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CERN clocks faster-than-light neutrinos
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Lord Error
Insane For Sony
Probably no need for it really, for any imaginable GPS application that's not measuring neutrino speedsZoramon089 said:
SouthernDragon
Member
EINSTEINNNNNNNNNNNNNNNN!
*shakes fist*
*shakes fist*
Lost Fragment
Obsessed with 4chan
nib95 said:
Not a good year for science? I'd say these things would make it a great year for science.
And dark matter exists. Not sure what you're on about.
edible_candle
Member
When/Where was this proven?nib95 said:
foodtaster
Banned
Dark matter does exist. Just not how we originally thought.
Lost Fragment
Obsessed with 4chan
nib95 said:
"Dark matter" is a generic term for the mass in the universe that we can't currently identify. The mass could be from God taking a shit in a parallel universe, causing excess gravity to seep over into our own universe. Or, there might be a fundamental flaw in our math. Whatever the case, dark matter exists with 100% certainty. It just might not be as exotic as some people assume when they hear the term.
Napoleonthechimp
Member
Every year is a good year for science.nib95 said:
I highly recommend watching the "world's toughtest fixes" episode on netflix. It features the partical collider and fixing one of the damaged magnetic sections.
http://movies.netflix.com/WiPlayer?movieid=70144791&trkid=3326467
http://movies.netflix.com/WiPlayer?movieid=70144791&trkid=3326467
You're thinking grammatically (or DMBSically).Mudkips said:
For something like temperature to be a dimension like space or time would require a more rigorous reworking of physics than faster than light particles (for example) will ever cause.
Under current accepted models temperature is not a dimension.
Neither does shits per year, even though I really want it to be, as it would make physics much more entertaining.
ThoseDeafMutes
Member
It's probably still too early to start dancing about being right. So I'll hold off for a few more weeks just in case.
Lord Error said:
Badastronomy covered that story.
http://blogs.discovermagazine.com/b...up-ftl-neutrinos-explained-not-so-fast-folks/
Short version is the CERN guys say they accounted for that, but there still might be errors. The other thing is, wouldn't doing the experiment multiple times likely pick up different satellites moving in different directions relative to the experiment?
Dr Zhivago
Member
Photons can't travel through the Earth like Neutrinos can.
The Technomancer
card-carrying scientician
Yeah, I think he was thinking mathematically/scientifically, not physically. Like if I'm working with a five dimensional array of numbers.Chichikov said:
DonasaurusRex
Online Ho Champ
nib95 said:
...hows that bad? science is all about finding better questions.
GDGF said:
I don't know about consensus, but one particle physicist I've spoken with about it (the neutrinos) is saying that the data suggests neutrinos are moving in and out of our observable 4D (X, Y, Z and time) space .. i.e. moving through another (set of?) dimensions before once again reappearing in our observable space-time. (my interpretation of what they said).
After all, it's widely accepted (by physicists) that we actually need at least 6-7 dimensions for our universe to make sense.
There was also something about the scientists involved not accounting for gravitational shift in their preliminary measurements, which would have accounted for something like 60 nanoseconds of the transit. (edit.. oh, I see an article was posted.) Well, this physicist still thinks that the data shows neutrinos are capable of superluminal speeds.. again confirming the need for more than four dimensions.
Faster-than-light neutrino experiment to be run again. Hopefully we get some results soon.
Witchfinder General
punched Wheelchair Mike
They talked about this on the last Skeptic's Guide to the Universe podcast and the consensus is that it's pretty much incorrect. They're waiting for the data to be sifted through and peer-reviewed but it seems doubtful that it will back up the claims.
ThoseDeafMutes
Member
Witchfinder General said:
There were, and still are good reasons to be extremely skeptical of the neutrinos actually breaking C. We've had a thread about it before, of course. Relativity is far too experimentally verified to be so wrong on such a fundamentally important principle. If these neutrinos are going FTL, then there must be some caveat that means it cannot transmit information superluminally, lest we run into severe problems of causality (the same way Quantum Entanglement cannot be used to send messages FTL, despite actually being FTL).
zomgbbqftw
Banned
Leonsito said:
ZING!
Witchfinder General said:
To be fair, I think the vast majority of the scientific community are expecting it to be incorrect. The issue is figuring out *how*. Because, as a great man (who didn't exist) once (never) said: Once you eliminate the impossible, whatever remains - however improbable - must be the truth.
onken
Member
Sorry for the kinda nooby science question but I always remember learning at school that if the Sun were to suddenly disappear the Earth would instantly move off its current trajectory (not after several minutes or whatever). The implication being that somehow the information that the Sun has disappeared would reach the Earth faster than the speed of light (instantly). How is this explained?
Nexus Zero
Member
onken said:
Simply that this wouldn't happen. Gravity communicates at the speed of light, so the Earth would not instantly move off its current trajectory. It would react after ~7minutes(?)
jchap
Member
onken said:
This is an often cited case to demonstrate that gravity distortions in space-time propagate at the speed of light. If the sun was to disappear it would take something like 8 minutes for the trajectory of earth to change. This has been proven experimentally by using laser interferometers to measure gravitational waves.
