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Can Relativity Explain Faster Than Light Particles?
gbrumfiel writes "Two weeks ago, researchers claimed particles called neutrinos were travelling faster-than-light and violating the laws of special relativity. But now it looks as though general relativity might be behind the experiment's unusual result. An independent analysis claims that the original experiment, known as OPERA, failed to take into account differences in earth's gravitational field between the neutrino source and the OPERA detector. As Nature News reports, gravity can distort time according to Einstein's theory, and the effect could explain why neutrinos appear to arrive 60 nanoseconds ahead of schedule. The OPERA team is now reviewing the new analysis."
c++
Nice try.
Sincerely,
Einstein
They are reviewing their own paper to make their methods clear. FTFA:
"Dario Autiero of the Institute of Nuclear Physics in Lyons (IPNL), France, and physics coordinator for OPERA, counters that Contaldi's challenge is a result of a misunderstanding of how the clocks were synchronized. He says the group will be revising its paper to try to make its method clearer."
Meaning: Contaldi didn't understand how OPERA did it, and thought they had commited a somewhat stupid mistake. OPERA says they didn't make that error, and that they'll rewrite that part of the paper to make this clear. In other words, this is not news at all.
NO ONE considered the time distortion of gravity? I mean, sure, it's the first time that the time distortion due to gravity has ever been significant in any practical application, but it's still a fundamen... wait, it's not the first time? You're saying that there's an 18-year-old system that relies on this principle to work properly? How many people use this obscure system? Every single person in the civilized world? You'd think that at least one of these researchers would have heard about it, then.
Mod parent up +5 informative - and thread over.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
The researchers made no such claim! In fact they explicitly said they disbelieved they saw faster than light particles, and that they thought their data was faulty somewhere. But what they DID do is ask for other scientists to check their data and find their data, and if possible recreate the experiment to help track down where the error was.
THIS IS CORRECT SCIENTIFIC PROCEDURE!
"Beware, you who seek first and final principles, for you are trampling the garden of an angry God and he awaits you just beyond the last theorem."
-Sister Miriam Godwinson
Sorry, everything reminds me of a SMAX quote after i've been playing. :)
Faster than light is still possible, but now it's due to gravitational effects instead of innate property of neutrinos. It makes finding the Higgs boson more important than ever.
Don't jumble words and think you know what's going on.
Let me guess - you're in management?
Faster! Faster! Faster would be better!
Are they using some other measurement of "speed" that isn't distance / time? It seems that slowing time down and going the same "speed" has the same net effect as going faster than the speed of light.
If it turns out that time dilation due to gravity is the reason, then the error must be in the ETRF2000 or it was applied incorrectly in this case (Neutrinos moving from A to B). Considering that hundreds of people work on this project it seems unlikely to me that such an error slipped through. They even took into account the very small distance change induced by the L'Aquila earthquake.
Even if it is just a matter of clarifying the paper, it's still peer review in action. When OPERA responds, Contaldi will have the opportunity to review their clarifications. Maybe he'll respond again and point out that OPERA is still in the wrong. Or maybe he'll be satisfied and move on. This is how science is done. How is that not news?
Oh, it's news all right. Just not end-of-the-world-as-we-know-it news. As pointed out in TFA, it's awfully hard to critique the experiment unless you're there seeing exactly what has been done. While I don't find it surprising that a few printed (or electronic) pages cannot describe hundreds of tons of equipment and countless hours of work it does speak to the complexity of modern science.
You wonder how much that is published isn't repeatable or understandable. Dropping rocks off off buildings and counting seconds with a stopwatch just doesn't cut it anymore. I read somewhere (can't quickly find it) that one of the drug companies (Bayer, IIRC) felt that over half of the experiments from the literature that they tried to repeat to consider the possibility of pharmaceutical development from the discovery, failed outright or gave much different results than published.
It's frustrating I suppose. We all know most research is wrong / useless - the hard part is teasing out which is or isn't.
Faster! Faster! Faster would be better!
It's not news for one of two reasons, because one of two things is true:
Contaldi has poor reading skills. 'Peer review' is of low value from people who can't understand straightforward explanations that were understood by others.
or:
Science is proceeding as normal, and the outcome is still unknown .
Wake me when science reaches a conclusion, every minor typography fix on this paper is not newsworthy.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
They didn't have to raise the speed of light; they just raised it a semitone.
That's right. The universal constant for the speed of light is c#.
