Physicists at CERN have recorded particles moving faster than light

[Asbo Zaprudder]

Re: Physicists at CERN have recorded particles moving faster than ligh

I just caught the end of this thread and haven't read the article, but has the possibility been raised that neutrinos travel at the "speed of light," but that light appears to travel slower because it's more interactive with matter, including all the virtual particles between point A and point B-- in other words, that photons get absorbed and re-emitted so many times that it adds to the travel time?

I assume you mean that the measured speed of light in vacuo isn't necessarily equal to the actual upper speed limit in Special Relativity. That would seem to be the simplest explanation - although there is still the problem of the lack of sufficient discrepancy in the observed arrival times between neutrinos and photons for supernova events. As I mentioned elsewhere, I'm wondering if this could be a quantum tunnelling effect due to passage through several hundred km of matter. Some measurements have claimed superluminal velocities for photons tunnelling across short barriers.

 

[RJDiogenes]

Re: Physicists at CERN have recorded particles moving faster than ligh

So it's only observed in mines? Interesting. Definitely worth following up on the quantum tunneling idea.

 

[Robert Maxwell]

Re: Physicists at CERN have recorded particles moving faster than ligh

Wouldn't that mean our established value for c is wrong?

 

[tighr]

Re: Physicists at CERN have recorded particles moving faster than ligh

Wouldn't that mean our established value for c is wrong?

Not necessarily. The constant "c" stands for speed of light in a vacuum, which is exactly what we've defined. The postulate is that light could travel faster than the established value of c for conditions we have yet to discover.

 

[YellowSubmarine]

Re: Physicists at CERN have recorded particles moving faster than ligh

IIUC, quantum tunnelling does allow particles to travel faster than light in random circumstances, but even then:
1) statistically, the average of the particles remains under the speed of light
2) statistically, it's impossible to transmit information using this approach, because the probability of the particle reaching you earlier is smaller than the probability of guessing the information by chance (or something)

So, if there are hot humanoid aliens on the other side of the universe, there is a probability that one of them gets dematerialized there and then materializes in my bedroom. Alas, the probability of that happening are smaller than the probability of a hot humanoid alien appearing out of nothing by pure chance.

Anyway, I take 1) to mean that if some particles speed up, some would slow down, and you'd read the average speed below C at the detector. Even if for some reason you could make the tunnelling asymmetrical, would that necessarily violate 2) as well? Wouldn't a violation of my assumption 1) also violate known assumptions that have conformed to other observations?

And why such quantum tunnelling suggestion doesn't imply ways to manipulate the randomness during e.g. tunnelling, or even building quantum FTL engines?

 

[RJDiogenes]

Re: Physicists at CERN have recorded particles moving faster than ligh

Wouldn't that mean our established value for c is wrong?

If you mean my original suggestion, then I suppose our established value for c would be wrong, but c and its implications would still exist. We just haven't been able to observe the actual value in practice because there's no true vacuum free of virtual foam.

 

[John O.]

Re: Physicists at CERN have recorded particles moving faster than ligh

Wouldn't that mean our established value for c is wrong?

Not necessarily. The constant "c" stands for speed of light in a vacuum, which is exactly what we've defined. The postulate is that light could travel faster than the established value of c for conditions we have yet to discover.

c is defined by other physical constants. 'c' itself in the theoretical sense could only be 'wrong' if one or more of the constants were different (e, pi, h).

 

[tighr]

Re: Physicists at CERN have recorded particles moving faster than ligh

c is defined by other physical constants. 'c' itself in the theoretical sense could only be 'wrong' if one or more of the constants were different (e, pi, h).

Untrue. 'c' itself is a constant according to SI units. It is explicitly defined as the speed at which light travels in a vacuum, and its value cannot change. This is independent of other constants such as e, pi, or h as you mention.

SI currently has c as a constant and the second as a constant. The only value that can change for c is the length of 1 meter, and its definition is already constrained by c.

