worlov Posted September 6, 2016 Posted September 6, 2016 Hello! I believe that LIGO-events have terrestrial origin (e.g. lightning strike). Registered traces could come from merger of two black holes or... there are the result of "jump phenomenon", if a sudden jump in amplitude occurs with increasing frequency : This is supported by 1. The frequency of the falling edge corresponds to one of own frequencies of the LIGO-detectors before and after the event: 2. The signal is harmonious. But due to limited sensitivity of the detectors it should be pulsed: ==> Perhaps the LIGO-operators should check their equipment carefully again before physicists publish the next sensation Best regards Walter Orlov
imatfaal Posted September 6, 2016 Posted September 6, 2016 I have not decyphered your unreferenced graphs but surely the event described as LIGO as a black-hole merger and by you as a local event such as a lightning strike was observed at two detectors seperated by a far chunk of the continental USA? Are you claiming that identical lightning strikes hit both Louisianna and Washington State at the same time? 1
swansont Posted September 6, 2016 Posted September 6, 2016 How about supporting it by weather reports showing lightning in the region? For all you've presented, the LIGO team could have considered and rejected this hypothesis already, either by knowing there was no lightning strikes at the time of the detection, or by knowing from other events that lightning does not actually give this signal.
ajb Posted September 6, 2016 Posted September 6, 2016 For sure, the team did not shout about their results until they were very sure that they measured something real. This took several month. I have no idea if lightning was considered as a possible source, however given two separated detectors and that the signal matches predictions (the classical ring down was observed) I think it is not a plausible source and would be discounted straight away.
worlov Posted September 6, 2016 Author Posted September 6, 2016 I meant: for example. I imagined that lightning strikes somewhere between two LIGO-detectors. Maybe they are sensitive enough. There may be other sources, but no earthquake, because the disruption must be of short duration.
ajb Posted September 6, 2016 Posted September 6, 2016 I meant: for example. I imagined that lightning strikes somewhere between two LIGO-detectors. Maybe they are sensitive enough. There may be other sources, but no earthquake, because the disruption must be of short duration. I am sure that they took their time in eliminating such things. They kept things quite for a while until the team was happy that they measured something interesting.
swansont Posted September 6, 2016 Posted September 6, 2016 I meant: for example. I imagined that lightning strikes somewhere between two LIGO-detectors. Maybe they are sensitive enough. There may be other sources, but no earthquake, because the disruption must be of short duration. They are 3000 km apart. How, pray tell, does a lightning strike affect both of them? And how come other ultra-sensitive experiments are unaffected by lightning strikes? Even absent any attenuation in the ground, the effect of a lightning strike has to drop off as 1/r as it propagates outward. As would any point source in a 2D system.
worlov Posted September 6, 2016 Author Posted September 6, 2016 They are 3000 km apart. How, pray tell, does a lightning strike affect both of them? And the black holes are distant from Earth over 1 billion light years, nevertheless, the detectors should have felt whose merger. I am sure that they took their time in eliminating such things. Perhaps there is still a discrepancy between optical sensitivity and mechanical stability. The detectors were originally built with smaller sensitivity. They were optical upgraded, but mechanically they may not be good enough for very small signals.
ajb Posted September 6, 2016 Posted September 6, 2016 Perhaps there is still a discrepancy between optical sensitivity and mechanical stability. The detectors were originally built with smaller sensitivity. They were optical upgraded, but mechanically they may not be good enough for very small signals. Why perhaps? I mean you have read the literature on this, right? You understand the kind of analysis involved? You do understand how well the signal matches the predictions? If you really have some evidence that a clear signal from a black hole merger was detected then write a paper.
swansont Posted September 6, 2016 Posted September 6, 2016 And the black holes are distant from Earth over 1 billion light years, nevertheless, the detectors should have felt whose merger. What's the relevance of one to the other?
Mordred Posted September 6, 2016 Posted September 6, 2016 A lightning strike has a different wave signature. Electromagnetic radiation ie lightning induction follows a transverse dipole wave pattern. The signature received by LIGO is a transverse quadrapole. This signature is only possible via gravity waves due to spin 2 statistics.
worlov Posted September 6, 2016 Author Posted September 6, 2016 I mean you have read the literature on this, right? You understand the kind of analysis involved? You do understand how well the signal matches the predictions? Can you identify a matched signal here: What's the relevance of one to the other? The sensitivity. 1 billion light years is a lot. The intensity falls also with distance. I think, one lightning is a piece of cake for LIGO detectors. A lightning strike has a different wave signature. Electromagnetic radiation ie lightning induction follows a transverse dipole wave pattern. The signature received by LIGO is a transverse quadrapole. This signature is only possible via gravity waves due to spin 2 statistics. You mean electromagnetic radiation. But I think about short punch < 0.1s.
