Fran?ois Meyer wrote: >In my view the two clocks are just synced to each other as far as this >experiment >is concerned. That does not change the point about gravitation though.
I emailed Contaldi about the TTD, and I've just had this interesting response from him: Carlo Contaldi wrote: |Dear Zefram | |thanks for the comments, I corresponded with the OPERA group and I agree |that the TTD is not a moving clock as I interpreted. However it is used |to calibrate a relative delay at both ends of the baseline using local |reference frequency generators and these would be susceptible to time |dilation effects as in the stationary part of my calculations. | |In addition the time scales over which they calculate the delays are |vastly different from those used in the measurement and it is not clear |at all that they have measured the noise on the relevant time scales. | |Effectively they are relying on the GPS signal at both ends being |synchronised at < ns and this is what I find hard to believe, |particularly on short time scales where atmospheric effects may induce a |much larger uncertainty than they have accounted for. | |I also agree that their Euclidean analysis may also introduce further |uncertainties. | |best | |Carlo So I think the state of play is: need more details from the OPERA team, and there's a world of error budget haggling to come. I couldn't figure out the operation of the time source system (local caesium plus GPS plus other bits) from the diagram in the PTB tech note. The details seem to matter quite a bit to the synchronisation. Does someone here know the equipment, or recognise the configuration? TvB? -zefram _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
