Simple geometric proof GR's GW's are impossible

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Q-reeus, Jul 7, 2016.

  1. Q-reeus Valued Senior Member

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    X, and in retrospect also Prof. Isi, hold that global constraints on GR GW metric perturbations are not an issue since space is being alternately created and destroyed - not just stretched and compressed. My problem with that remains the same - for transverse perturbations it implies objects e.g. 'sticks' do not scale with the metric so as to preserve proper spacings.
    For a spherically symmetric geometry like exterior Schwarzschild metric, there is indeed more space created owing to presence of a gravitating mass. All without violating the principle that metric scaling acts identically on everything within - afaik another way of stating SEP (strong equivalence principle). This nice compatibility fails in GR GW situation.

    How long it takes to exhaustively compare predictions of all currently viable competitor theories is anybody's guess. Won't be soon - unfortunately.
     
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  3. James R Just this guy, you know? Staff Member

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    paddoboy:

    No need to ask. It's obvious that q-reeus is of the strong belief that GR is wrong, and q-reeus believes that gravitational waves as described by GR are impossible.

    I think that q-reeus is most likely wrong, but I do not have the time to be able to make a definitive judgment on this, based only on the material presented here and my existing knowledge. Moreover, I am not heavily invested in who is right or wrong on this. If q-reeus should happen to be proved correct, we'll hear about it in all the reputable science journals later. I can wait. I don't need the answer now. I'll let the experts do the work on this.

    This thread is a challenge to GR, so it does not stand unchallenged. q-reeus obviously thinks he has a solid argument against GR. Any real argument of that kind will need the maths to support it. In this thread, I've seen occasional hints of some maths, but with little to no detail. I haven't read up on Carver Mead's theory or his mathematics, and I don't know whether he even agrees with q-reeus's position.

    You're quite right that it will be very big news indeed if q-reeus from sciforums manages to overturn GR on the basis of his "no GR gravitational waves" argument. I'd say he has a lot of work still to do to do that, based on what I've seen so far.

    I already read it. To summarise this quote from the email, Dr Isi says, in effect:
    • Experiments can't prove GR (or, indeed, any theory).
    • Non-GR physics is always a possibility.
    • The LIGO results are consistent with GR [but bear in mind that they may well be consistent with some other theory, too].
    • The degree of agreement between experiment and theory is quantifiable (indeed, that is a vitally important part of experimental physics), and there is good agreement between LIGO and GR.
    Nothing in this quote disputes what I wrote: "The experts seem to be keeping an open mind regarding whether Carver Mead's theory works or not."
     
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  5. James R Just this guy, you know? Staff Member

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    No need to do that, though. If Carver Mead's theory is the one you like, just work on comparing that one for a start.
     
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  7. Q-reeus Valued Senior Member

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    I like it for both it's compatibility with existing tests, and that GW's in G4v as vector fields acting within spacetime, rather than distortions of spacetime, have no prima facie global constraint issues. As for working on it, currently there is only the merger chirp data from those two aLIGO events. Unlike continuous wave situation which has been worked through in detail, only heavy number crunching with supercomputers have a hope of distinguishing between theories. And my guess is even there it will take additional detections which involve additional detectors e.g. VIRGO expected online in 2017.
     
  8. paddoboy Valued Senior Member

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    Don't be so pedantic James. While this thread is by its nature a "challenge to GR" on this forum, it means absolutely nothing in the greater scheme of things, and remains unknown in academia in general. The already admitted lack of replies from experts that q-reeus himself has claimed to have e-mailed, and his paltry excuse in not publishing what replies he did get, says a lot as to any supposed challenge that some believe exists.
    Plus two replies from experts one being Kip Thorne, like yourself, seem to treat this whole affair with some contempt, and I believe they have good reason to do so:
    Not withstanding any fabricated conspiracy nonsense of course.
     
    Last edited: Aug 15, 2016
  9. The God Valued Senior Member

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    Can you be more specific on this ? What conspiracy and by whom and against whom ?
     
  10. paddoboy Valued Senior Member

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    The conspiracy crap most alternative hypothesis pushers, claim with mainstream academia, being recalcitrant and not wanting to let go etc etc...you know. We have them here,

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  11. The God Valued Senior Member

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    Have you heard of Carver Mead ? Do you think he would talk of conspiracy biad by GR guys to push his theory?
     
  12. paddoboy Valued Senior Member

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    Professor Mead is a scientist and does not participate on this forum.
    I'm speaking of course of our own online conspiracy adherents.
    And of course Professor Mead has invalidated nothing as yet, and I'm not holding my breath!
     
  13. Q-reeus Valued Senior Member

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    In view of the reappearance of a self-exiled member recently, I also make a reappearance in order to preemptively tidy up this thread.
    Previously indicated my changed position re viability of GR style GW's elsewhere, iirc most recently here: http://www.sciforums.com/posts/3450810/
    Have nothing further to add or change from there, except for....

