CERN team claims measurement of neutrino speed >c

[aanandpatel]

In 1987, there was a supernova in the Large Magellanic Cloud. This is roughly 50,000 light years away from the Earth. Scientists detected light from the supernova and neutrinos from the supernova at the exact same time meaning they have the exact same velocity. This experiment used distances of thousands of light years whereas the one at CERN used measly distances.

 

[ghwellsjr]

If one would like to make a sharp conclusion about the neutrino speed, they should send light photon through the same path using the same way of synchronization.

If you send light through the same path, you don't need any synchronization because you will have a genuine race. But whose going to fund digging the hole (and evacuate it)?

 

[Drakkith]

In 1987, there was a supernova in the Large Magellanic Cloud. This is roughly 50,000 light years away from the Earth. Scientists detected light from the supernova and neutrinos from the supernova at the exact same time meaning they have the exact same velocity. This experiment used distances of thousands of light years whereas the one at CERN used measly distances.

This is not true. The neutrinos were detected 3 hours prior to the visible light due to the ability of neutrinos to pass through most normal matter and the light having to wait until the expanding remnants of the star were transparent enough for it to escape.

http://en.wikipedia.org/wiki/Sn_1987

 

[Passionflower]

If one would like to make a sharp conclusion about the neutrino speed, they should send light photon through the same path using the same way of synchronization. So, if the light reaches Rome earlier by 60 ns, it would draw a doubt that the neutrino moves faster than light

I doubt the photon would get very far. ;)

 

[Drakkith]

If one would like to make a sharp conclusion about the neutrino speed, they should send light photon through the same path using the same way of synchronization. So, if the light reaches Rome earlier by 60 ns, it would draw a doubt that the neutrino moves faster than light

I believe the path the neutrinos take is through solid rock. Light would not be able to travel through it.

 

[aanandpatel]

This is not true. The neutrinos were detected 3 hours prior to the visible light due to the ability of neutrinos to pass through most normal matter and the light having to wait until the expanding remnants of the star were transparent enough for it to escape.

http://en.wikipedia.org/wiki/Sn_1987

Apologies for the mistake - was quoting Michio Kaku.

 

[Drakkith]

Apologies for the mistake - was quoting Michio Kaku.

I assume that he was not concerned with technical accuracy since it was just a quick answer to the question asked.

 

[Adel Makram]

I believe the path the neutrinos take is through solid rock. Light would not be able to travel through it.

yes correct, but still there must be some way to work it out
For example:
1) light photon can be emitted from swiss lab as a radio signal above the ground and then received at italy. Then calculating the effective speed by considering all distances taken
2) repeating the same experiment but with different way of synchronization. For example, the synchronization can be done using a fixed stationary point mid way between the 2 labs to avoid the relative motion of staleitte

 

[Drakkith]

yes correct, but still there must be some way to work it out
For example:
1) light photon can be emitted from swiss lab as a radio signal above the ground and then received at italy. Then calculating the effective speed by considering all distances taken

The distance traveled by the light is not the same as the neutrinos then. Remember, they are timing this down to nanoseconds.

2) repeating the same experiment but with different way of synchronization. For example, the synchronization can be done using a fixed stationary point mid way between the 2 labs to avoid the relative motion of staleitte

How does that fix anything? I looks like it would just add another point to do all the math for.

 

[Adel Makram]

The distance traveled by the light is not the same as the neutrinos then. Remember, they are timing this down to nanoseconds.



How does that fix anything? I looks like it would just add another point to do all the math for.

for the second statement, it does a lot. Because many of critics of the CERN experiment claims the incorrect synchronization was the reason of the result. The synchronization was done using a moving satelitte which draws a doubt about correct synchronization of clocks at the 2 ends. But if we have a fixed point mid-way between the 2 labs which emits 2 radio-signals to the 2 labs to start the down-counting, the synchronization becomes perfect assuming the c is constant in 2 direction

 

[easyrider]

Any news/updates regarding this? Has it been confirmed/refuted? I am assuming it hasnt, does anyone know when a different group will test it?

 

[OnlyMe]

The Cohen-Glashow paper, in view of the ICARUS results, implies that, should the FTL neutrino results be confirmed, then electrons and/or positrons would have to be capable of FTL travel as well.

I don't believe that follows, from the situation, as it stands. Cherenkov radiation is already observed for charged particles and only requires that they exceed the speed of light in a medium other than vacuum.

The Cohen-Glashow paper was projecting a similar effect for FTL neutrinos, even though they have no charge, interact only weakly with matter and are traveling thorugh solid rock and earth, where light may not pass. This has only been theorized. Not proven or confirmed. The ICARUS data essentially demonstrates a lack confirmation, of the predicted theoretical result.

Neutrinos are sufficiently different from electrons and other subatomic particles, that I am not sure much of what, may or may not be observed regrading neutrinos, could be applied directly to other particles.

