Technical Ben wrote:So the moving atomic clock took a route over a mountain, said mountain/altitude change was not accounted for and relativity/gravity is too blame for the subsequent 60-70ns? Oh, rather an east one to find out then?
Basically, one-way measurements at lightspeed are tricky, because you need a timer at the sender and the receiver, and these timers need to be in sync to a very high degree of accuracy.
How do you get that?
Well, say you had a super-accurate clock that you can carry around. You start at the sending end, and use this super accurate clock to calibrate your sending timer. Then, you lug the clock to the receiving end, and you calibrate the receiving timer.
Now, both the sending and receiving timers should be sync'd up, because you sync'd both of them off the same super-accurate clock, right?
Right. Except not.
That super accurate clock that you lug around has to go from one place to another, which means that it is going to undergo time dilation effects from various sources of special relativity (the paper lists three). So you need to know the magnitude of these effects that can accumulate in the time between calibrating the sender and the receiver.
So there's good news about this. This means that they can repeat the synchronization and calibration of the timers at CERN and OPERA and see if they observe the same effect, or if that TOF delta is different. They can also do the calibration in reverse order, to see if we get subluminal neutrinos instead of superluminal ones. This would be easier and faster than waiting on a different detector to attempt the same results.