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AFP - Getty Images
The detectors of the OPERA experiment to measure neutrinos rise from the floor of the Italian National Institute of Nuclear Physics INFN's Gran Sasso Laboratory. Two human figures on the left and right edges of the picture provide a sense of scale.
Researchers say new tests have confirmed earlier indications that neutrinos can travel faster than light, but not everyone is convinced.
The claim runs so counter to a century's worth of physics that most observers won't be content until the findings from the OPERA experiment are repeated under a variety of conditions, by different teams of researchers. If the results hold up, that would require a reinterpretation of Albert Einstein's special theory of relativity, which effectively sets the velocity of light in a vacuum as a cosmic speed limit.
The latest round of tests was conducted to address some of the criticisms that cropped up in the wake of the OPERA team's initial announcement about faster-than-light neutrinos in September.
"A measurement so delicate and carrying a profound implication [for] physics requires an extraordinary level of scrutiny," Fernando Ferroni, president of the Italian Institute for Nuclear Physics, or INFN, said in a news release. "The experiment OPERA, thanks to a specially adapted CERN beam, has made an important test of consistency of its result. The positive outcome of the test makes us more confident in the result, although the final word can only be said by analogous measurements performed elsewhere in the world."
"OPERA" is a tortured acronym that stands for "Oscillation Project with Emulsion-tRacking Apparatus." The team's researchers shoot beams of neutrinos from the CERN particle-physics center on the French-Swiss border to INFN's Gran Sasso Laboratory, more than 450 miles (730 kilometers) away. The travel time for each pulse of neutrinos is measured to an accuracy of billionths of a second. In the faster-than-light experiment, the researchers reported that the neutrinos arrived 60 nanoseconds earlier than a light beam would have.
The revised experiment sent out 3-nanosecond-long bursts of neutrinos, spaced by as much as 524 nanoseconds, INFN said. "This permits to make a more accurate measure of their velocity, at the price of a much lower beam intensity; only 20 clean events have been collected by OPERA in this phase. Additional events could be eventually collected in the next year run," the institute said.
The Associated Press reports on the faster-than-light neutrino research.
Jacques Martino, director of France's National Institute of Nuclear and Particle Physics at CNRS, was quoted as saying that the search for potential experimental errors "is not over."
"There are more checks of systematics currently under discussion," he said. "One of them could be a synchronization of the time reference at CERN and Gran Sasso independently from GPS, using possibly a fiber [cable]."
Some physicists criticized the initial experiment because they thought it did not fully account for the relativistic effects of the Global Positioning System, which was used to track the elapsed time as well as the distance traveled between CERN and Gran Sasso.
INFN said the updated results have been submitted for review and publication in the Journal of High Energy Physics. But ScienceInsider's Edwin Cartlidge reported that about 15 of the experiment's nearly 200 collaborators have declined to lend their names to the journal submission, on the grounds that further confirmation is required.
An unnamed source on the OPERA team told ScienceInsider that the controversy over the faster-than-light findings was exhausting. "Everyone should be convinced that the result is real, and they are not," the source was quoted as saying.
Other researchers, including physicists with the MINOS experiment at Fermilab, are working up independent analyses of neutrino runs to assess the OPERA team's findings. The initial outside assessments are expected to become available within six months or so, but end-to-end replications of the experiment could take significantly longer.
Update for 2 p.m. ET Nov. 18: In response to some of the comments below, I've changed the headline on this item, which originally read "Faster-than-light neutrinos confirmed." I realize the new headline still implies that superluminal neutrinos actually exist even though the evidence for that is in dispute, but I hope you'll understand that this is shorthand for "New experiment continues to support hypothesis about faster-than-light neutrino travel."
More on the faster-than-light controversy:
- Neutrinos spark wild scientific leaps
- Faster-than-light neutrinos? Not so fast, some say
- Challenging Einstein is usually a losing venture
- Interactive: Putting Einstein to the test
- 'Virtually Speaking Science': Podcast on weird physics
Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or following the Cosmic Log Google+ page. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.
Leave a Comment:
What would be the significance of breaking the light speed barrier?
