If you’re tracking the interesting news from CERN on neutrinos moving slightly faster than the speed of light, be advised that there is an upcoming CERN webcast on the matter at 1400 UTC later today (the 23rd). Meanwhile, evidence that the story is making waves is not hard to find. I woke up to find that my local newspaper had a headline — “Scientists Find Signs of Particles Faster than Light” — on the front page. This was Dennis Overbye’s story, which originally ran in the New York Times, but everyone from the BBC to Science Now is hot on the trail of this one.
The basics are these: A team of European physicists has measured neutrinos moving between the particle accelerator at CERN to the facility beneath the Gran Sasso in Italy — about 725 kilometers — at a speed about 60 nanoseconds faster that it would have taken light to make the journey. The measurement is about 0.0025 percent (2.5 parts in a hundred thousand) greater than the speed of light, a tiny deviation, but one of obvious significance if confirmed. The results are being reported by OPERA (Oscillation Project with Emulsion-Tracking Apparatus), a group led by physicist Antonio Ereditato (University of Bern).
Neutrinos are nearly massless subatomic particles that definitely should not, according to Einstein’s theory of special relativity, be able to travel faster than light, which accounts for the explosion of interest. According to this account in Science Now, the OPERA team measured roughly 16,000 neutrinos that made the trip from CERN to the detector, and Ereditato is quoted as saying that the measurement itself is straightforward: “We measure the distance and we measure the time, and we take the ratio to get the velocity, just as you learned to do in high school.” The measurement has an uncertainty of 10 nanoseconds.
It’s hard to do any better than Ereditato himself when bringing caution to these findings. Let me quote the Science Now story again:
…even Ereditato says it’s way too early to declare relativity wrong. “I would never say that,” he says. Rather, OPERA researchers are simply presenting a curious result that they cannot explain and asking the community to scrutinize it. “We are forced to say something,” he says. “We could not sweep it under the carpet because that would be dishonest.”
And the BBC quotes Ereditato to this effect: “My dream would be that another, independent experiment finds the same thing. Then I would be relieved.” One reason for the relief would be that other attempts to measure neutrino speeds have come up with results consistent with the speed of light. Is it possible there was a systematic error in the OPERA analysis that gives the appearance of neutrinos moving faster than light? The timing is obviously exquisitely precise and critical for these results, and a host of possibilities will now be investigated.
This paragraph from a NatureNews story is to the point:
At least one other experiment has seen a similar effect before, albeit with a much lower confidence level. In 2007, the Main Injector Neutrino Oscillation Search (MINOS) experiment in Minnesota saw neutrinos from the particle-physics facility Fermilab in Illinois arriving slightly ahead of schedule. At the time, the MINOS team downplayed the result, in part because there was too much uncertainty in the detector’s exact position to be sure of its significance, says Jenny Thomas, a spokeswoman for the experiment. Thomas says that MINOS was already planning more accurate follow-up experiments before the latest OPERA result. “I’m hoping that we could get that going and make a measurement in a year or two,” she says.
Unusual results are wonderful things, particularly when handled responsibly. The OPERA team is making no extravagant claims. It is simply putting before the scientific community a finding that even Ereditato calls a ‘crazy result,’ the idea being that the community can bring further resources to bear to figure out whether this result can be confirmed. Both the currently inactive T2K experiment in Japan, which directs neutrinos from its facility to a detector 295 kilometers away, and a neutrino experiment at Fermilab may be able to run tests to confirm or reject OPERA’s result. A confirmation would be, as CERN physicist Alvaro de Rujula says, ‘flabbergasting,’ but one way or another, going to work on these findings is going to take time, and patience.
The paper “Measurement of the neutrino velocity with the OPERA detector in the CNGS beam” is now up on the arXiv server (preprint).
Addendum: For an excellent backgrounder on neutrino detection and the latest measurements, replete with useful visuals, see Starts With a Bang. Thanks to @caleb_scharf for the tip.
