[ntp:questions] questions Digest, Vol 113, Issue 20

William Unruh unruh at invalid.ca
Fri Mar 14 19:50:40 UTC 2014

On 2014-03-14, Jochen Bern <Jochen.Bern at LINworks.de> wrote:
> On 14.03.2014 05:30, questions-request at lists.ntp.org digested:
>> From: Mauricio Tavares <raubvogel at gmail.com>
> Do you remember the headlines a couple months ago when physicists
> thought they had measured particles traveling a percent or so faster
> than the speed of light? That was a clock out of sync by some fraction
> of a second, too. They had miscalculated the correction needed to
> counter the GPS signal's propagation delay from the surface to the
> cavern where the particle detector's master clock sits.

WEll, not quite. There was a weak connection on the fibre cable bringing
the signal down to the experiment (under the mountain). I think that
meant that the rising edge of the pulse used as the time standard was
being sampled further along than they thought. There problem remember
was in the nanosecond regime. 

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