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Speed-of-light experiments yield baffling result at LHC

bbc.co.uk

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Re: Speed-of-light experiments yield baffling result at LHC

#111

Post by [deleted] »

tjic wrote: post #89
olihb wrote: post #53

Earlier quoted context omitted.

Scientist rarely keep the data secret. It's the basis of peer review. There's a reason why open access journals (PLoS One) are getting so popular, scientists want to be known and publish. In my experience, ego is a currency much more valuable than money in academic circles.

> Scientist rarely keep the data secret. It's the basis of peer review. In a better world, that would be true. In this world, it's not. Most of the climate science data that Phil Jones and others have worked with, and most of their models are secret. It is THIS that makes me keep at least one ear open for the "anti-" side in the climate debate. Real science SHOULD be conducted out in the open.

[deleted]

Re: Speed-of-light experiments yield baffling result at LHC

#112

Post by Tycho »

tjic wrote: post #89
olihb wrote: post #53

Earlier quoted context omitted.

Scientist rarely keep the data secret. It's the basis of peer review. There's a reason why open access journals (PLoS One) are getting so popular, scientists want to be known and publish. In my experience, ego is a currency much more valuable than money in academic circles.

> Scientist rarely keep the data secret. It's the basis of peer review. In a better world, that would be true. In this world, it's not. Most of the climate science data that Phil Jones and others have worked with, and most of their models are secret. It is THIS that makes me keep at least one ear open for the "anti-" side in the climate debate. Real science SHOULD be conducted out in the open.

The models are secret... wait, seriously??

Re: Speed-of-light experiments yield baffling result at LHC

#114

Post by jarek »

cpeterso wrote: post #109
nickolai wrote: post #70

Similar results seem to have already been obtained in the past http://en.wikipedia.org/wiki/Neutrino#Speed QUOTE In the early 1980s, first measurements of neutrino speed were done using pulsed pion beams (produced by pulsed proton beams hitting a target). The pions decayed producing neutrinos, and the neutrino interactions observed within a time window in a detector at a distance were consistent with the speed of lig…

> ... found the speed of 3 GeV neutrinos to be 1.000051(29) c. What does the "(29)" in "1.000051(29) c" mean?

Repeating. It's 1.000051292929292929...

edit: sorry if that's incorrect in this case. "1.000051(29)" is one of the formats of indicating repeating decimals, per http://en.wikipedia.org/wiki/Repeating_decimal#Notation

Re: Speed-of-light experiments yield baffling result at LHC

#115

Post by BoppreH »

cpeterso wrote: post #109
nickolai wrote: post #70

Similar results seem to have already been obtained in the past http://en.wikipedia.org/wiki/Neutrino#Speed QUOTE In the early 1980s, first measurements of neutrino speed were done using pulsed pion beams (produced by pulsed proton beams hitting a target). The pions decayed producing neutrinos, and the neutrino interactions observed within a time window in a detector at a distance were consistent with the speed of lig…

> ... found the speed of 3 GeV neutrinos to be 1.000051(29) c. What does the "(29)" in "1.000051(29) c" mean?

I'm not sure, but I think it represents uncertainty over the last digits.

So 1.000051(29) would be equivalent to 1.000051 +- 0.000029.

Re: Speed-of-light experiments yield baffling result at LHC

#116

Post by gecko »

cpeterso wrote: post #109
nickolai wrote: post #70

Similar results seem to have already been obtained in the past http://en.wikipedia.org/wiki/Neutrino#Speed QUOTE In the early 1980s, first measurements of neutrino speed were done using pulsed pion beams (produced by pulsed proton beams hitting a target). The pions decayed producing neutrinos, and the neutrino interactions observed within a time window in a detector at a distance were consistent with the speed of lig…

> ... found the speed of 3 GeV neutrinos to be 1.000051(29) c. What does the "(29)" in "1.000051(29) c" mean?

Those figures are being provided because they were measured, but they are within the expected experimental error for the device.

Re: Speed-of-light experiments yield baffling result at LHC

#117

Post by msutherl »

Confusion wrote: post #84
Permit wrote: post #65

Earlier quoted context omitted.

Perhaps I misinterpreted, but I think DenisM was talking about something completely different. He mentioned that because of a lack of density in the leading photons, the first piece of equipment missed the measurements while the second one picked it up. That would a problem with the system they're measuring with, not at all to do with treating light as a single entity.

As I interpreted it, the critical part of his explanation is the fact that the higher density part shifted from the back to the front. If that change in density would be due to actual photons shifting that way, then those photons would have traveled faster than light (whereas the entire 'blob', on average, traveled exactly at the speed of light).

Could be explained if the photos leaving the source look like this: :::::..... and arrive like this: :::::.::, where the 'tip' folds back on itself to become visible, still before the original bulk of the photon cluster.
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