    The remaining issue this thread, and in e.g. this post: - viability of Carver Mead's G4v has evidently now been settled in the negative: https://arxiv.org/abs/1709.09660
    See e.g. last part of Introduction there. One must always accept valid observational evidence as the decider.

    But to repeat - GR style pure tensor + & x GW's does not 'prove' GR to be correct. See e.g. https://arxiv.org/abs/1710.03794 for a thorough survey of the difficulties involved in deciding between the many competing theories out there.
     
  14. paddoboy Valued Senior Member

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    Thank you qreeus, didn't expect you to miss me so much. I also accept your admittance that you were wrong...not that I am an expert mind you, we all know different and I'm always open on that score...The simple undeniable fact though is that no one will invalidate any mainstream scenario, or incumbent theory from the realms of their lounge chair in front of a computer, in discussion on a public science forum.
    In the meantime here are some interesting facts you may be interested in....

    https://arxiv.org/ftp/arxiv/papers/1710/1710.05832.pdf

    GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
    Abstract:

    On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0 × 104 years. We infer the component masses of the binary to be between 0.86 and 2.26 M⊙, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17–1.60 M⊙, with the total mass of the system 2.74þ0.04 −0.01M⊙. The source was localized within a sky region of 28 deg2 (90% probability) and had a luminosity distance of 40þ8 −14 Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology


    VI. CONCLUSIONS
    In this Letter we have presented the first detection of gravitational waves from the inspiral of a binary neutron star system. Gravitational-wave event GW170817, observed and localized by the two Advanced LIGO detectors and the Advanced Virgo detector, is the loudest gravitational-wave signal detected to date. This coalescence event was followed by a short burst of γ rays observed with the Fermi GammaRay Burst Monitor [39–42] and INTEGRAL [43,44]. The coincident observation of a gravitational-wave signal and a γ- ray burst appears to confirm the long-held hypothesis that BNS mergers are linked to short-γ-ray bursts [196,197]. Subsequent observations have determined the location of the source and followed its evolution through the electromagnetic spectrum [50]. Detailed analyses of the gravitational-wave data, together with observations of electromagnetic emissions, are providing new insights into the astrophysics of compact binary systems and γ-ray bursts, dense matter under extreme conditions, the nature of gravitation, and independent tests of cosmology. Less than two years after the debut of gravitational-wave astronomy, GW170817 marks the beginning of a new era of discovery.
    :::::::::::::::::::::::::::::::::::::::::::::::::::::

    And if you havn't been keeping abreast of the news, the following was a foregone conclusion but always great to rehash, don't you think?
    >>>>>>>>>>>>>>>>>>>
    https://www.ligo.caltech.edu/news
    https://www.ligo.caltech.edu/news/ligo20171003

    Nobel Prize awarded to LIGO Founders
    News Release • October 3, 2017

    The LIGO Laboratory, comprising LIGO Hanford, LIGO Livingston, Caltech, and MIT are excited to announce that LIGO’s three longest-standing and greatest champions have been awarded the 2017 Nobel Prize in Physics: Barry Barish and Kip Thorne of Caltech and Rainer Weiss of MIT.

    The announcement was made this morning by the Nobel Committee in Stockholm Sweden. First broadcast live, you can watch the recording here: Nobel Prize in Physics Announcement

    LIGO Executive Director, David Reitze, had this to say in response to the win

    “I’m positively delighted that the Nobel Committee has recognized the LIGO discovery and its profound impact on the way we view the cosmos. This prize rewards not just Kip, Rai, and Barry but also the large number of very smart and dedicated scientists and engineers who worked tirelessly over the past decades to make LIGO a reality.“

    A flurry of congratulations from all over the LIGO Laboratory has come in:

    “Rai made this happen, person by person and idea by idea. He really worked to enable individuals to help in the adventure, and no problem was too small to get his complete attention if it was in the way of success. Between the human legacy of a generation of scientists and engineers, and the scientific legacy of this step forward in physics, Rai earned this prize.”

    --David Shoemaker (MIT), leader of the Advanced LIGO Project
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


    The next few years should be highly enlightening and we really need to keep in touch and rehash what the professionals and those with their nose to the grid stone are discovering and finding. All the best qeerus.
     
  15. Q-reeus Valued Senior Member

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    Thanks for that sincere-I'm-sure ending. Yes I had already looked at the your above posted article re BNS merger awhile back. Unfortunately it contained afaik nothing definitive re distinguishing various gravity theory models. Which is why I chose the arXiv article linked to in #330.
     
  16. paddoboy Valued Senior Member

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    It fits with the GR model and that's what counts, I'm sure you'll agree.
    We'll talk again after the next discovery/finding, OK? I'm anxious to keep you filled in on this exciting new physics and knowledge.
    You know where to find me...or would you like the other forum address I'm now participating in?
     
  17. Q-reeus Valued Senior Member

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    Your choice paddoboy.
     
  18. paddoboy Valued Senior Member

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    Thanks!

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