Months after researchers reported that they measured neutrinos traveling faster than light, they're finding that the incredible result may have been due to a bad connection rather than a violation of Albert Einstein's special theory of relativity.This doesn't necessarily invalidate the basic finding, however:
* * *
Now sources familiar with the OPERA review say scientists have identified two potential problems with the experimental apparatus. One has to do with a fiber-optic connector that sends a GPS time stamp to the experiment's master clock. That connector may not have been functioning correctly when the neutrino-timing measurements were made, and as a result, the recorded flight time would be shorter than the actual time. That alone could explain the seemingly faster-than-light results.
Another potential problem has to do with the oscillator that was used to generate the time stamps for GPS synchronization. This problem could have made the flight time look longer than it really was.
But rather than invalidating the stunning superspeed finding, the flaw may have led scientists to underestimate it.
Citing sources familiar with the experiment, Science magazine’s website reported Wednesday that the 60-nanoseconds discrepancy that led to the startling speed conclusion came from a bad connection in a fiber optic cable connecting a GPS receiver (used to correct the timing of the neutrinos' flight) and a computer.
After tightening the connection and then remeasuring the time it takes data to travel the length of the cable, researchers found that the data arrive 60 nanoseconds earlier than assumed, the website said. (More data will be needed to confirm this hypothesis.)