Page 1 of 3 123 LastLast
Results 1 to 30 of 88

Thread: Times Below the Planck Time?

  1. #1
    Join Date
    Apr 2012
    Posts
    641

    Times Below the Planck Time?

    ''Hawking's singularity theorem is for the whole universe, and works backwards-in-time: in Hawking's original formulation, it guaranteed that the Big Bang has infinite density. Hawking later revised his position in A Brief History of Time (1988) where he stated "There was in fact no singularity at the beginning of the universe" (p50). This revision followed from quantum mechanics, in which general relativity must break down at times less than the Planck time. Hence general relativity cannot be used to show a singularity.''

    excerpt from the holy book, wiki.

    Sure, quantum mechanics doesn't deal with singularities... but I wonder what motivated the above. Saying General Relativity breaks down at times less than the Planck Time, surely is essentially meaningless anyway, since we cannot measure anything which exists below the Planck Time or if we could it would essentially seem not to change at all. Does anyone have an incline to how Hawking is managing that arguement?

  2. #2
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    19,908
    On the face of it you seem to have found a chicken-or-egg issue with Hawking's argument. If Quantum Mechanics isn't the be-all and end-all at the Planck scales, then you can have singularities (unless there's some other yet-unknown issue). I'm sure people will be along soon with good explanations of what is and isn't known.
    Forming opinions as we speak

  3. #3
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    At abount the Planck energy it is predicted that all four forces will unify. Since we cannot produce a common framework to describe Standard model forces and gravity I think we can take this as an indicator that GR (and the Standard model) are totally broken at this point!

    I'd also stress that these units only state that the Planck length/time are the smallest increments we could measure in current physics models. We know our models are not complete (the GR/SM problem) and we know that they cannot be used below these scales. That does not mean that some more complete theory cannot work at sub-Planck scales.

  4. #4
    Join Date
    Aug 2003
    Location
    The Wild West
    Posts
    7,599
    Quote Originally Posted by Aethelwulf View Post
    Sure, quantum mechanics doesn't deal with singularities... but I wonder what motivated the above.
    I'm no pro in this field, but for one thing, quantum mechanics doesn't deal with gravity. And GR is smooth and continuous, but QM is discrete. I guess mainly, as one approaches the Planck scale, Heisenberg Uncertainty becomes more and more applicable, and GR doesn't deal with that. At Planck scales the very geometry of space becomes jittery and uncertain*, and no one has figured out how to define the metric in such an environment; hence, GR is left behind.

    _______________
    * I'm not sure what the conjugate variable is in this situation.
    Everyone is entitled to his own opinion, but not his own facts.

  5. #5
    Join Date
    Apr 2012
    Posts
    641
    Yes I would agree with that all. I think Hawking is jumping the gun a little. On one hand, physics breaks down in the presence of singularities which are indeed predicted by GR, however, GR breaks down in the face of understand quantum mechanics. There is definately a ''missing peice'' we need to solve, perhaps a new type of physics, but dismissing singularities altogether seems like he is dodging a bullet without providing a complete understanding of both situations.

  6. #6
    Join Date
    Sep 2011
    Posts
    403
    Quote Originally Posted by Shaula View Post
    ..... We know our models are not complete (the GR/SM problem) and we know that they cannot be used below these scales. That does not mean that some more complete theory cannot work at sub-Planck scales.
    If correctly attributed to Newton, The clockwise theorem could be a possibility. Could this model be a kind of time division multiplexing in which a particular channel is devoted to our current universe? In this case motion could be interpreted as oscillatory and wavelike for every particle correlated to Mark and Space of the clock pulse similar to a charge and decharge process(the only reason that charge particles exist!). In this case regarding the topic of the thread, Perhaps, Hawking has come to the conclusion that the lower limit for the current universe actually exists.

  7. #7
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    Given that the phrase "The Clockwise Theorem" returns zero Google hits I suspect it is not well developed enough to feature in a Q&A thread. "It could be the burbleburlbeburble theorem" is an equally valid comment.

  8. #8
    Join Date
    Sep 2011
    Posts
    403
    Quote Originally Posted by Shaula View Post
    Given that the phrase "The Clockwise Theorem" returns zero Google hits I suspect it is not well developed enough to feature in a Q&A thread. "It could be the burbleburlbeburble theorem" is an equally valid comment.
    Sorry, Clockwork Universe Theory. I wonder why no one pays enough attention to this theory compared to the theories that you mentioned(GR/SM), at least to some extent.

  9. #9
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    Oh that one - because it is utterly incompatible with Quantum mechanics, is more of a vague idea than a theory, makes no useful predictions and solves no problems. It requires more and more elaborate fixes to fill in its failings with respect to QM and violates Bell's Theorem quite spectacularly.

