CERN team claims measurement of neutrino speed >c

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  • #626
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Even if these results are confirmed, SR will no more disappear than Newtonian mechanics has. The fact that predictions involving SR have, in at least certain situations, been confirmed to 11 decimal places seems to be a pretty good indication that it is extremely useful, even if it turns out not to be exactly correct.

Also, Einstein made no reference to the Michelson Morley experiment in his original paper; and, it is not entirely clear whether he knew about it at all at that time. His original postulates are based more on the theoretical understanding of Maxwell's equations and of inertia than on specific results in the search for the ether.


if CERN proved true, it will not only disqualify SR based on supraluminal travel but also because it implies that C is not invariant ,,, Even in Einstein own words “ if c proved not invariant, SR and GR would collapse like a castle of cards”
SR can not be dealt on the same footing as newton mechanics. If you want similar example, you may consider quantum mechanics. Both Newton and quantum mechanics introduced a physical functions to build up theories. That was the concept of force f=ma in Newton approach and the concept of wave function in case of QM.
 
  • #627
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if CERN proved true, it will not only disqualify SR based on supraluminal travel but also because it implies that C is not invariant ,,, Even in Einstein own words “ if c proved not invariant, SR and GR would collapse like a castle of cards”
SR can not be dealt on the same footing as newton mechanics. If you want similar example, you may consider quantum mechanics. Both Newton and quantum mechanics introduced a physical functions to build up theories. That was the concept of force f=ma in Newton approach and the concept of wave function in case of QM.

You are completely missing my point. If you ask an engineer to design a bridge, he's not going to go use GR and Quantum Mechanics, he's going to use Newtonian physics because it is indistinguishable from more correct pictures of physics at the precision relevant for bridge building. Similarly, even if the OPERA results are validated, SR will still be used for a great many applications because it is indistinguishable from whatever more correct physics replaces it at the precision necessary for those applications. That was my point about precision measurements. SR has worked well enough for those so far; so, a more correct theory is only needed when the precision becomes so great that the theories become distinguishable.
 
  • #628
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the work in theoretical physics does not and will not aim to improve the accuracy of measurement to any degree of precision. If it does, then the Heisenberg notation of Matrix representation of QM might not be needed as long as the wave-representation was enough to get into the same results. The work in theoretical physics rather deals with hypothesis that may be even impossible to validate it experimentally, yet still has a beautiful logic to work on it.
 
  • #629
Is there any information on a marked energy difference for the pion's other decay products? Are the Muons lower in energy than expected, or higher perhaps?
 
  • #630
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Recently, one has claimed that the 60 ns early arrival of the neutrino is due to failure of synchronization between the location`s clocks because of the motion of the satellite from west to east relative to the earth frame of reference.
I think, if the satellite moves from the west to the east relative to the earth, the earth should appear moving from the east to west relative to it. So when attempting to synchronize clocks by send 2 light signals from the satellite, the eastern end on the earth,which near Rome, should receive the signal before the western end, near Geneva. Therefore, the down-counting should begin in Rome before Geneva start to send the neutrino. That should lead to a apparent delay in the arrival of neutrino to Rome which is against the actual result, assuming the neutrino moves with speed of light c.

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
 
  • #631
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.
 
  • #632
ghwellsjr
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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)?
 
  • #633
Drakkith
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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
 
  • #634
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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. ;)
 
  • #635
Drakkith
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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.
 
  • #636
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.

 
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  • #637
Drakkith
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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.
 
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  • #638
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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
 
  • #639
Drakkith
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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 travelled 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.
 
  • #640
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The distance travelled 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
 
  • #641
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Any news/updates regarding this? Has it been confirmed/refuted? Im assuming it hasnt, does anyone know when a different group will test it?
 
  • #642
OnlyMe
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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.
 
  • #643
OnlyMe
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Any news/updates regarding this? Has it been confirmed/refuted? Im 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.
 
  • #645
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?
 
  • #646
PAllen
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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.
 
  • #647
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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?
 
  • #648
OnlyMe
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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.
 
  • #649
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... 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.
 
  • #650
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Has there ever been any other times neutrinoes were recorded travelling 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?
 

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