Thread: Neutrinos observed travelling faster than the speed of light

Originally Posted by stormcrow

What I want to know is, assuming this evidence is factual, how does this affect the special theory of relativity? Even though the neutrino has surpassed the speed of light, the speed of light remains the same. Does this require the theory to be revised because I always assumed that the view that "nothing can travel faster than the speed of light" is an assumption considering that it can always be falsified by future observation or experiments.

@neiltyson: Misbehaved neutrinos? Three options: 1) Mistake; 2) They live backwards in time -- okay w/ Einstein; 3) Extend Relativity

First, it's CERN, not Cern. FFS there's so many mistakes in "journalism" these days, I can't take anything seriously because it looks like some high-school kid has written it.

Second, does anyone know how the hell they're going to replicate it? lol

There's only one multi billion dollar particle accelerator, as they say.

It's already been replicated and falsified by that supernova observation that some people mentioned.

Nobody mentioned anything about supernovas...

I think cmind is talking about the recent supernova in which (if the neutrino observation is factual) we would have detected the neutrinos before the light from the supernova itself but that doesn't appear to be the case.

Originally Posted by BLUELINE976

@neiltyson: Misbehaved neutrinos? Three options: 1) Mistake; 2) They live backwards in time -- okay w/ Einstein; 3) Extend Relativity

I was hoping for a more in depth explanation considering I'm not too knowledgeable about particle physics or physics in general. What does it mean that "They live backwards in time"? So you think that relativity will still be valid (from 2] and 3] ) but possibly open to revision?

Originally Posted by Xei

Nobody mentioned anything about supernovas...

Get your head out of your ass, Aspie.

Originally Posted by stormcrow

I think cmind is talking about the recent supernova in which (if the neutrino observation is factual) we would have detected the neutrinos before the light from the supernova itself but that doesn't appear to be the case.

Yep, that's the one.

That is of course a different circumstance. The neutrinos at CERN have much higher energies than stellar neutrinos for one thing, which may be important for the anomalous effect. This won't be settled until the specific experiment is explained.

Originally Posted by Xei

That is of course a different circumstance. The neutrinos at CERN have much higher energies than stellar neutrinos for one thing, which may be important for the anomalous effect. This won't be settled until the specific experiment is explained.

But if said neutrinos have a higher energy (and thus a higher mass) wouldn't it be harder for them to accelerate to the speed of light than stellar neutrinos? I was under the impression that neutrinos could travel close to the speed of light because they had little to no mass? Also what is the difference between a stellar neutrino and the one's at CERN? I'm guessing that the ones at CERN were created in the particle collider? Sorry for asking so many questions (if anyone has any literature or any lectures on the topic I would appreciate it very much).

What this actually means is that neutrinos can have more than infinite mass and are obviously the source of dark matter! lol No, but actually there's no problem with relativity if they were created going above the speed of light to begin with, they just couldn't decelerate passed it.

Originally Posted by stormcrow

But if said neutrinos have a higher energy (and thus a higher mass) wouldn't it be harder for them to accelerate to the speed of light than stellar neutrinos? I was under the impression that neutrinos could travel close to the speed of light because they had little to no mass? Also what is the difference between a stellar neutrino and the one's at CERN? I'm guessing that the ones at CERN were created in the particle collider? Sorry for asking so many questions (if anyone has any literature or any lectures on the topic I would appreciate it very much).

Apparently the particles at CERN have energies of the order of 1,000 times that of the stellar ones, which is ostensibly the major difference. Although the neutrinos are harder to accelerate, presumably the accelerator is sufficient, and what they were expecting to see was very close to light speed. Of course, if the result is correct then what we are talking about isn't acting in accordance with the current laws of physics, and would represent some kind of novel effect anyway.

Originally Posted by Xei

Apparently the particles at CERN have energies of the order of 1,000 times that of the stellar ones, which is ostensibly the major difference. Although the neutrinos are harder to accelerate, presumably the accelerator is sufficient, and what they were expecting to see was very close to light speed. Of course, if the result is correct then what we are talking about isn't acting in accordance with the current laws of physics, and would represent some kind of novel effect anyway.

