CERN team claims measurement of neutrino speed >c

[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.

 

[Saw]

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.

I tend to agree with you. FLT is theoretically possible subject to most unlikely conditions. Causality is a logical must you cannot do without. However, probably this thread is more focused on finding the flaw in CERN experiment. The old one is contaminated with the LET issue. It may be more adequate to start a new one.

 

[TrickyDicky]

Causality is NOT necessarily violated by FTL travel.

This is obvious, that even people who are supposed to have a minimumm knowledge of relativity seem often confused about it suggests to me a FAQ devoted to clarify it might help.

 

[Dale]

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.

That is close enough to agreement for me. I don't think that the "ala carte" part of the discussion is appropriate to this thread, so I will not pursue it here and will simply encourage you and gvk to do the same.

If you wish to continue that then I encourage you to start a new thread on the topic and I will participate.

 

[nsaspook]

Timing delay errors from fiber-optic cable visual.

I built a prototype device to detect bad fiber cables using time delay changes and made a few videos to check pulse delay calibration. These changes in time delays are from only moving the fiber a very small distance from the fully locked position. The display sync is locked on the send pulse on the left, the received (delayed) pulse is on the right.

http://flic.kr/p/bmmGau

 

[Galteeth]

Timing delay errors from fiber-optic cable visual.

I built a prototype device to detect bad fiber cables using time delay changes and made a few videos to check pulse delay calibration. These changes in time delays are from only moving the fiber a very small distance from the fully locked position. The display sync is locked on the send pulse on the left, the received (delayed) pulse is on the right.

http://flic.kr/p/bmmGau

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

 

[jambaugh]

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.

That may be giving up too much. The "idea of space-time" invokes some form of relativity principle which via Lie group deformation and stability arguments leaves either SO(4) (euclidean relativity, we can rotate 360° and travel back in time) ISO(3) (Galilean relativity) or SO(3,1) (Einstein Special Relativity). The implications rule out all but SO(3,1) given a vast amount of observational data and mathematical realities. One might argue that the constant c is incorrect but too much empirically verified evidence depends on the given value.

[For reference see Segal's work on stability of Lie groups under deformation, I have no specific citation but he showed that all semi-simple Lie groups are stable under small perturbations of their algebraic structure (when constrained to still yield a Lie group)]

It all means that Minkowski space-time is on as solid a footing as Euclidean spatial geometry, and these may only be invalidated (without wholly abandoning unified space-time) in the same way, i.e. allowing for curvature in the respective spatial or space-time geometries, i.e. invoking a form of GR.

To abandon locally Lorentzian physics would require abandoning unified space-time all-together and consider some alternative theory with preferred frames and an absolute time... and of course describe a mechanism by which we seem to see Lorentzian physics e.g. Lorentz's original notion that an aether causes slowing of clocks and shrinking of objects.

In short...

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

is giving up on "space-time" all together. We would have to go back to the pre-Einstein aether or something similar.

This is why I'd give long odds that any claim to FTL signals is some combination of analytical or experimental error.

 

[jambaugh]

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.

No, you can't "tweak" SR. The "mathematics of SR in and of itself" would have to be abandoned. The mathematics of deformation of the algebra dictates that any variation of the group structure (which defines the value of c) is equivalent to a rescaling of the representation (change in t and x units). This has physical implications e.g. a gravitational field as you vary the group over space-time as in GR. If SR with the current c value is wrong it must be a.) drastically wrong and b.) there must be some additional mechanism making it appear right, and so c.) there's no reason to hold onto any relativity theory or unified space-time except aesthetic preference.

 

[GTOM]

I think the question is, can something be outside the boundaries of Lorentz transformations, or not?
Otherwise, i can rather accept LET than SR, since we learned, that space actually isn't empty, it is filled with "dark energy" (aether?).

 

[Dickfore]

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.[/QUOTE]

Yes, this press release is one day after the following news article from Science:

http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html

dated February 22, 2012

 

[cdux]

In layman's terms is the neutrino faster than light buried by the consensus?

 

[yuiop]

In layman's terms is the neutrino faster than light buried by the consensus?

Think so.

 

[Enoy]

ICARUS posted yesterday a paper where they show that neutrinos from cern to ICARUS was exactly at the light speed 299792,458 km/s :-(

http://arxiv.org/abs/1203.3433

If similar experiments, at OPERA and Fermilab later this year, finds the same result, that V-C = 0, it means that neutrinos that moves through the Earth can not move faster than light inside Earth (mass-densities). And in my opinion this means that aether-theory actually is finally falsified in an absolute way ! The reason for why I mean this, is that if there is an aether that light spreads through, this aether should have been "more thin / thinner" inside mass densities like the earth, and then massless particles / light-photons would have spread faster through this thinner aether inside Earth ! But now that (if) it is not true that speed limit is higher inside earth, this means that an aether can NOT be real !

 

[Ryan_m_b]

BBC reports slow neutrinos - http://www.bbc.co.uk/news/science-environment-17364682

 

[Dickfore]

Is someone still moderating this thread? I would appreciate if the mention of aether is purged out of this thread.

 

[PhilDSP]

Isn't the fact that a massive particle has been measured to travel at c slightly upsetting in itself?