A Celebration of Gravity Waves at the University of Maryland Nov. 1 2016

Discussion in 'Physics & Math' started by danshawen, Oct 28, 2016.

  1. danshawen Valued Senior Member

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    I'll be attending this:

    http://umd.imodules.com/s/1132/form2016.aspx?sid=1132&pgid=5025&gid=1&cid=7373&ecid=7373&post_id=0

    and before you ask, I will not be there to heckle Kip Thorne; only to humbly congratulate him on being right when so many of us thought the whole idea was wrong. Thank goodness he and others stuck with it. I was wrong and he and his team were right.

    It is fitting that such a celebration should eventually come to the institution that hosted the development of Joe Weber's early and not nearly sensitive enough gravity wave detectors. In a way, this is Joe's final vindication as well.

    Peter Shawhan, a principal investigator at LIGO will also be there. It is likely we are actually related on my father;s side of the family.. The branch of our family from Kent County, MD later moved to the Frederick, MD vicinity for a few twigs of our family tree and never changed the original spelling.

    Peter has already presented several colloquia lectures on the first detections of gravity waves. The second gravity wave detection event, a merger of black holes at much lower total mass lasted about 2 seconds in real time (as compared to about 0.2 seconds for the first one involving about 50 solar masses) and contained much detail which was missing in the first detected event. Evidently, the greater the merging masses the higher the frequency "chirp" of the resultant gravity waves.

    If there is any physics question you may wish asked at the conference, I would be happy to oblige by asking it for you, if for whatever reason you have not signed up to attend the event.
     
    Last edited: Oct 28, 2016
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  3. paddoboy Valued Senior Member

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    That's terrific and congrats on accepting you were wrong.
    Your "so many of us thought the idea was wrong" statement though is false I suggest.
    Forums such as this cannot be used as a guide for obvious reasons.
    Most physicists and cosmologists accepted gravitational waves, knowing that their detection was going to require incredible sensitivities.
    My own "lay person's" thoughts on the matter, went simply along the lines of "if spacetime can be warped, bent, twisted in the presence of mass, why not GW's?
     
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  5. paddoboy Valued Senior Member

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    If you are able to, you could ask about the work of Professor Carver Mead and the possibilities of gravitational waves in G4V
    here.....
    https://arxiv.org/abs/1503.04866
     
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  7. danshawen Valued Senior Member

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    An LIGO antenna pattern/configuration question. Good one. Any others?
     
  8. danshawen Valued Senior Member

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    In and around College Park (particularly coming from my direction) is the worst commute times in the area, made worse by the work currently underway on Metro. A slightly late start due to an ongoing family emergency made it even worse by delaying my departure until rush hour, so I never made it to the event; just gave up, turned around and headed back home. It was a bad commute when I went to school there, but now it's a heavy traffic nightmare. Sometimes, you just can't get there from here. At least, no one's life depended on my getting there.
     
  9. Q-reeus Valued Senior Member

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    Honestly, how can you repeat that error after so many corrections, beginning back in post #8 here:
    http://www.sciforums.com/threads/di...m-primordial-black-holes.158149/#post-3412606
    and continuing on to end of that page, and then on to p2 regarding another Dan repeat-error aspect of GW's. Please DO contact Shawhan, point him to that thread, and invite a response. There is a very simple scaling law at play and to keep claiming the inverse - *after* having ostensibly agreed with my finding, is both bizarre and irritating. The counterintuitive difference in detection spans can only be down to some aspect of aLIGO sensitivities - not a reflection of the fundamental merger physics.
     
  10. danshawen Valued Senior Member

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    I will attempt to contact him (or you can). I believe your analysis, am not repeating his error, if that is what it is, and am not trying to be irritating. My mother is dying, and I'm certain Peter's inbox is full about now.

    Thank you for your response.
     
  11. danshawen Valued Senior Member

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    I will attempt to contact him (or you can). I believe your analysis, am not repeating his error, if that is what it is, and am not trying to be irritating. My mother is dying, and I'm certain Peter's inbox is full about now.

    Thank you for your response.
     
  12. Q-reeus Valued Senior Member

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    Sorry to hear that. You have my sympathies. Family matters first. Don't stress re the GW issues, they are not important and can wait.
     
  13. Q-reeus Valued Senior Member

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  14. danshawen Valued Senior Member

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    Peter's presentation may have been referencing "chirp mass":

    https://en.wikipedia.org/wiki/Chirp_mass

    which seems to be some sort of conjugate mass derived of the evolution of the chirp waveform. With this definition applied, what Peter said in his presentation makes perfect sense, even if my own interpretation of it here really didn't.

    As far as I can determine, you are both correct. Enough, or do you need to rub my nose in my own poop some more?
     
  15. Q-reeus Valued Senior Member

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    If you need fine details about a binary with some arbitrary mass ratio then knowing chirp mass is very convenient, but has zero relevancy to the simple matter of scaling of frequency and duration (somewhat arbitrarily defined by cycle-count or elapsed-time between given relative amplitudes markers for the chirp envelope) vs overall system mass. What Shawhan stated, and you kept repeating, is simply wrong. I'm not out to rub your nose in anything, just clear up what is the actual physics.
     
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  16. danshawen Valued Senior Member

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    Thanks for that.
     
  17. Q-reeus Valued Senior Member

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  18. danshawen Valued Senior Member

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    I see no reason to do that now. Thanks to you, I understand that the chirp mass he was talking about is something mathematically derived from the chirp waveform. It will take more than a few minutes of study to understand all of the import of that. I anticipate a great deal of discovery in this field, and as far as I can see, all of the researchers are doing a great job.
     
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  19. Q-reeus Valued Senior Member

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    OK then.
     
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  20. danshawen Valued Senior Member

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