CERN team claims measurement of neutrino speed >c

[sshai45]

In the earlier news it was about a bad connection between the GPS and the computers, now its about a loose fiber optic cable connecting with atomic clocks.

You sure? This here:

http://www.reuters.com/article/2012/02/22/us-physics-neutrinos-cable-idUSTRE81L2B820120222

says "a loose fiber optic cable linking a Global Positioning System satellite receiver to a computer."

 

[Passionflower]

If this loose cable thing is confirmed I think it is very worrying, not for the particular experiment where the Neutrino speed was anomalous but for all other experiments.

All other experiments before and after would have potentially given false data and nothing would have been suspected, only now when we found 'impossible' results do we check.

Seems they need to hire a guy who checks the cables before every experiment.

 

[CaptFirePanda]

Yes, because that guy would never make a mistake!

 

[Drakkith]

If this loose cable thing is confirmed I think it is very worrying, not for the particular experiment where the Neutrino speed was anomalous but for all other experiments.

All other experiments before and after would have potentially given false data and nothing would have been suspected, only now when we found 'impossible' results do we check.

Seems they need to hire a guy who checks the cables before every experiment.

Mistakes happen. There's no reason to suspect all of our results to be faulty based on one mistake in one piece of equipment.

 

[Vanadium 50]

Realize that there is no official statement; people are just repeating rumors. Wait a half day.

 

[GTOM]

About the Einstein was wrong posts : I think many people want to believe this, because they share the fear, that it makes interstellar travel impossible, and we will be doomed here, and i guess some of them will keep searching.

Well, it would have been really good to see another major breakthrough :(, i wait until they recheck the results.

 

[Histspec]

Realize that there is no official statement; people are just repeating rumors. Wait a half day.

There is now an official statement by OPERA:
http://www.nature.com/news/flaws-found-in-faster-than-light-neutrino-measurement-1.10099
And the press release update from February 23:
http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html[/URL]

They say that there were actually [B]two[/B] possible sources of error (in opposite directions), which might significantly influence their former result. They will check it in May.

 

[kmarinas86]

All other experiments before and after would have potentially given false data and nothing would have been suspected, only now when we found 'impossible' results do we check.

Seems they need to hire a guy who checks the cables before every experiment.

Right on.

 

[Enoy]

Here is the press release from Cern:

"OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran SassoUPDATE 23 February 2012

The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino's time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May. "

 

[lmoh]

Here is the press release from Cern:

"OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran SassoUPDATE 23 February 2012

The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino's time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May. "

Do both effects account for the 60 ns effect together, or is it just the fiber cable? I keep hearing more about the second cause, but very little about the first.

Well anyways this is sort of embarassing. Who've thought that for years, there has been a loose cable in the system and nobody knew about it.

 

[Enoy]

I will not be surprised if theese two issues only is shown to be of minor significance for the time measurement, when they start up the experiment in the spring coming. The issues even might cancel each other out with regards to time-measurments-errors. The reason for this, I think, is due to the fact that Fermilab also got results for a couple of years ago that showed faster than light neutrinos, but with too big uncertanties to make the result noteworthy. And, also due to the fact that the scientific community lacks both experimental and theoretical understanding of the physical reality inside the reference frame of mass-densities like planets, and how such frames might affects the the physical relations, compared to that we are used to namely empty space/vacuum.

Sincerly
me

 

[CaptFirePanda]

As mentioned above, CERN has commented on that and another hardware issue that would have resulted in a delayed response to the neutrino's arrival. So there are 2 conflicting hardware glitches at play here.

 

[ardenmann0]

I will not be surprised if these two issues only is shown to be of minor significance for the time measurement, when they start up the experiment in the spring coming. The issues even might cancel each other out with regards to time-measurments-errors. The reason for this, I think, is due to the fact that Fermilab also got results for a couple of years ago that showed faster than light neutrinos, but with too big uncertanties to make the result noteworthy. And, also due to the fact that the scientific community lacks both experimental and theoretical understanding of the physical reality inside the reference frame of mass-densities like planets, and how such frames might affects the the physical relations, compared to that we are used to namely empty space/vacuum.

Sincerly
me

So you think it's just minor significance. Then how do you explain this:

http://news.yahoo.com/faulty-wire-error-blamed-faster-light-particles-233455932.html

"After tightening the connection and then measuring the time it takes data to travel the length of the fibre, researchers found that the data arrive 60 nanoseconds earlier than assumed," it added.

"Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis."