Everything, really. I goes against all our best scientific theory. Theories that have been confirmed to amazing accuracy.
But it's an extraordinary claim and is going to need extraordinary proof to back it up. My money would be on an error in the data or methodology.
Doesn't relativity itself insure that you can never accurately measure "the" speed of anything?
No, but quantum theory says that we can never know a speed and position of a particle with arbitrary accuracy. We can measure the speed (momentum) with the needed precision if we don't care about the position.
Joe...; The argument is null for the manner in which he/she offers a test of their own. The statement is for the writer to see their own writing in print.
I didnt think it sounded angry at all, Joe. But I am a science nerd too. I think most people who are more than 'moderately' intelligent are easily frustrated by the ignorance of others and I also think its perfectly natural. But we are so serious and focused at a higher intensity, I also think that's why we die so much earlier than people who dont give a crap. You were 100% correct in your first post. Must have a control in any experiment or its all THEORY
Science is such dogma, prove what we "know" is wrong and all the zealots come out. From what I was taught @ Eberly (PSU) 20 years ago about Black Holes that we KNEW to now, dramatically different. World didn't change.
Why rattling the old FTL chain gets so minds in a bunch is beyond me? Science evolves. The theories of a German who was dead before Pong will be adjusted. Newton's were, Al's will be too.
doesn't the 'big-stretch' begin here?...I'm stay'n tuned cause there's still 15 out of 200 very smart ones believe this experiment may be faulty?
Einstein disguised as Robin Hood
With his memories in a trunk
Passed this way an hour ago
With his friend some jealous monk?
Saint Dylan
The science mainscreamers really get fluffed over this subject. The only conclusion one can reach is that they spend wayyyy too much time secluded from the rest of their species because when they come out to talk, it sounds like the Spanish Inquisition. The holy grail is Einstein's special theory of relativity and heretics, blasphemers and infidels will be burned at the stake for even thinking that it may be imperfect.
In some ways, it is humorous because the average layman; the working Joes and Janes of the world, really don't give a flying rat's bonkus either way. Regardless of what is faster, it won't pay their bills, put food on the table or keep their kids in shoes.
If you do not give a crap, then I suggest you throw away the computer you wrote your post on, throw away your GPS, Iphone, heck, even many VHS machines, before they stopped making them, prevented the flashing12:00 by setting the time from the atomic clock in Colorado (a lot of wrist watches do this too), disconnect your electricity and go live in a cave, for all you electronic gadgetry use relativity and/or quantum mechanics in one way or another.
How will the speed of light benefit the average layman? They are currently developing photon and/or plasmonic basic computers (means it will be really really fast). If particles are even faster then light, that could be the basis of the generation after the light based ones.
We geeks might not have the best social skills, but if you do not understand what we are saying, I suggest you pay more attention in science class (or if you are out of school, pick up a book, cause you can not use an eReader, it uses relativity too...)
A simple explanation of OPERA results without strange physics
http://arxiv.org/abs/1110.0239
This is inline with my initial post back in September when the results were first released.
Post 1.
As for the observers, they have rechecked the setup for months so every single parameter must have been checked with a "monte carlo" analysis.
if I were to put a wager, i would say because this is "beam" (a very sharp and narrow cloud of millions if not billions) of muon neutrinos (fermions), by the time the beam takes to reach the sensors (454 mi) the "ambient temperature" of the cloud (this cloud is moving through rock and not "vacuum") has dropped and has expanded the cloud's initial calibrated length. So the lead edge (for measurement purposes) has displaced forward the equivalent of 60 +/- 10 nanoseconds.
Post 2.
Convincing argument by R van Elburg, even with the 64 ns correction it still puts the speed of a massive lepton at the speed of light. This correction does not eliminate the main issue, massive particle should not travel at the speed of light.
My hope is that even with van Elburg correction the muon neutrinos do travel at c =/- normal variance and even more important that if there is sufficient oscillations to tau neutrinos that the variance in the speed would be longer. I hope they repeat this experiment until all the questions on the relevant parameters are answered.
I would like to know the variances of the electon, muon and tau neutrinos compare to the photon.