So it is a law that nothing can travel faster than light (the validity of relativity hinges on this law?) and not just an inductive assumption? Hmm I wish I knew more about relativity perhaps the implications of this observation would sink in easier...

As far as I know (which is three or four lectures), special relativity is just a consequence of the constancy of the speed of light (and some obvious assumptions), which, regardless of any experiments on neutrinos, is an observed fact. This single fact directly implies a different model for space. It's worth bearing in mind through all of this that special relativity keeps satellites in space, so it will never be proven fundamentally wrong in any meaningful sense; at the worst it will be proven to have some additional features or caveats.

It's my belief that pretty much all knowledge is an inductive assumption, but physical theories are definitely all inductive, so the light 'speed limit' is certainly an inductive claim. But the thing is that the basis for this claim, which is the constancy of the speed of light, is always seen to be true, so it in the inductive model of truth it ranks extremely highly.

Every star in the night sky is proof that general relativity is correct.

Originally Posted by cmind

Every star in the night sky is proof that general relativity is correct.

lol...except, it's the opposite.

Originally Posted by stormcrow

But if said neutrinos have a higher energy (and thus a higher mass) wouldn't it be harder for them to accelerate to the speed of light than stellar neutrinos?

I'm not really sure. But no thing can accelerate to the speed of light.
It has to always be going at the speed of light. Photons are always going ~3million metres per second (in a vacuum).

And as wayfaerer said, if the neutrinos created were instantly going at the speed of light or above, then it doesn't disprove anything.

I think. I'm not a professor or anything, just my laymen understanding of it.

Also, it could just be another case of needing a super special relativity. Like neutrinos obey some other law.

Originally Posted by tommo

Second, does anyone know how the hell they're going to replicate it? lol

There's only one multi billion dollar particle accelerator, as they say.

The neutrinos didn't come from the LHC. Several other locations are set up to replicate the experiment.

I have only heard of one place. And it is the CERN particle detector.

It is km's underground and filled with water. Afaik it's the only one of it's kind because of those factors that make it so hard/expensive to build.

Okay my mistake.... OPERA particle detector.

But the point is, I don't think anyone else has the equipment to replicate this;
The ability to direct a beam of neutrinos 730km to a particle detector under 1.4km of rock.

quantic inductions speed is infinite so that passes the speed of light

Originally Posted by tommo

I have only heard of one place. And it is the CERN particle detector.

It is km's underground and filled with water. Afaik it's the only one of it's kind because of those factors that make it so hard/expensive to build.

Okay my mistake.... OPERA particle detector.

But the point is, I don't think anyone else has the equipment to replicate this;
The ability to direct a beam of neutrinos 730km to a particle detector under 1.4km of rock.

Well it doesn't have to replicate the experiment exactly, just the principle. CERN even asked specific laboratories elsewhere in the world to help out. Fermilab in the US and some place in Japan have run similar experiments in the past.

Hmmmm, fair enough.

Well I guess we'll just have to wait and see.

Very interesting. Keep me posted Xei.

Originally Posted by stormcrow

What I want to know is, assuming this evidence is factual, how does this affect the special theory of relativity? Even though the neutrino has surpassed the speed of light, the speed of light remains the same. Does this require the theory to be revised because I always assumed that the view that "nothing can travel faster than the speed of light" is an assumption considering that it can always be falsified by future observation or experiments.

SR most definitely does not rule out faster than light travel. It does specify three things:

1) no object can accelerate from less than the speed of light to lightspeed or faster .
2) no object moving faster than the speed of light can decelerate to the speed of light or slower.
3) an object moving at the speed of light in one reference frame will be moving at light speed in all reference frames, always.

Also, an object moving at faster than the speed of light will be viewed as moving backwards in time in some reference frames.

This will be really cool if it's true.

Looks like the time reference they used is in motion, and subject to relativistic effects itself.... Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity - Technology Review

Originally Posted by Forsaken

Looks like the time reference they used is in motion, and subject to relativistic effects itself.... Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity - Technology Review

Followup: FTL neutrinos explained? Not so fast, folks. | Bad Astronomy | Discover Magazine