Tuesday, October 18, 2011

Update: Not Faster Than Light, Maybe.

PC Magazine, via Ritholtz:
Last month, a team of international researchers shocked the scientific world with the news that particles they had been firing for several years from the CERN particle accelerator in Switzerland at detectors at the OPERA facility in Gran Sasso, Italy placed about 450 miles away appeared to be arriving at their destination faster than the time it would take light to get there.
The particles, traveling through air, water, and rock, shouldn't have hit the Gran Sasso detectors sooner than about 2.4 thousandths of a second after being fired, which is the time it would take light to travel the distance between the two points. Yet the CERN researchers reported that their neutrinos were getting to the target 64 nanoseconds faster—meaning that they were traveling faster than light, supposedly impossible according to the Theory of Special Relativity.
Now other scientists say that a failure to fully account for the effects of relativity is what caused the original researchers to supposedly mis-measure the time it was taking the neutrinos to travel using a GPS satellite, despite the CERN team saying they had factored relativity into their calculations.
A new paper by Dutch researcher Ronald A.J. van Elburg lays out the case that the GPS satellite measuring the neutrinos' movements was also moving relative to the CERN and OPERA facilities as it orbited the Earth. Briefly, van Elburg asserts that the effects of relativity as they pertain to the GPS satellite's measurements require two corrections to the perceived time of travel.
Lo and behold, it turns out that applying that double correction shaves 64 nanoseconds off the neutrinos' travel time, according to van Elburg, "[t]hus bringing the apparent velocities of neutrinos back to a value not significantly different from the speed of light."
I'm not surprised there might be a small measurement or correction error.  This has always been over my pay grade, but relativity may hold up.  Good, I didn't quite understand it anyway, and didn't have any new theory, so this keeps me from having to work at it.

No comments:

Post a Comment