I'm not up on my particle physics, but unless our understanding of C is off and what that really means, this seems just plain WRONG.
http://www.telegraph.co.uk/science/8782895/CERN-scientists-break-the-speed-of-light.html (http://www.telegraph.co.uk/science/8782895/CERN-scientists-break-the-speed-of-light.html)
It is, of course, science news journalism, but it honestly doesn't make any sense. No quantum travels faster than the speed of light in a vacuum, since the mass would escalate to infinity. At least, thats how I understood it.
Apparently Fermi-lab saw the same result a few years ago, but their statistical error was too high to be sure what they got was correct, so they didn't publish.
As for the speed of the light barrier, well one of the PhD students here put it better than I can:
"Einstein said nothing (massive) can be accelerated to or beyond the speed light, but his theory doesn't exclude the possibility of having something which is already faster than the speed of light once it was created (and hence avoid the necessity of crossing the 'speed of light' barrier). "
Of course that would involve odd things like imaginary or negative mass, I believe.
Anyway, I think they are putting the paper up on ArXiv tomorrow, so I'm waiting for that.
Also:
http://www.scientificamerican.com/article.cfm?id=particles-found-to-travel
Read it yesterday on BBC, not too sensationally written, mostly they're looking very hard for ways where the F they made a mistake :) But they can't find any (yet), hence them asking the scientific community for scrutinization.
http://www.bbc.co.uk/news/science-environment-15017484
Quote from: Rumckle on September 23, 2011, 06:46:09 AMAs for the speed of the light barrier, well one of the PhD students here put it better than I can:
"Einstein said nothing (massive) can be accelerated to or beyond the speed light, but his theory doesn't exclude the possibility of having something which is already faster than the speed of light once it was created (and hence avoid the necessity of crossing the 'speed of light' barrier). "
Hey, that's from K-PAX!
http://www.imdb.com/title/tt0272152/quotes?qt=qt0318911
I didn't know it was for serious, too.
The speed of light is very closely linked to a photon in terms of smallest fastest particle. Because of the way maxwells equations are set up the photon is assumed not to have mass. If indeed it did have a tiny mass it would make absolute c slightly above what we have now.
Can you calculate that from:
(∇2 - 1/c2 d2/dt2) E = 0
or do you have do start before that? (just out of curiosity, because I don't remember hearing that before)
Quote from: Rumckle on September 23, 2011, 09:01:19 AM
Can you calculate that from:
(∇2 - 1/c2 d2/dt2) E = 0
or do you have do start before that? (just out of curiosity, because I don't remember hearing that before)
Ehm, I dunno. My innital guess is no because of the precision you would have to know E
My go-to physics guru is dead, so my non-authoritative response would be to agree with Faust. I'll see what else I can dig up.
Quote from: Faust on September 23, 2011, 08:27:36 AM
The speed of light is very closely linked to a photon in terms of smallest fastest particle. Because of the way maxwells equations are set up the photon is assumed not to have mass. If indeed it did have a tiny mass it would make absolute c slightly above what we have now.
This is the closest to what I could come up with. If neutrinos have essentially less mass than photons (which is so close to zero that we don't normally register it in equations), then it's very possible they could exceed light speed since that is based on photon "mass".
Can't we do an "absolute zero" type extrapolation for this, like what is done for Kelvins? Since we've never measured anything at absolute zero temperature either.
I'm assuming they thought of such explanations since they said they checked for systemic errors, hence they ask the scientific community to scrutinize their findings?
So, I think we can't say much about it until there is some follow-up. If anyone hears of a follow-up, please to post!! :)
The follow-up is: physicists are confused, and not sure what to make of it all.
Quote from: ϗ, M.S. on September 23, 2011, 09:37:59 PM
Quote from: Faust on September 23, 2011, 08:27:36 AM
The speed of light is very closely linked to a photon in terms of smallest fastest particle. Because of the way maxwells equations are set up the photon is assumed not to have mass. If indeed it did have a tiny mass it would make absolute c slightly above what we have now.
This is the closest to what I could come up with. If neutrinos have essentially less mass than photons (which is so close to zero that we don't normally register it in equations), then it's very possible they could exceed light speed since that is based on photon "mass".
Thank you, over at another forum people are now facebook stalking me and denying my qualifications all because I suggested this.
Quote from: Faust on September 23, 2011, 09:52:25 PM
Quote from: ϗ, M.S. on September 23, 2011, 09:37:59 PM
Quote from: Faust on September 23, 2011, 08:27:36 AM
The speed of light is very closely linked to a photon in terms of smallest fastest particle. Because of the way maxwells equations are set up the photon is assumed not to have mass. If indeed it did have a tiny mass it would make absolute c slightly above what we have now.
