[time-nuts] Speedy neutrino puzzle solved

Magnus Danielson magnus at rubidium.dyndns.org
Sun Oct 16 09:50:11 UTC 2011


On 10/16/2011 02:39 AM, Javier Herrero wrote:
> El 16/10/2011 02:14, iovane at inwind.it escribió:
>> And further, what the author states, in other words, would mean that
>> the two clocks at Earth, in the frame in which the measurement was
>> made, were off by 60 ns, isn't it?
> More or less :) I'm also not sure of the accuracy of the phrase "The
> clocks in the OPERA experiment are orbiting the earth in GPS
> satellites", since as far as I've understood the GPS is used to use
> common view for comparison of the Cs clocks. And it seems that the
> author does not know that relativity has already been taken into account
> in the GPS system.

A first compensation of relativity is done by shifting the frequency 
such that the fixed satellite would use 10,23 MHz as observed from the 
earth. This frequency is used in 120, 154, 1 and 1/10 multiples for 
carries and chip-rate of pseudo-random noise in the set of gears 
providing time distribution. The one relative effect which they maybe 
didn't account for is the Sagnac effect, which Tom estimated being about 
2.3 ns which matches the difference found in the time-difference 
testing. This effect comes from the spinning of the earth.

Much of the effects is first degree compensated when doing a common view 
comparision, and the GPS clock is only a transfer clock, not the clock 
of the measurement.

A much more detailed analysis would be required of the timing system 
then provided by that 4 page paper, detailing the processes in the GPS 
receivers, post-processing etc. Also, a full review of the timing system 
would need to analyse the internal distribution system and verify that 
on both sites. Also, the timing of the neutrinos in the detectors and 
their location when detected etc also needs to be looked at. So far, I 
have only been looking at this quickly and the reasonability of things 
being done correctly. Both the main paper and the PTB preliminary report 
is unsatisfactory in the details for full analysis, but they seem 
reasonable.

> I'm of the same opinion as Magnus: I do not think that this paper will
> bebunk the OPERA one, not even a little :)

Indeed. It was a very sloppy attempt.

Cheers,
Magnus



More information about the time-nuts mailing list