BETA
This is a BETA experience. You may opt-out by clicking here

More From Forbes

Edit Story

Gravity May Have Thrown Off Faster-Than-Light Neutrino Calculations

Following
This article is more than 10 years old.

I'll say this for the OPERA team in Italy - their decision to open up their faster-than-light neutrino results to the physics community has produced an absolutely fascinating burst of activity and creativity in finding explanation for those results. There are already literally dozens of papers up on the subject, and I only wish I had time to read them all.

The fact remains, though, that unless OPERA's results are independently verified, the general view in the physics community is that the faster than light result is most likely a measurement error. In fact, a new paper written by Carlo Contaldi at Imperial College challenges the calculations themselves that the OPERA team used to arrive at their faster-than light findings.

In any good heist, synchronized watches are essential for determining timing, so that a precision plan can go off without a hitch.  Similarly, the clocks in a speed measurement need to be synchronized to ensure that velocity is calculated correctly. The basic problem with OPERA's calculations, Contaldi suggests, is that the clocks used to measure the neutrinos' velocity weren't properly synchronized.

In the case of the faster-than light measurements, the clocks were synchronized using GPS timestamps. But, argues Contaldi, that's not good enough. That's because the gravity on different places on the Earth isn't constant. (You can see a graphical depiction of gravitational differences in the image to the right.) The gravity at the CERN site where the neutrinos left, for example, is actually slightly greater than the gravity at the OPERA detector site. As a consequence, time would appear to move more slowly at CERN from the vantage point of the OPERA detector. Failing to take this into account, Contaldi contends, means that "[t]he resulting measurement that the neutrino velocity differs from c is not only unsurprising but should be expected in their setup."

Naturally, the OPERA group disagrees with this. According to Nature News, Dario Auteiro of the OPERA group has countered that Contaldi didn't properly describe the means through which the OPERA group synchronized their clocks. The OPERA group will be revising their paper to make that method clearer. It will be interesting to see how this argument develops.

Follow me on Twitter or Facebook. Read my Forbes blog here.