Welcome to the Panopticon. Used to be a prison, now it's your home.
If a particle has mass, its velocity will be less than C. If a particle has no mass, its velocity will equal C.
Perhaps they have a mass that varies based on electrical charge! We could call it 'the mass effect'.
Perhaps all this is just a ARG for Mass Effect 3.
If corporations are people, aren't stockholders guilty of slavery?
huh??
The speed of light is constant across all frames of reference. Frames of reference that are moving relative to each other will perceive light generated by the other frame of reference as having a different "clock" (i.e., frequency), but the speed of the red/blue shifted light will be the same in both frames of reference. The speed of light itself does vary across mediums (say, water vs glass vs air vs vacuum), but that doesn't come into play here. Also, they weren't measuring, directly, the speed of the neutrinos. They were comparing the time of the neutrinos' arrival at different sites and they found a difference that was unexpected. However, that measurement depends very much on the clocks being in sync, and this is what TFA is discussing.
The bending of light in a refractive medium is completely unrelated to the bending in a gravitational field, and your conclusion that the latter involves the speed of the light being altered is false.
E = mc^2 refers to rest energy, it is the amount of energy you get if you convert an unmoving mass directly into energy. Photons, having no mass, have no rest energy by definition. 0 * c * c = 0. E / 0 is undefined, not infinite. Literally the only line of your reply without a significant error is the first one. E=mc^2 has nothing to do with the assertion that massless particles must travel at c, that comes from other parts of special relativity.
Actually, the theory of special relativity has no problem with particles going faster than light. The problem lies with accelerating particles from slower than light in vacuum to faster than light in vacuum. Or, for that matter, with slowing down from faster to slower than c.
Would it be possible to have neutrino generators and detectors at both sites and test the speed in both directions? That would probably mean testing the speed between CERN and Fermilab. That way, if there was an error in clock synchronisation, it would show up because the neutrinos would take longer in one direction than the other.
If C# is now the speed of light- does that mean that Java exceeds the speed of light?
"That's the way to do it" - Punch
I worked it out half way.
Then I worked out half of the remaining math.
Then I...
An important change for education.
If a particle has mass, its velocity will be less than C. If a particle has no mass, its velocity will equal C.
REST mass... </pedantic>
WARNING! This girl exceeds the MAXIMUM SAFE standards established by the FDA for BRATTINESS
SR is based upon three assumptions or principles:
1. Causality (cause before effect)
2. Relativity (the laws of physics are the same for all reference frames, i.e. there is no 'privileged' reference)
3. Constancy of the speed of light (as was implied by Maxwell's equations)
Maintaining all three principles at once is how we end up at the rules of time dilation. Because of time dilation, if one could communicate between two inertial reference frames faster than light, then some observer would say that the message was received before it arrived -- which violates Causality for that observer, which would violate Relativity. With a few messages between ships traveling at relativistic speeds, it is possible to craft a scenario where the ship that sends the first message receives a response prior to having sent it -- Causality is then broken according to all observers.
Any method of information transfer that occurs FTL -- regardless of method -- breaks causality, and thus Special Relativity.
However if no information is sent, then this isn't a problem. This is why Quantum Entanglement experiments do not violate SR, because no information transfer, and thus causality violation, is possible.
Tachyons that can be used to send information contradict SR.
There are other formulations of tachyons which do not allow information transfer, and they are the ones that are consistent with SR.
This experiment, however, definitely involved information transfer. If its results hold up, then SR and one of its basic assumptions is in trouble. It could be Causality. How effin' weird would that be?
But most likely we live in a causal universe, and they did not send information FTL.
The enemies of Democracy are
Maybe, but the promise of "emit once, observe everywhere" never panned out....
The enemies of Democracy are
no experiment has yet to show that photons have no mass.
That's because it's a very hard thing to show. What they have shown experimentally is that the mass has to be smaller than 10^-18 eV/c, which is 1.782662 x 10^-54 kg, which is 1 / 10^-24th the mass of an electron which is by far the lightest particle predicted.
And I'd be interested to hear how E=mc^2, a central component of special relativity, causes it to conflict with general relativity. Do tell!
Basically the sun revolves around the earth - what ever we think now is correct no matter what anyone else says.
