Last Call

Looks like somebody found the asterisk in the world neutrino speed record and has put forth a case as to why the observation that neutrinos are faster than light has a huge hole in it:

In the original experiment, called OPERA, scientists measured how long it took for particles called neutrinos created at CERN to arrive at the Gran Sasso Laboratory in Italy.  The distance between the laboratories (roughly 454 miles), and the fact that Gran Sasso is located underneath quite a bit of mountain, complicated the experiment since synchronizing two clocks in different locations is extremely difficult. In order to account for this, the scientists relied on the time signal from an orbiting GPS satellite. Using this benchmark, the researchers found that the neutrino arrived 60 nanoseconds earlier than light would.

However, it’s this reliance on an orbital clock that van Elburg says is causing the results observed in the OPERA experiment. The way the OPERA scientists structured the experiment, they assumed that their GPS-syncronized clocks would function as if they were on the ground. However, those clocks are receiving a signal from an orbiting satellite, which is moving in reference to the Earth. This creates two frames of reference for the experiment, and not one, says van Elburg.

When it comes to relativity, frame of reference is everything. The satellite in this experiment was moving from West to East, tilted 55º in reference to the equator. Taken from this vantage point, the distance between the source of the neutrinos at CERN and the detector in Italy are actually changing. The excellent Physics arXiv blog at MIT’s Technology Review quotes van Elburg as saying, “From the perspective of the clock, the detector is moving towards the source and consequently the distance travelled by the particles as observed from the clock is shorter.”

Van Elburg says that this would throw off the experiment’s timing by 32 nanoseconds on each end of the experiment, for a total of roughly 64 nanoseconds of error in the experiment overall. This would mean that neutrino speed is quite similar to that of light, but not faster.

Yeah.  Oops.  That's going to be a bit of a problem there, folks.  Shame, I was hoping the numbers would have held up through this, but now there's a perfectly good explanation as to why it appeared like neutrinos were faster than light: the clock was moving too.

There goes my warp engine design.