CERN team claims measurement of neutrino speed >c


by turbo
Tags: anisotropy, cern, ftl, gps, new math books
ZapperZ
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Jun12-12, 01:56 PM
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Quote Quote by TrickyDicky View Post
Sorry, I thought this thread was specifically for discussion of that paper, if that is no longer the case I guess I'll just have to try elsewhere.
But the result of that paper has been clearly shown to be invalid! That's the whole point of the last few posts since that CERN press report! Or did you completely missed it?

It makes discussion of the original paper to be entirely moot!

Zz.
TrickyDicky
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Jun12-12, 01:57 PM
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Note also that my questions were about that paper in the light of the new information released about the possible source of errors.
TrickyDicky
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Jun12-12, 02:03 PM
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Quote Quote by ZapperZ View Post

It makes discussion of the original paper to be entirely moot!
Even to get a better understanding of how exactly is the result invalidated according to the CERN press report? You give the term "discussion forum" a different sense from the one I'm used to. I thought one of the goals of such forums was asking questions in order to understand scientific issues thru the clarifications of other more learned forum members.
ZapperZ
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Jun12-12, 02:09 PM
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Quote Quote by TrickyDicky View Post
Even to get a better understanding of how exactly is the result invalidated according to the CERN press report? You give the term "discussion forum" a different sense from the one I'm used to. I thought one of the goals of such forums was asking questions in order to understand scientific issues thru the clarifications of other more learned forum members.
Unless you are in possession of a detailed report on the exact timing errors that was done in the original OPERA result (i.e. you have the post-mortem analysis of those loose connection), what exactly do you have to base on in doing your "discussion"? The original OPERA paper certainly didn't have any. And the recent report on those loose connectors certainly have been lacking in the details on what exactly is the timing errors and how they were measured. So what exactly are you going to base your discussion on? SPECULATION? Guess work?

The same "philosophy" what was imposed upon in the beginning to urge people to read the original OPERA paper BEFORE they jump in into this discussion is also at work here. It means that the discussion must be based on something concrete, rather than something pluck out of thin air without any basis. Until the OPERA group publish clearly the post-mortem of the original result, you and I do not possess any kind of data or information to make an informed discussion of what actually happened. So how would such a discussion gives you a "better understanding"? A better understanding on how to make guesses?

Zz.
TrickyDicky
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Jun12-12, 02:30 PM
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Quote Quote by ZapperZ View Post
Unless you are in possession of a detailed report on the exact timing errors that was done in the original OPERA result (i.e. you have the post-mortem analysis of those loose connection), what exactly do you have to base on in doing your "discussion"? The original OPERA paper certainly didn't have any. And the recent report on those loose connectors certainly have been lacking in the details on what exactly is the timing errors and how they were measured. So what exactly are you going to base your discussion on? SPECULATION? Guess work?

The same "philosophy" what was imposed upon in the beginning to urge people to read the original OPERA paper BEFORE they jump in into this discussion is also at work here. It means that the discussion must be based on something concrete, rather than something pluck out of thin air without any basis. Until the OPERA group publish clearly the post-mortem of the original result, you and I do not possess any kind of data or information to make an informed discussion of what actually happened. So how would such a discussion gives you a "better understanding"? A better understanding on how to make guesses?

Zz.
OK, I understand you are an experimentalist , if you think there is no room for informed discussion from the data published so far I'll take your word. Let's not waste more time. However curiously from your words you seem to think (correct me otherwise) we all must agree that the original Opera experiment is dead and buried and noone should have any doubt about it unless he or she is an imbecile, and that without having all the data to supposedly have an informed discussion according to you as an experimentalist.
Ilmrak
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Jun26-12, 04:15 AM
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Quote Quote by TrickyDicky View Post
So far I've obtained two different explanations to my query, one that the loose wire error is purely sistematic and fixed (74ns) and the other that it actually it is responsible for the broad variation of [itex]\delta[/itex]t in the first longer Opera experiment from 2008-2011.
Both answers are incompatible; as I said since the cable problem is considered a sistematic error I was thinking in terms of the first explanation, and with the reasonable assumption that neutrinos speed cannot oscillate so much in such a short distance (732km), I'm still missing something in the sense that the offered solution would work perfectly if the 60ns [itex]\delta[/itex]t was not just an average. Of course my concern is only directed to the original experiment, not to the recent brief short pulsed ones. But I think it is important given the uproar it generated to have it all well clarified.
I think your question has been misunderstood here. Let me try to interpret it, correct me if I'm wrong.

I read your question like “How could there be such a wide distribution in arrival times of neutrinos? Is it due to the loosing cable?”

If this was your question, then the answer is that the loosing cable caused (mainly) a systematic error which shifted the time distribution without deforming it significantly.
This mean that the variance of the time distribution is still there when you fix the cable. It is due mainly to three contributions (to my knowledge): a difference in neutrinos velocity, that is though negligible; a difference in the path followed (they are not created and received all in the same starting and ending points); other experimental errors.

I hope this could help.

Sorry for the bad English,

Ilm
mfb
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Jun26-12, 12:02 PM
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The wide time distribution in the original publication has a simple explanation: The proton beams used to produce the neutrinos were long (~10µs if I remember correctly). Timing was not the main purpose of the experiment, just something which could be done in addition to the mixing measurements. After timing became interesting, they used short pulses (2ns?), as they are better to measure the flight time.

The 60ns were obtained by comparing the proton distribution (in time) with the neutrino distribution. Compared to the speed of light, a shift (but no broadening of relevant size) between the two was observed.


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