And this comment from a new Athena Andreadis post is quite interesting:
If it proves true, it won’t give us hyperdrives nor invalidate relativity. What it will do is place relativity in an even larger frame, as Eisteinian theory did to its Newtonian counterpart. It may also (finally!) give us a way to experimentally test string theory… and, just maybe, open the path to creating a fast information transmitter like the Hainish ansible, proving that “soft” SF writers like Le Guin may be better predictors of the future than the sciency practitioners of “hard” SF.
@Joy, totally agree with you on SN 1987a.
I hope they can replicate the result using much shorter pulse at much greater distance. For now, my money is on Einstein.
Avatar2.0
why is that the most likely explanation. It can also just be that a neutrino just move faster than light.
I’m now starting to think that there has been no explanation for earlier experiments that seemed to consistently give a negative squared rest mass of the electron neutrino, and a reluctance to stress over this lack. If that that reflects a real trend in the particle physics world, I might be asking the wrong questions.
Is there perchance a well know trend in one subfield of modern physics for once promising researchers to drop out and become preternaturally good stockbrokers? If so, just tell me what they were once working on. That’s all I need to know.
In order for classical Special Relativity to be wrong:
“Neutrinos arriving a tiny bit early is fundamentally different than Neutrinos arriving before they were sent, and the OPERA Neutrino researchers are not claiming the latter. It is similar to the distinction between “extremely difficult” and “Intrinsically Impossible.” ”
– David Dilworth
See:
http://cosmologyscience.com/cosblog/?p=1878
henk
“why is that the most likely explanation. It can also just be that a neutrino just move faster than light.”
Because it contradicts the known rules the least:
No extra dimensions.
No the neutrino travels faster than light in its own frame of reference aka it’s a tachyon – which would open the gates for a LOT of mind-bending conundrums.
Of course, the neutrino travelling faster than light only in our frame of reference also gives rise to some paradoxes (apparent paradoxes, whose solution we do not yet have?) – mostly related to travel into the past/causality.
They claimed a 20 cm accuracy concerning the ~450 mile distance span between the sending and receiving locations, but I think such distance measurements should now be otherwise confirmed by laser shots by a surveying team without using the GPS system for any part of it. I’d bet a six pack that the GPS system is the culprit. Presently my best guess is that there was an error in the calculated distance as it relates to the differences in altitude of 8,300 ft.
From what I’ve read the GPS system has some cool algorithms for correction but I don’t expect this kind of accuracy requirement concerning 8,300 ft. difference in altitude has ever needed this kind of accuracy or been tested before concerning big differences in altitude between two points and then confirmed by surveying the distance.
My expectation is that future experiments in Japan and the U.S. on a level plane will show no such discrepancy. I think these muon neutrinos were traveling at a speed a little less than the speed of light and the actual distance is about 20 meters less than what the GPS system indicated. My prediction is that it is a fault in the GPS programming related to presently unknown aspects of gravity as it relates to the speed of light.
forrest, I recommend that you read the paper to see what they did rather than criticize a construction of your own invention.
With all due respect, this statement is incorrect, at least within the framework of special relativity. If something is even just a tiny bit faster than light in one reference frame, it is easy to find another reference frame in which it arrives before it was generated. This violates causality, ergo is impossible. Or so goes the argument.
@ Ron S,
I did read the paper concerning what they did. That is how I knew they used the GPS system as a primary indicator of distance followed be calculation. They also claimed a 20 cm accuracy of distance. An inaccurate distance calculation/ measurement of about ~20 meters too long, would account for the observed error based upon my calculations.
“With all due respect, this statement is incorrect, at least within the framework of special relativity. If something is even just a tiny bit faster than light in one reference frame, it is easy to find another reference frame in which it arrives before it was generated. This violates causality, ergo is impossible. Or so goes the argument.”
How do you find this inertial frame?
Are you saying the experimenters could have claimed they detected the neutrinos before they sent them?
They did not claim that.
forrest, then you also reviewed the multiple ways they verified the time and distance calibrations? Do you see where they made an error of the magnitude you suggest? Their net error bars are less than what you assert.