Mordred Posted September 6, 2016 Posted September 6, 2016 (edited) So your suggesting a lightning strike occured precisely halfway between two detectors 300 miles apart. After all if the lightning occured closer to one than the other there would be a significant difference between detectors in both wavelength and amplitude. Sorry but as mentioned. Wrong wave pattern its not a tranverse dipole. Which is what lightning would emit. The detectors are designed to detect quadrapole waves. The left column specifies strain. Which is based upon the formulation of a quadrapole not dipole wave. A quadrapole wave contracts x plus and minus axis while simultaneously expanding the y plus minus axis. Then next half cycle the opposite. Hence the L shape of the detectors. This doesn't occur for a dipole wave... The two arms of the detector can discern between a quadrapole vs a dipole wave by studying which axis experience strain in which direction. The design can easily discern the difference between the two wave types. Edited September 6, 2016 by Mordred
worlov Posted September 6, 2016 Author Posted September 6, 2016 So your suggesting a lightning strike occured precisely halfway between two detectors 300 miles apart. Allright. Then one can look for other sources... Finally, America is not a desert, but an industrial country
swansont Posted September 6, 2016 Posted September 6, 2016 The sensitivity. 1 billion light years is a lot. The intensity falls also with distance. I think, one lightning is a piece of cake for LIGO detectors. What you think is irrelevant. It's what you can show. How about some actual science?
Mordred Posted September 6, 2016 Posted September 6, 2016 (edited) Allright. Then one can look for other sources... Finally, America is not a desert, but an industrial country Once again they can filter out the interference signatures from the waveform data. Gravity waves has a unique signature... The Ligo scientists have had years to fine tune the filters for mechanical vibration, electromagnetic radiation etc. Use of two detectors at great distance from each other is extremely effective at isolating localized interferance. Edited September 6, 2016 by Mordred
ajb Posted September 6, 2016 Posted September 6, 2016 Can you identify a matched signal here: Probably not - this sort of thing is not my area of expertise. But then this is irrelevant as I have not claimed anything here other than I know that people have put a lot of effort into being sure that have measured something real. Gravity waves has a unique signature... This really needs stressing again - the wave form measured fits the models very well including the 'ring down' towards the end of the merger.
worlov Posted September 6, 2016 Author Posted September 6, 2016 Probably not - this sort of thing is not my area of expertise. It is GW151226 Here you can read quite a lot of signatures. A unique signature is the idealism.
Mordred Posted September 6, 2016 Posted September 6, 2016 (edited) the signature is the black line waveform. That's the signature of the GW itself. As you can see that signature is identical on both detectors. Well with a slight time delay. As the wave hit one detector before the other. Edited September 6, 2016 by Mordred
worlov Posted September 6, 2016 Author Posted September 6, 2016 As you can see that signature is identical on both detectors. This is even one and the same curve... only flipped horizontally. It does not come from the measurement data. It is considered as matching to the measured data... How many signatures are still fit to this noise?
Mordred Posted September 7, 2016 Posted September 7, 2016 (edited) I really don't know how much you understand on the transverse traceless guage and spin statistic aspects of a GW wave vs an electromagnetic wave. Do you understand what is meant by [latex]h_+, h_x[/latex] polarization? If I express this distinction "gravity has spin 2 which is invariant under 180 degree rotations, electromagnetism has spin 1 which is invariant under 360 degree rotations." would you understand the distinction in the trasverse traceless guage? How good is your GR? if I post the metrics involved, to show different aspects and predictions of the signal do you feel comfortable enough with GR tensors? the math to show gravity waves can be a bit daunting, but I could post several key equations to decipher the black line signal. Are you familiar with [latex]A^{TT}_{\mu\nu}[/latex] where [latex]A^{\mu\nu}=h_+\epsilon^{\mu\nu}_++h_x\epsilon^{\mu\nu}_x[/latex] ? I'm trying to guage your math skills and familiarity Edited September 7, 2016 by Mordred
worlov Posted September 7, 2016 Author Posted September 7, 2016 I am the man of practice. And I see that the data trace are pretty wild. Why is left side approximated with a wave and right side with a straight line? Finally, if only the shape of the detectors is crucial, why do we need mechanical damping?
swansont Posted September 7, 2016 Posted September 7, 2016 You have two options here, and need to decide which one you are going to exercise. You can ask questions about the experiment and the related physics, or you can make claims of your own about them. IOW, are you here to lecture, or to learn, about this particular topic. Pick one.
imatfaal Posted September 7, 2016 Posted September 7, 2016 I am the man of practice. And I see that the data trace are pretty wild. Why is left side approximated with a wave and right side with a straight line? Finally, if only the shape of the detectors is crucial, why do we need mechanical damping? So it is just incredulity born out of ignorance. I have no idea of the signal algorithms used to extract data from the measurements - but at a rough guess I would say that they were searching for signals that were replicated in both detectors and (whilst this is massively simplified) subtracted noise that appeared in only one detector. Your query regarding left side and right side would be answered in that on the left side the measurements were in both signals and on the right side it is just noise from one signal. Mechanical damping is necessary because otherwise even a distinguishable signal is swamped by noise - whilst post-observation processing can remove some noise your signal to noise ratio must be of such a level that you can actually pickup the signal with your equipment. Take another - massively simplfied - example you are seeking to tell whether an orchestra 20 miles away is playing Mozart or Beethoven; your most sensitive microphone might just pickup enough sound when the wind is in the right direction, the cloud level is correct, the orchestra is at a loud section etc. Now it is clear that you have more chance of this working in a quiet wilderness rather than placing your delicate microphones at an Airport where the first jet engine would blow their internals to smithereens
worlov Posted September 7, 2016 Author Posted September 7, 2016 I have no idea of the signal algorithms used to extract data from the measurements... That's true even. If you have time, you can try out here: https://losc.ligo.org/s/events/GW151226/LOSC_Event_tutorial_GW151226.html Mechanical damping is necessary because otherwise even a distinguishable signal is swamped by noise... We misunderstand us. From outside comes only brief disturbance. The signal itself is generated by LIGO detectors: "jump phenomenon"!
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