 

[OnlyMe]

Any news/updates regarding this? Has it been confirmed/refuted? I am assuming it hasnt, does anyone know when a different group will test it?

As I mentioned a page or so back, it is my understanding that CERN will be making a short burst neutrino stream available, later this year. This should provide more data.

I also heard that Fremi was upgrading some equipement necessary to run a duplicate, but I have no idea how long those equipement upgrades will take. I believe they were mostly timing issues. I believe earlier results from Fermi suggested an FTL neutrino, but the data was within the margin of error of their equipment, at the time... Or something to that effect.

I have heard nothing more about any thing happening in Japan and I don't know if there is anywhere else that could, duplicate the experiment.

 

[lalbatros]

What should understand and think from this paper?:

Superluminal Neutrinos at OPERA Confront Pion Decay Kinematics

 

[Edgard Four]

Is the neutrino speed measured by OPERA stable over the experiment period ?

In the OPERA experiment, does the measured speed of neutrinos present variations with respect to the position of the Earth on its orbit around the sun at the measurement time?

 

[PAllen]

What should understand and think from this paper?:

Superluminal Neutrinos at OPERA Confront Pion Decay Kinematics

Interesting paper. My take is that it adds yet more falsification to claims that the OPERA result could be 'easily' accommodated with minor modifications to current theory. Instead, it supports the view that QFT would need radical surgery of unknown nature to deal with a confirmed OPERA result.

 

[easyrider]

As I mentioned a page or so back, it is my understanding that CERN will be making a short burst neutrino stream available, later this year. This should provide more data.

I also heard that Fremi was upgrading some equipement necessary to run a duplicate, but I have no idea how long those equipement upgrades will take. I believe they were mostly timing issues. I believe earlier results from Fermi suggested an FTL neutrino, but the data was within the margin of error of their equipment, at the time... Or something to that effect.

I have heard nothing more about any thing happening in Japan and I don't know if there is anywhere else that could, duplicate the experiment.

I thought they already did a shorter burst and got the same result?

 

[OnlyMe]

I thought they already did a shorter burst and got the same result?

They did a short test run, that was reported in section 9 of the revised paper, Measurement of the neutrino velocity with the OPERA detector in the CNGS beam. It was more a proof of method than a full experimental run.

And yes it did support the earlier result and addresses a few of the earlier criticisms. Still for results like these there needs to be a great deal more data and preferably from more than one lab.

 

[lalbatros]

... Still for results like these there needs to be a great deal more data and preferably from more than one lab.

... and different experimental techniques, specially regarding time measurement.

 

[easyrider]

Has there ever been any other times neutrinoes were recorded traveling FTL?

It was supported that neutrinoes travel at c when they got the data from the supernova, correct? Why would they travel at c there but travel FTL in this experiment?

 

[Drakkith]

Has there ever been any other times neutrinoes were recorded traveling FTL?

It was supported that neutrinoes travel at c when they got the data from the supernova, correct? Why would they travel at c there but travel FTL in this experiment?

We don't know. This is the first time it's happened. (Or rather this is the first time that our observations have shown us that it *might* have happened.

 

[fellupahill]

So I take it there is no front runners for theories if it is decided that they were pretty sure opera was right?

 

[cbetanco]

So I take it there is no front runners for theories if it is decided that they were pretty sure opera was right?

It would probably require some Lorentz and CPT violations such as in the Standard Model Extension, but several measurements have put very tight contraints on such models.

http://arxiv.org/abs/0801.0287
http://rmp.aps.org/abstract/RMP/v83/i1/p11_1

 

[lmoh]

Has there ever been any other times neutrinoes were recorded traveling FTL?

FTL neutrinos apparently have been recorded in 2007 by Fermilab scientists in 2007 I heard, but the results weren't as accurate as the CERN experiment and the results were dismissed as "inconclusive", however they are looking to repeat the neutrino experiment (with upgraded equipment) to see if they get the same results.

 

[GTOM]

Can we explain CERN results if speed of light is anisotropic?

http://vixra.org/pdf/1110.0037v1.pdf

This article claims, that GPS system shows, that while speed of light is isotropic in the frame of Earth's gravity field, it is anisotropic in the frame of rotating Earth.
IMHO Michelson-Morley experiment didnt disprove that, due to the length contradiction of the interferometer's arm.

Can this be an explanation for the seemingly FTL results of CERN neutrions?

 

[harrylin]

http://vixra.org/pdf/1110.0037v1.pdf

This article claims, that GPS system shows, that while speed of light is isotropic in the frame of Earth's gravity field, it is anisotropic in the frame of rotating Earth.
IMHO Michelson-Morley experiment didnt disprove that, due to the length contradiction of the interferometer's arm.

Can this be an explanation for the seemingly FTL results of CERN neutrions?

