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Danish physicists claim to cast doubt on detection of gravitational waves
- CamperBob2 8y agoAt least a few other detections have been reported by LIGO, and I assume that they, like the first one, are correlated in the data from Hanford WA and Livingston LA. Doesn't anyone looking to debunk the LIGO results need to first explain what is producing correlated signals at interferometers thousands of miles apart? Also, are the incidents we're receiving in the US producing similar data at VIRGO in Italy? If so, then wow, Jackson has a tough case to make. If not, then why not?
- raverbashing 8y ago> Doesn't anyone looking to debunk the LIGO results need to first explain what is producing correlated signals at interferometers thousands of miles apart? > Also, are the incidents we're receiving in the US producing similar data at VIRGO in Italy? Yes and yes (also there was the optical/GRB confirmation for one of the events) That's why I'm siding on the LIGO side of this The whole article sounds like some "skeptics gone wild" trying to start a car with a banana then saying cars are fake because of it (and that's my behaved way of phrasing it)
- v_lisivka 8y ago> That's why I'm siding on the LIGO side of this Are you sure? Because then you must accept that c≠const, thus Ether exists.
- raverbashing 8y agoI don't remember anything being discussed on that area based on LIGO data
- kryptiskt 8y agoNo, I don't have to accept that, because I already know from my undergraduate physics that light doesn't travel at c in a medium.
- v_lisivka 8y agoLIGO measurements are performed in ultra-high-vacuum[0], so it's not a "speed of light in a medium" it's "speed of light in the vacuum", AKA c. [0]: https://www.ligo.caltech.edu/page/vacuum https://www.ligo.caltech.edu/page/vacuum
- v_lisivka 8y agoAdmins, it looks like I have personal haters. Can you fix this, please?
- gliptic 8y agoThere's a much more reasonable explanation for the downvotes. You're making a very dubious claim without even trying to back it up.
- v_lisivka 8y agoNobody of downvoters asked for anything nor contested my arguments. English is not a my native language and I'm busy right now, so I prefer to be concise. Basically, LIGO is oversized and much more precise version of Michelson-Moorley experiment. What else I need to show you or tell you to convince? Everybody already know role of Michelson-Moorley experiment in development of GR/SR theories. Michelson-Moorley experiment was performed with precision of up to 1E-17 and found nothing, so it was reasonable to post theories assuming that c=const. LIGO performed with precision of 1E-18 and found deviations, so it no longer true unless LIGO is wrong (distance to Alpha Centaur is just 4E16 meters, so it's possible), so it's why I asked "are you sure?".
- kurthr 8y ago
- scott_s 8y agoI'm on LIGO's side on this one, but I disagree that one must be able to offer an alternative explanation in order to claim a result is bogus. That is, I don't need an alternate theory in order to falsify yours. Again, to be clear: I think the LIGO results are probably correct. There's a bunch of corroborating evidence, and from the outside it appears they've been acting is very much good faith. I'm just making an epistemology quibble.
- pbhjpbhj 8y agoAgreed: the scientific community is supposed to havea consensus on [Popperian] falsificationism but seem to act like they don't really believe it quite often.
- no_identd 8y ago> the scientific community is supposed to havea consensus on [Popperian] falsificationism You couldn't have it more wrong. See here, with more physics relevant points: http://www.mdpi.com/2073-8994/3/3/611 http://www.mdpi.com/2073-8994/3/3/611 [PDF only] And here with more science relevant points: http://www.mdpi.com/2078-2489/2/4/635/htm http://www.mdpi.com/2078-2489/2/4/635/htm [Different article, mobile friendly]
- CamperBob2 8y agoThat is, I don't need an alternate theory in order to falsify yours. I phrased that poorly: what the critics need to explain is the apparent agreement between the prior model and the observations. It wasn't just a case where someone looked at an oscilloscope screen and said, "Whoa. Look at that. Aliens!" As I understand it, the LIGO results showed good conformance to their predictions. Does that make their position completely bulletproof? No, nothing in science ever is, but it does place Jackson's dispute into the category of "extraordinary claims."
- dnautics 8y agoThe question is as follows:. How frequent are all blips that might be classified as X overall, and from that, what is the expected rate of spurious correlation? To arrive at this one must have access to quite a bit of comprehensive data collected in an unbiased fashion.
