What if something went faster than light?

[Willis666]

When I heard about the faster than light neutrinos, I began wondering about what changes that would make in physics. I thought one would be that humans may eventually go at the speed of light. Another is that Einstein was wrong on one thing, and could have been wrong on some other things. What else is there? Somebody once told me that if you went faster than light, you could go backwards in time?

Thanks!

 

[JHamm]

Another is that Einstein was wrong on one thing, and could have been wrong on some other things.

One important basis in science is that an argument is independent of the person presenting it, it is quite dangerous to accept or dismiss something simply because of WHO said it.

 

[phinds]

When I heard about the faster than light neutrinos, I began wondering about what changes that would make in physics. I thought one would be that humans may eventually go at the speed of light. Another is that Einstein was wrong on one thing, and could have been wrong on some other things. What else is there? Somebody once told me that if you went faster than light, you could go backwards in time?

Thanks!

Going FTL is a false premise. From a false premise, you can deduce absolutely anything and everything. I deduce from our ability to go FTL that the big bang was caused by two really large unicorns clashing horns.

The consensus, even among the CERN experimenters is that there are no FTL neutrinos, what there is is a very meticulously done experiment in which they have not yet been able to find the measurement error.

 

[Pengwuino]

Not many changes would really need to be made. Assuming special relativity holds has been wildly successful over the past 100+ years. If neutrinos are not confined to special relativity's restrictions, it would simply be an exception that would have to be taken into account.

It's just like Newtonian mechanics being supplanted by relativity. Everything in our daily life is pretty much governed by Newtonian mechanics. When I drop a ball, I don't need to talk about relativistic effects to do a good experiment. It works perfectly well in a certain domain. If neutrinos are not restricted by special relativity, then it just means that they're governed by a different theory we don't know yet.

@phinds

I disagree that it's a false premise. If, amazingly, those neutrinos were going faster than light, it simply means that neutrinos are apparently only governed by SR approximately. In General Relativity, the problem exists. We know GR is probably not the whole story, so it's foolish to say that no experiment could ever show SR is wrong (or at least, not exact for all particles). Falsifiability must be preserved.

 

[danR]

Going FTL is a false premise. From a false premise, you can deduce absolutely anything and everything. I deduce from our ability to go FTL that the big bang was caused by two really large unicorns clashing horns.

The consensus, even among the CERN experimenters is that there are no FTL neutrinos, what there is is a very meticulously done experiment in which they have not yet been able to find the measurement error.

Could you cite a source for the consensus? The only information I can glean from a leading spokesman is an agnostic position:

"Despite the latest result, said Autiero, the observed faster-than-light anomaly in the neutrinos' speed from Cern to Gran Sasso needed further scrutiny and independent tests before it could be refuted or confirmed definitively. The Opera experiment will continue to take data with a new muon detector well into next year, to improve the accuracy of the results."
​

www.guardian.co.uk/science/2011/nov/18/neutrinos-still-faster-than-light?newsfeed=true

 

[phinds]

Could you cite a source for the consensus?

I have no specific reference, other than the LONG thread on this forum about the results (I HAVE read other reports, but have no references to any of them)

 

[danR]

I have no specific reference, other than the LONG thread on this forum about the results (I HAVE read other reports, but have no references to any of them)

You mean the CERN thread. I have trouble with that discussion; it seems to have settled down to a dispute over just where the measurement error lies, rather than what are we going to do if it there is no error at all (and if Glashow is wrong, etc). After your post I tried searching the CERN site itself for recent news releases about the results, but couldn't find anything.

A few papers have addressed the matter and one has argued causality need not be breached by FTL neutrinos. There is also the Scharnhorst effect predicted between Casimir plates, also not breaching causality, but the effect would be immeasurably small.

Neutrino dispersion relation changes due to radiative corrections
as the origin of faster-than-light-in-vacuum propagation in a
medium.

http://arxiv.org/abs/1109.5411
​

I'm not qualified to judge the soundness of his arguments, however.

 

[phinds]

Dan, I'm not particuarly qualified to judge this, but I believe that it says something significant that, as you say, the CERN thread has settled into a discussion of where the measurement error is. Physicists LIKE exciting new things, and FTL is VERY exciting, so the general disbelief about the CERN results seems significant to me.

Yes, it COULD still be an indication of FTL travel, but I won't believe that until there is more conclusive evidence and I really don't expect to see any.