Questioning LIGO

Well. Cat, meet pigeons..

A paper appeared on the arXiv this week with the following abstract:

To date, the LIGO collaboration has detected three gravitational wave (GW) events appearing in both its Hanford and Livingston detectors. In this article we reexamine the LIGO data with regard to correlations between the two detectors. With special focus on GW150914, we report correlations in the detector noise which, at the time of the event, happen to be maximized for the same time lag as that found for the event itself. Specifically, we analyze correlations in the calibration lines in the vicinity of 35 Hz as well as the residual noise in the data after subtraction of the best-fit theoretical templates. The residual noise for the two more recent events, GW151226 and GW170104, exhibits equivalent behavior with respect to each of their time lags. A clear distinction between signal and noise therefore remains to be established in order to determine the contribution of gravitational waves to the detected signals.

I’m going to tread carefully here because (a) I have a number of colleagues at Cardiff who are directly involved in the analysis of LIGO data; (b) one of the authors of the new paper (Panel Naselsky) is a longstanding collaborator of mine; and (c) the new paper has not yet been refereed.

In fact I’m planning to visit Copenhagen in July/August and will catch up with Panel and the other authors then.

Whether or not the points raised in the new paper are correct – and I am firmly agnostic, having not done the analysis myself – I think it’s entirely reasonable of the authors to subject the LIGO data to independent analysis. That’s how science is supposed to work; the relevant data are in the public domain now. 

No doubt the LIGO consortium will respond officially in due course. Of course, if anyone would like to comment unofficially then they are free to do so through the box below.
Update: Here is a fairly detailed rebuttal post.

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15 Responses to “Questioning LIGO”

  1. Michel C. Says:

    A third detector is needed…

  2. Gravitational effects are changes of speed (acceleration/delay) and direction. These changes go hand in hand with changes in mass/energy. How can these processes produce a detectable surplus given the constancy of E/M (E = MCC)?

    • telescoper Says:

      I’m afraid this question betrays a basic lack of understanding of physics.

      • For me it is difficult to understand physics that does not seem logic to me , but I am eager to learn. My problem is minor in comparison with all the unsolved problems/inconsistencies in physics Also in the case of gravitational waves there is no general agreement as yet about the nature of the detected pulses (hope this is the right word). Furthermore the true source of gravity is unknown as yet.

        One physicist says that string theory must be true because of its beauty, the other ( a Nobel laureate ) says it is medievel religion. So, does it matter that I am only someone who is interestred in physics?

      • telescoper Says:

        If you want to understand physics you need to study it systematically. Start with a school textbook on mechanics before even thinking about string theory!

  3. Anton Garrett Says:

    Am I right in thinking that they are questioning *only* the time delay between the observations? In that case the detection of gravitational radiation stands, and only the limited information about what part of the sky it came from is thrown into question. Perhaps the last sentence of the Abstract, which appears to question the detection of gravitational radiation at all, is too strong?

  4. I have done so and I still do. I keep on searching for answers. Your ad hominems and value judgements are not very helpfull, just like the value judgements on string theory from renowned physicists.
    I am going to try and find substantive answers/comments elsewhere. Wish you all the best.

    • telescoper Says:

      I gave you advice, not value judgement. It’s up to you whether you accept it. Bye.

    • Anton Garrett Says:

      You need to walk before you can run. If you are genuinely interested in physics – and genuine interest is always welcome – then you need to educate yourself in it, by which I mean be able answer examination questions that have been set at progressively higher levels in the subject. Mathematics is necessary as it is the language of physics. Best wishes in this task.

      • I don’t agree with this. People who want to participate in the Olympic marathon need to walk before they can run, but people who just want to watch the marathon, enjoy it and ask why did they accelerate there, or why did they drop back there, don’t even need legs. Science is mainly a spectator sport. A link to the sticky bead argument would hopefully have sufficed to answer the original question. https://en.wikipedia.org/wiki/Sticky_bead_argument

      • telescoper Says:

        I disagree with the statement “science is mainly a spectator sport” – it’s a lot more than that.

  5. I have written extensive rebuttals exposing the flaws of LIGO after each of the team’s previous two claimed discoveries. Am I allowed to post the links to these articles?

    if so, they are as follows:

    http://plasma.pics/problems-with-the-ligo-gravitational-wave-discovery/

    http://plasma.pics/flawed-second-ligo-gravitational-wave-discovery/

    • telescoper Says:

      I’ve allowed the links but I have to say that there’s nothing in these articles that amounts to a rebuttal.

      The time series data for these LIGO events are in the public domain and are available to download. The detections are easily verified.

  6. I can see how my “science is mainly a spectator sport” could be misunderstood. By that I don’t mean that science isn’t useful for curing diseases, making lives more comfortable or understanding our impact on the planet. What I meant was that hopefully most people interested in science, and in particular what it says about our place in the universe, are not professional scientists. Most people have other important roles to play in society and perhaps don’t have the time or the inclination to learn all the mathematics necessary to understand exactly what their tax pounds are spent on and what it says about the nature of reality. But they still do have a right to ask questions and hold scientists to account, even if they’re not able to answer examination questions at progressively higher levels.

    We see an example of this with the current issue of questioning the LIGO results. The vast majority of people, the majority of scientists, even most people in LIGO will, like in the OP, not bother to work through the mathematics or crunch the data themselves. In a large number of cases this will be because they don’t have the time or the inclination or the expertise. But they are still allowed to ask questions and judge for themselves whether the answers they get sound plausible or not. In that sense, science is mainly a spectator sport.

    • Questions should be informed, otherwise one ends up looking like the A&R man asking “Which one is Pink?” 🙂

      Sure, it is fine learning about, and even asking questions about, things in which one is not an expert. This is different from saying “the entire scientific community has overlooked some basic stuff”.

      If one has a question, ask the question, don’t couch it in the framework of one’s own misunderstanding.

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