Even if the results hold valid and the neutrinos do travel very close to speed of light with a consistant variance it could be a better explanation for mass. The Higgs boson would longer be necessary to explain mass because if we can deduce that bosons do indeed have structure then the variance of the shell wall could be the transition from zero VEV (nothingness) to a non-zero VEV (mass).
I conjecture that it may also explain gravity but that is more difficult to visualize.
This experiment could end up being much more valuable than the search for the Higgs boson at ATLAS.
One thing I've been wondering about: When the OPERA team did their initial experiments, were they actually trying to measure the speed of neutrinos, or was the experiment originally intended for some other purpose, and then somebody noticed this anomaly and it snowballed from there? It seems odd that someone would just wake up one morning and say "Hey, lets see if neutrinos can go faster than light". There must have been some theoretical underpinnings to the work.
Metaluna, you are right on!
Project X planned at Fermilab will answer you excellent question. http://projectx.fnal.gov/
The ultimate goal is to obtain a cleaner fission reaction for next generation nuclear power reactor design.
As a minimum they are hoping to achieve "transmutation" of nuclear waste. Change the radioactive isotopes to neutral by products and hence a clean nuclear power cycle. This would be a very good thing.
Metaluna - Check out the OPERA site : http://operaweb.lngs.infn.it/. The purpose of this experiment is to try to understand more about neutrino oscillations.
The universe and everything around us is a cycle. The more we look in the smallest of places, the more we find that are even smaller. So small that there'll be a point where we can't detect anything any smaller, but it's there. The same as the Universe, or Universes! Yes, I said it. Because of these cycles, there's a constant, never ending conundrum of more stuff. So the universe as we know it is (could) be many universes making up a megaverse. And now for speed, chances are there's something faster than a neutrino, we're just not going to discover it for quite some time, and then our theories will be bashed...again.
Speed cannot be limited in this cycle, as well as size, no matter how small or how large you go, something will ALWAYS be smaller, or larger somewhere. The only limitation to these is our perception of how we see the world. When we learn to differentiate between one state and the next, we discover more new and exciting things.
The point of my post? Don't ever rely on an individuals perception, or that of a collective to be the truth, because the more you dig, the more you'll unravel, and it will never stop.
"The only limitation to these is our perception of how we see the world." Amen.
And there will always be confusion for those who think 'our' perception is absolute.
Are they taking the earths rotation speed into account in their measurements?
Currently my money is on time dilation caused by the neutrino passing slightly closer to the center of Earth's gravity well.
Why are they worried about syncing time clocks or whatever? Just fire a beam of neutrinos and a beam of light at the same time - and see which one gets there first? Easy solution.
Light doesn't travel through 500 miles of rock very well; neutrinos do.
However, s.t. like the experiment you suggest was tried: a supernova produces both neutrinos and light, at roughly the same time. A burst of neutrinos believed to have come from the 1987 supernova was recorded at approx 4 hours before the light arrived; the diff is attributed to the structure of a supernova explosion (neutrinos produced first, light burst comes later, when a shock wave hits the "surface" of the star). Had the neutrinos traveled as much faster than light as implied in this new experiment, they should have arrived several years earlier (the distance to the supernova is ~168,000 light years). This is one reason some scientists disbelieve the results of this experiment.
Does this mean the neutrino's mass is greater than infinite?
I haven't heard any physicists say this, but I suppose one possibility is that their mass is an imaginary number, which would make them tachyons. What it would mean for their mass to be an imaginary number is anybody's guess.
perlmutter, reiss, and smith stated the the universe is gaining speed in its expansion, and that finally it will speed in the expansion beyond the speed of light, this proves, but the possibility exists that it may already be speeding faster, we should try to measure that.
A neutrino is faster than a photon, wow who knew? :) why would it be a shock? there is probably a different velocity for many sub atomic particles , and i would bet a different vibrational frequency also. light seems to be a constant , seems to mean the "push" upon departure is constant. is that the case with neutrinos? what is their initial impetus?
light leaves a galaxy traveling at the speed of light, that light is going the speed of light that the galaxy is added to the speed the light has inherently , right, so light is faster than light under the right circumstance.