ThoseDeafMutes
Member
Zzoram said:
More likely that his teacher was wrong and taught them incorrect stuff. It wouldn't be the first time.
DoDonGouki
Member
by Tommaso Dorigo@science20
OPERA Confirms: Neutrinos Travel Faster Than Light!!
OPERA Confirms: Neutrinos Travel Faster Than Light!!
The OPERA Collaboration sent to the Cornell Arxiv a new preprint today, where they summarize the results of their analysis, expanded with additional statistical tests, and including the check performed with 20 additional neutrino interactions they collected in the last few weeks. These few extra timing measurements crucially allow the ruling out of some potential unaccounted sources of systematic uncertainty, notably ones connected to the knowledge of the proton spill time distribution.
These benefits come from CERN, where proton bunches have been made much shorter: down to three nanosecond long pulses. That means that OPERA can measure the speed of each detected neutrino separately! Of course, with such short pulses, the statistics of protons on target is "only" of 4x10^16, but this is still enough to reach meaningful results from the additional data.
The figure below show the timing structure of the proton bunches. The black arrow spans 20 nanoseconds to size up the horizontal scale.
As a sidebar to the improvements yielded by the reduction in the pulse duration, and the related checks that were performed on the source, apparently allowed CERN to spot some less than perfect sinchronisms in the apparatus responsible for the creation of the beam. In particular, the horns that focalize the beam are brought to the right magnetic field by currents that are ramped up before the particles pass through them. It transpired that due to some imperfect arrangement, the currents might still have been ramping up during the passage of the particles, with the result that the focusing of the beam could be less good than predicted.
This might bring into the Opera speed measurement some systematics due to the fact that the neutrinos produced later -the trailing ones from the spill- woud be better focused (field closer to plateau in the horns). However, this potential issue is made irrelevant by working with very narrow proton pulses (however ramping, the current is practically constant during a very narrow proton spill).
So what does OPERA find ? Their main result, based on the 15,233 neutrino interactions collected in three years of data taking, is unchanged from the September result. The most interesting part of the new publication is instead that the find that the 20 new neutrino events (where neutrino speeds are individually measured, as opposed to the combined measurement done with the three-year data published in September) confirm the earlier result: the arrival times appear to occur about 60 nanoseconds before they are expected.
The figure below, taken from the paper, shows the individual timing measurements of the neutrino interactions from the narrow spills taken between end of October and beginning of November. The red line indicates the average of the 20 measurements.
It is necessary here to note that since distance from source to detector and time offsets necessary to determine the travel time of neutrinos have not been remeasured, the related systematics (estimated as well as -possibly- underestimated ones) are unchanged. The measurement therefore is only a "partial" confirmation of the earlier result: it is consistent with it, but could be just as wrong as the other.
Just to make an example, I will reiterate here the doubts I have on one of the time offsets necessary to obtain the timing measurement in Gran Sasso: an 8-km-long light guide brings in a 40,000+-1 ns offset: in order to determine a "delta t" of 60 nanoseconds, a subtraction of that large number has to be made. This offset was measured three years ago, and could have changed if the refraction index had changed even very slightly (e.g. due to aging of the plastic material). This offset was not remeasured in the new analysis, and the possible associated systematic uncertainty remains in my mind an issue.
One peculiar aspect of the new neutrino interactions is that they highlight the presence of a rather large "jitter" effect: the timing of each neutrino interaction appears to be subject to a "smearing of width of the order of 25 nanoseconds. This could imply that something in the timing measurement is not well under control. Note that such a jitter could not easily be spotted in the global time distribution of the 15,223 neutrinos collected in the last three years; its effect on the global probability density function (which spans 10.5 microseconds) is too small to produce a global shape difference.
Another note is that OPERA accepted the criticism moved by many on the technique of producing a global probability density function for all proton spills, to compare it then to the observed neutrino timing distribution. They performed a measurement where they analyze the data without adding the functions, and they obtain a consistent result.
Regardless of all the considerations I made above on systematic uncertainties that might still affect the measurement, I must say I am rather positively impressed by at least a couple of things: first, that Opera has worked like a single man in the attempt of making more solid an already quite scrupulous result; and second, that the OPERA researchers seem now to stand behind the measurement much more united than they were two months ago.
In other words, those in OPERA who did not sign the first preprint - because they probably did not have enough time to scrutinize all the aspects of the measurement - are now apparently all willing to sign the new one, and probably ready to submit the resulting publication to a scientific magazine. Since I know several members of OPERA and I judge them all serious and scrupulous physicists, their willingness to sign the paper means that we need to take it more seriously than (at least a few among us) have so far.
Here is a quote from the conclusions in the Opera article:
And finally:
What will happen next ? Other experiments are already planning equivalent measurements, of course. We owe it to OPERA and its six-sigma result to have opened (or should I say widened, given the previous less exciting measurement by MINOS?) a new avenue of investigations of the physics of neutrinos: a unexpected one, for sure, and probably one which will not bear fruit in the end (but this of course is my personal bias) - but nonetheless some interesting fresh air in neutrino physics!
TacticalFox88
Banned
HOLY FUCK YES! YES! YES!!!!
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