    That's pretty much why it can be ignored here.

  10. #10
    Join Date
    Apr 2012
    Posts
    641
    I wouldn't be too hung up on violating Bells Theorem just yet. It is violated in the presence of quantum mechanics anyway.

  11. #11
    Join Date
    Sep 2011
    Posts
    403
    One more point to add: Nowadays the term DIGITAL could have some meaning. Digital has proved that it can save full information of analogue domains. Perhaps this term would be the most appropriate that QT supporters should take into consideration.

  12. #12
    Join Date
    Apr 2012
    Posts
    641
    In fact, violation of Bells theorem gives rise to experimental varification of spin 1/2 particles.

  13. #13
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    Hmm, not seen that use of Bell's theorem before. I thought that the inequality was violated in the way QM predicted it would be, which was what ruled out many deterministic/local variable theories. The theorem is based on the violation of the inequality - is that what you mean?

  14. #14
    Join Date
    Apr 2012
    Posts
    641
    Actually no. The spin microframe and the resonance fringe are predicted in such violations

    http://arxiv.org/ftp/arxiv/papers/0707/0707.1763.pdf

  15. #15
    Join Date
    Aug 2003
    Location
    The Wild West
    Posts
    7,599
    Quote Originally Posted by Aethelwulf View Post
    Actually no. The spin microframe and the resonance fringe are predicted in such violations
    http://arxiv.org/ftp/arxiv/papers/0707/0707.1763.pdf
    Man, the author of that paper has quite the publication history and list of PhD students graduated. If that's you, congratulations. I, on the other hand, couldn't quite make it through the abstract.
    Everyone is entitled to his own opinion, but not his own facts.

  16. #16
    Join Date
    Apr 2012
    Posts
    641
    No that isn't me

  17. #17
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    I misunderstood you - I thought what you were saying was that experimental confirmation of fermions was dependent on a violation of Bell's theorem not covered by QM.

    I'd need to do some work to understand that paper - it looks on first glance like it uses a model I am not familiar with as its base in an attempt to do away with uncertainty. Interesting approach if I am right about that but I always get nervous around attempts to remove the probabilistic aspects of QM. Conservative, I guess! I grew up with gods that played dice.

  18. #18
    Join Date
    Apr 2012
    Posts
    641
    Hmmmm... I'm not exactly sure the paper says it is doing away with uncertainty. I might have missed that part, a lot goes on in the paper. Probabilities will always be apart of quantum mechanics.

  19. #19
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    From the conclusion:
    The statistical interpretation of quantum mechanics [19],[20] provides a physical basis for rationalizing the
    experimental results and avoids paradoxes [21]. All spin attributes are simultaneously elements of physical reality
    [2] for microstates so probability is not needed. However probability is needed in QT [22] and is found here to be a
    consequence of the lack of resolution of some local variables, see e.g. Eq.(3.3), due to effects such as phase
    randomization and averaging, which occurs naturally or as a result of preparation for direct measurement [19]. In
    such processes the hidden variables cannot be individually resolved and ensembles are formed.
    Doing away with is perhaps too strong a phrase - but AIUI it is stating that there are hidden variables and that the uncertainty we see is due to the fact that these variables operate at such small scales that they are 'blurred' by the effects the paper talks about. The biparticle links or ensembles then cause this blurring to 'propagate' through the system. But I have only skimmed the paper, I may be wrong.

  20. #20
    Join Date
    May 2008
    Location
    The Netherlands
    Posts
    10,441
    Quote Originally Posted by Cougar View Post
    Man, the author of that paper has quite the publication history and list of PhD students graduated. If that's you, congratulations. I, on the other hand, couldn't quite make it through the abstract.
    Me neither. I'm quite clueless on the subject, but I can't help notice that it doesn't seem to be published. Absent peer-review, how much value should be put on such a paper? I'm not arguing that answer should be 'none', I'm just curious how this status affects the paper's credibility. Is being published less of a requirement in this field?
    ____________
    "Dumb all over, a little ugly on the side." -- Frank Zappa
    "Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
    "This is really very simple, but unfortunately it's very complicated." -- publius

    Moderator comments in this color | Get moderator attention using the lower left icon:
    Recommended reading: Board Rules * Forum FAQs * Conspiracy Theory Advice * Alternate Theory Advocates Advice

  21. #21
    Join Date
    Mar 2008
    Posts
    5,195
    Its a bit like a tv picture. GR deals with the big picture and Qm deals with the individual bits that make up that picture. Its difficult to describe the big picture from one individual piece and likewise its difficult to desribe the make up of one individual piece from the big picture. We know that both form what we observe but it appears we need to describe them seperately to fully understand them. As an analogy, asking what happens below Planck time is similar to asking what happens below each pixel to form a picture. It may require a different set of rules, even maybe a different type of physics. currently we can only speculate and perhaps our concerns should lie with fully understanding what we can observe and measure first of all.