Obviously if the neutrinos are indeed traveling sub-c (most likely) there is an error somewhere. They failed to find that error after a great deal of effort, including redundant measurements and using a variety of measurement techniques.
The error is going to be something very subtle, hopefully leading to a better understanding of particle interactions.
Victor Stenger on speedy neutrinos: did we cause God?
By Jerry Coyne on Why Evolution is True for September 28, 2011:
Over at Puffho, Victor Stenger ponders the evidence for faster-than-light neutrinos in a nice piece called “No cause to dispute Einstein.” Many of us know Victor as an eloquent atheist/physicist, but he also informs us us that he worked for thirty years on neutrinos. Clearly, he’s eminently qualified to pronounce on the CERN experiments suggesting that those particles can move faster than light.
Stenger makes two points. First, like many physicists he’s wary of the results, mainly because they’re contradicted by earlier data on supernovas:
However, a big fly in the ointment is the supernova in the Large Magellanic Cloud, which sits just outside our galaxy 168,000 light-years from Earth. It was first seen by the naked eye on February 24, 1987. Three hours before the visible light reached Earth, a handful of neutrinos were detected in three independent underground detectors. If the CERN result is correct, they should have arrived in 1982. So, if I were a wagering man, I would bet the effect will go away because of some systematic error no one has yet been able to think of.
Full article here:
http://whyevolutionistrue.wordpress.com/2011/09/28/victor-stenger-on-speedy-neutrinos-did-we-cause-god/
@Ron S,
My present expectation is that the main “error” concerning distance is with the GPS system. I think the “error” relates to the programming of the GPS system which involves a variation in the speed of light as it relates to the GPS system that I won’t go into. If I am correct, I believe they will not find the problem unless they survey the distance instead of relying on the GPS system. I also read that they also used fiber optic cables as a double check for part of the distance. This I believe also may have the same built-in error.
Such a survey may take some time and expense since the distance is 450 miles long but as others have mentioned, it would be one of the easiest explanations, a low hanging fruit so to speak :)
Gas ‘n’ Air
This week, a selection of papers discussing the recently discovered faster-than-light neutrino effect
kfc 10/01/2011
New Constraints On Neutrino Velocities
Superluminal Neutrinos Without Revolution
On the Possibility of Superluminal Neutrino Propagation
The Hypothesis of Superluminal Neutrinos: comparing OPERA with other Data
Relativistic Superluminal Neutrinos
The OPERA Neutrino Velocity Result And The Synchronisation Of Clocks
A Possible Statistical Mechanism Of Anomalous Neutrino Velocity In OPERA Experiment?
A Comment On The OPERA Result And CPT
Superluminal Neutrinos And Extra Dimensions: Constraints From The Null Energy Condition
http://www.technologyreview.com/blog/arxiv/27212/
No, of course they didn’t. But it follows rigorously in the mathematical framework of special relativity. It can be shown that if anything is faster than light in some reference frame, another reference frame can be found (by mathematical transformation) in which the object moves backwards in time. I suppose a frame that moves at near light speed opposite to the object or something similar. As I remember this is the essence of the mathematical proof that c can not be exceeded, but it’s been a while… Also, AFAIK, general relativity does not change this conclusion, but makes it more general.
If the incomming tauino is absorbed at the ‘low’ side of the resonant wave packet of an electron orbit and there is a mediating boson which will leave that tauino as an electron and convert the original electron into a tauino then:
1 the recoil of the original action will be countered by the recoil of the ejected tauino
2For the action to be elastic the boson will have to act in zero time interval
3. The boson will have the status of a virtual particle
4. The electron orbit will experience a phasse shift of pi
This action would be the equivalent of ‘tunneling’ and accelerate the tauino by
1.66E-18 sec. about 3.6E9 such actions would be needed to obtain the 60E-9 sec early arival of tauinos
Over the 730km. CERN to Gran Sasso lab. there are about 1.46E15 atoms allowing a probability of 2.5E-6.