 

[CaptFirePanda]

So you think it's just minor significance. Then how do you explain this:

"After tightening the connection and then measuring the time it takes data to travel the length of the fibre, researchers found that the data arrive 60 nanoseconds earlier than assumed," it added.

"Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis."

Please read the press release below (it has been posted already). There are thought to be two possible sources for measurement error: one that could have increased the size of the measured effect and one that could have diminished it.

Enoy is considering the possibility the the 2 effects might cancel each other out and the 60 μs anamoly would remain as such.

Here is the press release from Cern:

"OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran SassoUPDATE 23 February 2012

The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino's time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May. "

 

[Histspec]

There is an interview with Dario Autiero (spokesman of OPERA), providing some details on both errors.

http://www.nytimes.com/2012/02/24/s...-because-of-technical-problems-cern-says.html

Regarding the first source of error that might increase the neutrino velocity, no numbers were given. However, then it is said regarding the second source:

The investigation discovered that for dimmer light pulses, the circuit receiving the data introduced delay — up to 60 billionths of a second — that could bring the neutrinos’ speed back under the speed of light.

There we have the 60ns again.

Regards,

 

[GTOM]

"Second, there was a possible faulty connection between the GPS signal and the OPERA master clock."

Havent they tryed, whether normal radio signals arrive 60ns earlier than expected?
(In some smaller surface experiment, to test the timing?)

 

[lalbatros]

Have the theoreticians been informed?
It would be ruthless to let them waste their time any longer.

 

[gvk]

It's good they found errors themself. Otherwise it would be a shame, especially when MINOS will spend couple millions to find their errors.

 

[gvk]

Have the theoreticians been informed?
It would be ruthless to let them waste their time any longer.

Serious theoreticians do not respond to the "discovery" of overturning all of modern physics.

 

[GTOM]

"Serious theoreticians do not respond to the "discovery" of overturning all of modern physics."

Sorry, i don't want to be rude, but IMHO, they shouldn't have cared about theory of relativity in the first place, if they had shared this mentality. Maybe the experiments were all faulty, they didnt check their apparatus...

Okay, of course everyone can commit errors, it can be pretty hard to find them, especially in such a case, i just don't understand, if there was such an error, and not a couple of tiny errors that accumulated, how could they not determine, that in general, timing is delayed with that much?

 

[gvk]

"Sorry, i don't want to be rude, but IMHO, they shouldn't have cared about theory of relativity in the first place, if they had shared this mentality."

Quite the contrary. It is because we are primarily concerned the theory of relativity, since "c" is a universal constant (not just speed of light but the foundation of our understanding of space-time).
Any experiment, asserting the existence of another fundamental constant of the space-time turns our entire understanding of the world.
I should add that this was not in the history of science and all previous discoveries have been built into the system of knowledge.

 

[GTOM]

I do understand it.

I wanted to express, that in the time of Einstein, even many scientists refused the idea, that there can be any wrong with the good Newtonian image of the world.
But even if those neutrinos were happen to travel, or jump FTL (it is still hard to believe, CERN team really committed SUCH an error, they knew they might become a joke like the unconnected cable guys...) that wouldn't mean obligatory, we should throw away everything.
GPS would still work with relativistic time corrections for example.
E=mc2, that could still remain, with maybe the exception of a 'ghost' particle.
Maybe everything could remain the same in three dimension, but it could have proved brane theories.

 

[lalbatros]

I do understand it.

I wanted to express, that in the time of Einstein, even many scientists refused the idea, that there can be any wrong with the good Newtonian image of the world.
But even if those neutrinos were happen to travel, or jump FTL (it is still hard to believe, CERN team really committed SUCH an error, they knew they might become a joke like the unconnected cable guys...) that wouldn't mean obligatory, we should throw away everything.
GPS would still work with relativistic time corrections for example.
E=mc2, that could still remain, with maybe the exception of a 'ghost' particle.
Maybe everything could remain the same in three dimension, but it could have proved brane theories.

GTOM,

I could as well say that adding dimensions is like adding epicycles to the Ptolemaic system.
If the OPERA results were true, it could be a terrible crisis as well as nice discovery.
We don't know.
For the moment, it's only a media story.

In addition, I strongly believe that their experiment is flawed, but I won't joke about this.
In the OPERA experiment, there is no reliable way to check the "zero delay".
It fully relies on a perfect knowledge of two chains of measurements: the GPS and the neutino beam.
Therefore, their error bar calculation is meaningless.
Systematic errors are the weak point, as their latest announcement proves.
It is a very nice experiment, but it can't prove anything except the skills of their team.

