Big story ....CERN scientists break the speed of light

del88 · 22-09-2011 11:10pm #1

Scientists said on Thursday they recorded particles travelling faster than light - a finding that could overturn one of Einstein's fundamental laws of the universe....

http://www.telegraph.co.uk/science/8782895/CERN-scientists-break-the-speed-of-light.html

the_monkey · 22-09-2011 11:34pm

Wow !!! , Can't wait for the religious fools on this - Einstein was wrong => the Bible is correct - well i'm convinced .... :rolleyes:

del88 · 22-09-2011 11:42pm

the_monkey wrote: »

Wow !!! , Can't wait for the religious fools on this - Einstein was wrong => the Bible is correct - well i'm convinced .... :rolleyes:

Maybe Jesus gave them an extra little push seems how the nutrinos were heading for rome.... he does work in mysterious ways ..

Iwannahurl · 22-09-2011 11:57pm

Upper limit on speed:

If the spatial distance between two events A and B is greater than the time interval between them multiplied by c then there are frames of reference in which A precedes B, others in which B precedes A, and others in which they are simultaneous. As a result, if something were travelling faster than c relative to an inertial frame of reference, it would be travelling backwards in time relative to another frame, and causality would be violated. In such a frame of reference, an "effect" could be observed before its "cause". Such a violation of causality has never been recorded, and would lead to paradoxes such as the tachyonic antitelephone.

So now you know.

thecornflake · 23-09-2011 2:07am

Iwannahurl wrote: »

Upper limit on speed:
If the spatial distance between two events A and B is greater than the time interval between them multiplied by c then there are frames of reference in which A precedes B, others in which B precedes A, and others in which they are simultaneous. As a result, if something were travelling faster than c relative to an inertial frame of reference, it would be travelling backwards in time relative to another frame, and causality would be violated. In such a frame of reference, an "effect" could be observed before its "cause". Such a violation of causality has never been recorded, and would lead to paradoxes such as the tachyonic antitelephone.
So now you know.

Grand, i just derived all my formulae for my new theorem from the results of the experiment that will be performed next week.

Killer Pigeon · 23-09-2011 11:07am

So, does this mean all the Relativity and Quantum Mechanics courses I'm taking this year are utterly pointless?

The Dagda · 23-09-2011 11:31am

Killer Pigeon wrote: »

So, does this mean all the Relativity and Quantum Mechanics courses I'm taking this year are utterly pointless?

Unforetunately it does, but the good news is, you can now go back and do something else. It's an ill wind...

Professor_Fink · 23-09-2011 12:09pm

The Dagda wrote: »

Unforetunately it does, but the good news is, you can now go back and do something else. It's an ill wind...

No it doesn't. Superluminal particles aren't specifically forbidden by either quantum mechanics or relativity, but we've never seen them, and they present so many paradoxes we never believed they could actually exist. However, they can present difficulties with formulating field theories.

Also, the experiment is probably wrong.

parrai · 23-09-2011 12:12pm

So say it's true, (or fair enough, they have said it's true) what are the practical/potential uses for this break through?

godtabh · 23-09-2011 12:18pm

Professor_Fink wrote: »

.

Also, the experiment is probably wrong.

Why do you say that?

Anonymo · 23-09-2011 12:28pm

Professor_Fink wrote: »

No it doesn't. Tachyons aren't specifically forbidden by either quantum mechanics or relativity, but we've never seen them, and they present so many paradoxes we never believed they could actually exist. However, they can present difficulties with formulating field theories.

Also, the experiment is probably wrong.

Just a couple of comments on this. Firstly, these are not necessarily tachyons. Though tachyons are the general name to things moving at greater than the speed of light, this discovery might not actually be saying anything about the speed of light. Instead it may be an indication that there are extra dimensions (offering a shorter path to the neutrinos). Tachyons are, as you mention, generally looked on as a sign of instability and it is the desire to avoid them, for instance, that limits the number of string theory dimensions to 10.

Your last claim that 'the experiment is probably wrong' could do with some explanation. The CERN guys are generally very careful. It could be that some systematic error has not been accounted for. That I would agree with, but not your statement.

zuutroy · 23-09-2011 12:50pm

What hasn't been mentioned is that the effect of doing the experiment in air. It's the speed of light in a vacuum that's the universal constant. Would like to see this addressed.

