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CERN press release regarding neutrino experiment
- saulrh 15y agoThis press release is a perfect example of how to write a press release for a high-profile, possibly groundbreaking discovery. Understated, but still properly summarizes the importance of the result, and above all doesn't make any hysterical claims. Instead, it just presents the discovery, cites the paper, gives some background, grabs quotes from the scientists to show the reasoning behind their actions, and leaves it at that. Beautiful.
- ajross 15y agoAll true. But to be fair, you're praising the easy stuff. This is one of those one-in-a-career, truly groundbreaking results. They don't have to sell it. They just write it up in plain language and it sells itself.
- stiller 15y agoBe that as it may, it wouldn't be the first time a scientist messed up the PR game. Galileo springs to mind.
- saulrh 15y agoThat's the thing - they resisted the urge to sell it. All of the other headlines are screaming about "time travel possible?" and "modern physics all wrong!", while this is just the plain language.
- cube13 15y agoMost importantly, they're not presenting the finding as fact. They're really asking for anyone that can prove them wrong, because they don't believe it, and are almost positive that there's something wrong with either their methodology or measurements.
- mechanical_fish 15y agoYes, this is one of the most painful things to do as an experimentalist. You just know that there's some kind of error in the data. Because -- in the memorable words of some teacher of mine [1] -- "you can't really believe an experiment until it's been confirmed by theory." And, yet, you've spent lots and lots of energy and you can't find the problem yourself. And what if there is something there? There are many famous cases of experiments that weren't confirmed by theory until well after the fact; theorists often don't bother to think about a particular corner of the unthinkable until an experiment calls attention to it. So you've just got to publish your data, but also be prepared to laugh it off when the mistake gets identified, or the data proves irreproducible. And then to spend the rest of your career laughing it off, because this spurious result may be the most famous thing you ever publish. You've got to have a good sense of humor to survive as an experimentalist. --- [1] I wish I remembered which teacher said this.
- drbaltar 15y agoI wonder how the Cold Fusion fiasco was presented back in the 90's? Not that they are at all similar, but those were certainly bold claims as well.
- aaronbrethorst 15y agoLate 1980s — early 90s, it turns out: http://en.wikipedia.org/wiki/Cold_fusion#Fleischmann.E2.80.93Pons_experiment http://en.wikipedia.org/wiki/Cold_fusion#Fleischmann.E2.80.9...
- jrockway 15y agoThe things that are advertised with bold claims are the things people want to believe. If cold fusion worked, it would mean free energy. Free energy would mean that we could all drive tanks around and eat animals without feeling bad, which would make us feel good. Hence, "cold fusion discovered! all of the world's problems are solved!!!!" The speed of neutrinos is less interesting, because I don't get anything out of it right now. A "huh" and some new physics textbooks and all that, at best. (I'm personally excited, but that's because I am more excited by unlocking the secrets of the universe than by being able to drive an SUV for free. Because I already have a vehicle whose energy source is practically free.)
- Florin_Andrei 15y ago> This is one of those one-in-a-career, truly groundbreaking results. And if it's wrong and you overstate it, it's again one of those one-in-a-career results, but merely because that's where your career as a scientist ends.
- arethuza 15y agoAlthough it is CERN that is getting most of the attention the lab receiving the neutrinos is pretty impressive - 1400m underground: "three large experimental halls, each about 100 m long, 20 m wide and 18 m high and service tunnels, for a total volume of about 180,000 cubic metres" http://www.lngs.infn.it/home.htm http://www.lngs.infn.it/home.htm
- sprovoost 15y agoTo put that in perspective: a 20 part per million difference in speed over 730 km distance is about 15 metres. So details about the detector are relevant, but they obviously know that.
- narag 15y agoIs this needed? Or could the reception be done in the surface? I mean, the interesting question is now: how much time will it take to repeat the experiment, either by others or by the CERN but with other reception point?
- joeyespo 15y agoFrom the release, there's a live webcast going on right now (16:00 CEST, Sept 23) at: http://webcast.cern.ch/ http://webcast.cern.ch/
- mladenkovacevic 15y agoJust watched the tail part of it. I have no clue what they were saying 99% of the time.... but they sure seem thorough as fuck
- jasonkeene 15y agoI so LOL'd when someone in the webinar pointed out that their measurement wasn't a vector so their paper should be titled neutrino speed not velocity. http://arxiv.org/abs/1109.4897 http://arxiv.org/abs/1109.4897
- nooneelse 15y agoThey know where the neutrinos were produced and where they were detected 730km away. That seems like enough for a pretty good guess at their direction of travel. But I guess they didn't really present that aspect of things.
- mladenkovacevic 15y agoA great article on various disagreements between Tesla's and Einstein's view of the physical world. http://www.writingriffs.com/2009/09/13/tesla-vs-einstein-transcending-the-speed-of-light-with-author-marc-seifer/ http://www.writingriffs.com/2009/09/13/tesla-vs-einstein-tra... Will Tesla have the last laugh?
- podperson 15y agoNot based on the linked article, which is horrible. I gave up when it was simultaneously trying to claim that the ether exists but space can have no properties.
- mladenkovacevic 15y agoclaiming what? who?
- viscanti 15y agoThe author could have done a better job of explaining this, if he would have said "Einsteinian Space" rather than "space" in that section. That's fairly easy to infer from the context, but it could have been explained better. Einstein viewed "space" as a vacuum. Tesla argues that view is flawed, that nothingness by definition can't have any properties, and as a result can't bend, because there's nothing to bend. He proposes aether/ether as an alternative explanation of "space".
- podperson 15y agoIf all that we're talking about is terminology then the entire article is pointless.
- Florin_Andrei 15y agoWhat a steaming pile of junk.
- hugh3 15y agoUsually I hate people who comment only with "I stopped reading at...", but in this particular case I'll make an exception. For myself. I stopped reading at: "As far as I know, no book on the history of physics mentions Tesla" which is a statement approximately as correct as "As far as I know, no book on the history of the United States mentions Woodrow Wilson"
- simplegeek 15y agoGuys, I'm sorry I missed this recent news but I've a question that I hope some people can answer for me. So does this mean that Einstein's theory might not hold? Do we see any well-established theories break as result of this? I'm totally naive about this but curious so any answers will be appreciated.
- orblivion 15y agoI'm not the best to answer this, but I'll briefly say that if Einstein's theories don't hold, it will be in the same sense that Newton's theories didn't hold post-Einstein. Newton's theories still apply, for all practical purposes, to all every-day life situations, and Einstein's theories will still apply, for all practical purposes, to every fringe case seen so far ("every-day" nuclear physics, etc) until this experiment. Einstein's theories will just break down in even more fringe situations, which we would have to start to understand the nature of now.
- mortenjorck 15y agoThe half-century after Einstein's pioneering work saw the world's basic conceptions of energy resources and of armed conflict transformed. One can only imagine the prospect of living in a post-FTL world.
- lutorm 15y agoWe sort of already know that "Einstein is wrong" in this strong sense, since GR is incompatible with quantum field theory. It still works just as well within its realm of applicability, though.
- Florin_Andrei 15y agoExactly. Even if the Opera experiment turns out correct, your GPS will not cease to function all of a sudden.
- docgnome 15y agoTo be honest, it's most likely someone making a mistake or equipment failure or something. We'll just have to wait and see if someone else can replicate it.
- deleted 15y ago[deleted]
- shimsham 15y agoinches vs centimetres. damn those units.
- hernan7 15y agoDo they at any time say how much faster than light are those neutrinos moving? 1% faster? 100 times faster? I couldn't see that info anywhere.
- bayes 15y agoa velocity 20 parts per million above the speed of light
- thoradam 15y ago0.002% faster.
- sneak 15y ago+/- 0.002%
- Arjuna 15y ago"+/- 0.002%" How did you derive a negative bound? A negative bound suggests that arrival times could be slower than c. The paper indicates that arrival times are always faster than c. From the paper: "An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (60.7 ± 6.9 (stat.) ± 7.4 (sys.)) ns was measured."
- sneak 15y agoPerhaps my one-word comment was an insufficient indicator of my sarcasm. 't'was a joke, good sir.
- gammarator 15y agoThis result is from a legitimate experimental group. It's much more likely to be experimental error than new physics, though: previous observations of neutrinos coincident with the light emitted by supernova 1987a (much, much farther away) indicate that neutrinos travel at light speed to 1 part in 10^8 [1,2] [1] http://adsabs.harvard.edu/abs/1989ARA%26A..27..629A http://adsabs.harvard.edu/abs/1989ARA%26A..27..629A [2] http://blogs.discovermagazine.com/badastronomy/2011/09/22/faster-than-light-travel-discovered-slow-down-folks/ http://blogs.discovermagazine.com/badastronomy/2011/09/22/fa... Also, https://www.xkcd.com/955/ https://www.xkcd.com/955/
- mrb 15y agoMy SWAG: the relativist effect of time being slowed down in Earth's gravity was not taken into account. (Time is slowed down, therefore neutrinos appear to arrive 60ns "early".) They spent a lot of time triple checking the accuracy of their instruments without seemingly thinking about higher level factors such as the Theory of relativity... http://static.arxiv.org/pdf/1109.4897.pdf http://static.arxiv.org/pdf/1109.4897.pdf Of course there are 99% chances I am wrong, but just throwing this out there :)
- Confusion 15y agoThere is a 100% chance that you are wrong. Do you honestly believe that they wouldn't think of taking that into account, if it could be relevant? That you can immediately think of it, but not an entire group of physicists; let alone a group trained and experienced in performing time-critical experiments? How far removed from reality do you believe physicists to be? Anyway, relativity cannot possibly be relevant in explaining the time difference. I will not explain why: please actually read what they published. It will be crystal clear why it isn't relevant.
- mrb 15y agoI meant to say they may have made a mistake on just this one relativist effect... even though I am sure they did think of it. BTW, relativity is relevant in the OPERA experiment. Theoretical physicist Luboš Motl explains why: http://motls.blogspot.com/2011/09/potential-mistakes-in-opera-research.html http://motls.blogspot.com/2011/09/potential-mistakes-in-oper...
- lutorm 15y agoYou didn't look at the webcast, did you? Someone asked this question and they said "no we took it into account in the sense that the clocks at CERN and Gran Sasso run at different speeds because they are at different elevations. However, that's only a 1e-18 effect and the signal is 1e-5.
- mrb 15y agoI am talking about the presence of the gravitational field, not its difference between the 2 sites. Anyway, I calculated gravitational time dilation on Earth out of curiosity. It has an effect of only about 1e-9.
- jchrisa 15y agolotsa basic FTL stuff here if people wanna get a broad picture http://www.weburbia.com/physics/FTL.html http://www.weburbia.com/physics/FTL.html
- hugh3 15y agoThat's a pretty good summary. It progresses from "things that might seem to be FTL but don't really count" through "things that are kinda sorta FTL in some sense but still don't carry any information" and into "highly speculative things which could potentially be properly FTL but haven't been shown to be possible".
- mootothemax 15y agoThere are a few interesting explanations in a Guardian article[1] published today: Heinrich Paes at Dortmund University and colleagues believe it might be possible for neutrinos to move through hidden, extra dimensions of space and effectively take shortcuts through space-time. "The extra dimension is warped in a way that particles moving through it can travel faster than particles that go through the known three dimensions of space. It's like a shortcut through this extra dimension. So it looks like particles are going faster than light, but actually they don't." Another potential explanation for the observation was given by Alan Kostelecky at Indiana University, who has devoted his career to violations of the limiting speed of light. He proposed in 1985 that an energy field that lies unseen in the vacuum might explain the finding. The field allows neutrinos to move faster through space than photons, the particles that make up light. "It may very well be that neutrinos travel faster than light does in that medium. It is not at all unreasonable that that would be the case." [1]http://www.guardian.co.uk/science/2011/sep/23/physicists-speed-light-violated http://www.guardian.co.uk/science/2011/sep/23/physicists-spe...
- Jach 15y agoNeither sound very good to me, nor are they really explanations. "Hidden" is just as bad as "magic" here. And isn't the second basically the standard aether theory that was soundly defeated at least 100 years ago? http://en.wikipedia.org/wiki/Michelson-Morley_experiment http://en.wikipedia.org/wiki/Michelson-Morley_experiment
- stianan 15y agoI don't understand how warping the extra dimension will make particles appear to move faster. Is it possible that it is everything else that is moving linearly along a fifth dimension, thus slowing us down, and these neutrinos were moving cleanly through space-time?
- deleted 15y ago[deleted]
- Symmetry 15y agoThe path from the things people observed to "and neutrinos travel faster than light" travels down a long string of inferences. Inferences about the equipment working properly and inferences about other aspects of physical law. Most likely this is a problem with the equipment. I'm sort of hoping that some other aspect of our knowledge of physics has been revealed to be off, though, since that is where real progress comes from. It might even be that the most straightforward but most improbable case is right, and these neutrinos actually are traveling faster than light. That would be awesome, but also terrifying since then its only a matter of technology to get a device that would permit communication with the past.
- ivan_ah 15y agoI watched the news conf. this morning. The neutrino production "curve" looks like a a square wave pulse as a function of time ____| |_____ and the detection points look like this ___________________________________| |_____ with ∆t ~= 700km/c time distance between the two pulses. The claim is that the "most likely guess" of the received pulse shape (obtained from many measurements) is too far right to be consistent with speed of light, but the ∆t measured where? between the onset of the pulses? between the place where the pulses go down? What they did some mega calculation (maximum likelihood stuff), to predict the best approximation to the shape of the pulse at the receiving end -- so somehow they take on the approximation of the whole pulse (which is much wider than the claimed discrepancy). They should downgrade the claim from: "speed of neutrinos is...." to: "speed of pulses of neutrinos ..... on average, as predicted by the maximum likely shape of the pulse", which sounds much less profound. The conf was good though, the speaker stood up to a lot of serious scrutiny. My guess is the problem is with the ML curve shape calculation.
- kmm 15y agoI've read the article[1] and what they do is compare the proton flux as measured in Geneva with the neutrino signal measured in Gran Sasso. The proton signal is timeshifted a small amount until the curves overlap maximally. Where the leading and trailing edge are is irrelevant here, as the complete shape of the pulses are compared. 1: http://static.arxiv.org/pdf/1109.4897.pdf http://static.arxiv.org/pdf/1109.4897.pdf
- lutorm 15y agoThey should downgrade the claim from: "speed of neutrinos is...." to: "speed of pulses of neutrinos ..... on average, as predicted by the maximum likely shape of the pulse", which sounds much less profound. This would apply to every paper in existence. If you want to know the methodology, you read that section of the paper. Putting it in the title only obscures the message. It's true that it makes the analysis a lot harder, and one of the questions after the talk was about making shorter bunches of neutrinos. The duration of the pulses are probably just set by the width of the proton bunches in the ring, in which case it would be nontrivial to make it much shorter.
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- gfaremil 15y agoDoes anybody know why they were doing this experiment (measuring speed fo neutrinos) at all? Were they assuming that neutrinos travel faster than speed of light in the first place?
- LXicon 15y agoas i understand it, they were doing experiments to watch how neutrinos change between "electron", "muon" and "tau" flavors. the timing of when the neutrino was sent from cern and viewed by the experiment was required to match what the neutrino was before and after.
- sprovoost 15y agoMy guess is there's something wrong with the statistical modeling, but I realize that's not a very useful statement. I missed the press conference, but I did read the paper and I even understood a few things. :-) It was good to see they even thought about seismic activity (centimeters). One thing I noticed in both the article and the media is that the effect is never expressed in terms of distance (about 15 meters), but only in terms of time and speed. It surprises me that they're able to determine the point of creation and detection of neutrinos in such huge instruments, but of course they know their stuff. I did get the impression it took a lot of modelling and advanced statistics to achieve that, hence my earlier "gut feeling" that there lies the problem. A few other possible explanation that crossed my mind and I'm sure are wrong and already thought about: * the distance between both sides was measured very accurately, above ground. The earth is not flat, so the distance underground is shorter. I'm too tired to calculate how much shorter. * relatistic effect of the beam going deeper underground on its way over; I read elsewhere that they already considered the effect of altitude difference between the two stations and that it was orders of magnitude smaller. * some other mistake in distance measurement; have they tried sending other, easier to measure, signals over to figure out the distance? Or some other independent way to measure that distance?
- libria 15y agoD of earth = 12756km, and assuming a sphere (my physics prof would be proud), I'm computing that 730km covers a ~6.6 degree arc. Also assuming a 100m underground tunnel, the distance would be 21m shorter than its above-ground measurement. Someone needs to recheck my math, though.
- sprovoost 15y agoAccording Arethuza's comment below, at least one of the labs is 1400 meters below ground. Also you need to calculate the straight-line distance between the two points, not the distance over the surface. Although for calculating the difference that's probably a good enough approximation. So if both stations are 1400 deep and your calculation is correct, the difference should be 14x21=300 meters. Which is a lot more than the 15m effect they found, which suggests they thought about this.
- TeMPOraL 15y agohttp://xkcd.com/812/ http://xkcd.com/812/ - relevant xkcd.
- guelo 15y agoThis article from a couple days ago did a good job of dampening any wild hopes http://io9.com/5843112/faster-than-light-neutrinos-not-so-fast http://io9.com/5843112/faster-than-light-neutrinos-not-so-fa... A probably nonsensical idea about the super-nova point they make: maybe what it means isn't that neutrinos are traveling faster than light but that they are traveling just ahead of light. In other words, they are some kind of shock wave moving through space at speed c but at a location just slightly ahead of the disturbance. Maybe we are detecting the supernova neutrinos a few nano seconds before when we're supposed to be. Still, it's probably a measurement error.