- TangoTrotFox 8y agoLet's say you see foot prints outside your house. And they look like deer footprints, and so you say they are. Somebody then shows that a small moose could have left similar tracks. You don't need to state what definitively left those tracks to say that it's premature to declare them deer footprints. In the signal world this is even more true, because with signals this faint everything is going to come down to probabilistic analysis. And so the real question is not binary (gravitational waves or not gravitational waves), but rather the chance that what was detected was caused by gravitational waves. And so anything that could confound those probabilities is as good as a refutation, even without any explanation for what did cause the observed phenomena. I have no opinion on the issue one way or the other, but I do have to say that the large numbers of appeals to authority and ad hominem from the LIGO researchers do not inspire confidence. People tend to resort to these sorts of responses for the lack of a rational refutation. I found a much more informative article on the issue here [1], surprisingly from Forbes. There too, the responses from the LIGO team feel off. For instance they were criticizing the Danish team for using the tutorials LIGO provided on their site alongside the data! I mean...??? Did LIGO ever publish the exact method used to obtain their results? [1] - https://www.forbes.com/sites/startswithabang/2017/06/16/was-it-all-just-noise-independent-analysis-casts-doubt-on-ligos-detections https://www.forbes.com/sites/startswithabang/2017/06/16/was-...
- simion314 8y agoHow is your analogy fit with the fact that there was a case where LIGO had a detection then many telescopes were pointing into that region of sky and "seen" the cause. https://www.newscientist.com/article/2150418-gravitational-waves-have-let-us-see-huge-neutron-stars-colliding/ https://www.newscientist.com/article/2150418-gravitational-w... This is evidence enough for me that LIGO is not detecting noise.
- SiempreViernes 8y agoI think Hossenfelder did a pretty bad jounalistic job in that column, which she defended by pointing out that she is not a journalist. Even reading that it was clear Jackson was probably wrong and had she not been an angry german she would have written that as her conclusion. Also the article you are commenting on directly cites that column by Hossenfelder.
- jobigoud 8y agoIn the general case no, you don't need to present an alternative theory to proove that a given existing theory is flawed or not self consistent or not consistent with observed data.
- CamperBob2 8y agoTrue enough in the general case as you say, but in this specific case, the data in question was (reportedly) a good fit for a pre-existing model. They made a prediction, ran an experiment, observed the predicted effect, drew a conclusion, and got a Nobel for their trouble. So the burden of proof is decisively on the accuser here, I'd think.
- mihaifm 8y agoThey claim it’s noise and pure coincidence. Some trains may have shaken the earth at the exact time the cosmic event happened. At least that’s what I take from the article.
- splittingTimes 8y ago"the controversy all boils down to a misunderstanding about LIGO's methods for analyzing its data." This plus the mentioned secrecy is the modus operandi in the physics community. No open data, no open calculation how you reached a certain theoretical result and no open code with which the simulation/analysis is done. There is also the case to be made for a reproducibility crisis in the hard sciences.
- punchingwater 8y agothe article states: > “But Reitze counters that the complete data from that first run is already available online. According to Shoemaker, this includes the relevant time series data and the programs used, but "it's not a trivial matter to use them." Caltech even held a training workshop on how to deal with gravitational-wave data. That's a pretty far cry from asking the physics community to take its analysis on faith...” Are you refuting this statement? To me, it looks like the data/analysis are open, but not yet independently verified due to difficult nature of problem space.
- smueller1234 8y agoI used to work in particle/astrophysics. By and large people weren't opposed to sharing their data and software. The degree of specific expertise it took to get results was staggerng though. It takes significant technical infrastructure and expertise to even just rerun an analysis on a big corpus of data. At that stage, you haven't even validated squat, just pushed some buttons to run other people's logic. Doing this properly takes person years of effort with little to no reward. In practice, there's usually at least two big experiments (not necessarily quite of the same generation) that were built by different groups which corroborate results. This is currently the best defense against big mistakes.
- splittingTimes 8y agoI did not read the article till the very last paragraph. My bad. Of course, I do not refute it. So in this particular case they went open source. However, from my experience in years of publishing to and reviewing for several APS journals, I stand by my statement. Because of 'publish or perish' nobody wants to give up any 'competitive edge' of their particular research. So there is no incentive system in place to foster an open source everything attitude.