This is the closest to what I could come up with. If neutrinos have essentially less mass than photons (which is so close to zero that we don't normally register it in equations), then it's very possible they could exceed light speed since that is based on photon "mass".
Thank you, over at another forum people are now facebook stalking me and denying my qualifications all because I suggested this.
This is the way of all science, at all times in history. First, new ideas are denounced, their proponents accosted and harassed, and treated as idiots. Second, the new idea is said to possibly have some value but there isn't enough evidence to treat it seriously. And third, the idea is formally accepted and treated as if it were always true, and people go back and find evidence that so and so philosopher suggested the same thing centuries ago, that it really wasn't original at all. :lulz:
Quote from: ϗ, M.S. on September 23, 2011, 10:15:35 PM
Quote from: Faust on September 23, 2011, 09:52:25 PM
Quote from: ϗ, M.S. on September 23, 2011, 09:37:59 PM
Quote from: Faust on September 23, 2011, 08:27:36 AM
The speed of light is very closely linked to a photon in terms of smallest fastest particle. Because of the way maxwells equations are set up the photon is assumed not to have mass. If indeed it did have a tiny mass it would make absolute c slightly above what we have now.
This is the closest to what I could come up with. If neutrinos have essentially less mass than photons (which is so close to zero that we don't normally register it in equations), then it's very possible they could exceed light speed since that is based on photon "mass".
Thank you, over at another forum people are now facebook stalking me and denying my qualifications all because I suggested this.
This is the way of all science, at all times in history. First, new ideas are denounced, their proponents accosted and harassed, and treated as idiots. Second, the new idea is said to possibly have some value but there isn't enough evidence to treat it seriously. And third, the idea is formally accepted and treated as if it were always true, and people go back and find evidence that so and so philosopher suggested the same thing centuries ago, that it really wasn't original at all. :lulz:
It's just depressing seeing it in special relativity and quantum mechanics, both of which are areas that the people working in widely admit is unfinished, an incomplete picture of what is happening.
Quote from: Cain on September 23, 2011, 09:47:28 PM
The follow-up is: physicists are confused, and not sure what to make of it all.
...And that's news, is it?
Quote from: Jasper on September 23, 2011, 11:16:01 PM
Quote from: Cain on September 23, 2011, 09:47:28 PM
The follow-up is: physicists are confused, and not sure what to make of it all.
...And that's news, is it?
IT IS NOW!
Quote from: ϗ, M.S. on September 23, 2011, 09:39:07 PM
Can't we do an "absolute zero" type extrapolation for this, like what is done for Kelvins? Since we've never measured anything at absolute zero temperature either.
IF the explanation is that photons have a real (albeit tiny) mass and therefore only travel at a near-unity fraction of c, then we'd need to figure out what their mass is first before any extrapolation takes place. Given that everyone is (was?) pretty sure that photons have no mass and that they've been pretty thoroughly studied, I suspect we don't have the instruments or the techniques to measure a photon's mass precisely enough in the first place.
My money's on photons have no rest mass, and the fact that neutrinos have nonzero mass does something something to spacetime that lets them travel through space relative to them at near c, but that appears to observers as above c? Like they make a chain of tiny wormholes or something? That's IF the results turn out to hold.
This blog is usually pretty accurate with it's particle physics:
http://resonaances.blogspot.com/2011/09/phantom-of-opera.html
Quote from: Rumckle on September 24, 2011, 07:20:47 AM
This blog is usually pretty accurate with it's particle physics:
http://resonaances.blogspot.com/2011/09/phantom-of-opera.html
"As everyone knows by now, the OPERA collaboration announced that muon neutrinos produced at CERN arrive to a detector 700 kilometers away in Gran Sasso about 60 nanoseconds
earlier than expected if they traveled at the speed of light (incidentally, trains traveling the same route arrive always
late)."
