Timo
February 22nd, 2012, 07:24 PM
Turns out a loose cable was to blame. Would be interesting to know how they define loose at CERN, considering that the cable only caused the results to be out by 60ns.
Since September, scientists have been scratching their head over results that appear to show neutrinos traveling between Switzerland and Italy faster than light would. As far as anyone could tell, the team behind the results had done everything they could to eliminate errors, and had even released some preliminary data that had strengthened their results. But the results remained difficult to square with everything else we know about how the Universe operates.
But now, ScienceInsider is reporting that there was a good reason the measurements and reality weren't lining up: a loose fiber optic cable was causing one of the atomic clocks used to time the neutrinos' flight to produce spurious results. If the report is confirmed (right now, there's only one source), then it provides a simple explanation for the fascinating-yet-difficult-to-accept results. According to the new report, researchers are preparing to gather new data with the clocks properly hooked into computers, which should definitively indicate whether the loose connection was at fault.
It's somewhat ironic that ScienceInsider, which is part of the American Association for the Advancement of Science, broke the news now. Over the weekend, the AAAS held its annual meeting, which included a discussion of the biggest news in physics, where the neutrino results were highlighted. The session indicated that five different neutrino experiments were upgrading their hardware in order to check timing, and some would have data before the year is out. So even if this report doesn't pan out, we should know more soon.
At the AAAS meeting's discussion, CERN's director of research, Sergio Bertolucci, placed his bet on what the results would be: "I have difficulty to believe it, because nothing in Italy arrives ahead of time."
UPDATE: Nature News has apparently received a statement from the Opera researchers. It indicates they have found two potential issues (one of them the optical cabling). The two issues would skew the results in opposite directions, which is why they will need new measurements to better understand whether both influence the results and, if so, what the net impact is.
http://arstechnica.com/science/news/2012/02/faster-than-light-neutrino-result-apparently-a-mistake-due-to-loose-cable.ars
Since September, scientists have been scratching their head over results that appear to show neutrinos traveling between Switzerland and Italy faster than light would. As far as anyone could tell, the team behind the results had done everything they could to eliminate errors, and had even released some preliminary data that had strengthened their results. But the results remained difficult to square with everything else we know about how the Universe operates.
But now, ScienceInsider is reporting that there was a good reason the measurements and reality weren't lining up: a loose fiber optic cable was causing one of the atomic clocks used to time the neutrinos' flight to produce spurious results. If the report is confirmed (right now, there's only one source), then it provides a simple explanation for the fascinating-yet-difficult-to-accept results. According to the new report, researchers are preparing to gather new data with the clocks properly hooked into computers, which should definitively indicate whether the loose connection was at fault.
It's somewhat ironic that ScienceInsider, which is part of the American Association for the Advancement of Science, broke the news now. Over the weekend, the AAAS held its annual meeting, which included a discussion of the biggest news in physics, where the neutrino results were highlighted. The session indicated that five different neutrino experiments were upgrading their hardware in order to check timing, and some would have data before the year is out. So even if this report doesn't pan out, we should know more soon.
At the AAAS meeting's discussion, CERN's director of research, Sergio Bertolucci, placed his bet on what the results would be: "I have difficulty to believe it, because nothing in Italy arrives ahead of time."
UPDATE: Nature News has apparently received a statement from the Opera researchers. It indicates they have found two potential issues (one of them the optical cabling). The two issues would skew the results in opposite directions, which is why they will need new measurements to better understand whether both influence the results and, if so, what the net impact is.
http://arstechnica.com/science/news/2012/02/faster-than-light-neutrino-result-apparently-a-mistake-due-to-loose-cable.ars