CERN team claims measurement of neutrino speed >c

Histspec

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

http://www.nytimes.com/2012/02/24/sc...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

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 dont want to be rude, but IMHO, they shouldnt 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 dont 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 dont want to be rude, but IMHO, they shouldnt 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 wouldnt 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

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

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...es-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/sciencein...uminal-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 wouldnt 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

Not necessarily. Alternatively, you could have a Lorentz 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 Lorentz 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 Lorentzian physics and not reject causality.

DaleSpam

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. 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?

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.

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

DaleSpam

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:
http://www.physicsforums.com/showthread.php?t=554741