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 Post subject: Particles recorded moving faster than light PostPosted: 2011-09-22 03:16pm
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http://www.reuters.com/article/2011/09/22/science-light-idUSL5E7KM3UU20110922

So, if this is true, this could be groundbreaking stuff, right? Anyone got any ideas of the implications of this?

I'm supposed to quote the article too, right?
Quote:
(Reuters) - An international team of scientists has recorded neutrino particles travelling faster than the speed of light, a spokesman for the researchers said on Thursday -- in what could be a challenge to one of the fundamental rules of physics.

Antonio Ereditato, who works at the CERN particle physics centre on the Franco-Swiss border, told Reuters that measurements over three years showed the neutrinos moving 60 nanoseconds quicker than light over a distance of 730 km between Geneva and Gran Sasso, Italy.

"We have high confidence in our results. But we need other colleagues to do their tests and confirm them," he said.

If confirmed, the discovery would overturn a key part of Albert Einstein's 1905 theory of special relativity, which says that nothing in the universe can travel faster than light. (Reporting by Robert Evans, editing by Tom Miles)


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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:30pm
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Well, could neutrinos carry information? For what little I know is really hard to interact with neutrinos so I would guess there are no way to accelerate them even further or make them carry information.

Also, until a peer review this would remain like something weird indeed.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:36pm
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Reuters doesn't say whether the neutrinos were moving faster than light in a medium, or faster than light would move over the same distance in a vacuum. Crucial difference, from a "does this contradict relativity" perspective.

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:43pm
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Moving 60 nanoseconds faster than light through the same medium, or 60 nanoseconds faster than light in a vacuum? If it's the former... well, I can see that happening, with my limited understanding. Neutrinos pass through solid matter goddamn effortlessly. They zip right on through them, 'cause they're so goddamn tiny. They have no charge and move at close to the speed of light in a vacuum, and generally don't react with matter at all. Photons on the other hand lose energy while passing through matter. The speed of light in Earth's atmosphere is not the same as the speed of light in a vacuum.

So... maybe. Maybe neutrinos could move that much faster than light when in a non-vacuum environment. To my understanding, only moving faster than light in a vacuum was ever declared to be borderline impossible. And since neutrinos have non-zero mass, I am highly skeptical that they were moving at the speed of light in a vacuum, never mind faster than it.

But since the goddamn article is so damn short and lacking in details and content I can't be sure of a goddamn thing.

Pre-Submit Edit, since others beat me to the punch:
Terralthra basically summed up most of my post and did it with far less words.
Quote:
Well, could neutrinos carry information? For what little I know is really hard to interact with neutrinos so I would guess there are no way to accelerate them even further or make them carry information.
I guess in theory they could CARRY information, but good luck recieving that information. :lol: Neutrinos are horrendously difficult to detect.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:45pm
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Terralthra wrote:
Reuters doesn't say whether the neutrinos were moving faster than light in a medium, or faster than light would move over the same distance in a vacuum. Crucial difference, from a "does this contradict relativity" perspective.


They do here
Reuters wrote:
A total of 15,000 beams of neutrinos -- tiny particles that pervade the cosmos -- were fired over a period of 3 years from CERN toward Gran Sasso 730 (500 miles) km away, where they were picked up by giant detectors.

Light would have covered the distance in around 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds -- or 60 billionths of a second -- less than light beams would have taken.


I think they mean that light (on vacuum) would traveled those 730 kilometers in 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds. However they explicitly don't say in vacuum, but I don't think that they will overlook that little detail if are daring to make it public already.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:51pm
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Well damn, if that's correct, then they may have indeed been moving faster than light in a vacuum. Or there were some significant errors over the course of three years, which seems... less likely? I'm uncertain. All I can say for sure is that this is a potentially interesting development and I'm curious to see what further study shows.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:53pm
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I fell that very same way too. Until some peer review this is going to be book marked but I'll not get overly excited about it. Sadly, I lack the sight to see the implicants of this discovery (if true). The practical ones I mean.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 03:54pm
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Lord Baal wrote:
Terralthra wrote:
Reuters doesn't say whether the neutrinos were moving faster than light in a medium, or faster than light would move over the same distance in a vacuum. Crucial difference, from a "does this contradict relativity" perspective.


