Note that if there is a dark matter/neutrino interaction present, the acoustic scale could be altered. Even after that derivation a sensitive experiment should be perceived to break it through further. Want the full story? This means that the shift can only be detected statistically, and it makes the result extremely vulnerable to unanticipated systematic errors, e.g., correlations between the time of emission of the neutrinos and their energy (which strongly affects the efficiency of detection) or the direction of emission. Is the speed of light in a vacuum already adjusted for virtual particle interactions? But if the neutrino has a non-zero rest mass, you should be able to boost yourself to move faster than the neutrino is moving. xcolor: How to get the complementary color. The OPERA experiment data showed neutrinos arriving at the detector surprisingly quickly, supposedly traveling faster thanthe speed of light. Gran Sasso is an underground facility for low-background experiments the detectors can't see GPS satellites directly, because there's a mountain in the way, and their access to the surface is via a tunnel whose main purpose is to carry traffic for a major Italian motorway. So it would. "There's no way that a neutrino could have covered the distance we're measuring down here in the time you measured up there without going faster than light!". Still, Autiero and his colleagues may have missed some unknown systematic uncertainties built into their equipment, says Kevin McFarland, a particle physicist at the University of Rochester in New York and a spokesperson for Fermilabs MINERvA neutrino experiment. Once Again, Physicists Debunk Faster-Than-Light Neutrinos What happened to the idea of tachyonic or other superluminal neutrinos? The neutrino was first proposed in 1930, when a special type of decay beta decay seemed to violate two of the most important conservation laws of all: the conservation of energy and the conservation of momentum. If neutrinos really traveled faster than the speed of light, the supernova's neutrinos should have arrived in 1983, not 1987. Thanks to GPS devices, the distance of this trip, about 730 kilometers, is known to within 20 centimeters a feat of accuracy that required closing a lane of traffic for a week in a tunnel above the detector in Italy. Neutrino is not faster than light. [8] In February and March 2012, OPERA researchers blamed this result on a loose fibre optic cable connecting a GPS receiver to an I believe this question needs a couple of years more investigation. Critics of the first report in September had said that the long bunches of neutrinos (tiny particles) used could introduce an error into the test. Ubuntu won't accept my choice of password. And thats unfortunate, because detecting these low-energy neutrinos the ones that move slow compared to the speed of light would enable us to perform an important test that weve never performed before. As an experimentalist I don't begrudge the OPERA guys their error at all. I thought it might be a good idea to list the possible systematic biases which could lead xkcd's character to win his bet. Create Your Free Account The official announcement of the result, on September 23 at the European physics laboratory CERN near Geneva, was met with cheering but also with a barrage of questions from those scrutinizing the experiment for unknown sources of error that may be misleading the physicists. But experimentally, we simply dont have the capabilities to detect these slow-moving neutrinos directly. This is a serious experiment, and these are serious people, says Smolin. Meanwhile, the detector in Italy is moving just as fast as the rest of the Earth, and from our perspective it's moving towards the source. The initial series of experiments, comprising 15,000 separate measurements spread out over three years, found that the neutrinos arrived 60 billionths of a second faster than light would have, travelling unimpeded over the same distance. Inside South Africas skeleton trade. And every neutrino weve ever observed moves at speeds indistinguishable from the speed of light. Learn more about Stack Overflow the company, and our products. I suspect that the syncronization used in the GPS is in the same as in the above paper and not as Einstein did. Relativity is really well-tested, and it's really hard to conceive of a way that neutrinos could travel faster than light without it having other consequences that we would have discovered by now. If you get rid of the speed limit principle, the magnetic field cannot exist anymore. This is a BETA experience. I can assure you that the OPERA people are acutely and painfully aware of the long history of highly "significant" bumps just going away. An explanation was found. Ask Ethan: Do Neutrinos Always Travel At Nearly The Speed Of Light? ), This is inspirational (for theorists and experimentalists alike) :D. MINOS is reporting a completely independent (different beam as well as different detectors) measurement as of July 2015: Are the observers using exactly identical detectors? @Sklivvz The mass of the neutrino is so small that it is irrelevant in the argument, if the refraction is of the order of magnitude of the measurement. A question of physics should be repeatedly be confirmed before a postulate or an inference can be derived. One of the most common skepticism of people who no nothing about the experiment is stuff like: You might worry about[] have they correctly accounted for the time delay of actually reading out the signals? The lowest-energy neutrinos weve ever detected have so much energy that their speed must be, at minimum, 99.99999999995% the speed of light, which means that they can move no slower than 299,792,457.99985 meters-per-second. rev2023.5.1.43405. If you catch a neutrino or antineutrino moving in a particular direction, you'll find that its [+] intrinsic angular momentum exhibits either clockwise or counterclockwise spin, corresponding to whether the particle in question is a neutrino or antineutrino. This doesn't seem right--- could a hardware problem actually do this? ', referring to the nuclear power plant in Ignalina, mean? Anyway, I'll be interested in seeing how it pans out. Next year, teams working on two other experiments at Gran Sasso experiments - Borexino and Icarus - will begin independent cross-checks of Opera's results. No, the detectors are not identical, but the offset they're measuring is not just what they read off their clocks. The team which found that neutrinos may travel faster than light has carried out an improved version of their experiment - and confirmed the result. Whether right-handed neutrinos (and left-handed antineutrinos) are real or not is an unanswered question that could unlock many mysteries about the cosmos. By filling spacetime with a field that has a preferred direction, the physicists create a universe that still has an ultimate speed limit just not one thats necessarily set by light. A high level description of the problem is given here and a more detailed explanation of the investigation is here. WebNeutrinos dont interact with matter much so basically pass right through. Read about our approach to external linking. I read the published article, Measurement of the neutrino velocity with the OPERA detector in the CNGS beam, with their findings. In 2004 Mewes and Alan Kostelecky of Indiana University in Bloomington published a paper in Physical Review D describing one such theory. Well yes, of course it's possible in the same way that it's possible that invisible neutrino fairies are messing around with the neutrinos underground and hence causing havoc with the mental health of physicists around the world. But if you could transform a neutrino into an antineutrino simply by changing your frame-of-reference, that would mean that neutrinos are a special, new type of particle that exists only in theory thus far: a Majorana fermion. Thanks for making a community wiki reply. Given how big this question is, maybe it would be best to delete this answer? 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