Killer Pigeon · 23-09-2011 1:17pm

Professor_Fink wrote: »

Also, the experiment is probably wrong.

It's either wrong or just sensationised.

Anonymo · 23-09-2011 1:24pm

zuutroy wrote: »

What hasn't been mentioned is that the effect of doing the experiment in air. It's the speed of light in a vacuum that's the universal constant. Would like to see this addressed.

Agree completely with this. However, they have calculated the result based on the speed of light in a vacuum. The speed of light through other media will presumably move at a lower velocity making the problem even worse. Nonetheless, this is just an assumption that I'm making and, like you, would like to see it addressed.

fontanalis · 23-09-2011 1:51pm

Was there an idea of somethign called inflation put forward years ago that claimed the expansion after the big bang may have travelled faster than light?

Anonymo · 23-09-2011 2:00pm

fontanalis wrote: »

Was there an idea of somethign called inflation put forward years ago that claimed the expansion after the big bang may have travelled faster than light?

In that case no information was moving faster than light. What was happening was that the fabric of spacetime itself was inflated (akin to inflating a balloon) and objects in the spacetime (like dots on the balloon) moved apart at faster than the speed of light. No information was transmitted between points. This is a fundamental difference.

The paradigm of inflation is quite widely accepted in cosmology. It is used to explain the fact that the temperature of the universe is so uniform, which couldn't have been the case unless there was a period of such rapid expansion in the early universe (unless some very exotic scenario is invoked).

Professor_Fink · 23-09-2011 2:26pm

Anonymo wrote: »

Your last claim that 'the experiment is probably wrong' could do with some explanation. The CERN guys are generally very careful. It could be that some systematic error has not been accounted for. That I would agree with, but not your statement.

Even they don't believe it, which is why they haven't claimed it as a discovery (despite the 6.1\sigma gap). Literally everyone I talked to today thought it was probably some form of unaccounted for systematic error. I literally don't know a single physicist willing to take an even money bet in favour of this.

Of course they are careful, which is what makes the story worth paying attention to, but as far as I can see the general feeling is that this will turn out like the pioneer anomaly.

Professor_Fink · 23-09-2011 2:28pm

Killer Pigeon wrote: »

It's either wrong or just sensationised.

Nope. If it's correct it is the most important experimental result in nearly 100 years.

Professor_Fink · 23-09-2011 2:29pm

zuutroy wrote: »

What hasn't been mentioned is that the effect of doing the experiment in air. It's the speed of light in a vacuum that's the universal constant. Would like to see this addressed.

Seriously? You think this passed vetting at CERN with that kind of elementary error?

Professor_Fink · 23-09-2011 2:33pm

Anonymo wrote: »

...it is the desire to avoid them, for instance, that limits the number of string theory dimensions to 10.

Really? The only proof I know is for bosonic string theory, but it is based on the differing number of spin eigenstates for massive and massless particles of fixed spin, and not on ruling out tachyons.

Anonymo · 23-09-2011 2:56pm

Professor_Fink wrote: »

Really? The only proof I know is for bosonic string theory, but it is based on the differing number of spin eigenstates for massive and massless particles of fixed spin, and not on ruling out tachyons.

To an extent I'm being a bit loose with this. By adding fermions to the theory the superstring theory will then have ghosts in the fermionic sector as well as the usual ghost (tachyon) state from the bosonic sector. Eliminating the ghosts in the fermionic sector fixes the spacetime dimension to be 10 which also eliminates the tachyon.

mcmoustache · 23-09-2011 3:06pm

Does this not contradict what was observed when SN1987A exploded. Then neutrinos were detected only hours earlier, if even that, than the photons.

If the CERN experiment was kosher, then the gap between neutrino and photon detection in the supernova event above would have been in the order of years and not hours as was observed*.

*60 nano seconds in 2 milliseconds means 60/2000000 = 0.00003. It means that the gap is .003%. The supernova was 160,000 light years away so the gap would have been about 5 years. It wasn't.

**(Info pulled from a slashdot post and not all my own work)

Anonymo · 23-09-2011 3:16pm

mcmoustache wrote: »

Does this not contradict what was observed when SN1987A exploded. Then neutrinos were detected only hours earlier, if even that, than the photons.

If the CERN experiment was kosher, then the gap between neutrino and photon detection in the supernova event above would have been in the order of years and not hours as was observed*.

