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bngbuck
SFN Addict
USA
2437 Posts |
 Posted - 09/23/2011 : 11:51:37
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This from the New York Times today:
Tiny Neutrinos May Have Broken Cosmic Speed Limit
The gist of this current communication from CERN seems to be that there may be new experimental evidence that would, to say the least, have a substantial impact on many of the current bedrock theories of particle physics and astrophysics.
| "These guys have done their level best, but before throwing Einstein on the bonfire, you would like to see an independent experiment,” said John Ellis, a CERN theorist who has published work on the speeds of the ghostly particles known as neutrinos. |
It would appear to me, as an fascinated but pitifully uniformed neophyte in this area of science, that substantially more than one independent experiment will be necessary before Einstien's work will be seriously challenged. A great deal of experimentation has been done since 1905, that appears to support the Special Theory of Relativity and its ramifications.
Incredible claims require incredible evidence, surely.
BUT.....
Alvaro de Rujula, a theorist at CERN, called the claim “flabbergasting.”
“If it is true, then we truly haven’t understood anything about anything,” he said, adding: “It looks too big to be true. The correct attitude is to ask oneself what went wrong.”
This layman's mind begins to boggle.
Well, it has been said that: the only entity in the whole of existence that does not change is change itself. To quote the ancient Persian Sufi, "This too, shall come to pass"
Any comment on this from the remarkable community of particle physicists who comment fom time to time on these pages? My education in this discipline is negligible. I am only here to learn, as I am not capable of teaching, at least not in this area of scientific investigation.
Do you pros feel that new evidence may have appeared - or even can appear - that may shake the very foundations of, (until now), both of the sturdy ivory towers of certitude -- that of the particle physicist and that of the astophysicist communities?
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 09/23/2011 : 13:03:28 [Permalink]
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I don't think many people can appreciate the difficulty of measuring detection of particles in the scale of nano-seconds. Just synchronising two atomic clocks to run within a few nano-seconds, then moving them apart, the distance between CERN and Rome...
For one thing, the speed of moving them apart and the change in altitude in Earth's gravity well on its way to Rome will possibly have an impact on the time-piece when they are running clocks in the GHz interval.
There are so many things that could go wrong, that any claim at this point about breaking the speed of light (in vacuum) is way premature, and very likely a mistake made somewhere.
Calling for other research-teams to try to duplicate the result is prudent.
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Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
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Tim Thompson
New Member
USA
36 Posts |
 Posted - 09/23/2011 : 14:04:13 [Permalink]
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One should not get too excited about press releases. Better to look here: Measurement of the neutrino velocity with the OPERA detector in the CNGS beam, submitted to the arXiv server on 22 September 2011 (it's my guess from the format that it will be submitted eventually to Physical Review Letters).
From the paper, a more informative & authoritative source than any press release:
"In this paper we report on the precision determination of the neutrino velocity, defined as the ratio of the precisely measured distance from CERN to OPERA to the time of flight of neutrinos traveling through Earth's crust. We used the high-statistics data taken by OPERA in the years 2009, 2020 and 2011. Dedicated upgrades to the timing systems for the time tagging of the CNGS beam at CERN and of the OPERA detector at LNGS resulted in the reduction of the systematic uncertainties down to the level of the statistical error. The measurement also relies on a high-accuracy geodesy campaign that allowed measuring the 730 km CNGS baseline with a precision of 20 cm."
First, it will take light in vacuo about 0.67 nanoseconds to cover 20 cm. So, the 60 nanoseconds time difference cited in the press release, if it stands up to scrutiny of the timing system, represents a significant difference. Timing technology is well developed and can handle 60 nanoseconds with room to spare. So are the techniques of geodesy well developed, and both are well described in the paper (including the effect of earthquakes on the baseline distance). It certainly looks like the authors have gone to much effort to make sure of themselves before making any announcement.