What I said before is that its possible that light could potentially travel faster through some unknown medium other than a vacuum, but such a thing isn't known to exist.

 

[Asbo Zaprudder]

Re: Physicists at CERN have recorded particles moving faster than ligh

Not quite - there are theories that the value of c has to be greater at high energies to preserve the Planck length, or that it must variable to explain the observed differences in the fine structure constant (which apparently isn't) over deep time and across the universe.

 

[matsuiny2004]

Re: Physicists at CERN have recorded particles moving faster than ligh

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[TheSeeker]

Re: Physicists at CERN have recorded particles moving faster than ligh

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Um, what?

 

[RoJoHen]

Re: Physicists at CERN have recorded particles moving faster than ligh

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Um, what?

Dude, it's so obvious.

 

[Robert Maxwell]

Re: Physicists at CERN have recorded particles moving faster than ligh

Obviously he edited his post so it was empty. Just ignore it.

 

[Ayelbourne]

Re: Physicists at CERN have recorded particles moving faster than ligh

Obviously he edited his post so it was empty. Just ignore it.

It was probably one of those low probability events of random information appearing out of nowhere.

 

[YellowSubmarine]

Re: Physicists at CERN have recorded particles moving faster than ligh

It's actually a post that travelled back in time during the OPERA experiment, but it's empty because superluminal neutrinos can't be used to transmit information and violate causality.

 

[think]

Re: Physicists at CERN have recorded particles moving faster than ligh

IIUC, quantum tunnelling does allow particles to travel faster than light in random circumstances, but even then:
1) statistically, the average of the particles remains under the speed of light
2) statistically, it's impossible to transmit information using this approach, because the probability of the particle reaching you earlier is smaller than the probability of guessing the information by chance (or something)

So, if there are hot humanoid aliens on the other side of the universe, there is a probability that one of them gets dematerialized there and then materializes in my bedroom. Alas, the probability of that happening are smaller than the probability of a hot humanoid alien appearing out of nothing by pure chance.

Anyway, I take 1) to mean that if some particles speed up, some would slow down, and you'd read the average speed below C at the detector. Even if for some reason you could make the tunnelling asymmetrical, would that necessarily violate 2) as well? Wouldn't a violation of my assumption 1) also violate known assumptions that have conformed to other observations?

And why such quantum tunnelling suggestion doesn't imply ways to manipulate the randomness during e.g. tunnelling, or even building quantum FTL engines?

But wait do not neutrinos follow the rules of super-symmetry thus making any action a reaction and any cause an effect ?

 

[ThankQ]

Re: Physicists at CERN have recorded particles moving faster than ligh

What I said before is that its possible that light could potentially travel faster through some unknown medium other than a vacuum, but such a thing isn't known to exist.

Let's just call it "the ether" and move on. I heard that worked for someone before.

 

[Lieut. Arex]

Re: Physicists at CERN have recorded particles moving faster than ligh

Oops. Gotta check those cables, folks.

http://www.space.com/14654-error-faster-light-neutrinos.html

 

[Mikhail]

GPS fault, no FTL in OPERA

It was announced that mistake in GPS module has been found

http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html

which affected the OPERA experiment, and created an impression of neutrinos travelling faster than light. Personally I was absolutely skeptical about the OPERA big claim in September, then I had some more thoughts, based mostly on respect to a hard work of professional experimentalists and on possible very, very tensed theories which could account for the OPERA result, making the world ugly non-relativistic. See also

http://motls.blogspot.com/2012/02/opera-gps-mistake-found-neutrinos.html

for more explanations.

I hope I do not have to remind anyone that warp drive you all as trek fans must be dreaming about has nothing to do with statement as OPERA did, even if the later appeared to be a correct one.

 

[Pavonis]

Re: Physicists at CERN have recorded particles moving faster than ligh

I figured it'd be something like that. A loose cable, a bad timer, imprecise calibration, something like that. All possibilities that were far more likely than superluminal neutrinos!