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CERN team claims measurement of neutrino speed >c 
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#739
Feb2812, 10:35 PM

P: 663

Timing delay errors from fiberoptic 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 


#740
Feb2912, 04:50 AM

P: 320



#741
Feb2912, 05:07 AM

Sci Advisor
PF Gold
P: 1,783

[For reference see Segal's work on stability of Lie groups under deformation, I have no specific citation but he showed that all semisimple Lie groups are stable under small perturbations of their algebraic structure (when constrained to still yield a Lie group)] It all means that Minkowski spacetime is on as solid a footing as Euclidean spatial geometry, and these may only be invalidated (without wholly abandoning unified spacetime) in the same way, i.e. allowing for curvature in the respective spatial or spacetime geometries, i.e. invoking a form of GR. To abandon locally Lorentzian physics would require abandoning unified spacetime alltogether 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... This is why I'd give long odds that any claim to FTL signals is some combination of analytical or experimental error. 


#742
Feb2912, 05:19 AM

Sci Advisor
PF Gold
P: 1,783




#743
Feb2912, 08:35 AM

P: 119

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 isnt empty, it is filled with "dark energy" (aether?). 


#744
Mar1512, 05:33 AM

P: 3,014

BREAKING NEWS: Error Undoes FasterThanLight Neutrino Results dated February 22, 2012 


#745
Mar1512, 09:50 AM

P: 190

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



#746
Mar1512, 10:40 AM

P: 3,967




#747
Mar1612, 09:17 AM

P: 6

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 VC = 0, it means that neutrinos that moves through the earth can not move faster than light inside earth (massdensities). And in my opinion this means that aethertheory 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 / lightphotons 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 !!!! 


#748
Mar1612, 10:13 AM

Mentor
P: 5,490

BBC reports slow neutrinos  http://www.bbc.co.uk/news/scienceenvironment17364682



#749
Mar1612, 10:52 AM

P: 3,014

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



#750
Mar1612, 10:53 AM

P: 612

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



#751
Mar1612, 11:03 AM

P: 3,014

It is. However, [itex](c  v)/c \equiv \epsilon \sim 10^{5}[/itex] is compatible with SR and the experimental uncertainty of all these experiments.
The energy of a particle travelling at this close speed to c is: [tex] \begin{array}{l} \frac{E}{m \, c^2} = \gamma = \left ( 1  \frac{v^2}{c^2} \right)^{\frac{1}{2}} \\ = \left[ 1  (1  \epsilon)^2 \right]^{\frac{1}{2}} \\ = \left[ 2 \epsilon \, \left( 1  \frac{\epsilon}{2}\right) \right]^{\frac{1}{2}} \\ \sim (2 \epsilon)^{\frac{1}{2}} \, \left[1 + \frac{\epsilon}{4} + O(\epsilon^2) \right] \end{array} [/tex] Considering the rest energy of neutrinos is of the order of 0.1 eV, this means that the energy of these neutrinos would be of the order of: [tex] \frac{0.1 \, \mathrm{eV}}{\sqrt{2 \times 10^{5}}} \sim 20 eV [/tex] which is negligible. Even higher energies would bring the speed of neutrinos so close to c that the difference could not be detectable in any terrestrial experiment. 


#752
Mar1612, 12:05 PM

P: 83

All right. Thank you, ICARUS.



#753
Mar1612, 12:56 PM

PF Gold
P: 821

This is in the news: http://www.physorg.com/news/201203...osscheck.html



#754
Mar1612, 02:40 PM

P: 3,060

ICARUS used a new measuring detector based on liquid argon time projection chambers, anybody knows why this way of measuring speed of neutrinos is better or more reliable than the one used by OPERA? or how this change in mesuring technique might affect the results?



#755
Mar1612, 02:43 PM

Sci Advisor
PF Gold
P: 5,087




#756
Mar1712, 01:40 AM

P: 295

Mistake of measurement (4 and 9) was very large according to dissagreement (0.3).
δt = (0.3 ± 4.0stat ± 9.0syst)ns Does this mean that both mistakes (stat and syst) are really much smaller if they would be more precisely determined? 


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