No. Add the speed of motion of the galaxy relative to you, to the speed of light, and you will measure the speed of light to be the same as if the source were stationary relative to you. Likewise if you are moving relative to the source. (Of course the two situations--the galaxy moving relative to you, and you moving relative to the galaxy--are indistinguishable.) This is what the (Special) Theory of Relativity was designed to explain.
If it doesn't turn out and GPS data is in error, then science is in for a wild ride. One could concieve that since neutrinos are or must be basically nuetral and carry no charge then there just may be nothing to hinder them, it could also define a new property of space or wilder yet of an as yet inconcievable subspace medium that might consist of dark energy and/or dark matter. It would be interesting to see how any quantum theories could play any role with nuetrinos. Seems that science should turn in the direction of increased nuetrino research...curious what applications and technologies could be developed as a result of further nuetrino research. Off the top I could guess neutrinos could have applications for interstellar communications and could be a method used by an advanced civilization for interstellar communications. Time and Space and Faster than light travel becomes an entirely new reality if not a sort of different plane of conciousness that is perceptible. It could be learned to accelerate neutrinos eventually beyond our current observations. Maybe nuetrinos are the new speed limit of light.
Even more interesting would be how neutrinos interact with gravity which if massless and no electrical charge neutrinos may or may not be affected by gravity or postively charged ions, electrons, or other component wavelengths and particles of light. One way neutrinos could interact with gravity would be like visualizing currents and eddies of neutrinos through space, or neutrinos could travel in straight lines in every direction.
OK the absurd? The neutrino is the God particle right under our nose.
Too, I AM NOT anti-scientist. I am aware that the people involved at Gran Sasso are clearly stating that they could have made an error. In fact, they HAVE made an error, they just have not found it yet. I was primarily railing against the horrific lack of basic science knowledge by so called science reporters and editors. I am honestly shocked that Alan Boyle is printing such drivel. The News media covered the E-Cat story with the same unquestioning enthusiasm that they covered this "non-story" with. If I am not mistaken, neutrinos's have recently been found to have a non-zero mass. That should automatically mean that they cannot attain (equal) the speed of light, much less faster.
I have no argument one way or the other but I have a few questions for anyone who might know the answers. How do they know the exact distance and time or speed? I thought that with GPS you could only come within a few feet of your location. Also how do they synchronize the time? How do you know start and end times within nanoseconds?
just like they could with pico-seconds...mathamatically. and Lasers.
Just bounce signals to and from GPS will give you the distance to within a few feet error, as you say, equivalent to approx. =/- 10 nsec.
Synchronizing the clocks is a bit more tricky since you have to account for Lorentz contraction, gravitational effects, neutrino oscillation and the Heisenberg uncertainty principle (and I believe the energy-time uncertainty should also have been considered because the neutrinos are changing in flavor and hence the entire beam is not moving with one reference frame but multiple frames.)
They would use a procedure called the Monte Carlo, an algorithm that after a sufficient number of iterations of running signals back and forth the two sites would converge to a defined (repeatable) result to within an acceptable error. Acceptable error is what is in question here and they will require a lot more simulation models before we can make any sense of this very important experiment.
Thanks TooMany. I misread the article and thought they had a light beam traveling with the neutrinos.
Mikey - Here is a link to the OPERA site : http://operaweb.lngs.infn.it/spip.php?rubrique1. They explain how they produced the neutrinos and how they are detected. Neutrinos have no charge assigned to them so they are not attracted to protons or electrons.
After reading through the OPERA site, I am curious about the oscillation between the muon and tau neutrino. I wonder what is happening with the spacetime in this oscillation? Could there be a jump in space with this oscillation that makes the neutrinos appear to be traveling faster than the speed of light?
Imagine that the time difference was due to the course being shorter than expected, rather than super-speed particles.
A 30ns time difference corresponds to the length being 17.99m shorter than expected. If I remember correctly, the receiving lab is underground; does it seem reasonable that they have misplaced the receiver by 18 meters? Yes.
Since they used the Monte Carlo the couldn't possibly get the geometry wrong. Also this experiment took years in the making and they would of conducted many many design reviews to get it right.
