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A LIGO Was It All Just Noise?

  1. Sep 28, 2017 #101
    The problem is that many times the skeptics aren't bound by any burden of proof. Often the skeptic is ill informed (and possibly has their own agenda) and makes disparaging, derisive claims that add nothing and only cast doubt. The baseless claims receive unwarranted attention and must be defended. Much of this discussion seems to follow that model.
     
  2. Sep 28, 2017 #102

    Ibix

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    True, but one presumes that a skeptic has some kind of response to "why on Earth would you think that's a relevant factor", which is all I think @Nugatory is asking. I don't think that it's unreasonable to ask a skeptic to provide some kind of order-of-magnitude calculation showing that the effect they're worried about is somewhere near a range that might affect the results. I can't even see why a linear speed relative to the CMB frame would be relevant unless the LIGO people were unaware that astronomical bodies move relative to the Earth, which seems slightly unlikely.
     
  3. Sep 28, 2017 #103
    Well if Redshift is relevant how much did the GW redshifted over time and loose energy?

    For Galaxies moving away we can keep track about what's going on, the Hubble constant, but a GW is just one short single pulse.

    Sure, we can know if it comes from one side or the other, 1 dimensional, but we know nothing about the 2nd dimension.

    An other issue is how symmetric is the Gravity Wave, two spiralling-colliding objects are not 100% spherical.

    Lots of unknowns!
     
  4. Sep 28, 2017 #104
    That's how democracy works, people get to ask questions. The duty of the opposition is to oppose. :wink:
     
  5. Sep 28, 2017 #105

    PeterDonis

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    Science is not a democracy.
     
  6. Sep 28, 2017 #106
    And regardless of the field, generally the less knowledgeable the opposition, the louder their claims.
     
  7. Sep 28, 2017 #107
    No, not in the sense of truth or usefulness of scientific findings.

    But lots of important projects are FUNDED by the democratic process, so it is wise to take questions and make the most advantage of "teachable moments." Taxpayers who fund these projects often do so not just for the advancement of science, but for the educational opportunities they afford both for students and the public at large. Good public relations means patiently answering a lot of questions that may be products of inadequate science education.

    If scientists are not prepared and willing to answer ill-informed questions, we should not complain too loudly next time the funding gets cut. One great lesson I learned at the Air Force Academy is that we're always on parade. Scientists would do well to learn the same lesson.
     
  8. Sep 28, 2017 #108
    Perhaps not a 'democracy' an sich, but people are allowed to ask questions in contrast to a dictatorship. And isn't it the duty of peers to analyze critically? Otherwise anyone can just publish and claim whatever they want.

    If it's not 'democracy' than what is the correct word for this 'interaction' to find the right consensus? I'm not sure if 'scientific method' fits the bill.
     
  9. Sep 28, 2017 #109

    PeterDonis

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    Yes. But who are "peers"? The proper definition of that term is not "anyone who has a question, no matter how ill-informed". The proper definition is "those who have sufficient understanding of the field to make informed criticisms".
     
  10. Sep 28, 2017 #110

    Nugatory

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    Of course people are allowed to ask questions. You asked, and your question was answered in posts 89, 91, 93, and 94: "No, we have the mathematical tools to show that the relative motion between the various sites will not introduce the sort of error that you're considering".

    What's not allowed is to argue because you don't understand or don't like the answer.
     
  11. Sep 29, 2017 #111

    mfb

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    The CMB is an arbitrary reference frame without relevance here.
    The sensitivity depends a bit on the direction - so what? I can't detect the Sun at night either. Is that an issue? Does that impact my observations of the Sun during the day?
    About 10%. Read the paper?
    For galaxies we don't rely on long-term observations of their distances either. The length of the measurement is irrelevant (apart from reducing statistical uncertainties).
    What does that even mean?
    There are no gravity waves. You mean gravitational waves. The emission is not spherically symmetric. So what?

    With that argument, you could stop all scientific progress by making up hundreds of nonsense suggestions and then watch the scientists refuting all of them while you simply make up hundreds of new ones.
     
  12. Sep 29, 2017 #112

    vanhees71

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    Indeed! Still some politicians don't get the idea that they cannot change the fundamental laws of nature by 2/3 majorities :biggrin:.
     
  13. Sep 29, 2017 #113
    "Science is a democracy, in that every scientist has a voice, but it is nothing like majority rule. Indeed, what ground can I stand on when the majority of my profession embraces a research program I can not accept even though accepting it would be to my benefit? The answer is that democracy is much more than rule by majority. There is a system of ideals that transcends majority rule."

    Excerpt from the chapter 'What is Science?' (The Trouble With Physics, Lee Smolin). I highly recommend reading the entire chapter, in it Smolin probably gives the most accurate definition of science given yet opposed to Popper, Kuhn, Lakatos and Feyerabend. In fact, I would probably make this chapter and the following compulsary literature for all science degrees.
     
  14. Nov 3, 2017 #114
    This paper was placed on the arXiv last month. The authors are researchers at the Perimeter Institute. They used techniques different from those used by both LIGO and the Danish group. They conclude that LIGO observed gravitational waves from black hole mergers, that there is no cross-correlation between noise in the detectors, and that the Danish group's apparent failure to use appropriate window functions casts doubt on their conclusions.

    Extraction of black hole coalescence waveforms from noisy data




     
  15. Nov 3, 2017 #115

    mfb

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    I'm not surprised, but it is nice to see that an independent analysis reproduces the results.
    Now we have this analysis, we have a binary black hole merger seen by LIGO and Virgo at the same time, and we have the neutron star merger with an optical counterpart. I think the question in the title has an absolutely clear answer.

    I wonder what the Danish group will do next...
     
  16. Nov 3, 2017 #116
    One would hope so, but
    According to this post from October 20 by 4gravitons (who is now at NBI), A LIGO in the Darkness, they also have problems with the neutron star observation. The last paragraph of the post-
    The 5th comment to the post, by 4gravitons, is especially problematic-
     
  17. Nov 3, 2017 #117

    mfb

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    Oh come on...
    That is basically accusing LIGO of active fraud. And if they do that, they could make their life much easier and claim LIGO didn't even record the published data.

    I think I'll just ignore them, that was the healthiest choice the whole time.
     
  18. Nov 3, 2017 #118
    Back in June when this all started I found this video of a talk given by Jackson- Understanding the LIGO gravitational wave event (GW150914)

    Regardless of his/their analysis, from the start of the video he seems to want to plant seeds of doubt and discredit LIGO as much as possible. At times it felt like I was watching a negative political attack ad. Anyone wanting perspective on this whole affair should listen to the talk.
     
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