This argument raises the same question as the Fred Hoyle 3.He = 1.C reaction where a defined energy level is critical, plus, in this case, a relevant boson.
Albert E. would still be upheld.
Neutrinos spark wild scientific leaps
By Alan Boyle
Commentators have been surprisingly fast to point to faster-than-light neutrinos as evidence that scientists could be wrong about lots of things, including the causes of climate change. But the most likely scenario is that special relativity — a theory that contends nothing can be accelerated beyond the speed of light in a vacuum — will turn out to be right. Or at least relatively right.
Two weeks after the neutrino experiments first came to light, the prevailing view among physicists is that the observations will somehow be shown to be wrong. The time measurements had to be made to an accuracy of billionths of a second. Synchronizing the time signatures over a distance of more than 450 miles of neutrino flight, from the CERN particle-physics center on the French-Swiss border to Italy’s Gran Sasso National Laboratory, is extremely challenging.
Full article here:
http://cosmiclog.msnbc.msn.com/_news/2011/10/07/8211350-neutrinos-spark-wild-scientific-leaps
[i]Eniac October 4, 2011 at 23:16
How do you find this inertial frame?
Are you saying the experimenters could have claimed they detected the neutrinos before they sent them?
They did not claim that.
No, of course they didn’t. But it follows rigorously in the mathematical framework of special relativity. It can be shown that if anything is faster than light in some reference frame, another reference frame can be found (by mathematical transformation) in which the object moves backwards in time. I suppose a frame that moves at near light speed opposite to the object or something similar. As I remember this is the essence of the mathematical proof that c can not be exceeded, but it’s been a while… Also, AFAIK, general relativity does not change this conclusion, but makes it more general.[/i]
Ok , well I will have to think about this more.
The question is…. are not cause and its effect still separated by a timelike interval?
I thought this was an integral part of Special Relativity and in GR … that effect must belong to the future light cone. It’s hard to see how these basic structures can be overthrown.
If it’s something that stems from the quantum domain, I have no idea about that QM has always bumfuzzled me.
Also the LHC would not work at all if SR were completely wrong, it is an integral part of the engineering that went into building it.
Exactly. The key here is that SR adds to the above a crucial phrase: “… in all inertial frames of reference”. FTL may look like it would conserve causality in some frame of reference, but it cannot do so in all. Only time-like trajectories are guaranteed to remain causal in all frames of reference.
Then the bartender tells the faster-than-light neutrino, “We don’t
serve faster-than-light neutrinos in this bar.”
A faster-than-light neutrino walks into a bar.
…machine. I just invented a time…
http://www.technologyreview.com/blog/arxiv/27260/
Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity
The relativistic motion of clocks on board GPS satellites exactly accounts for the superluminal effect, says physicist.
kfc 10/14/2011
It’s now been three weeks since the extraordinary news that neutrinos travelling between France and Italy had been clocked moving faster than light. The experiment, known as OPERA, found that the particles produced at CERN near Geneva arrived at the Gran Sasso Laboratory in Italy some 60 nanoseconds earlier than the speed of light allows.
The result has sent a ripple of excitement through the physics community. Since then, more than 80 papers have appeared on the arXiv attempting to debunk or explain the effect. It’s fair to say, however, that the general feeling is that the OPERA team must have overlooked something.
Today, Ronald van Elburg at the University of Groningen in the Netherlands makes a convincing argument that he has found the error.
First, let’s review the experiment, which is simple in concept: a measurement of distance and time.
The distance is straightforward. The location of neutrino production at CERN is fairly easy to measure using GPS. The position of the Gran Sasso Laboratory is harder to pin down because it sits under a kilometre-high mountain. Nevertheless, the OPERA team says it has nailed the distance of 730 km to within 20 cm or so.
The time of neutrino flight is harder to measure. The OPERA team says it can accurately gauge the instant when the neutrinos are created and the instant they are detected using clocks at each end.