They do here
Reuters wrote:
A total of 15,000 beams of neutrinos -- tiny particles that pervade the cosmos -- were fired over a period of 3 years from CERN toward Gran Sasso 730 (500 miles) km away, where they were picked up by giant detectors.

Light would have covered the distance in around 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds -- or 60 billionths of a second -- less than light beams would have taken.


I think they mean that light (on vacuum) would traveled those 730 kilometers in 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds. However they explicitly don't say in vacuum, but I don't think that they will overlook that little detail if are daring to make it public already.


No, they still do not clarify that. Your pardon, if I do not trust popular media's science reporting.

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 04:03pm
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Would you like to do the maths about how much light would take to travel 730 km at vacuum? That would clear the doubt away. However I think is implied, I don't think they are measuring the speed of light on a medium made of solid rock, or even worst one randomly made up by water rock and air. That would be silly don't you think?



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 04:04pm
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Terralthra wrote:
No, they still do not clarify that. Your pardon, if I do not trust popular media's science reporting.
I trust math, though. Light would take around 2.43501789 milliseconds, or "2.4 thousandsths of a second" as the article put it, to travel the described distance in a vacuum. So we know at least that they're probably comparing it to the speed of light in a vacuum. But there's room still for other explanations, so I color myself cautiously intrigued. It might turn out only to be that the speed of light was a tiny fraction faster than we'd previously calculated. It might be that there were some small mistakes made. 60 nanoseconds is a very small margin of error. It may turn out this is another case of media's reporting of science being fucked up (I'm still favouring that as most likely). Or it may turn out the neutrinos really were travelling fractionally faster than the speed of light in a vacuum. But that possibility is still one I am incredibly skeptical of.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 04:06pm
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Terralthra wrote:
No, they still do not clarify that. Your pardon, if I do not trust popular media's science reporting.
Would you like to do the maths about how much light would take to travel 730 km at vacuum? (I see SilverWingedSeraph already done them) That would clear the doubt away. However I think is implied, I don't think they are measuring the speed of light on a medium made of solid rock, or even worst one randomly made up by water rock and air. That would be silly don't you think?

However I, as mr. Seraph remain skeptical about this, and my biggest bet would be in an human error.

No need to ask for pardon by the way. :)



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 04:13pm
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Lord Baal wrote:
However I think is implied, I don't think they are measuring the speed of light on a medium made of solid rock, or even worst one randomly made up by water rock and air. That would be silly don't you think?
Well, see, the thing is, the scientists at CERN could have been comparing the speed of neutrinos to the speed of light through Earth's atmosphere, and then the media would of course, not mention that fact because it's less interesting and not as SHOCKING AMAZING NEWS. Even if the neutrinos were only moving faster than light through Earth's atmosphere, that's still pretty amazing, and a cool thing to detect.

But it wouldn't revolutionise physics as we know it! Thus it wouldn't be newsworthy without some spin.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 04:20pm
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No, that I get it, things can be faster than light in other mediums that are not vacuum (emitting Cherenkov radiation in the process if I'm not mistaken). I share your skepticism about this, but I think this more like a human error anyway. Well have to wait and see.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 06:46pm
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A total of 15,000 beams of neutrinos -- tiny particles that pervade the cosmos -- were fired over a period of 3 years from CERN toward Gran Sasso 730 (500 miles) km away, where they were picked up by giant detectors.


Light traveling 730 kilometers would need 2.4 milliseconds to do so. So if they're right, then they have broadcast neutrinos faster than light. I'm skeptical of their claims. *

Incidentally, I highly doubt that they managed to create a tube of vacuum 730 kilometers in length without anyone having heard of it before. They're probably sending those neutrinos through rock and air, but that doesn't matter, since the speed is still greater than would have been if they were traveling through vacuum.


* PS: this is what is known as an "understatement". :wink:



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 07:10pm
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Lord Zentei wrote:
I'm skeptical of their claims. *


So are they; enough so that they aren't actually CLAIMING anything. This BBC piece makes that more clear (bolding added for the impatient)

Quote:
Puzzling results from Cern, home of the LHC, have confounded physicists - because it appears subatomic particles have exceeded the speed of light.

