If the basic model underlying the original LIGO finding would predict no correlation between the recordings, then a significant amount of correlation should lead scientists to revise the model, and reexamine the findings. Very much standard scientific practice.
But the signal is still stronger than the noise
Besides the "poking the data in weird ways until it stops meaning anything" issue
Correlation as used here and put simply means that when the signal coming out of one the detectors increases, the signal coming out of the other detector (which is physically separated from the first detector by a very large distance) also increases, and when the signal coming out of the first detector decreases the signal coming out of the second detector also decreases.
The existence of that mathematical correlation between those two signals coming out of those two remote detectors absolutely implies there is a causation to the correlation (yes, mathematical correlation can imply a causation, even while it alone is not able to indicate what that causation is).
The question at hand is not whether there is a correlation or whether there is a causation. The question is what is the causation for the correlation and whether that causation is a gravity wave or something else.
The odds are extremely good that that causation is a gravity wave, but it's a big enough experiment and a big enough result that it's worth looking very closely at the analyses that argue in favor of it being a gravity wave (and those that argue against it).
The more important point, however, is that a correlation between A and B does not imply that A causes B or B causes A. It could also be that unknown factor C causes A and B.
Your point is a very good one, though. If we view causation through a causal graph, such that vertices are variables and direct causal links are arrows (directed edges), a statement "correlation doesn't imply causation" can be taken to mean several things:
* From correlation, we cannot determine the direction of the arrow.
* From correlation, we cannot claim there *is* a (direct) arrow between two vertices.
* From correlation, we cannot claim there is even a path from one vertex to the other.
Scientists keep saying and repeating how correlation doesn't mean anything to the point it's become a joke
Now they are dabbling about a spurious correlation in a small section of the data? For real?
No, really, if anyone would be trying to prove anything based on that correlation alone they would have been laughed and dismissed by the majority of the scientific community
But suddenly when it's to reject a result then it's important?
> points out that Jackson’s team could have misused a common data-processing technique called the Fourier transform... The error, Harry writes, has to do with the technical assumption that the input data signal be “cyclical,”
Correct. Not to mention the sample is too short (and the even is short as well and there's noise and the sampling rate is not too big).
If you play with FFT on these conditions you start seeing things that "aren't there"