CERN (LHC) scientists 'break the speed of light'

"Guy_Fawkes" said
That's amazing! I hope they can confirm this!

"DrCaleb" said
That's amazing! I hope they can confirm this!

"eureka" said

The evidence is pretty scanty yet.

The OPERA team timed the neutrinos using clocks at each location that were synchronized using GPS (Global Positioning System) signals from a single satellite. Contaldi's paper says the group's calculations do not take into account one aspect of Albert Einstein's general theory of relativity: that slight differences in the force of gravity at the two sites would cause the clocks to tick at different rates.

Because the CERN site lies closer to the centre of the Earth than Gran Sasso, and consequently feels a smaller gravitational pull, a clock at the beginning of the neutrinos' journey would actually run at a slightly slower rate to the clock at the end. "It would reduce the significance of the result," Contaldi says.

Because two clocks are needed to time the neutrinos' journey � one at the beginning, and one at the end � they must be synchronized to within nanoseconds to get an accurate measurement, explains Toby Wiseman, a theoretical physicist also at Imperial College London. Measuring the speed of light on this journey would be much easier, because the beam can be reflected back to its origin, and the round trip timed with just one clock. "Whether they have or haven't synchronized their clocks correctly is the crucial question," says Wiseman.

Contaldi admits that his original analysis posted at ArXiv wrongly assumed that OPERA's timings relied on a clock being moved from one end of the beam to the other. But even synchronizing the clocks using GPS does not remove the difference in the time dilation effect, which Contaldi says could amount to tens of nanoseconds.

That effect would reduce the statistical significance � which OPERA claimed was six standard deviations � of the group's result (five is enough to count as strong evidence in the field of particle physics). Contaldi says the additional error would reduce that number to two or three standard deviations, enough to make only a tentative claim of a faster-than-light effect.