But the tricky part is keeping the clocks at either end exactly synchronised. The team does this using GPS satellites, which each broadcast a highly accurate time signal from orbit some 20,000km overhead. That introduces a number of extra complications which the team has to take into account, such as the time of travel of the GPS signals to the ground.
But van Elburg says there is one effect that the OPERA team seems to have overlooked: the relativistic motion of the GPS clocks.
It’s easy to think that the motion of the satellites is irrelevant. After all, the radio waves carrying the time signal must travel at the speed of light, regardless of the satellites’ speed.
But there is an additional subtlety. Although the speed of light is does not depend on the the frame of reference, the time of flight does. In this case, there are two frames of reference: the experiment on the ground and the clocks in orbit. If these are moving relative to each other, then this needs to be factored in.
So what is the satellites’ motion with respect to the OPERA experiment? These probes orbit from West to East in a plane inclined at 55 degrees to the equator. Significantly, that’s roughly in line with the neutrino flight path. Their relative motion is then easy to calculate.
So from the point of view of a clock on board a GPS satellite, the positions of the neutrino source and detector are changing. “From the perspective of the clock, the detector is moving towards the source and consequently the distance travelled by the particles as observed from the clock is shorter,” says van Elburg.
By this he means shorter than the distance measured in the reference frame on the ground.
The OPERA team overlooks this because it thinks of the clocks as on the ground not in orbit.
How big is this effect? Van Elburg calculates that it should cause the neutrinos to arrive 32 nanoseconds early. But this must be doubled because the same error occurs at each end of the experiment. So the total correction is 64 nanoseconds, almost exactly what the OPERA team observes.
That’s impressive but it’s not to say the problem is done and dusted. Peer review is an essential part of the scientific process and this argument must hold its own under scrutiny from the community at large and the OPERA team in particular.
If it stands up, this episode will be laden with irony. Far from breaking Einstein’s theory of relatively, the faster-than-light measurement will turn out to be another confirmation of it.
Ref: http://arxiv.org/abs/1110.2685: Times Of Flight Between A Source And A Detector Observed From A GPS Satellite.
Here is someone with access to the public media podium who does not “get” how or why science works the way it does and uses the whole FTL neutrino story to warp said events and twist things to promote his own agenda. Either that or he does get it but is twisting things for himself regardless.
http://whyevolutionistrue.wordpress.com/2011/10/17/charles-krauthammer-gets-science-wrong/
Ljk, I feel that you may be missing a subtlety here. What if you see science as the art of producing decision procedures for predicting outcomes, rather than the more mundane alternative definition of science as a body of naturalistic explanation of the world around us.
By the second definition you could at least reasonably argue that the discipline of science itself had been brought into question by FTL neutrinos. If, however, you hold the former opinion, there is little leeway for any doubt. In this second case, even if all our models are proved false, their predictive value up to the threshold of superlatively extreme situations still holds true. In many cases it will give predictions that are more than a million better than any other way of guessing outcomes.
Take anthropogenic warming for instance. Isn’t it enough to claim that science can deliver better predictions of future climate than any other discipline? Isn’t it also one of sciences strengths to be able to estimate the likely variance. The general public may want absolute certainty, but if some try to pretend that science delivers this, rather than educating the public to its true nature, could this attitude endanger the publics reverence toward science, and thereafter society itself?
In that regard the evidence for FTL neutrinos is not important. What is important is whether there is evidence that some scientists cling to their paradigms so tightly that this distortion to their objectivity could invalidate anything that could be classed as an extrapolation (such as models for climate that only seem to work in the freak conditions of the Holocene stability).
At first glance the article that you indirectly cite gets science very wrong. However it is just possible that it is addressing the issue that should be of foremost concern to us. I invite you to think of a completely new perspective where the real danger to science, is the subconscious feeling that many scientists hold, that our models and paradigms are the reality.
Higgs Rumor Roundup
Posted on November 10, 2011 by woit
As far as I’ve been able to tell, there’s still nothing definitive one way or the other about the SM Higgs, as the experiments continue to analyze data from the now-finished 2011 pp run.