  22. #22
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    Quote Originally Posted by slang View Post
    Me neither. I'm quite clueless on the subject, but I can't help notice that it doesn't seem to be published. Absent peer-review, how much value should be put on such a paper? I'm not arguing that answer should be 'none', I'm just curious how this status affects the paper's credibility. Is being published less of a requirement in this field?
    The first two statements of the paper, the foundation of a lot of the rest of it, are from another unpublished paper by the same author (submitted to Journal of Physics A) which has a last revision date of 2009 and was first sent to arxiv in 2007 and from the 1935 paper by EPR on their paradox. A lot of the rest of the other references are to very old papers.

    Please note than none of this says "ignore the paper" - it looks quite interesting but without spending a week or more relearning stuff I am in no position to judge what it is saying. The more I look at it the more cautious I get about it. But the person who wrote it is far smarter than me and I'd like to see what a review panel of equally bright people said about it. It could be a very significant piece of work if it ties in with some of the other advanced gravity theories.

  23. #23
    Join Date
    Apr 2012
    Posts
    641
    The idea's brought forth in the paper truely are revolutionary. Most physicists believe that the electron is pointlike, but if this paper if correct, then it would seem to suggest that the electron really does have internal degrees of freedom, called the spin microframe which consist of two internal degrees of freedom.

    I think that would be hard for the public to chew, so this tiny snag I predict is what has kept it from peer review. Of course, this is not the way science should work, that even revolutionary idea's should not be shunned --- but unfortunately, the physics community is one of the most brutal.

  24. #24
    Join Date
    Apr 2012
    Posts
    641
    I don't follow all the math, but the parts which I can, the math seems correct.

  25. #25
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    I think that would be hard for the public to chew, so this tiny snag I predict is what has kept it from peer review. Of course, this is not the way science should work, that even revolutionary idea's should not be shunned --- but unfortunately, the physics community is one of the most brutal.
    Rigorous is the word. As part of said community I rather object to this stereotype of us as quashing new ideas because we are all set in our ways.

    And if you cannot follow the paper then you are no more suitable than I am to judge its worth. That is what peer review is for and what it does well. I have seen a lot of speculative and novel ideas pass peer review, if this one hasn't then I would guess that there is a problem neither of us are able to see.

  26. #26
    Join Date
    Apr 2012
    Posts
    641
    I don't get it all, doesn't mean I don't get it.

  27. #27
    Join Date
    Apr 2012
    Posts
    641
    It is a remarkably technical paper afterall.

  28. #28
    Join Date
    Apr 2012
    Posts
    641
    Quote Originally Posted by Shaula View Post
    Rigorous is the word. As part of said community I rather object to this stereotype of us as quashing new ideas because we are all set in our ways.

    Well I don't. I think it sums the scientific community, the majority rather well. Look at Everette the third, creator of the universal wave function and many worlds interpretation. He is legendary today, but after his thesis on the many worlds, he left physics for good because of the harsh reception of his new theory, even from prominent scientists.

  29. #29
    Join Date
    Mar 2010
    Location
    United Kingdom
    Posts
    4,157
    Quote Originally Posted by Aethelwulf View Post
    It is a remarkably technical paper afterall.
    Which means it requires a highly technical panel to review it.

    Well I don't. I think it sums the scientific community, the majority rather well.
    OK, well I will not assault you with my brutality any more then. I'll stop my utterly unjustified requests for review, evidence and prediction and let you get on with it.

  30. #30
    Join Date
    Apr 2012
    Posts
    641
    Quote Originally Posted by Shaula View Post
    Which means it requires a highly technical panel to review it.


    OK, well I will not assault you with my brutality any more then. I'll stop my utterly unjustified requests for review, evidence and prediction and let you get on with it.
    Could you have distorted what I said any more?

Similar Threads

  1. Ep. 218: Max Planck
    By Fraser in forum Astronomy Cast
    Replies: 0
    Last Post: 2011-Apr-08, 06:20 PM
  2. Replies: 0
    Last Post: 2010-Apr-22, 02:30 PM
  3. Planck time refresh rate
    By LSDreamer in forum Space/Astronomy Questions and Answers
    Replies: 4
    Last Post: 2005-Dec-30, 07:03 PM
  4. Planck Time = 0,0,0,0?
    By Jerryf in forum Space/Astronomy Questions and Answers
    Replies: 5
    Last Post: 2005-Oct-13, 04:44 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
here
The forum is sponsored in-part by: