Intermittency and strong solar wind-IMF epsilon coupling are common to all seven GW triggers, prominent in ground magnetometer field data, and in the coordinated almost-periodic global CG lightning triggering for periods identical to noise-lag correlations in LIGO strain.

Even underlying spectral components (ordinary broadband, upchirped, log-normal ELF) in pre-whitened LIGO transient time series are related by a single scaling constant and show amplitude and partition related by the same cutoffs as expected for signal for thunderstorms in the same topographic-ionospheric waveguide.

]]>Peter: What you say is possible. However this is in conflict with the claim in the tests of GR paper arxiv:1602.03841 in the section titled “Residuals after subtracting the most-probable waveform model. ” It says “Our analysis reveals that the GW150914 residual favors the instrumental noise hypothesis over the presence of a coherent signal as well as the presence of glitches in either detectors;” It maybe that in this paper a more sensitive analysis has been done and traces of residual signal has been found.

]]>The problem here is you cannot “throw into the ring zero signal”.

I think that’s why you need a third detector to characterize the correlated noise between the other two detectors. Unless you can identify all possible sources of noise and distinguish it from a GW signal to establish a clear signal to noise ratio.

I still think Ligo measured GWs though.

]]>I agree. But the Danish Abstract ended, “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.” And the paper itself concluded, “The purpose in having two independent detectors is precisely to ensure that, after sufficient cleaning, the only genuine correlations between them will be due to gravitational wave effects. The results presented here suggest this level of cleaning has not yet been obtained and that *the detection of the GW events needs to be re-evaluated with more careful consideration of noise properties.*” If nobody is suggesting that gravitational waves have not been detected then these statements written as punchlines are, frankly, misleading.

I don’t think there’s any question that there’s been a detection. The question is whether there’s an effect on the parameter estimates..

]]>It’s an Ockham analysis. Suppose temporarily that there is only one detector. You throw into the ring (1) zero signal vs (2) black hole merger with parameters unknown, and calculate the probabilities of the two hypotheses, giving a prior to and marginalising over the parameters. Supposing that (2) is the clear winner, you then do parameter estimation.

That should settle whether gravitational waves really have been detected. That the second detector saw something of similar profile at almost exactly the same time obviously firms it a good deal, and you can make that formal too with more work.

]]>You can use the LIGO data to get a posterior probability defined over the parameters of the models in a well-defined way, but you will inevitably find that the `best fit’ model leaves residuals when it is subtracted.

A Bayesian approach of this sort would give a probability but would assume that the set of templates is exhaustive. I guess looking at the residuals is a kind of sanity check to see if there is any evidence that even the best-fitting template(s) can’t fit the data.

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