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Given current accuracy of the techniques, is it possible to identify a real, existing tunnel (stright I think) to make the direct comparison of the speed of light and of neutrinos? The hypotetical tunnel from CERN to OPERA would-be too long. If we were able to increase accuracies by two decades, then would a 7.3 Km tunnel suffice ? The 60ns difference would become around 600ps. Suppose there is such a tunnel, suppose it can be availabe to physicists. Apart from all the logistics problems of generating and detecting light and neutrinos at the two ends of such tunnel, are there other difficulties?

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Related: When the speed of light has been measured, recently? and What is the highest accuracy of measuring time differences achievable today?. Note that T2K will likely have reported in long before then and the matter may disappear. –  dmckee Dec 15 '11 at 15:24
BTW--It is not clear that you are going to get a big improvement in timing accuracy as these things are set by (1) the precision to which you can match some feature (often the rising edge) of the pulses in calibration data (2) light and electronics noise in the detector and (3) any multiplicity of paths that might generate a particular signal (as in reflection in hodoscopes and light guides). Still, there are new detector technologies coming down the pipe, and perhaps some of them will be more amenable to precision time matching. –  dmckee Dec 15 '11 at 16:57
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Unlike neutrinos, light will be slowed down by gas in the tunnel, which would have to go through the Earth. It is much cheaper and easier to mathematically analyze the OPERA results to find their error, were they ever to release their detailed protocol, which is unlikely, because they don't seem to want the error discovered.

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Why do you believe that OPERA is hiding something. –  Hans-Peter E. Kristiansen Dec 15 '11 at 21:41
Because they haven't published the detailed satellite data and correction algorithm, instead they ask the rest of the world to trust their accounting for relativistic effects related to the rotation of the Earth. I would ask them to make their GPS algoritms public. If they don't publish enough to check their GPS independently, which they haven't, they should lose their funding. –  Ron Maimon Dec 15 '11 at 22:08
There is_no_way an international collaboration with 200 physicists is hiding anything. I am saying that not because that with so many people someone would leak something, but because in science you do not hide things. One man can be corrupt and hide everything. An international collaboration plays by the rules of established science. You don't just pull their funding because of one man who has not read all the publications. –  Hans-Peter E. Kristiansen Dec 15 '11 at 22:42
@Hans-Peter E. Kristiansen: Obviously they aren't purposefully hiding something, it not a conspiracy, it's just a collective phenomenon in large collaborations. Each person who is entrusted with this relativistic correction or that calculation, or this bit of programming has an incentive to keep his or her work as private as possible, both because this guarantees their position (nobody else knows how to do it) and because if, heaven forbids they made a mistake, they can catch and fix it themselves without anyone else finding out. Leadership must push against this tendency. OPERA's doesn't. –  Ron Maimon Dec 16 '11 at 1:10
Ron, have you ever been part of one of these organizations? I've been in half a dozen and haven't observed this behavior in any of them. There is intense internal scrutiny and competition for most parts and a fair amount of people peering over your shoulder even we you're working on a modest little corner of the experiment. Presentations at collaboration meetings can be very trying times if you aren't sufficiently prepared. –  dmckee Dec 16 '11 at 1:17
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