' and 'independent' are kind of mutually exclusive, don'tcha
    think?
     
  5. Yeah, you're a bit loopy too.

    Will the universe simply disintegrate one day?

    What is your opinion on where things are going to 'end up'?

    Bigger things... not the smaller realm.

    Oh, and check the January Scientific American for an article about
    Einstein's flaws with relation to a certain epoch in the early moments
    at the beginnings of our material universe.

    The 'Of course he was wrong about this too" post was kind of stupid.
    Everybody was wrong about things back then. HE was closer than most
    about most of it. Period.
     
  6. Bill Sloman

    Bill Sloman Guest

    As I said, you've misunderstood what's being discussed. There's no
    evidence that the firewall does or doesn't exist - it's an artefact of
    a particular theoretical approach - while entanglement is real, so
    it's the theory that predicts the firewall that might be flawed.

    <snip>
     
  7. Jamie M

    Jamie M Guest

    Hi,

    I've never seen any compelling evidence for "spooky action at a
    distance" type entanglement, but lots of paradoxes and problems are
    created if you believe in it, and the firewall idea is just one
    more.

    cheers,
    Jamie
     
  8. Same magazine volume I mentioned has just such an article in it.
     
  9. The article was called "Strange and Stringy".
     
  10. Jamie M

    Jamie M Guest

  11. Tim Williams

    Tim Williams Guest

    Most problems are consistent with hidden variables, i.e., at the moment an
    entangled particle system is created, the particles themselves are in
    whichever state -- you just can't tell which states they are until they
    hit the detector(s).

    With this view, Schroedinger's equation isn't a description of the
    physical world, but only tells you what's observable (you can't observe
    the hidden variable directly, because your tools are too clumsy -- knock
    an electron with a photon and it's spinning wrong, etc.).

    Problems that are not consistent with this include time-dependent
    interference. A classic experiement takes a two arm interferometer, with
    one arm perturbed (like with a 1/4 wave plate or something, so
    interference still occurs, and produces a certain result). (I don't
    remember the particular details, so I'm going to botch this explanation.)
    When a particle is fired, the 1/4 wave plate is momentarily modulated,
    just as the particle is passing. If the particles' behavior is consistent
    with hidden variables (i.e., the state of a given particle is
    distinguishable* and unchanged), interference cannot occur because, at the
    moment the one particle passed the now-changed piece of apparatus, there
    is no way for that change to propagate back up the beam to interfere with
    the other particle. Moreover, the experiment can be done with opposed
    interferometer arms, ruling out line-of-sight, light speed information
    propagation.

    *Distinguishability is an important topic in QM and statistical mechanics.
    Electrons are all identical particles; the only way you can identify one
    is if it's put into a particular state (energy, momentum, postion,
    spin..). If you put a bunch of electrons into states with equal energy
    levels, you have no way of knowing whether those electrons switched
    places. They could've shuffled around and you wouldn't know. This is
    called a degenerate state, and has thermodynamic implications: because the
    states are indistinguishable, they are only counted once, so the entropy
    (S = k_B ln W, where W is the "number of states") is lower than if the
    energy levels are all a little bit different (and thus you could tell if
    one of the electrons switched places, because it would've had to exchange
    energy to do so).

    Most of QM is consistent with hidden variables; QM, entirely, is not. As
    far as I know, QM *is* consistent with hidden variables *with retarded
    potentials*, but it's up to you which you find more disagreeable:
    instantaneous propagation, or propagation at light speed both forward *and
    backward* in time!

    Which isn't as horrible as it sounds. Feynman and Wheeler spent a long
    time developing QED (i.e., QM (Schroedinger's) with electrons (the Dirac
    equation), and E&M (Maxwell's), combined in a complete theory) using
    retarded potentials. There are no antiparticles in this theory; what we
    call antiparticles are simply the regular things going backwards through
    time. Almost all reactions are reversible, so hey, why not?

    Tim
     
  12. Jamie M

    Jamie M Guest

    Hi,

    That's the same with "un-entangled particles" too, you can't tell which
    state they are in until they hit the detector. So what extra property
    is the word entangled describing in this case?
    The beam that passes through the momentarily modulated plate is
    changed, so I don't see why you would expect there to be the same
    interference (as without the modulation) with the other beam. The only
    reason to expect something different is if you assumed there is spooky
    action at a distance entanglement between the two beams? Maybe I'm not
    understand the point of the experiment, if you could send a link for
    it I'd like to check it out. If you reverse the modification with
    another in phase modulated 1/4 wave plate then the two beams should
    interfere the same as before.

    cheers,
    Jamie
     
  13. Jamie M

    Jamie M Guest

    Hi,

    I think its more likely to get some positive results with matter
    entanglement than "photons". Matter can be entangled but EM waves can't
    IMHO! :)

    "Entangled Atomic Beams"
    http://physics.aps.org/story/v6/st20
     
  14. josephkk

    josephkk Guest

    It seems to me that the "firewall" explanation would require a "glowing
    ring" around a black hole. Do we observe that?

    ?-)
     
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