Thread: Faster Than Light?

The latest experiments beaming neutrinos from Cern in Geneva to Grand Sasso has produced the same result again
even having adjusted the length of the neutrino chains used. So what does that tells us?

I for one am still a bit sceptical, the distance between the send and recieving points is quoted as 732 Km ie the distance of the SECANT drawn between
the 2 points [ not as the crow flies ] One wonders how accurate the distance measurement can be ? Given that Italy has some vey active volcanic areas
- therefore subject to a lot of movement, I would say that a measurement of the tolerance required would be very difficult to make.

SOME MATHS

Given that light travels 11.3 inches in a nano second - the 6 billionths of a second discrepancy represents a distance 67.8 inches.
732 Km = 454.8 miles = 28,816,128 inches 67.8 is 1 /425,016 th of 28.8 million

My speculation is that although the timings may well be superbly accurate, the speed calculation depends on an equally accurate distance measurement
with a miniscule margin of error that may not be acheivable. This experiment needs to be repeated to as many different points on the Earth as possible.

Originally Posted by tszy

One wonders how accurate the distance measurement can be ? Given that Italy has some vey active volcanic areas
- therefore subject to a lot of movement, I would say that a measurement of the tolerance required would be very difficult to make.

I am less concerned about the distance than the timing. The distance was measured with an error of 20cm (0.67ns). There is a very nice graph in the paper (page 10) showing the slow change due to continental drift (< 1cm/year) and the big jump (~7cm caused by the L'Aquila earthqauke).

This experiment needs to be repeated to as many different points on the Earth as possible.

I don't think anyone will argue with that! The race is on...