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Do they propose a mechanism for how there could be simultaneous correlations between the two detectors that aren't gravitational waves? There's few enough forc

Do they propose a mechanism for how there could be simultaneous correlations between the two detectors that aren't gravitational waves? There's few enough forces that can act through kilometers of solid earth that I'd be willing to take it as a given that they're uncorrelated, absent a signal... but then, I'm not a physicist. Even more I'm-not-a-physicist-y speculation; could the additional correlation be some secondary gravitational wave effect hidden under the main signal, pointing to another aspect of the phenomenon?

fleitz 9y ago
If gravity is waves, it stands to reason that there would be lots of noise that correlated as various events in the universe reach earth.
- posterboy 9y ago
  gravity isn't waves, I think that was an overly simplistic description, but the explanation for noise does stand to reason, imho.
  - maxander 9y ago
    Gravity isn't waves, but it's a field that waves can exist in. (Similar to, the ocean isn't a wave but it can contain waves.)
spuz 9y ago
I think the argument is that any correlation in the noise must be simply coincidental. In other words, the detection could be explained by chance rather than some true physical phenomenon measured by both detectors. But, LIGO ran their detectors for 8 years at a lower sensitivity with no detections. Almost as soon as they turned on the upgraded detectors in September 2015, they detected the first event (GW150914) which appeared at a level that would have been undetectable previously. Also, they have made two other detections in the 1.5 years since. My guess is that if these events were due to flawed analysis, then we should have seen something during those first 8 years.
- mannykannot 9y ago
  While I think it is unlikely that there is a problem here, one has to consider that upgrading the sensitivity could introduce or reveal a systematic error. Also, it is not just a correlation that has been observed - it is a correlation that has a specific form, a rising fundamental frequency that happens to in line with what we would expect from merging black holes. I know there's an element of circularity in the argument, but what are the chances of that particular sort of signal arising from a spurious correlation?

fleitz 9y ago

If gravity is waves, it stands to reason that there would be lots of noise that correlated as various events in the universe reach earth.

posterboy 9y ago
gravity isn't waves, I think that was an overly simplistic description, but the explanation for noise does stand to reason, imho.
- maxander 9y ago
  Gravity isn't waves, but it's a field that waves can exist in. (Similar to, the ocean isn't a wave but it can contain waves.)

spuz 9y ago

I think the argument is that any correlation in the noise must be simply coincidental. In other words, the detection could be explained by chance rather than some true physical phenomenon measured by both detectors. But, LIGO ran their detectors for 8 years at a lower sensitivity with no detections. Almost as soon as they turned on the upgraded detectors in September 2015, they detected the first event (GW150914) which appeared at a level that would have been undetectable previously. Also, they have made two other detections in the 1.5 years since. My guess is that if these events were due to flawed analysis, then we should have seen something during those first 8 years.

mannykannot 9y ago
While I think it is unlikely that there is a problem here, one has to consider that upgrading the sensitivity could introduce or reveal a systematic error. Also, it is not just a correlation that has been observed - it is a correlation that has a specific form, a rising fundamental frequency that happens to in line with what we would expect from merging black holes. I know there's an element of circularity in the argument, but what are the chances of that particular sort of signal arising from a spurious correlation?