But it is critical to observe that (a) the neutrinos are plowing through 730 km (454 miles) of Earth's crust, and (b) neutrinos are particles with a positive real mass. One would not be surprised to see neutrinos travel through Earth's crust faster than would electromagnetic radiation. However, one should be surprised to see them travel through Earth's crust faster than the speed of light in vacuo. Whether or not this would constitute a violation of special relativity is not at all obvious. Remember some years back, when under special laboratory conditions, laser pulses traveled through special filters, apparently faster than the speed of light in vacuo (e.g., Wang, Kuzmich & Dogariu, 2000). It has also been known for a long time that quantum tunneling can proceed faster than implied by light speed over the same distance (e.g., Hartman, 1962).
The final result reported in the paper is a time difference (neutrinos arriving before light would) of ... 60.7 ± 6.9 (stat) ± 7.4 (sys) nanoseconds, combining low & high energy neutrinos, which are systematically slightly different from each other. Here "stat" is the statistical uncertainty and "sys" is the systematic uncertainty. That's 60.7 ± 14.3 nanoseconds altogether, or anything from 46.4 to 75.0 nanoseconds.
Certainly, if this superluminal propagation speed stands up to scrutiny, it "would be a striking result pointing to new physics in the neutrino sector" (as the paper tells us). A final interpretation of the implications of this result must rely on a detailed understanding of the quantum mechanical interaction between the neutrinos and Earth's crust, especially the possible effect of tunneling. |
The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell |
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bngbuck
SFN Addict
USA
2437 Posts |
Posted - 09/23/2011 : 14:43:13 [Permalink]
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Tim Thompson.....
Thank you, Mr. Thompson, for your concise and highly authoritative response to my post. Questions involving particle and astrophysics frequently appear in these fora, and it seems, at times, that there is more an atmosphere of amateur night extant rather than a discussion involving professional and well-informed academics and those who actually have career experience in theoretical and applied physics.
The personal information you provided when you joined SFN (BS and MS degrees in physics, 28 years at JPL, and the dead-serious persona projected from the delightful photograph that you supplied) have persuaded me that we finally have someone whose voice carries serious gravitas. I thank you again for your input, and I sincerely thank you for adding a level of academic and experiencial knowledge to the Wiki-chair scientists that frequently argue these subjects here.
I sincerely hope that you will continue to actively comment in the future on those subjects in which you certainly appear to have significant expertise. And welcome to SFN. |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 09/23/2011 : 14:46:56 [Permalink]
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Actual paper is here.
Years ago, there was "news" of photons going "faster than light" which actually turned out to be that the experimental setup took a packet of photons and mushed them all toward the packet's leading edge, so that the average speed was greater than c while the leading edge's speed was still exactly c.
In this current experiment, however, it looks like they're seeing an entire packet of events time-shifted ahead of where it "should" be if the packet moved at c, without changing the shape of the packet. It still seems like they're trying to get some sort of average time-of-arrival, though, and that's where I would look for problems with the methodology were I more competent. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 09/23/2011 : 14:52:15 [Permalink]
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| And that's what I get for pausing my post for an hour and not checking to see if the thread had changed before writing the last half of my last sentence and hitting "Submit." |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 09/23/2011 : 18:12:17 [Permalink]
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This observation has already spawned its first joke, which I heard from my brother this evening. Ahem...
"We don't serve faster-than-light neutrinos in here!" said the bartender.
So, a neutrino walks into a bar..." |
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Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom.
You fiend! Never have I encountered such corrupt and foul-minded perversity! Have you ever considered a career in the Church? - The Bishop of Bath and Wells, Blackadder II
Baculum's page: http://www.bebo.com/Profile.jsp?MemberId=3947338590 |
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the_ignored
SFN Addict
2562 Posts |
Posted - 09/23/2011 : 18:35:17 [Permalink]
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| Now, I have to track your brother down... |
>From: enuffenuff@fastmail.fm
(excerpt follows):
> I'm looking to teach these two bastards a lesson they'll never forget.
