Wednesday, October 4, 2017

Nobel prize for gravitational waves

The NY Times reports:
Rainer Weiss, a professor at the Massachusetts Institute of Technology, and Kip Thorne and Barry Barish, both of the California Institute of Technology, were awarded the Nobel Prize in Physics on Tuesday for the discovery of ripples in space-time known as gravitational waves, which were predicted by Albert Einstein a century ago but had never been directly seen. ...

Einstein’s General Theory of Relativity, pronounced in 1916, suggested that matter and energy would warp the geometry of space-time the way a heavy sleeper sags a mattress, producing the effect we call gravity. His equations described a universe in which space and time were dynamic. Space-time could stretch and expand, tear and collapse into black holes — objects so dense that not even light could escape them. The equations predicted, somewhat to his displeasure, that the universe was expanding from what we now call the Big Bang, and it also predicted that the motions of massive objects like black holes or other dense remnants of dead stars would ripple space-time with gravitational waves.
These articles cannot resist making all about Einstein. But Einstein did not really believe in the geometry of space-time, or in black holes, or in the Big Bang, or in gravitational waves.

You might say: "Who cares what Einstein believed? His equations imply those things, whether he believed in them or not."

I would not say that they are his equations. Grossmann and Levi-Civita convinced him to use the Ricci tensor, and the equation is Ricci=0. Einstein's contribution was minor.

Einstein is mainly famous because he is credited for special relativity, and the only reason he is credited for that is that supposedly Lorentz and Poincare had some faulty beliefs about the interpretation of the equations. Everyone agrees that Lorentz and Poincare had all the equations before Einstein. So if the credit is based on who had the equations, not who have the proper beliefs, then Einstein should get no credit for special relativity. (I say that Einstein was the one with the faulty beliefs about special relativity, but most ppl do not agree with me on that point.)

Anyway, congratulations to the Nobel winners and the LIGO team. It is nice to see a prize given within a couple of years of the discovery being made.

5 comments:

  1. Roger,
    before you congratulate, maybe you should look over a few problems with the 'discovery'.
    .
    http://www.nbi.ku.dk/gravitational-waves/gravitational-waves-comment2.html
    .
    http://www.nbi.ku.dk/gravitational-waves/hannover-presentation.html
    .
    This isn't looking through a telescope and saying "There it is." This is making up a computer modeled image of something never observed before, and using it as a 'template' to locate such a signal in a lot of noise, claiming your best fit IS therefore what your imaginary template is SUPPOSED to be. There are so many problems with this, starting with the obvious: how do you know your template is correct? Has the 'detected' orbiting black holes been confirmed by some other means than massaged noise from laser interferometry? Black holes if they are anything as imagined should have some pretty telling astronomical evidence that other means of detection could find, especially if a location was provided.
    .
    There are several different scenarious:
    1. Nothing is there. LIGO results would be further in question then. Gravity waves have not been confirmed.
    .
    2. Something is there but not orbiting black holes. LIGO results are still wrong, they may have been detecting something purely electromagnetic, not gravitational in nature, in any case gravity waves will not have been confirmed.
    .
    3. Two black holes are located where LIGO indicated. All evidence points to confirmation of LIGO being correct, then and only then, can you have your party.
    .
    I'm sorry, but am I the only one thinking this?
    Where on Earth are the healthy skeptics?
    It's going to be a tad more awkward than 'Ooops!' if this thing blows up in their faces after all the prizes and endorsements have been handed out. Granted, they have had some experience after the Nobel-Prizus-interuptous of BICEP2.
    .


    As I've said elsewhere, and quote effortlessly:
    “Nothing leads the scientist so astray as a premature truth.”
    . Jean Rostand

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  2. I have posted some skepticism about LIGO before. There is now a European detector, and I am counting on the Europeans to keep the LIGO folks honest.

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  3. Roger,

    Prof. Thomas Levenson has blogged a bit about the history of gravitational waves; see here: https://inversesquare.wordpress.com/2017/10/03/cosmic-goodness-immigrant-edition/ , esp. from this point onwards:

    "You can follow this prize---as so many before it---back to Albert Einstein. As Mavalvala explains, the concept of the gravitational wave emerges directly from Einstein’s theory of gravity, the General Theory of Relativity.

    To say "directly" is, as usual, a bit of misrepresentation."

    Would like to see if you have any comment(s)/additions to make about it.

    Best,

    --Ajit

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  4. I complained about some need for a correction in the New York Times after gravitational waves were announced. Then they had Lawrence Krauss do a little bit of a backpedaling about Einstein. The problem with the physics Nobel is that it's outdated and doesn't recognize ACTUALLY important findings. There is no Nobel for inventors and even the medicine Nobel is all about theory. For instance, I live in Western New York and Roger certainly knows (via Tom Cori) that the Coris discovered the Cori cycle here. Roswell Cancer Institute is a joke today. It just sucks money and never properly investigated immunology. However, I remember Wilson Greatbatch living just a little ways from my house and he never got a Nobel for inventing the pacemaker and creating a great local company that produces them. Pompous BS.

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  5. Roger,
    There is a problem with merely reproducing a signal on another detector. You have to confirm that the signal is what you claim it is. Until orbiting black holes are actually found by something other than gravity waves, and are located in the same place the gravity waves indicated, they have made an unsubstantiated claim. The signal like I stated above could be caused by something other than what they claim. Like I said earlier, I'm surprised at the lack of honest skepticism.

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