- flexie 8y agoThe article keeps talking about "Danish" this and that. The only one of the so called Danish physicists quoted in the article is Andrew Jackson who is American. I believe this is the paper it all relates to: https://arxiv.org/abs/1706.04191 https://arxiv.org/abs/1706.04191 None of the authors are Danish, but most are related to the Niels Bohr Institute. Andrew Jackson probably has a lot of Danish colleagues at the Niels Bohr Institute, which of course is in Copenhagen, and many of them might agree with him and some might have been involved in the study. He probably also lived in Denmark for many years and he might even have gotten Danish citizenship, family and he might even speak Danish. The same might apply to some of the other authors. But you wouldn't call Einstein a Swiss, Austro-Hungarian or American physicist although he did most of his important work in those countries (and actually obtained both Austrian and American citizenship), would you? I am aware of the Copenhagen school quantum physics/ the Copenhagen interpretation, and that the article might try to play on that old thing in the hopes that we might see a new Danish school in physics. But why?
- wheels 8y agoYou could call Einstein one of those labels and it wouldn't be much odder than calling him German. He was actually born in The Kingdom of Würtemburg, at the beginning of the "German Empire" (a federation of kingdoms whose borders were very different from today's Germany). And even then, what we now call "Germany" is something that only came into existence in the 1990s. A lot of people try to project nation-states backwards through history, but they're a relatively recent notion, and their current configuration even more so. Specifically, he lived in the German speaking part of two of those countries, and it doesn't make sense to refer to German-speaking regions of the late 1800s and early 1900s by 21st century labels.
- testrun 8y agoNot quite, what we call now Germany came in existence in 1871. Since then Germany lost a lot of territory. Einstein was born in 1879.
- mikekchar 8y agoI have no idea with what nationality Andrew Jackson identifies with, but as an immigrant myself, your comment puts my back up a bit. How much of one's life must be spent in a country before being considered "from" that country in your philosophy? If you are born in one country does it indelibly mark you for life? Do you have to be raised in a country in order to identify with it? If you move somewhere, live many years there, have a family there, speak the language, follow the customs, have citizenship there and have no intention of every living anywhere else are you still cursed with your original nationality? Do you feel that such people who have not spent the entirety of their life in a single location need some sort of asterisk next to their nationality? Not a "real" Danish person. Can never become one. I can understand your question: are they really Danish physicists, or simply physicists working in Denmark. Personally, I don't care but I suppose if you are thinking that Denmark is claiming something they don't deserve, then I suppose it's not a crazy question. However, I hope you can see that the way you put it could be pretty insulting to someone who literally is Danish, but just happens not to be born there.
- consp 8y agoHow does this interpretation error result in the actual finding of an optical counterpart to the gravitational wave in the region it was supposed to be in? (see GW170817) Or are they only trying to weigh in on the first detection?
- SiempreViernes 8y agoApparently jackson just don’t trust the GW collaborations at all, so I guess he just puts it down to chance?
- perlgeek 8y agoMy understanding is that the neutron star merger observation was the first of this kind that humanity has ever done. Calling that a coincidence isn't a very convincing argument.
- SiempreViernes 8y agoIt was the first time we recogniced these transients as ns-ns mergers, but there is very likely other events hidden in archival data. Simply put, gw170817 looked fairly boring in the waveband that has good skycoverage, so without the ligo trigger most observatories wouldn’t have bothered looking. The article states that jackson had some objection to the signal processing done for gw170817, but nothing really about what he has to say regarding the transient found in the ligo-virgo error contours.
- JohannesH 8y agoI find it odd that the responses from the LIGO team and supporters are so hostile, while it seems Jackson have a fairly constructive perspective: Jackson says he hope that “our concerns will be taken constructively and lead both to improved methods for data analysis and to a better understanding of LIGO’s results and its exciting long-term potential.” It seems to me that Jackson just wants to eliminate potential flaws in the result rather than overturn the result itself. Isn't that exactly what we expect from the scientific method? I wonder if it is a media created image that the tone between the teams are so hostile instead of collaborative.
- TrinTragula 8y agoThe article clearly states: "While LIGO has gained a (not entirely undeserved) reputation for excessive secrecy, Shoemaker says the collaboration has spent a great deal of time interacting with Jackson and his group over the last two years to improve their understanding of LIGO's methods, including extended visits to the Niels Bohr Institute and inviting Jackson et al. to discuss the issue in depth in teleconferences with LIGO team members. So if LIGO's response whenever that drum begins banging anew sometimes comes off as a bit exasperated, there's a very good reason for it." I think you are overlooking into this, there is no hostility whatsoever.