Starting Monday is the HCP 2011 conference which at one point seemed to be a possible venue for announcement of confirmation of hints from early this summer of a Higgs around 140 GeV or so. Those hints disappeared later in the summer, so conventional wisdom recently has been that not much new will come out next week in Paris.
A new blog entry from one of the organizers refers to this disappointment, leading to worries about conference attendance, but adds some dramatic and mysterious news at the end. It seems that some experimental collaboration requested a last-minute slot at the conference to unveil a new result that might be the highlight of the conference.
They’re on for 15 minutes on Monday, still not announced which collaboration this is, who the speaker is, or what their title is. This may very well have nothing to do with the Higgs: maybe something else travels faster than the speed of light…
Full article here:
http://www.math.columbia.edu/~woit/wordpress/?p=4136
Measurement of the neutrino velocity with the OPERA detector in the CNGS beam
The OPERA Collaboraton: T. Adam, N. Agafonova, A. Aleksandrov, O. Altinok, P. Alvarez Sanchez, A. Anokhina, S. Aoki, A. Ariga, T. Ariga, D. Autiero, A. Badertscher, A. Ben Dhahbi, A. Bertolin, C. Bozza, T. Brugière, R. Brugnera, F. Brunet, G. Brunetti, S. Buontempo, B. Carlus, F. Cavanna, A. Cazes, L. Chaussard, M. Chernyavsky, V. Chiarella, A. Chukanov, G. Colosimo, M. Crespi, N. D’Ambrosio, G. De Lellis, M. De Serio, Y. Déclais, P. del Amo Sanchez, F. Di Capua, A. Di Crescenzo, D. Di Ferdinando, N. Di Marco, S. Dmitrievsky, M. Dracos, D. Duchesneau, S. Dusini, J. Ebert, I. Efthymiopoulos, O. Egorov, A. Ereditato, L. S. Esposito, J. Favier, T. Ferber, R. A. Fini, T. Fukuda, A. Garfagnini, G. Giacomelli, M. Giorgini, M. Giovannozzi, C. Girerd, J. Goldberg, C. Göllnitz,
et al. (122 additional authors not shown)
(Submitted on 22 Sep 2011 (v1), last revised 17 Nov 2011 (this version, v2))
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on high-statistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies.
An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (57.8 \pm 7.8 (stat.)+8.3-5.9 (sys.)) ns was measured. This anomaly corresponds to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c = (2.37 \pm 0.32 (stat.) (sys.)) \times10-5.
The above result, obtained by comparing the time distributions of neutrino interactions and of protons hitting the CNGS target in 10.5 {\mu}s long extractions, was confirmed by a test performed using a beam with a short-bunch time-structure allowing to measure the neutrino time of flight at the single interaction level.
Comments:
32 pages, 18 figures
Subjects:
High Energy Physics – Experiment (hep-ex); High Energy Physics – Phenomenology (hep-ph)
Cite as:
arXiv:1109.4897v2 [hep-ex]
Submission history
From: Pasquale Migliozzi Dr. [view email]
[v1] Thu, 22 Sep 2011 17:59:33 GMT (4763kb)
[v2] Thu, 17 Nov 2011 11:17:26 GMT (6498kb)
http://arxiv.org/abs/1109.4897v2
Thanks for the update ljk, but the more I investigate better my “they’re tachyons AND refracting” speculation looks to me. Many comments that I have read at other sites seem puzzled that even if neutrinos are tachyons their speed was too independent of their energies and too much faster than light. Obviously refraction could boost neutrinos speed significantly above their speed in vacuum so that was no problem. Now refraction index is dependant on wavelength and thus energy, but when I looked up this dependence on wavelength in Wikipedia it seemed so low that an experiment with energies only differing by a factor of two might have difficulty detecting it at those tolerances.
Please, could someone who knows better show me what’s wrong (other than that most physicists share a religious belief in causality or freewill). It just can’t be that simple.