> Personal visit by mates of mine. No violence, just a wee little chat.
>
> **** has also committed more crimes than you can count with his
> incitement of hatred against a religion. That law came in about 2007
> much to ****'s ignorance. That is fact and his writing will become well
> know as well as him becoming a publicly known icon of hatred.
>
> Good luck with that fuckwit. And Reynold, fucking run, and don't stop.
> Disappear would be best as it was you who dared to attack me on my
> illness knowing nothing of the cause. You disgust me and you are top of
> the list boy. Again, no violence. Just regular reminders of who's there
> and visits to see you are behaving. Nothing scary in reality. But I'd
> still disappear if I was you.
What brought that on? this. Original posting here.
Another example of this guy's lunacy here. |
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Randy
SFN Regular
USA
1990 Posts |
Posted - 09/23/2011 : 19:45:36 [Permalink]
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Originally posted by The Rat
This observation has already spawned its first joke, which I heard from my brother this evening. Ahem...
"We don't serve faster-than-light neutrinos in here!" said the bartender.
So, a neutrino walks into a bar..." |
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Brilliant!
Dave, can your brother fix the problems in the U.S.?
ha |
"We are all connected; to each other biologically, to the earth chemically, to the rest of the universe atomically."
"So you're made of detritus [from exploded stars]. Get over it. Or better yet, celebrate it. After all, what nobler thought can one cherish than that the universe lives within us all?"
-Neil DeGrasse Tyson |
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Dave W.
Info Junkie
USA
26022 Posts |
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sailingsoul
SFN Addict
2830 Posts |
Posted - 09/26/2011 : 09:09:56 [Permalink]
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Originally posted by The Rat
This observation has already spawned its first joke, which I heard from my brother this evening. Ahem...
[quote]"We don't serve faster-than-light neutrinos in here!" said the bartender.
So, a neutrino walks into a bar..." |
That's kind of got it backwards. In that the neutrino comes in after the comment. Shouldn't it be something like this?
" We don't serve light in here" said the neutrino bartender, "So a photon walks into a bar..." SS |
There are only two types of religious people, the deceivers and the deceived. SS |
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 09/27/2011 : 20:37:15 [Permalink]
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Originally posted by Randy
Originally posted by The Rat
This observation has already spawned its first joke, which I heard from my brother this evening. Ahem...
"We don't serve faster-than-light neutrinos in here!" said the bartender.
So, a neutrino walks into a bar..." |
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Brilliant!
Dave, can your brother fix the problems in the U.S.?
ha
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Depends on how many republicans he can, uh, take for a little ride... |
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom.
You fiend! Never have I encountered such corrupt and foul-minded perversity! Have you ever considered a career in the Church? - The Bishop of Bath and Wells, Blackadder II
Baculum's page: http://www.bebo.com/Profile.jsp?MemberId=3947338590 |
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 02/24/2012 : 07:48:24 [Permalink]
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So...
It turns out they have found two possible malfunctions which may be responsible for the faster-than-light neutrino measurement.
They didn't use two atomic clocks synchronized against each other, as I would have expected, but synchronised both time-pieces against a GPS-signal.
Two problems with the GPS system and its connection to the master clock in the experiment could provide timing offsets large enough to account for the neutrinos apparent faster-than-light flight.
http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html
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Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
| Edited by - Dr. Mabuse on 02/24/2012 07:53:13 |
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Dave W.
Info Junkie
USA
26022 Posts |
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 03/18/2012 : 15:21:28 [Permalink]
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| Excellent blog post! Thanks for that link, Dave. |
Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
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podcat
Skeptic Friend
435 Posts |
Posted - 03/18/2012 : 20:17:04 [Permalink]
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Actually, the joke works because faster-than-light speed is faster than walking.
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“In a modern...society, everybody has the absolute right to believe whatever they damn well please, but they don't have the same right to be taken seriously”.
-Barry Williams, co-founder, Australian Skeptics |
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The physics world is abuzz with news that a group