- ianai 8y agoI have two coworkers like that. No matter how much communication we have seemingly nothing ever gets settled nor progress made. The one calls himself an anarchist. There’s a large difference between constructive “skepticism” and destruction of progress - but so much can hide under the false umbrella of “just trying to understand.”
- tandr 8y agoI am genuinely curious - how do you (did?) resolve that kind of work-place conflict?
- 8y ago
- deytempo 8y agoIt doesn’t make sense to me that something which emanates outward can in any way cause things to move inward. It just seems to violate logic itself. I find it more likely that there’s some fundamental aspect of space itself we are missing which is a purely inward phenomenon. I suppose that force itself too could be described as a wave but more in the way that you can describe pulling on an elastic rope that’s tied to something can be described as a wave. Also if we did live in a holographic universe, there could exist forces which are simply there and are completely unexplainable from within the hologram.
- claudiawerner 8y agoDoesn't a field emanate outwards from a point, but may draw things inwards? Both the gravitational and electric fields can attract. Of course the fields don't work as waves but they is emanation restricted to waves?
- wlesieutre 8y agoChanges in an electric field propagate outward at the speed of light, otherwise you could instantaneously transmit data over a distance by changing the strength of the field. I'd say that counts as emanating.
- EliRivers 8y agoIs this logic also violated by seeing a magnet pick up a piece of metal? Something is clearly emanating outwards from the magnet, yet the piece of metal is attracted inwards. It doesn't have to make sense to you, but the experimental evidence seems pretty solid. some fundamental aspect of space itself we are missing which is a purely inward phenomenon A fundamental aspect of space... purely inward phenomenon... That sounds like gravity, as described by general relativity.
- DEADBEEFC0FFEE 8y agoMagnets are still magical for me.
- 8y ago
- spuz 8y agoPresumably if LIGO fell victim to a statistical fluke of noise in the data because they underestimated the likelihood of such a fluke then those flukes should have happened during the decades when they were running multiple detectors at lower sensitivity. Is it possible that the probability of these flukes occurring sits just within the window of "likely enough to happen and still be mistaken for a true signal" and "not so likely that it would have happened more than once in the last 10 years". My question is, are the Danish considering the fact that this kind of noise will occur regardless of the sensitivity of the detectors?
- torpfactory 8y agoThe detection of GW170817 is the nail in the coffin here. A gravitational wave corroborated by numerous other teams and instruments detecting the same event using completely different physical principles. There is almost zero likelihood of such a coincidence.
- jschwartzi 8y agoYes, in this case the theoretical models predict a gravitational wave to coincide with the observations from other trusted instruments. There may be systematic issues with LIGO's analysis, but it would appear that LIGO also reliably detects astronomical events which suggests that it does actually detect the waves themselves and not just coincidental artifacts in the analysis.
- DoctorOetker 8y ago"And contrary to Jackson's assertion in the article, a technical paper really is in the works at the LIGO collaboration detailing how it has handled the noise in its data—noise just hasn't been a top priority." where in which article is Jackson claiming that "LIGO does not have a noise-handling technical paper in the pipeline" so to speak? this is a really weird comment in the conclusion...
- DoctorOetker 8y ago>On that point, people seem to be in agreement. But Reitze counters that the complete data from that first run is already available online. The italics are the link to https://www.gw-openscience.org/about/ https://www.gw-openscience.org/about/ is this hug of death? where can I actually find their data and materials?
- 8bitsrule 8y agoScience needs to re-learn how to live without so much religion. Observation is expensive, interpretation is cheap.
- 8bitsrule 8y agoIf you're going to downvote, at least have the courage to voice your objection. I thought that was supposed to be a privilege here, not an opportunity to skulk behind a rock. I'll reply with a similar but lengthier remark from another contributor. Possibly it won't go over your head. ------------- I've thought for some time that the slow down in "fundamental invention" that some have observed since roughly the late 1960s to early 1970s is the result of "scientific fundamentalism" and Skepticism. Look into the backgrounds and thoughts of people like Einstein, Tesla, Engelbart, Turing, Edison, or Schrodinger, and you generally will not find them to be fundamentalist-positivist Skeptics. It seems like the general intellectual trend from roughly 1970 until maybe 2010 or so was the rise of fundamentalism of every kind, both religious and secular... - (api; 2015 https://news.ycombinator.com/item?id=10288033 https://news.ycombinator.com/item?id=10288033)