NOT-AS-FAST NEUTRINOS: The Gran Sasso National Laboratory of the Italian Institute of Nuclear Physics, located nearly a mile below the surface of the Gran Sasso mountain about 60 miles outside of Rome, detects tiny particles called neutrinos.
Image: Paolo Lombardi INFN-MI
The final nail in the coffin may have been dealt to the idea that neutrino particles can travel faster than light.
The same lab that first reported the shocking results last September, which could have upended much of modern physics, has now reported that the subatomic particles called neutrinos "respect the cosmic speed limit."
Physicist Sergio Bertolucci, research director at Switzerland's CERN physics lab, presented the results today (June 8) at the 25th International Conference on Neutrino Physics and Astrophysics in Kyoto, Japan.
"Although this result isn't as exciting as some would have liked, it is what we all expected deep down," Bertolucci said in a statement.
The new findings come from four experiments that study streams of neutrinos sent from CERN in Geneva to the INFN Gran Sasso National Laboratory in Italy. All four, including the experiment behind the first faster-than-light findings, called OPERA, found that this time around, the nearly massless neutrinos traveled quickly, but not that quickly. [10 Implications of Faster-Than-Light Neutrinos]
Last year, OPERA measured that neutrinos were making the 454-mile (730-kilometer) underground trip between the two labs more speedily than light, arriving there 60 nanoseconds earlier than a beam of light would.
At the time, the physicists were stunned because such a result seemed to break Einstein's prediction that nothing could travel faster than light. This idea is at the heart of his theory of special relativity, on which much of our modern technology and scientific understanding is based.
The OPERA researchers weren't sure what could explain their anomalous results, having checked and rechecked their work, so they released their findings to the larger community of physicists in hopes that experts around the world could help them figure it out.
"The story captured the public imagination, and has given people the opportunity to see the scientific method in action — an unexpected result was put up for scrutiny, thoroughly investigated and resolved in part thanks to collaboration between normally competing experiments," Bertolucci said. "That's how science moves forward."
Labs around the world, including the other experiments at Gran Sasso — called Borexino, ICARUS and LVD — as well as the MINOS experiment in Illinois and the T2K project in Japan, tried to recreate the OPERA findings. None were able to do so: Every time, neutrinos appeared to obey the speed limit of light.
Now, the OPERA scientists think their original measurement can be written off as owing to a faulty element of the experiment’s fiber-optic timing system.
- Wacky Physics: The Coolest Little Particles in Nature
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- The Physics of 7 Everyday Things
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24 Comments
Add CommentSo it's not just a good idea, it's still the law:
Reply | Report Abuse | Link to thisSPEED LIMIT
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The original CERN press release dated 23 Sep. 2011 quoted CERN Research Director Sergio Bertolucci:
Reply | Report Abuse | Link to this“When an experiment finds an apparently unbelievable result and can find no artefact of the measurement to account for it, it’s normal procedure to invite broader scrutiny, and this is exactly what the OPERA collaboration is doing, it’s good scientific practice.”
Please see the chain of press releases at http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html
Most of the irresponsible speculation came from 'science' reporting sites like all those referenced in this report.
It would have been more satisfying to hear exactly the difference between these latter results and the original ones. And the reasons for the difference.
Reply | Report Abuse | Link to thisVery good point. The Science News article is a little edgey, but is better and includes links to some very good sources. Please see http://news.sciencemag.org/scienceinsider/2012/06/once-again-physicists-debunk.html?ref=hp
Reply | Report Abuse | Link to thisNice to see real science occurring. As cool as it would have been for that to be real, the team did it right. Put the results out there for the purpose of more testing to get to a real result, when they could not seem to explain what they observed.
Reply | Report Abuse | Link to thisThe world does not get enough real science occurring unfortunately but at least we know it is happening occasionally.
Just because all natural things have to obey the light speed cops, doesn't mean we have to. I bet we will find a way to blow that light speed law right out of the Universe and leave all those natural things far behind scratching their heads in disbelief.