 

[n4n0b0y]

This seems to be more a confirmation of superstring theory extra spatial dimensions than a blow to the structure of relativity theory. and even if the neutrinoes weren't entering impossible-to-detect miniature spatial dimensions on their way to the finish-line (which would mean that they weren't going >c), i would bet my considerable (not) savings on systematic error.

 

[lmoh]

I will not be surprised if theese two issues only is shown to be of minor significance for the time measurement, when they start up the experiment in the spring coming. The issues even might cancel each other out with regards to time-measurments-errors.

Yeah, that was what I was wondering as well, though I am still thinking that there is the possibility that the errors both account for the early 60 ns time, and a more likely one at that considering the implications of the result. And even if they both cancel each other out and the result stays about the same, the experiment has been shown to not be as perfect as originally suspected, so there is also the possibility of another error.

 

[Histspec]

Much information can also be found at

http://profmattstrassler.com/2012/02/24/finally-an-opera-plot-that-makes-some-sense/

According to a German OPERA member, the cable error might be up to 100ns, and the (opposite) oscillator error might be smaller than the first effect.
Both errors collectively could explained the 60ns, and their focus is on the cable error.

http://news.sciencemag.org/scienceinsider/2012/02/official-word-on-superluminal-ne.html

 

[gvk]

"...in the time of Einstein, even many scientists refused the idea, that there can be any wrong with the good Newtonian
image of the world."

Again, not quite right.

Even before the Einstein's birth the relativity theory already implicitly existed. The Lorentz transformations were already
existed in Maxwell equations but nobody knew about it.
Lorentz, Poincare, Einstein and Minkowski made a huge impact by showing this and explained how our space-time is constructed and that Newtonian mechanics is a particular case of the relativistic theory.

Now let consider "...that wouldn't mean obligatory, we should throw away everything."

FTL means first and foremost the violation of causality principle. This is such a thing without which GR, QM, QED, QCD, SM,
GUT etc. ... (all the theories containing 4-D psedoeucledian metric) will collapse. 5th, 6th etc dimensions does not
help in that case.
Moreover, with the violation of causality principle, there are a hundreds new effects should exist. But in reality they don't! The Cherenkov's radiaton of neutrinos is the first lieing on the surface, but think about spin's effects which are mostly due to the relativity and a lot of such. All formulas contained "c" should be revised somehow.
You may see it's a totally different story in comparison with SR.

 

[kmarinas86]

FTL means first and foremost the violation of causality principle.

Not necessarily. Alternatively, you could have a Lorentz violation [strike]of the concept of a spacetime continuum, which connects time and space as a manifold in a way using a preferred maximum speed (the speed of light). Some alternatives, such as Lorentzian Ether Theory, do not invoke spacetime as a geometrical manifold.[/strike] We have a choice of deciding that FTL is to be interpreted as causality violation or as a Lorentz violation [strike]of the idea of a spacetime continuum[/strike]. If FTL is demonstrated, I would make my decision basically on the idea of parsimony. I would reject [strike]spacetime[/strike] Lorentzian physics and not reject causality.

 

[Dale]

Not necessarily. Alternatively, you could have a violation of the concept of a spacetime continuum, which connects time and space as a manifold in a way using a preferred maximum speed (the speed of light). Some alternatives, such as Lorentzian Ether Theory, do not invoke spacetime as a geometrical manifold. We have a choice of deciding that FTL is to be interpreted as causality violation or as a violation of the idea of a spacetime continuum. If FTL is demonstrated, I would make my decision basically on the idea of parsimony. I would reject spacetime and not reject causality.

Nonsense, it isn't an ala carte menu where you can pick and choose. If the hypothetical FTL phenomenon were relativistic then causality would be violated. If the FTL phenomenon were causal then it would violate relativity. You wouldn't get to choose which you prefer; experimental results would make the choice for you.

 

[kmarinas86]

Nonsense, it isn't an ala carte menu where you can pick and choose. If the hypothetical FTL phenomenon were relativistic then causality would be violated.

Nonsense. Spacetime continuum + FTL implies causality violation, but FTL and no spacetime continuum does not imply causality violation. Do you realize that the whole "going back in time" notion in the context of FTL travel strictly depends on the idea of spacetime?

If the FTL phenomenon were causal then it would violate relativity.

Right. So why are people saying that it would violate relativity AND causality? The whole notion that FTL would violate causality is based on the idea of the spacetime continuum, which SR depends on. Yes, the physics of SR (which assume causality) would be violated, but mathematics of SR devoid of physical interpretation would not be, unless you can somehow prove that the time dilation of the neutrino was not negative.

