Physicists at CERN have recorded particles moving faster than light

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

Coolness.

 

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

The result would tend to agree with measurements that implied that neutrinos have imaginary mass and thus are perhaps tachyonic in nature. There is much hand wringing about this on various blogs around CERN with people worrying that their grandfather might get bumped off. The prosaic answer is that it might all turn out to be systematic error that has led to this 6 sigma observation.

 

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

My understanding is that tachyons are expected to not violate causality because it's either impossible to measure their position, or because they exist for a minimal period of time, and the detectable disturbances they create always travel at sublight speed. How does this relate to neutrinos? Do we know that these things do not apply to them? If they do not, is there any other mechanism that can stop causality violations?

In short, does this violate it, and if not, why not?

 

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

This is sort of old news. As long ago as 15 years back there were reports of particles being clocked faster than light. And reportedly some particles were time-shifted too. Still, it's nice to have something like CERN come out with this so people become aware. Also, wasn't testing the speed of light one of CERN's mandates, too?

Alex

 

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

One suggestion is that neutrinos can take shortcuts by oscillating out of the brane of our universe into neighbouring branes, which photons cannot do. Even if not the case, it sounds like a handy plot MacGuffin for a S-F author to exploit.

 

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

Why is everybody in such a hurry to disprove Einstein these days?

[yt]http://www.youtube.com/watch?v=GrsN8iTwFiw[/yt]

 

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

The CERN study was actually investigating flavor changing, they really weren't out to show that neutrinos could move FTL. Which doesn't surprise me, the idea that they do/can is so absurd nobody would've thought to actually approach it as a research topic

It's a fascinating claim... I will be anxious to see what it turns up but I am cautiously skeptical. I'd love to hear them determine that... its a verification of multidimensionality, or a sign of spacetime warping, or perhaps an indication that neutrino mass fluctuates and can locally become negative.... but the margin of error is very nearly the margin by which it's faster. I was reading on SlashDot - 732 km column the beam passed through they believe they know it accurately to about 20 cm. In 60ns, a beam of light apparently travels about 18 meters, so that's the spatial difference we're talking about. They claim their margin of error on the travel time is +/- 10ns but some informed individuals on SlashDot were questioning whether perhaps they had mischaracterized the kaon/pion decay times; or, perhaps, discovered new modes of decay which were fudging their 'start times'.

In any case I do hope it leads to an important discovery, whatever it may be, and not someone facepalming over a computational error or an equipment glitch. They said they did it 15,000 times to be sure.

Someone already posed this question - but what is known about neutrino information-containment? For instance it's been suggested that tachyons could not be encoded with information. Supposing these neutrinos are found to rotate in and out of an extra dimension which allows them to move quasi-FTL - they would be useful for FTL communication if 1) they could be encoded with information, 2) they could be generated easily like radio waves and 3) could be absorbed/detected easily. That 3rd one's a biggy.

 

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

Please correct me if I'm wrong, but is there anything in the formulation of Special Relativity that demonstrates that the maximum speed (presumably of information) has to be identically equal to the speed of light? I thought that the identification of the two things as being equal was an assumption. If so, perhaps that assumption needs examining. However, as you say, if no information can be transmitted, then there is no Lorentz violation.

 

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

http://images.cheezburger.com/completestore/2011/9/23/72569c4c-1e86-45e9-b95c-1c11a3fafb2a.jpg

Sorry, it was just too tempting.

 

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

Very interesting results. As other have said, the community need to cross-examine their data more than once, because systematic errors are sneaky like that. But if it's true, we are in for a great time in fundamental physics. Let's hope so.

 

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

Neutrinos exceeding the speed limit would just have to happen in Italy, wouldn't it. I bet they're all driving tiny little Fiats.

 

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

60 nanoseconds faster than light? Is that really that awesome? A photon is influenced by electromagnetic fields, a neutrino isn't. And then isn't 60 nanoseconds more likely to be a computational issue?

I think that's a good point.


***
Some articles say that the time at start and end point is measured using GPS and that the nanosecond difference might be caused by that. D'oh!

 

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

Somebody made the same joke today at work. "In Italy, nobody respects the speed limit."

 

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

We're not even certain that gravitons travel at the speed of light. The solution for the propagation of gravitational waves in General Relativity yields a speed of c (again assumed to be the speed of light), but only in the weak field limit after applying a great deal of linearisation to the equations. Experiments have not tied down the difference between the speeds of light and gravity to better than 1% - as far as I'm aware.

 

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

I'm having a little difficulty with the idea of a particle that has "imaginary mass." I get how imaginary numbers work in math--it's like having a number line orthogonal to the "real" number line.

But how can something have "imaginary mass"? I can understand positive mass and zero mass. Is "imaginary mass" basically "negative mass"? Would that imply it exerts an anti-gravity force?

Wiki sidesteps the whole idea of what "imaginary mass" would mean for physics, which just makes me even more curious.

 

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

Imaginary mass is what skinny girls complain about when they bitch about how fat they are.

 

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

The actual paper from preprint server arXiv, for anyone interested.

 

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

The usual way of sidestepping the imaginary mass problem is to have only the square of the mass be a physical observable. It's the mass squared that turns up in measurements of the cut off in the beta decay energy spectrum, and in the equation for the four-momentum. Of course, it does imply that the mass squared is negative. Beats me how a superluminal particle with imaginary mass would move under gravity, but I seem to recall reading that tachyons and matter tardyons are expected to be mutually repulsive gravitationally speaking.