Neutrinos sent through the ground from Cern toward the Gran Sasso laboratory 732km away seemed to show up a tiny fraction of a second early.

The result - which threatens to upend a century of physics - will be put online for scrutiny by other scientists.

In the meantime, the group says it is being very cautious about its claims.

"We tried to find all possible explanations for this," said report author Antonio Ereditato of the Opera collaboration.

"We wanted to find a mistake - trivial mistakes, more complicated mistakes, or nasty effects - and we didn't," he told BBC News.

"When you don't find anything, then you say 'Well, now I'm forced to go out and ask the community to scrutinise this.'"


Caught speeding?
The speed of light is the Universe's ultimate speed limit, and much of modern physics - as laid out in part by Albert Einstein in his special theory of relativity - depends on the idea that nothing can exceed it.

Thousands of experiments have been undertaken to measure it ever more precisely, and no result has ever spotted a particle breaking the limit.

But Dr Ereditato and his colleagues have been carrying out an experiment for the last three years that seems to suggest neutrinos have done just that.

Neutrinos come in a number of types, and have recently been seen to switch spontaneously from one type to another.

The team prepares a beam of just one type, muon neutrinos, sending them from Cern to an underground laboratory at Gran Sasso in Italy to see how many show up as a different type, tau neutrinos.

In the course of doing the experiments, the researchers noticed that the particles showed up a few billionths of a second sooner than light would over the same distance.

The team measured the travel times of neutrino bunches some 15,000 times, and have reached a level of statistical significance that in scientific circles would count as a formal discovery.

But the group understands that what are known as "systematic errors" could easily make an erroneous result look like a breaking of the ultimate speed limit, and that has motivated them to publish their measurements.

"My dream would be that another, independent experiment finds the same thing - then I would be relieved," Dr Ereditato said.

But for now, he explained, "we are not claiming things, we want just to be helped by the community in understanding our crazy result - because it is crazy".


"And of course the consequences can be very serious."

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 07:17pm
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Sriad wrote:
So are they; enough so that they aren't actually CLAIMING anything. This BBC piece makes that more clear (bolding added for the impatient)


I know that they're not making a definitive claim, I am perfectly able to read. So shove your high horse bullfuckery.

I find it particularly hilarious that you highlight the part where the article says "they are being very cautious of their claims" and then say that they're not claiming anything. If they're being very cautious of their claims, then yes, they ARE making claims - very cautious ones to be precise, and ones that pertain to what their results show. This is what I'm skeptical of.

The latter "we are not making claims" refers to a definitive statement - they're waiting for confirmation.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 07:24pm
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This is why I love science.

Even if they were wrong, they'be tried everything yo check their results and are now opening them up for other people to scrutinise.

And the whole time, you can bet that people are trying to figure out how to reconcile these potentially game changing observations with extant theories.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 08:03pm
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Lord Zentei wrote:
Light traveling 730 kilometers would need 2.4 milliseconds to do so. So if they're right, then they have broadcast neutrinos faster than light. I'm skeptical of their claims. *

Incidentally, I highly doubt that they managed to create a tube of vacuum 730 kilometers in length without anyone having heard of it before. They're probably sending those neutrinos through rock and air, but that doesn't matter, since the speed is still greater than would have been if they were traveling through vacuum.

But it does matter, because if they did that, they could actually compare it to more directly. Though there's a more important problem: to get that kind of conclusion in to good statistical significance, you need to measure the distance between when where the neutrinos were emitted and detected to sub-meter accuracy, i.e., from within their ~1km emitter and detector. How are they doing that from within a mountain and how accurate are their instruments at measuring that?

I'm not sure what's going on, since it's very unlikely that the scientists haven't already thought of such sources of error, but I can't think of how could you calibrate such measurements from within a mountain in the first place. A systematic error seems likely.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 08:06pm
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Lord Zentei wrote:
Sriad wrote:
So are they; enough so that they aren't actually CLAIMING anything. This BBC piece makes that more clear (bolding added for the impatient)


So shove your high horse bullfuckery.