You wouldn't get to choose which you prefer; experimental results would make the choice for you.

Experimental results may narrow down the options, though not necessarily down to one possibility.

 

[Dale]

Nonsense. Spacetime continuum + FTL implies causality violation, but FTL and no spacetime continuum does not imply causality violation.

It has nothing to do with spacetime, just relativity (i.e. the Lorentz transform). Even for LET with no spacetime, if the FTL phenomenon followed the Lorentz transform (relativity) then causality would be violated.

This discussion is not really appropriate for this thread. We have had a very long recent thread on this topic:
https://www.physicsforums.com/showthread.php?t=554741

 

[kmarinas86]

It has nothing to do with spacetime, just relativity (i.e. the Lorentz transform). Even for LET with no spacetime, if the FTL phenomenon followed the Lorentz transform (relativity) then causality would be violated.

This discussion is not really appropriate for this thread. We have had a very long recent thread on this topic:
https://www.physicsforums.com/showthread.php?t=554741

This still doesn't prove that you cannot have an ala carte decision concerning these experiments.

To broaden my point, and to put LET itself under possible question, the discovery of FTL travel could be interpreted as:

1) A violation of causality, and thus a violation of the physics of SR (which assumes causality).
2) A Lorentz violation, and thus a violation of SR, LET, and other Lorentzian theories.

I will concede though that, yes, you could say that Lorentz transforms, and not so much the idea of spacetime, is responsible for the notion that FTL travel implies causality violation.

I still don't agree with [STRIKE]you[/STRIKE] gvk that FTL travel somehow inherently violates causality. That is my point. There is no reason why FTL travel should imply causality violation, especially if discovery of FTL travel raises doubt about certain physical theories from which this notion arises in the first place.

In the name of Ockham's razor, I would give up "Lorentzian physics" before I give up causality.

 

[kmarinas86]

FTL means first and foremost the violation of causality principle.

That's not true at all. See the analysis of my previous post.

This still doesn't prove that you cannot have an ala carte decision concerning these experiments.

To broaden my point, and to put LET itself under possible question, the discovery of FTL travel could be interpreted as:

1) A violation of causality, and thus a violation of the physics of SR (which assumes causality).
2) A Lorentz violation, and thus a violation of SR, LET, and other Lorentzian theories.

I will concede though that, yes, you could say that Lorentz transforms, and not so much the idea of spacetime, is responsible for the notion that FTL travel implies causality violation.

I still don't agree with you that FTL travel somehow inherently violates causality. That is my point. There is no reason why FTL travel should imply causality violation, especially if discovery of FTL travel raises doubt about certain physical theories from which this notion arises in the first place.

In the name of Ockham's razor, I would give up "Lorentzian physics" before I give up causality.

Discovering FTL travel could be interpreted as a violation of causality OR a violation of Lorentzian physics. You CAN choose one OR the other, exclusively. Causality is NOT necessarily violated by FTL travel.

 

[lmoh]

If the hypothetical FTL phenomenon were relativistic then causality would be violated. If the FTL phenomenon were causal then it would violate relativity.

I am certainly no expert on the subject, but I can never really understand the hype about time travel if there actually were FTL neutrinos. On the one hand, people are saying that relativity is false and our physics would have to be changed, but on the other hand, people are making claims about time travel which I always assumed was based on the physics we supposedly have to change. Am I making any sense here or am I missing something?

 

[kmarinas86]

I am certainly no expert on the subject, but I can never really understand the hype about time travel if there actually were FTL neutrinos. On the one hand, people are saying that relativity is false and our physics would have to be changed, but on the other hand, people are making claims about time travel which I always assumed was based on the physics we supposedly have to change. Am I making any sense here or am I missing something?

You absolutely are making sense, IMHO. This is one of those things that have disturbed me quite a bit. Even Michio Kaku himself has spread these notions simultaneously.

I think the issue comes from the fact that FTL travel would violate the standard physical interpretation of the mathematics of SR, as opposed to the mathematics of SR in of itself. Thus, the "physics" of relativity would change if FTL travel was discovered, but that doesn't mean that much of the math goes away. Scientists would likely use the mathematics of Lorentz transformations (being the "convenient" mathematical tool that it is) even after discovering FTL travel, and thus, in response to such a discovery, they would grab onto the "fantastic" notion that backwards time travel is somehow validated, rather than to the idea that Lorentzian physics is violated, for the latter does not in an obvious way offer an "exciting" hope to inspire the imagination of adventurers.