Faulty wiring has been proposed as the glitch that caused a European physics experiment to clock particles flying faster than light.
Scientists at Italy’s OPERA experiment reported in September that nearly weightless particles called neutrinos were apparently traveling from the CERN laboratory on the Swiss-French border to an underground detector in Italy, 730 kilometers away, faster than the speed of light. The apparent violation of Einstein’s theory of special relativity immediately produced a chorus of theorists offering reasons why neutrinos simply could not be going that fast (SN: 11/5/11, p. 10).
“It was always clear to me that the results could not have been true,” says Nobel Prize-winner Sheldon Glashow, a physicist at Boston University and an early critic of the finding.
Yet during a second run of the experiment in November, neutrinos again appeared to arrive in Italy 60 nanoseconds earlier than light covering the same distance in a vacuum would have (SN: 10/22/11, p. 18).
On February 23 the OPERA team announced what might be causing the surprising observations: A bad connection with a cable that relays satellite GPS signals to keep the experiment’s clocks in sync could have made each particle’s trip seem to take less time than it actually did.
With technical problems clouding its results, the OPERA team will tighten its cables and repeat the experiment. MINOS, a neutrino experiment run by Fermilab near Chicago, will also go ahead with plans to time neutrinos sent from there to Minnesota.
“We should have been more cautious in the way we framed the results,” says Luca Stanco, a physicist who works on OPERA at the National Institute of Nuclear Physics in Padua, Italy. “Now we are a little embarrassed.”