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Author Topic:   Einstein is rolling over in His Grave, or Cern makes a big mistake
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 2 of 74 (634564)
09-22-2011 5:39 PM
Reply to: Message 1 by ramoss
09-22-2011 5:10 PM


Who bets the results can not be duplicated?
Probably not, but I still wouldn't say that "Cern makes a big mistake". The caution shown and requests for duplication are exactly what we want to see in such circumstances.
The big problem is that such superluminal neutrino speeds have not been seen over vastly greater distances - primarily with supernova explosions.
A 60ns difference compared to light over the observed distance works out to be a ~2 year difference compared to light with supernova SN1987A. This is something completely at odds with observation where the initial neutrino burst arrived 3 hours before the light (owing to the mean free path through the star for the shock wave being much longer for the neutrino component compared to the photon component)

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 8 of 74 (634598)
09-23-2011 2:26 AM
Reply to: Message 6 by Dogmafood
09-22-2011 10:00 PM


Do you mean that the path is shorter for the neutrino's?
Yes - see Crash's explanation above.

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 28 of 74 (635529)
09-29-2011 3:33 PM
Reply to: Message 19 by RAZD
09-29-2011 8:39 AM


Re: so why not just change the speed of light?
hey Raz (or ZD now, I guess)
What I don't understand is why the speed of light is not adjusted to this new experimental result.
Everyone else seems to have covered this. c is just too well measured for any adjustment at this scale. The precision to which c is known is critical in the construction and operation of the LHC and all similar hardware.
It would still have the neutrinos arriving earlier than photons from supernova, wouldn't it?
Yep, by 20 parts per million. So over a journey of 168,000 years (SN1987A is 168,000 light years away), the neutrinos would arrive 3 years early, not 3 hours early as observed.

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 45 of 74 (637490)
10-16-2011 4:30 AM
Reply to: Message 42 by Percy
10-15-2011 10:21 AM


Re: Physics Saved!
This proposed solution has yet to be vetted, but I bet it sticks.
Hmmm. While the general principle suggested may well lie behind the discrepancy, the particular paper in question leaves much to be desired. The doubling of the 32ns to 64ns is especially amusing/worrying*.
Faster than light particles, physics overturned, physicists baffled, science in an uproar: sheesh!
Yep, popualr science press working its wonders yet again...
*
quote:
In other words the observed time of flight should be about 32 ns shorter than the time-of-flight
using a baseline bound clock. Now we should examine the experiment again to identify potential
other locations where these types of error can be made. Most of the corrections to the result
are estimated using baseline based clocks, these corrections do not change the expected observed
time-of-flight. However to relate baseline time to GPS clock time the GPS clock time is corrected
for time-of-flight of the radio signals. It is likely that this is also done using the baseline reference
frame where the clock reference frame should be used. As this involves the same clock and the
same events the error should be the same, i.e. from the baseline reference frame the time-of-flight
of the radio signals in the clock reference frame is overestimated by ǫ and hence we expect that
the total error is in the order of 2ǫ = 64 ns.
Edited by cavediver, : No reason given.

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 49 of 74 (637565)
10-16-2011 4:53 PM
Reply to: Message 47 by DWIII
10-16-2011 3:06 PM


Re: Physics Saved!
Like I said, I may be missing something here.
Well, it's the obvious sense-check to make - and you're quite right that the relevant gamma seems way too small to be the root cause of the discrepancy. If you look at his paper, his effect depends on v/c, not gamma, which explains how he gets the right order correction. But I have zero time to try to decipher his reasoning, especially as it means getting into the Opera paper (something I haven't even looked at yet given the same lack of time) At the moment, I'm far from convinced...

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 58 of 74 (641423)
11-19-2011 8:46 AM
Reply to: Message 56 by 1.61803
11-18-2011 10:55 AM


Re: Follow-on experiment confirms original result
This must be what they are doing, because for a particle to travel fast as light or faster it in theory would have infinite energy right?
Not really. The whole "need infinite energy to go the speed of light" is rather misleading. Particles with well-defined rest mass travel slower than light. You can accelerate a particle to 99.9999% of the speed of light (as measured in the laboratory frame), but jump into the particle's frame and your back to stationary with respect to light. So which view is correct?
The speed of light is not something that is a "bit faster" than a relativistic proton zipping around the LHC ring. It is something entirely different. You cannot hypothetically give a massive particle "infinite energy" and suddenly it hypothetically travels at c.
Particles with zero rest-mass travel at c. And they cannot do otherwise.
Particles that travel faster than c are tachyons, and they are a different beast again. They only exist superluminally: they cannot "slow-down" to c and then become subluminal; you do not need "infinite energy" to make a tachyon.
If these neutrinos are tachyonic, they are created tachyonic. They are not created subluminal then accelerated to superluminal speed, a process which is utterly non-sensical as per the above explanation.
So does it make sense for the neutrinos to be tachyonic? Not really. Tachyons as we understand them aren't really particles in the way we would normally understand the concept. Yet these neutrinos are acting like subluminal particles but appear to be travelling superluminally. That is problematic.
The biggest problem is that if everything is as the experiment would have us believe, then much of the above explanation can be dismissed as it is based on an understanding that doesn't include this type of behaviour!! Yet we have the most accurate theories known to man based on these explanations. And we have previous neutrino studies that show no evidence of this tachyonic behaviour. So, inspite of the latest results, I remain highly skeptical.
Neutrinos could be zipping in and out of other dimensions or quantum tunneling through space time.
Possibly, but again we have never seen this behaviour before. And it is not the case that the neutrinos are passing through some exotic region of space-time. We may think that a mountain range, solid ground, and a reassuring 1G gravtational field are significantly different to empty space, but on the grand scale of the Universe, we're just a little barely-noticeable bump in the local space-time curavture...

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 61 of 74 (641575)
11-20-2011 11:28 AM
Reply to: Message 59 by Wollysaurus
11-20-2011 12:43 AM


Re: Follow-on experiment confirms original result
but could you put in layman's terms what a zero mass particle that exists in velocities exceeding c would mean...?
First off, tachyons are not massless. Something that is massless travels at c. Tachyons have mass, but just to cause greater confusion, that mass is imaginary, i.e. the squared mass is negative.
What would the confirmation of the existance of such a particle mean in practical terms, for us social "science" types who don't have the background in mathematics or the phycial sciences to appreciate such concepts on paper? If any?
Not much. We know that GPS works, that particle accelerators work, etc, so SR and GR are good approximations of reality. But to those of us in fundemental phsyics, if it is not a mistake, and if it is not a "cheat" (some higher-dimensional physics leaking into the experiemnt) then it is not far from discovering that 2+2=5. Everyone is asking what are the ramifications of this result if true, and we're floundering around trying to work out what the result actually means! At this stage we have no idea.
Edited by cavediver, : No reason given.

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