OMG -- of course! You can't synchronize (all) clocks on the Earth's
surface -- it's a rotating frame, and Sagnac comes around and bites you
on the bumm if you try! Yet by using the GPS satellite signals, which
are available everywhere, they were doing essentially that: using a
"universal" time value, which doesn't produce a sensible result on the
Earth's surface.
Using clocks in another frame (the GPS clocks) to synchronize the clocks
in the rotating frame (on the surface of the earth) just adds confusion,
it doesn't avoid the problem, which is fundamental. In particular, if
you sync your (rotating) clocks with an external source, then when you
measure light speed you find it's anisotropic -- it's faster one way
than the other.
The only way to deal with it an experiment like this it is to pick just
two clocks and E-sync them using point-to-point two-way light travel (or
use some other source, but then figure out what the E-sync times would
have been and use the computed values). Apparently, they didn't do that.
When I say it's "fundamental", I mean that if you use two-way light
signals to sync pairs of clocks on the Earth's surface, and you do it
for a chain of pairs of clocks reaching all the way around the Earth,
you will find the clocks at the beginning and the end of the chain are
stubbornly out of sync, even though the clocks all the way back along
the chain were in sync. And you can't avoid it by using some other
clock source.
See, for example,
http://www.physicsinsights.org/sagnac_1.html
On 11-10-14 01:42 PM, Terry Blanton wrote:
On Fri, Sep 23, 2011 at 10:30 AM, Terry Blanton<[email protected]> wrote:
Don't bury Einstein yet:
http://www.newscientist.com/article/dn20957-dimensionhop-may-allow-neutrinos-to-cheat-light-speed.html
"Sher also mentions a third option: that the measurement is correct.
Some theories posit that there are extra, hidden dimensions beyond the
familiar four (three of space, one of time). It's possible that the
speedy neutrinos tunnel through these extra dimensions, reducing the
distance they have to travel to get to the target. This would explain
the measurement without requiring the speed of light to be broken."
Those neutrinos probably knew a short cut in the other 6 dimensions.
Well it wasn't extra dimensions. It was relativity itself. They
needed entangled clocks!
http://www.technologyreview.com/blog/arxiv/27260/?p1=blogs
"Faster-Than-Light Neutrino Puzzle Claimed Solved by Special Relativity"
T
