Register to reply 
CERN team claims measurement of neutrino speed >c 
Share this thread: 
#145
Sep2311, 08:19 PM

P: 986

What bothers me most about this result is not so much the claim of v > c, as the magnitude of the effect. It is way, way too strong.
It is incompatible with QGinspired Lorentzviolating dispersion relations (it's too strong, by something like 13 orders of magnitude, compared to what we'd expect.) It is incompatible with tachyons (for tachyons, speed goes up as energy goes down, and that would be hard to miss  for starters, MINOS would've seen the arrival time anomaly of ~2000 ns.) The energy scale implied by this value of (vc)/c is in the MeV range. I could accept a slightly superluminal mass eigenstate with negative m^2 on the same order as mass differences measured in neutrino oscillations; or even a value like those produced in tritium beta decay experiments (where m^2 values down to ~100 eV^2 have been reported). But none of these values would come even close to producing a 10^5 effect in the speed of travel at 17 GeV. It has to be an unaccountedfor systematic error, a largeextradimensions effect that increases the strength of QGinduced Lorentz violation, or something completely unexpected. I'm leaning towards a systematic error. 


#146
Sep2311, 08:28 PM

P: 1,011




#147
Sep2311, 08:29 PM

PF Gold
P: 7,363

We have a lot of stars to look at and supernovas of all types get lots of attention. Still, we don't know all that we need to about the birth, life, and death of stars. We have some compelling models, but our lives are very short and the lives of stars are very long, so there is a sampling problem... 


#148
Sep2311, 08:39 PM

PF Gold
P: 4,781




#149
Sep2411, 12:12 AM

P: 4

'Just standing back, ignoring the particle physics, looking a this from a nuts and bolts perspective ...
60ns. 18m. This seems too crazybig to be a systematic error, right? What about this: GPSbased distance measurements are made at the earth's surface. Then, most significantly at the OPERA detector, adjustments are made for the detector's position relative to the GPS receiver. So, if the neutrino detector is 1400m underground, and 50m toward CERN, the correction is about 50m. Right? Wrong. Since the earth isn't flat like it used to be (sorry, I can't cite a reference for this offhand), two deep holes some distance apart are not parallel. They converge toward the earth's center. The bottom of the 1400m deep hole at OPERA is in fact 26m closer to CERN than the top of the hole where the GPS receiver is, if you work out the numbers. (The extreme case would be a 1400m hole in New Delhi, India, which is about 1400m closer to New York. With OPERA and LHC only 730km apart, the effect is much smaller, but relevant.) 26 metres. That would quite nicely explain the 60ns premature neutrino detection within statistical error. Of course, the scientists already must have considered this, right? It sure would be embarrassing if they didn't. 


#150
Sep2411, 12:20 AM

P: 986




#151
Sep2411, 12:21 AM

P: 89




#152
Sep2411, 05:26 AM

Sci Advisor
PF Gold
P: 2,259

Again. this is NOT a problem with GPS time keeping, 60 ns is a very long time inmodern time metrology . 


#153
Sep2411, 05:37 AM

P: 3,188

*v of equator: 40000 km / (24x60x60) s 


#154
Sep2411, 05:40 AM

P: 1

Hi everyone, interested newbie.
Was sent a link today to a page that explains why the result was wrong statistically (http://johncostella.webs.com/neutrinoblunder.pdf). Leaving aside any concern on the background of the person involved, I was left unconvinced by the argument put forward but I don't know enough to be able be definitive about it. Could one of the more knowledgeable people (particularly in statistics) have a quick read and post their thoughts? 


#155
Sep2411, 06:10 AM

Emeritus
Sci Advisor
PF Gold
P: 16,458

According to the Costella paper, if I want to measure the distance between the left end of a piece of wood and a point to its left, it depends on how long the piece of wood extends to the right. That's nonsense.



#156
Sep2411, 06:54 AM

P: 3,060

As hamster 143 correctly answered the "FTL neutrinos" are assumed to be neutrinos because they are expected to be the neutrinos coming from the accelerator (measuring the time distributions of protons for each extraction for which neutrino interactions are observed in the detector) based on measured neutrino interaction time distributions. These statistical results can't completely rule out for instance that the "arriving" neutrinos' signal is due to some local neutrinolike interaction totally unrelated to the proton accelerator. 


#157
Sep2411, 07:24 AM

P: 36

in one of the videos about OPERA, I saw a mention of fiber carrying light along the path  assuming that this light is subject to the same mass distributions as you ghc mentioned, couldn't you work backward with this fiber as the calibration point for c, and determine if the neutrinos have traveled faster than the photons in this fiber?



#158
Sep2411, 07:58 AM

Emeritus
Sci Advisor
PF Gold
P: 16,458




#159
Sep2411, 10:37 AM

PF Gold
P: 1,662

IF something is moving faster than light then the Lorentz factor γ (using c as a constant) must be somewhat 'adjusted', right? The Lorentz factor appears in several equations in Special Relativity, including time dilation, right? Time dilation is used in the GPS system to adjust the clocks involved for relativistic effects, right? Lorentz factor as a function of velocity So, how can we trust the GPS timing if we at the same time are looking for data that will 'overthrow' the scientific foundation the system is built on?? I don’t get it... Please note: I know that I’m wrong (to many extremely smart people around to miss this), I just can’t see it myself... 


#160
Sep2411, 10:58 AM

P: 3,060

If experimental error is not found,the very detection of neutrinos 60ns before they should if they were coming from the accelerator should make you consider this possibility, unless you are one of those speculating about the fall of modern physics as we know it. 


#161
Sep2411, 11:54 AM

Emeritus
Sci Advisor
PF Gold
P: 16,458

You can see it graphically in the paper; figure 11. 


#162
Sep2411, 12:23 PM

P: 94




Register to reply 
Related Discussions  
CERN, speed of light...  Special & General Relativity  6  
Does neutrino oscillation from electron neutrino to muon neutrino conserve energy?  High Energy, Nuclear, Particle Physics  4  
Avg Speed of Relay team (x and t are not given)  Introductory Physics Homework  1 