Reply | Report Abuse | Link to thisI recommend reading "Quantum mechanics: Get real", http://www.nature.com/nphys/journal/v8/n6/full/nphys2325.html
Reply | Report Abuse | Link to thisI think the research is missing the point. Neutrinos could possibly be arriving at a point in time before photons spawned by the same event, not because they are travelling faster than the photons, but because they are taking short cuts. Right now the path taken by a photon actually DEFINES what a straight line is,(the shortest distance between two points, but is it?) This is although we know that they, or space itself, can be deflected by the gravity of other massive objects in space, but suppose the neutrino is deflected LESS than the photon, and the evidence supports this, then it would be bound to arrive at a target, say Earth, some appreciable time before the photon.
Reply | Report Abuse | Link to thisWell, actually, neutrinos generated at some location here on Earth must pass through the Earth to reach a significantly distant detector. The experiment does not generate any photons, but they couldn’t pass through the Earth, anyway. The distance neutrinos traversed is estimated using GPS locations for a position near the neutrino emission device (the precise location of neutrino generation cannot be determined) and the detectors. Standard geodesy routines used estimated the linear distance between those two points at 731 km.
Reply | Report Abuse | Link to thisHowever, neutrinos with even tiny mass moving at relativistic velocities through the non-Euclidean space within the Earth will not likely follow a strictly linear path. Moreover, being more affected by gravitation than photons, they might actually traverse a shorter distance through curved space than would light (if it could pass through the Earth).
At any rate, the actual path and distance through the Earth traversed by neutrinos cannot be definitively determined. As a result, their speed cannot be precisely determined, relative to the speed of light in a vacuum traversing an identical distance.
As a layperson I cannot assess the potentially variable uncontrolled factors dynamically affecting the paths taken by neutrinos, but some may be addressed in the report: Wolfgang Kundt, (2011). "Speed of the CERN Neutrinos released on 22.9.2011 - Was stated superluminality due to neglecting General Relativity?", http://arxiv.org/abs/1111.3888v1
I should have mentioned, though, that the researchers fixed the (cable) problems identified and reran their tests. The new tests produced results that are consistent with neutrinos propagating at the speed of light. They did not claim to have determined the precise speed of neutrinos relative to the speed of light - I suspect because of the uncertainties that have been identified...
Reply | Report Abuse | Link to thisI have a lay person's question?
Reply | Report Abuse | Link to thisCan we measure the speed of something faster than light??
I don't know if any physicist will respond: as I understand no hypothetical superluminal particle has ever been detected. Please see http://en.wikipedia.org/wiki/Tachyon
Reply | Report Abuse | Link to thisExcellent point. We would all like to find out exactly what are the results of the latest experiments, especially Opera. Sergio Bertolucci might be distorting the truth when talking about neutrinos "being consistent with the speed of light". It seems they still found neutrino events slightly faster than light. During 1987 supernova, neutrinos arrived five hours before photons, and that is a fact. Are the physicists taking for fools all the others? How can a particle with mass have the same speed as that of light? The Lorentz invariant would be infinite. So, simple logic, something must be wrong or incomplete with relativity. Many people think the physicists are perpetuating a huge fraud in order to protect their books, careers, and their grants.
Reply | Report Abuse | Link to thisSo, are the neutrinos slightly faster than light? E pur si muove?...please, Lords of physics, give us the facts, in exchange for the money you receive for so many years.
Excellent point made by outsidethebox. We would all like to find out exactly what are the results of the latest experiments. Sergio Bertolucci might be distorting the truth when talking about neutrinos "being consistent with the speed of light". It seems they still found neutrino events slightly faster than light. During 1987 supernova, neutrinos arrived five hours before photons, and that is a fact. Are the physicists taking for fools all the others? How can a particle with mass have the same speed as that of light? The Lorentz invariant would be infinite. So, simple logic, something must be wrong or incomplete with relativity. Many people think the physicists are perpetuating a huge fraud in order to protect their books, careers, and their grants.
Reply | Report Abuse | Link to thisSo, are the neutrinos faster than light? E pur si muove?...please, Lords of the physics, give us the facts, in exchange for the money you receive for so many years.
This reminds me of a schoolboy question. How would you measure the speed of light?
Reply | Report Abuse | Link to thisAnswer: Use a flashlight, ruler and stopwatch.
NOTE: It is essential that the stopwatch is accurate.
Why did this even get widespread media notice in the first place? It was an obvious instrumental problem from the very beginning?