Again, if there is an oversight it would have some thing to do with interpreting the leading edges of quantum mechanics. This experiments is one of the first to challenge us with our understanding and capability to produce a measurement system to deal with neutrinos.
Another very important experiment in the horizon is Project X at Fermilab.
You are incorrect about time equalling accuracy. There have been several NASA missions that failed in spite of extensive planning, notably:
- The original Hubble mirror was flawed due to the fact that engineers at Perkin-Elmer ignored good readings that showed that the mirror was flawed in favor of a bad reading from a "better" device.
- The Mars Climate Orbiter was lost due to the fact that the telemetry from the orbiter and the ground crew were using different unit systems
And so on. Generally, the more people that are involved in the design of the device, the more pathways that error can creep in.
There is the NOVA Fabric of the Universe series currently airing on our local PBS. Last show was about quantum physics at the quantum level and it aint anything like the physics we use everyday. This sounds like some of the things particles do at the quantum level.
A quick review:
1. The index of refraction is defined as the speed of light in a vacuum divided by the speed of light in a material (glass or quartz, or air). This under the assumption that no information can be propagated faster than the speed of light in a vacuum.
2. Under the particle attribute of the particle/wave duality nature of light, propagation is slowed when the photon, freely traveling at the speed of light (and represented by a long wave packet of nearly exact momentum and wavelength) is momentarily trapped in a localized state (a short wave packet of much more indefinite momentum and zero average speed). The uncertainty principle states that deltaE*deltat <=Planck's constant. If the available absorption energy is small, the time stopped is longer before re-emission , thus the average speed is lowered and the index is higher. Materials which can absorb the photon without re-emission are opaque. Vacuum offers no possibility of momentary absorption, thus the speed is that of light in a vacuum.
3. This theory of the speed of propagation of electromagnetic energy (photons) as the result of virtual absorption/re-emission makes it very difficult to accept results which amount to the propagation of information (the pulse of neutrinos) faster than the speed of light.
4. A new theory would require that instead of the virtual absorption resulting in a delay in time at the same point, it would result in re-emission at a point in space further along the original trajectory at the same time, not delayed. At first glance this might satisfy the conservation of energy and momentum, but would certainly not be anything I have seen discussed in the literature. No real disclaimer there, since I spent my career in solid state physics and do not have a grasp of the vast literature in this field.
A quick review:
1. The index of refraction is defined as the speed of light in a vacuum divided by the speed of light in a material (glass or quartz, or air). This under the assumption that no information can be propagated faster than the speed of light in a vacuum.
2. Under the particle attribute of the particle/wave duality nature of light, propagation is slowed when the photon, freely traveling at the speed of light (and represented by a long wave packet of nearly exact momentum and wavelength) is momentarily trapped in a localized state (a short wave packet of much more indefinite momentum and zero average speed). The uncertainty principle states that deltaE*deltat <=Planck's constant. If the available absorption energy is small, the time stopped is longer before re-emission , thus the average speed is lowered and the index is higher. Materials which can absorb the photon without re-emission are opaque. Vacuum offers no possibility of momentary absorption, thus the speed is that of light in a vacuum.
3. This theory of the speed of propagation of electromagnetic energy (photons) as the result of virtual absorption/re-emission makes it very difficult to accept results which amount to the propagation of information (the pulse of neutrinos) faster than the speed of light.
4. A new theory would require that instead of the virtual absorption resulting in a delay in time at the same point, it would result in re-emission at a point in space further along the original trajectory at the same time, not delayed. At first glance this might satisfy the conservation of energy and momentum, but would certainly not be anything I have seen discussed in the literature. No real disclaimer there, since I spent my career in solid state physics and do not have a grasp of the vast literature in this field.
Ok, Prof, answer this question.
If, indeed, the results hold up and the muonic neutrinos and by extrapolation electronic neutrinos) do propagate at the speed of light.
Does this indicate the possibility of supersymmetry between the fermion electronic neutrino and the W and/or Z boson (I dare mention the Higgs boson since the aforementioned symmetry could rule it out and unnecessary to explain mass (the soliton of the boson condensate)?