*60 nano seconds in 2 milliseconds means 60/2000000 = 0.00003. It means that the gap is .003%. The supernova was 160,000 light years away so the gap would have been about 5 years. It wasn't.

**(Info pulled from a slashdot post and not all my own work)

Yep and this is probably the main reason that the result is not believed. The main systematic must be something to do with the distance measurement. For the supernova measurement neutrinos are compared directly to photons. The reason photons arrive later is because they are scattering off each other - they are moving faster than the neutrinos but the neutrinos are moving freely. The issue with this experiment is that photons cannot pass through mountains! So the neutrino speed must be calculated by knowing the distance extremely accurately.

zuutroy · 23-09-2011 4:09pm

Professor_Fink wrote: »

Seriously? You think this passed vetting at CERN with that kind of elementary error?

No, just that I haven't seen it addressed anywhere. I just can't help thinking there'll be some caveat or technicality that will make it a damp squib.

Professor_Fink · 23-09-2011 4:16pm

zuutroy wrote: »

No, just that I haven't seen it addressed anywhere. I just can't help thinking there'll be some caveat or technicality that will make it a damp squib.

Then watch the webcast. They've been through the entire experiment and timing procedure in detail.

Iwannahurl · 23-09-2011 4:19pm

Professor_Fink wrote: »

Nope. If it's correct it is the most important experimental result in nearly 100 years.

Fair enough, we assume this new finding is provisional until replicated. And replicated more than once, presumably, given the maxim that extraordinary claims require extraordinary proofs.

The hypothesis that neutrinos are faster than light has been around for a while, it seems.

So this is the first convincing observation that it might be true?

May I ask you to speculate, in layman's language that I can understand, what the implications of this discovery might be, if it is shown to be a real phenomenon?

Might it help to solve one or two of the unsolved problems in Physics, for example?

Professor_Fink · 23-09-2011 5:03pm

Anonymo wrote: »

Yep and this is probably the main reason that the result is not believed.

Actually, no, its not a contradiction. The supernova data is for energies centred on 10MeV where as the OPERA result is for 17GeV, which is a huge difference. There have been proposed models where the velocity is energy dependent, and the current results support that.

On the other hand, you are right that it is held up as a reason not to believe the current results.

Turtwig · 23-09-2011 5:08pm

Just for some lulz.:D

FISMA · 23-09-2011 6:02pm

Professor_Fink wrote: »

No it doesn't. Superluminal particles aren't specifically forbidden by either quantum mechanics or relativity...

+1

Professor_Fink wrote: »

Also, the experiment is probably wrong.

+1

Agreed.

First, Einstein said no [material] thing, that is of matter, can go the speed of light or faster. If you read Einstein's works, you'll see that he held out the possibility of a superluminal realm. One where greater than lights speeds were possible. The only caveat being that we would not be able to sense/perceive such a realm.

Kudos to the people at Cern and I hope that their results are independently verified. However, until such time as they are, I'll keep the cork on the Champagne...

GenghisCon · 23-09-2011 6:04pm

A lament for C, as sung by an Irish bachelor farmer.

Sung to the air of “The sea around us” by Dominic Behan

My mind it is troubled as I set out on my toil.
With spade and with hoe I attend to the soil.
But news I’ve received has shook me to my core,
Relativity it seems may be special no more.

(chorus)
The C oh the C, is grá geal mo chroi!
You were immutable or so it appeared to me…
But now it would seem you’re as fickle as could be,
and neutrinos may even be swifter than thee?

If neutrinos have mass but can beat light to the punch…
…what does it mean for E = MC such n such ?
But if neutrinos change state can they skip forward in time…
and not be the same particle that crosses the finish line?

(chorus)

If the ether is dense, light may even twist a wee bit.
If space time was flat a neutrino wouldn't win in a fit.
Could it be that the limit and light’s speed are not one and the same…
and that neutrino and anti-neutrinos are just arbitrary names?

(chorus)

But what do I know? this matters not one jot.
There’s more spuds to be set as I bemoan my lot.
My sheepdog’s got pleurisy, we’ve got more bugs than bed,
and from the smell of that box, Schrödinger’s cat is certainly dead.

(chorus)

Gandalph · 23-09-2011 9:23pm

It was only a matter of time, Usain Bolt came close to beating the speed of light in training one day.

Big story ....CERN scientists break the speed of light

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