Reply | Report Abuse | Link to thisNonsense!
Reply | Report Abuse | Link to thisI think these guys had better check and double check their clocks a little better before they go outside and yell that these little particles, or whatever they are, can move faster than light!But anyway it is such subtle measurements that we probably had better forgive them! Who has not have a setback in our lives' endeavors. And from a setback we can learn a great deal, sometimes, as unbelievable as it may seem,a lot more than in a victory. Anyone successful, that has live long enough, knows that very well! So, get up on your two feet, and keep moving! I am quite sure you will have better luck next time. And we are very grateful for your efforts! One last reflection, one day, who knows, we may get up and move a step a ahead faster than light, beating all odds, and doing the entirely unexpected. there is still a long way to go. Only the ones that do no act do not make mistakes.
Reply | Report Abuse | Link to thisIf a hypothetical superluminal particle's position can be established at two different times, then yes.
Reply | Report Abuse | Link to thisIf not, then maybe no.
"So, are the neutrinos slightly faster than light?"
Reply | Report Abuse | Link to thisNo.
(The SN1987A neutrinos arrived before the light, because they were emitted before the light.)
There is a fundamental flaw inherent in the final conclusion that neutrinos travel at luminal velocity; since they are "nearly massless" particles but still of finite mass, then according to special relativity theory
Reply | Report Abuse | Link to thisthey cannot violate its main tenet that they must travel at subluminal velocity. ie, m>0 => V<c ; m=0 => v=c.!!!
Whew, that’s not shocking results but a great relief! Indeed, the fact that nothing can move faster than light has a more fundamental and simple explanation. In the final perspective on the nature of things, ours is a vibrant universe, filled with, yes, the classic ether, which unique and single medium is but a a voidless and seamless continuum of mass-energy, in which photons (basic energy particles) are the evaporated state of the mass-energy, or matter, vibrant at terminal speed c; and electrons and nucleons (basic matter particles)are the condensed form of matter, vibrant at sub-c speeds.
Reply | Report Abuse | Link to thisFor simplicity to explain basic principles, consider the single dipole particle, the proton or the electron. At rest in inertial space, the dipole breathes, with net emission of mass-energy at its north pole and around the equator over the exhalation half cycle; and net absorption of mass-energy at the south pole and around the equator ever the inhalation half cycle. [these equatorial exchanges fundamentally cause the spin of the particle to wax from zero to the specific quantum of h/2pi, over exhalation and lose the spin quantum completely to zero over inhalation, to give the particle its statistical and characteristic half-spin, (h/2pi)/2.]
Under acceleration, the vibrant dipole moves against the ether, with the south pole leading. A quantum of mass-energy of the particle attains speed c at the rarefied wake (north) and evaporates off, which emission at the stern is seen as the ultimate cause for the motion of the body, and which forward thrust results in the ramming of the dipole against the ether in front, causing a bow shock through the ether. (And this basically is magnetic radiation, caused thus only by dipole particles of matter moving through the space of the ether.) Under the bow shock, the particle recoils (and this basically is inertial resistance). For more on this perspective, which would reinstate the supremacy of Newtonian classical mechanics for all time, do kindly access:
http://www.sittampalam.net/Synopsis.htm
http://www.sittampalam.net/Relativity.htm and
http://www.sittampalam.net/TheNeutrino.htm
(Links in these pages open best with Internet Explorer.)
Thank you all for your time here. Cheers!
A photon moves at the speed of light with respect to any and all observers. Its own time is infinitely dilated. It fills the universe because it can travel everywhere without passage of its own time; it does not age and effectively time does not exist for it. Which means that it has no own oscillation, because the frequency is missing - without the passage of time frequency is meaningless. The photon therefore must be a stationary condition of energy and the apparent oscillation is something external observers ascribe to it and perceive differently according to their individual frames of reference. How is this affected when light moves slower in a refractive medium?
Reply | Report Abuse | Link to thisIf this is *IF* we were traveling in a craft at light speed, and we were to turn on the head lights, would the photons simply pile up on the bow of our craft? Or, would they travel in front of us, going away, at the speed of light measured by our craft?
Reply | Report Abuse | Link to thisSo how fast is light, anyway? And, would you care to prove it in a court of law?