No, see for example post #153 of this thread.

https://www.physicsforums.com/showthread.php?p=3519400#post3519400

In addition, it turned out that the effect is in the wrong direction.

Harald

 

[GTOM]

Thanks for the answer.


"It was supported that neutrinoes travel at c when they got the data from the supernova, correct? Why would they travel at c there but travel FTL in this experiment?"

It is just my speculation, but if the supernova produced tachyons (above "normal" neutrions), they could have arrived a hundred maybe thousand years ago (given the 168.000 light years distance)... smaller streams of them might be only considered as random noise.

 

[fellupahill]

FTL neutrinos apparently have been recorded in 2007 by Fermilab scientists in 2007 I heard, but the results weren't as accurate as the CERN experiment and the results were dismissed as "inconclusive", however they are looking to repeat the neutrino experiment (with upgraded equipment) to see if they get the same results.

If you read the thread, that was mentioned like 100x lol.

Even get info on what "upgraded equipment" is.

Thanks for the answer."It was supported that neutrinoes travel at c when they got the data from the supernova, correct? Why would they travel at c there but travel FTL in this experiment?"

It is just my speculation, but if the supernova produced tachyons (above "normal" neutrions), they could have arrived a hundred maybe thousand years ago (given the 168.000 light years distance)... smaller streams of them might be only considered as random noise.

Source?
I know you said speculation, but do researchers who believe in tachyons believe they come from supernovae

 

[San K]

does substituting value of c with neutrino speed make results more or less accurate?

does substituting value of c with neutrino speed (in the relativistic equations) make results more or less accurate? when comparing with experimentally observed data.

or is the effect too small for us to determine?

The time dilation, lenght/mass increase equations have vsquare divided by csquare in them.

now if we were to increase the value of c by a little bit (i.e. 60nanosecond per 730 kms, i.e. Increase the value of c to the recently (supposedly) observed speed of neutrino):

would the (new) theoretical value of time/lenght/mass dilation (after increasing value of c to speed of neutrino) match:

1 more closely/accurately to experimentally observed data
or
2 less closely/accurately to experimentally observed data?

for example in the collider -- particles decay bit slower than expected due to time dilation due to higher speed

Or for example in the famous equation of e = mc(squared)

do the theoritcal results, from the relativistic equations, become more, or less, accurate?

 

[elfmotat]

Neutrinos don't travel at only one speed.

 

[San K]

Neutrinos don't travel at only one speed.

agreed, thanks. For a moment let's forget neutrinos.

Now if we increase the value of c by 730kms/60 nanoseconds in the relativistic equations what happens to the results/mathematical answers? Do they become more, or less, accurate?

or is the effect too small for us to verify experimentally?

 

[PAllen]

Various experiments show that the limiting velocity and mass/energy factor corresponds to light speed by much better precision than the OPERA discrepancy. Thus, replacing the value of c with the OPERA measurement will conflict with many other observations. If the OPERA result is true, theoretical fixes will be much more complex than this.

See especially :

# Guiragosian et al., Phys. Rev. Lett. 34 no. 6 (1975), pg 335.

Relative velocity measurements of 15 GeV electrons and gammas. No significant difference was observed within ~2 parts in 10^7. See also Brown et al.
# G.L. Greene et al.,“Test of special relativity by a determination of the Lorentz limiting velocity: Does E=mc2?” Physical Review D 44 (1991) R2216.

An analysis combining the results of several experiments gives the result that the Lorentz limiting velocity must be equal to the speed of light to within 12 parts per million.

Both of these have error bounds much smaller than the OPERA discrepancy.

From:

http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#limiting_velocity

 

[San K]

Very informative. Thanks PAllen

 

[alexg]

Neutrino velocity and GPS corrections

According to this, the relativistic corrections for the GPS were done using the GPS satellite as the rest frame, instead of using the Cern Opera site as the rest frame. The difference in the timing is 60 nanoseconds, which is exactly the difference calculated by Opera.

http://www.technologyreview.com/blog/arxiv/27260/

My question is, I've never seen this refuted, yet I've never seen this accepted as the explanation for the 'superluminal' neutrinos.

Does anyone know more about this?

 

[bcrowell]

According to this, the relativistic corrections for the GPS were done using the GPS satellite as the rest frame, instead of using the Cern Opera site as the rest frame.[...]Does anyone know more about this?

Van Elburg is a physicist who wrote an incompetent paper. Technology Review is edited by someone who is not a physicist, and who therefore was apparently not competent to figure out that Van Elburg's paper was incorrect.

The error in the paper is simply that he didn't bother to learn anything about GPS or the coordinate systems it uses, and he then proceeded to write a paper about GPS. His assumptions about how GPS works are all wrong. GPS uses general relativity, and general relativity doesn't have global frames of reference at all, so GPS uses coordinate systems, not frames of reference. He seems to have assumed that GPS uses a frame of reference tied to a satellite, which isn't true.