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Not so fast after all

by humanino
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humanino
#1
Feb22-12, 03:12 PM
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I came here thinking you would already be discussing. It is a just a rumor, but don't we love them ? Let us keep an eye, or an ear, on what will hopefully come out soon.

Error Undoes Faster-Than-Light Neutrino Results
It appears that the faster-than-light neutrino results, announced last September by the OPERA collaboration in Italy, was due to a mistake after all. A bad connection between a GPS unit and a computer may be to blame.

Physicists had detected neutrinos travelling from the CERN laboratory in Geneva to the Gran Sasso laboratory near L'Aquila that appeared to make the trip in about 60 nanoseconds less than light speed. Many other physicists suspected that the result was due to some kind of error, given that it seems at odds with Einstein's special theory of relativity, which says nothing can travel faster than the speed of light. That theory has been vindicated by many experiments over the decades.

According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos' flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed. Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis.
Faster-than-light neutrino result reportedly a mistake caused by loose cable
At the AAAS meeting's discussion, CERN's director of research, Sergio Bertolucci, placed his bet on what the results would be: "I have difficulty to believe it, because nothing in Italy arrives ahead of time."
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Astronuc
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Feb22-12, 03:13 PM
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We're waiting for a formal announcement (press release) from CERN.
humanino
#3
Feb22-12, 03:15 PM
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Quote Quote by Astronuc View Post
We're waiting for a formal announcement (press release) from CERN.
Wise attitude. I am really just teasing, because this announcement will probably take a while. Despite the surrounding noise (which I am contributing today), CERN has been very cautious.

Jimmy Snyder
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Feb22-12, 03:17 PM
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Not so fast after all

Quote Quote by humanino View Post
I came here thinking you would already be discussing. It is a just a rumor, but don't we love them ? Let us keep an eye, or an ear, on what will hopefully come out soon.

Error Undoes Faster-Than-Light Neutrino Results


Faster-than-light neutrino result reportedly a mistake caused by loose cable
Sounds reasonable to me. My GPS tells me I'm in Timbuctoo when I'm really in Hainesport.
bp_psy
#5
Feb22-12, 03:24 PM
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In before the CERN faster then light cover up conspiracy theories.
humanino
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Feb22-12, 03:26 PM
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Quote Quote by Jimmy Snyder View Post
Sounds reasonable to me. My GPS tells me I'm in Timbuctoo when I'm really in Hainesport.
Would not that be about 10 [itex]\mu[/itex]s-light apart ? Where does your wife say you are ?
humanino
#7
Feb22-12, 03:28 PM
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Tell them a "neutrino walks in bar" joke. Meet somebody who works at CERN.
Jimmy Snyder
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Feb22-12, 04:04 PM
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Quote Quote by humanino View Post
Would not that be about 10 [itex]\mu[/itex]s-light apart ? Where does your wife say you are ?
Timbuctoo is in Westampton, just about 500 nanoseconds from Hainseport. My wife thinks I'm in the living room. Actually, I'm in the family room, but it's not prudent to contradict her so I'm moving.
Borek
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Feb22-12, 04:16 PM
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Quote Quote by humanino View Post
I came here thinking you would already be discussing.
And you were right, we know about it for two and half hour:

http://www.physicsforums.com/showthread.php?t=532620

Just see the last page of the FTL neutrino thread.
Jimmy Snyder
#10
Feb22-12, 04:19 PM
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So my theory that the speed of light is actually d has been exploded?
CaptFirePanda
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Feb22-12, 04:26 PM
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explocec.
Moonbear
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Feb22-12, 04:27 PM
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Since the initial announcement, my bet has been on a detector error. Would this count as a detector error, or some other type of error? I just want to know if I can collect my bets if this ends up being the official explanation. (Oh, wait, I didn't actually place any cash bets...drat! I guess I don't care then. )
Astronuc
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Feb22-12, 06:29 PM
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Quote Quote by Moonbear View Post
Since the initial announcement, my bet has been on a detector error. Would this count as a detector error, or some other type of error? I just want to know if I can collect my bets if this ends up being the official explanation. (Oh, wait, I didn't actually place any cash bets...drat! I guess I don't care then. )
I'd call it a system error. Apparently the detector worked fine, but the transmission of the information was delayed.

There is a good reason that PF has a relatively strict prohibition on overly-speculative posts.
Moonbear
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Feb22-12, 06:36 PM
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Quote Quote by Astronuc View Post
I'd call it a system error. Apparently the detector worked fine, but the transmission of the information was delayed.
Drat! Oh, wait, I didn't bet any real money, so it's all good. Really, the biggest mistake they made was the big press release of the initial report before they went through and double checked all of these systems for errors. On the other hand, it's a good lesson for the public about scientific method and that nothing is a foregone conclusion until it has been checked, checked again, and checked some more. And, even then, it's not a foregone conclusion.
Astronuc
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Feb22-12, 06:42 PM
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Quote Quote by Moonbear View Post
Drat! Oh, wait, I didn't bet any real money, so it's all good. Really, the biggest mistake they made was the big press release of the initial report before they went through and double checked all of these systems for errors. On the other hand, it's a good lesson for the public about scientific method and that nothing is a foregone conclusion until it has been checked, checked again, and checked some more. And, even then, it's not a foregone conclusion.
The authors reported concerns about errors. I seem to remember some experimenters not putting their names on the released report. Quite a few folks here expressed the concern about error and the need to check each and every detail. Of course, others started speculating about FTL this and that, or the demise of special relativity.

I wonder if scientists succumbing to the pressure/temptation to be the first to announce a discovery - or to publish?
DaveC426913
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Feb23-12, 06:20 PM
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I am not surprised that the results turned out to be wrong. I have a lot of confidence in our current theories and the results they've been giving.

I am surprised that the error turned out to be something so embarrassingly avoidable.

I had assumed that a research team doing experiments like this (that will be scrutinized by the whole world) would be diligent enough to have more than one independent measurement system. I'd think they'd see a discrepancy in their two measurements and quickly get to the root of it. Surely they didn't just trust all their hardware software and processes without checks and balances?

I guess the answer is: yes they did and it is commonplace.
Jimmy Snyder
#17
Feb23-12, 06:32 PM
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Quote Quote by DaveC426913 View Post
I am not surprised that the results turned out to be wrong. I have a lot of confidence in our current theories and the results they've been giving.
Me too. Special relativity has withstood every experimental test for over a hundred years. I don't know of any other theory that has done so well for so long.


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