We used to think the earth was flat, and we were wrong. Then we thought the earth was a sphere and we were wrong (it's actually an oblate spheroid). But if you think believing the earth is a sphere is just as wrong as thinking the earth is flat, then you're wronger than the both of them. (paraphrased from Asimov). We know Newtonian physics is wrong, relativity significantly improves on the accuracy of Newtons predictions. That doesn't mean I drop an apple and expect it not to fall because Newton was wrong. Similarly, we know that relativity is wrong (the predictions break down in several extreme situations), but that doesn't mean that I expect E=mc^2 to be wrong tomorrow or time dilation to be proven wrong or any of the other well known relativistic effects. They have been shown empirically to be correct to fractions of fractions of a percentage point, that evidence doesn't just go 'poof' when a more refined theory comes along.
If C# is now the speed of light- does that mean that Java exceeds the speed of light?
No, Java is still slow.
But then when in stronger gravity you'll have to slow it down again. It's not just the clocks speeding up and slowing down. The gravity from stars and other massive astronomical objects wouldn't bend light if gravity didn't affect its speed too. The same principle that makes a refracting medium bend light can be used to explain how light bends in a vacuum in the presence of strong gravity.
In other words, c isn't a constant in all cases depending on the frame of reference. At least for now that's my opinion, and there has been an oversight.
Seems to me c is a constant across all reference frames, and that's exactly the property that caused this observation.
They measured neutrinos.
Checked the speed and saw it was > c.
Said "OH SHIT!".
Observers see a particle traveling at c.
They check with their buddies who sent it.
To the people measuring the shit, that incoming particle (which they observed at speed c) had to have been sent 60 nanoseconds (or whatever it was) before their buddies claimed to have sent it.
But according to the timestamps, the speed must have been > c.
The timestamps were inaccurate because they didn't account for gravity's effect on time.
The difference in the gravitational field at the source and detectr (actually along the whole path), caused a difference in the time field, while the neutrinos happily moved along at slightly less than c.
It's explained by Rudolf the Redshift Reindeer.
Escher was the first MC and Giger invented the HR department.
Santa Claus is completely imaginary, and therefore also has a completely imaginary mass. It is well known that objects with imaginary mass are tachyonic. Being tachyonic, Santa Claus can even be at two places at the same time!
The Tao of math: The numbers you can count are not the real numbers.
Just like Newton's laws used to be the law for some time. And before that, Earth used to be the centre of the universe, and we knew that for fact. So obviously, relativity must hold true forever and ever.
Escher was the first MC and Giger invented the HR department.
Steve ?
Religion is what happens when nature strikes and groupthink goes wrong.
The bending of light by the deformation of space-time is completely unlike or related to the refraction of light. The first is light following the curvature of space, and all frequencies of light would follow the same path (remember Galileo's experiment from the tower of Pisa? Two different particles are accelerated by gravity in precisely the same way.) The second is a wave function across the boundary of two different optical media. Waves with longer period (lower frequency) are bent more than waves of shorter period (higher frequency.) You can do this experiment with water in a wave tank and see the phenomenon clearly. Unrelated phenomena.
this site is not a joke (well, not intentionally) and it has more than 0 contributors:
http://conservapedia.com/Counterexamples_to_Relativity
#s 13 and 25 are my personal favorites.
"They were pure niggers." – Noam Chomsky
After I saw this quote I figured they'd have to find some error in their observations. (Emphasis added.)
"...If the observation is confirmed, it may be the most important discovery in science in the last 100 years.
"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."
(Quote stolen from Quark Soup)
Neutrinos do have mass, this is why they oscillate between 3 states. However the mass is very slight.
Also the neutrinos arrived ahead of the photons in SN1997 by a small amount (days, IIRC. it should be years at the speed discrepancy quoted by CERN). This different is explained by the fact that neutrinos hardly interact with matter and so could escape the core of the supernova before the photons could.
The arxiv blog recently had a roundup of papers discussing this: http://www.technologyreview.com/blog/arxiv/27212/ They fall into three groups: (1) Suggestions of how the experiment might have given a wrong result. (2) Theoretical arguments that constrain the interpretation and make the result seem implausible if taken at face value. (3) Theoretical papers saying what it could mean if it really was new physics. The Nature article seems to show that the Contaldi paper was based on a misunderstanding of how the experiment was done. However, the Nature article points to a new paper by Henri that wasn't included in the arxiv roundup: http://arxiv.org/abs/1110.0239
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no, his progress is a logarithmic growth function. the last digit of the math will take eternity to calculate.
-- no sig today