I didn't mean to come off high-horsed, just posting an article that highlights their caution.

So counter-fuck you for misunderstanding! ;)

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 08:10pm
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I can see how the time of emission is crucial given such short time intervals, but does the uncertainty in the distance within the 1 km emitter/receiver really make the experiment that inaccurate with such a huge distance (730 km) between the emitter and receiver?



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 08:11pm
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Sriad wrote:
I didn't mean to come off high-horsed, just posting an article that highlights their caution.

So counter-fuck you for misunderstanding! ;)


LOL, OK fair enough. We're both fucked.



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 08:59pm
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I'd really like to see the actual work once it goes online. Would answer a lot of these little questions.

The distance between detector and emitter almost certainly isn't an issue; even with my GPS and their facility's blueprints they could know to within about a meter; the 60 nanoseconds reported is a difference of 18 meters for C in a vacuum. Beyond that I imagine there would be measurements done with other neutrinos to establish an even more precise baseline... or something.

As a side note, neutrinos have clocked >C before, but there was enough of an error window to write it off without much fuss. This might tell us we have a surprisingly poor understanding of neutrino production/detection.

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 09:14pm
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Sriad wrote:
I'd really like to see the actual work once it goes online. Would answer a lot of these little questions.

The distance between detector and emitter almost certainly isn't an issue; even with my GPS and their facility's blueprints they could know to within about a meter; the 60 nanoseconds reported is a difference of 18 meters for C in a vacuum. Beyond that I imagine there would be measurements done with other neutrinos to establish an even more precise baseline... or something.

As a side note, neutrinos have clocked >C before, but there was enough of an error window to write it off without much fuss. This might tell us we have a surprisingly poor understanding of neutrino production/detection.


That's what i expect will end up coming out of this. Better calibration and detection would probably over turn this, which is why it reads less "Hey, we just overturned special relativity!" and more "Uh, guys? We're wrong but we don't know exactly how. Suggestions?".

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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 09:26pm
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RE the earlier discussion of comparing the neutrino speed to c in a vacuum versus the speed of light in a medium --- as far as neutrinos are concerned, the earth and everything on it is as empty as the vacuum of space is empty to us. They interact so weakly that the neutrinos detected were the same neutrinos emitted; there's no absorption-transmission mechanism to slow them down, as there is for light traveling through a transparent medium. So the comparison is, in fact, to c in a vacuum.

It's also making waves in the physics community. Nobody believes it, of course, but everybody's interested in it nonetheless, because the expected value of revolutionary physics is so high (tiny probability of truth * very, very interesting and exciting new physics if true). My GR prof works in Lorentz parity violation (whatever that means), and one of the first results he published was a prediction that neutrinos travel faster than c. He doesn't believe the measurement, but if he's right he's a big deal.

Anyway, my impression is: palpable excitement + extreme skepticism. Special relativity is, after all, absolutely the most experimentally well-attested theory in history. If something is breaking it ... well, Exciting Times :)



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 Post subject: Re: Particles recorded moving faster than light PostPosted: 2011-09-22 09:45pm
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Lord Zentei wrote:
I can see how the time of emission is crucial given such short time intervals, but does the uncertainty in the distance within the 1 km emitter/receiver really make the experiment that inaccurate with such a huge distance (730 km) between the emitter and receiver?

Absolutely. If you detect a neutrino, you don't know exactly where it came from. What you actually want is the distance and duration from the emission event to the detection event; otherwise you can't calculate the speed. So it's not just when and where it was within the detector and emitter, but I think it's probably the largest contributor to error.

Lord Zentei wrote:
The distance between detector and emitter almost certainly isn't an issue; even with my GPS and their facility's blueprints they could know to within about a meter; the 60 nanoseconds reported is a difference of 18 meters for C in a vacuum.

That's not the biggest issue, but trying to calibrate GPS measurements is going to introduce its own error (remember that you're under a mountain; you can't just stick a GPS right by your equipment or some other reference point within the facility to see where it is). Though yes, that part's going to be easier than figuring where it happens within the equipment, and how accurate they need it depends on how statistically significant they want their result to be.



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