:lulz:
Quote from: Rumckle on September 24, 2011, 07:20:47 AM
This blog is usually pretty accurate with it's particle physics:
http://resonaances.blogspot.com/2011/09/phantom-of-opera.html
QuoteWe should weigh this evidence against the analysis of OPERA which does not appear rock solid. Recall that OPERA was conceived to observe tau neutrino appearance, not to measure the neutrino speed, and indeed there are certain aspects of the experimental set-up that call for caution. The most worrying is the fact that OPERA has no way to know the precise production time of a neutrino it detects, as it could be produced anytime during a 10 microsecond long proton pulse that creates the neutrinos at CERN. To go around this problem they need a statistical approach. Namely, they measure the time delay of the neutrino arrival in Gran Sasso with respect to the start of the proton pulse at CERN. Then they fit the time distribution to the templates based on the measured shape of the proton pulse, assuming various hypotheses about the neutrino travel time. In this manner they find that the best fit is for the travel time is 60 nanoseconds smaller than what one would expect if the neutrinos traveled at the speed of light. However, one could easily imagine that the systematic errors of this procedure have been underestimated, for example, the shape of the rise and the fall-off of the proton pulse have been inaccurately measured. OPERA does a very good job arguing that the distance from CERN to Gran Sasso can be determined to 20 cm precision, or that synchronizing the clocks in these two labs is possible to 1 nanosecond precision, but the systematic uncertainties on the shape of the proton pulse are not carefully addressed (and, during the seminar at CERN, the questions concerning this issue were the ones that confounded the speaker the most).
IOW, when your range of error is large, your precision is weak, especially when you can't actually account for the error properly. I expect that the replication will show this.
But I am glad I didn't jump jump to the "you're wrong" conclusion immediately.
From some guy who uses his mighty skills to theorycraft for WoW (http://maintankadin.failsafedesign.com/forum/viewtopic.php?f=2&t=32147&sid=aae8ecb284e5061386d54006864b1fd9#p682391)
QuoteThis really feels like a total non-story to me, but I'm a little biased since I have a thesis to defend on the topic next week. The neutrinos saw a fractional advancement of ~60 nanoseconds in a total traversal time of 2.4 milliseconds. Without more information, it's impossible to tell whether 60 ns is relevant.
For example, I have an experiment running right now where photons are "traveling" faster than the speed of light. That doesn't mean that Einstein causality is wrong, or that the cornerstones of physics are crumbling beneath our feet. It means that someone out there doesn't understand what those cornerstones actually say, and what their implications are.
There's nothing special about making a particle appear to travel faster than the speed of light. It happens all the time. The speed of light is only the cosmic speed limit for signal transit, so unless you can prove that those neutrinos carry information, it's meaningless. I'd like to know the temporal width of their neutrinos, simply because that would help determine if what they're seeing is interesting. If they're seeing 60 ns of advancement on a 100+ nanosecond particle, then the results aren't ground-breaking, even if they are surprising (is rock really that dispersive?).
The confusing part, to me, is why the very first thing they thought of wasn't dispersive propagation effects. Maybe particle physicists don't see that very often?
That quote honestly doesn't make any sense at all.
Ok, I have a new physics guy -- as it turns out, he's been working on a nutrino project in Japan for a few years (this guy, (http://superk.physics.sunysb.edu/~alpinist/) if you want to check my references).
Anyway, this is his take on it:
QuoteMost likely, there is an error somewhere. Measuring the time between the birth of neutrinos and its arrival at a detector 730 km away accurately is not a trivial task. They say that they accuracy is 10 ns, which is very hard to achieve. 10 ns corresponds to 2 m of electric cable.
In regards to the idea that particles that were created already moving at the speed of light, the neutrinos are created from decaying pions that are created from protons hitting a target. To produce neutrino already moving faster than c you will need protons with literally infinite energy.
He also provided this link: http://news.sciencemag.org/sciencenow/2011/09/neutrinos-travel-faster-than-lig.html which says:
QuoteThe big question is whether OPERA researchers have discovered particles going faster than light, or whether they have been misled by an unidentified "systematic error" in their experiment that's making the time look artificially short. Chang Kee Jung, a neutrino physicist at Stony Brook University in New York, says he'd wager that the result is the product of a systematic error. "I wouldn't bet my wife and kids because they'd get mad," he says. "But I'd bet my house."
Jung, who is U.S. spokesperson for a similar experiment in Japan called T2K, says the tricky part is accurately measuring the time between when the neutrinos are born by slamming a burst of protons into a solid target and when they actually reach the detector. That timing relies on the global positioning system, and the GPS measurements can have uncertainties of tens of nanoseconds. "I would be very interested in how they got a 10-nanosecond uncertainty, because from the systematics of GPS and the electronics, I think that's a very hard number to get."
And finally:
(http://imgs.xkcd.com/comics/neutrinos.png)
Thanks, LMNO. Error bars are not to be ignored.
Also, the GPS XKCD reference is cool for me, because the time dilation offset in global positioning experiments is a direct result of the Hafele-Keating Experiment which showed time dilation in jets going different directions around the planet. And Joe Hafele is my grandfather.