An experiment that claimed to clock neutrinos travelling faster than the speed of light, a result which, if true, would have upended modern physics as we know it, may have been fatally flawed. Glitches in the GPS system used to synchronize atomic clocks in the study may have tainted the outcome, according to a number of sources.
Science Insider broke the news Wednesday, simultaneously thrilling skeptics in the physics community and breaking hearts among those who had hoped to form the vanguard of a new time-travelling elite. Citing “sources familiar with the experiment” Edwin Cartlidge wrote that “a bad connection between a fiber optic cable … and an electronic card in a computer” appears to account for the 60 nanoseconds faster than light speed the neutrinos were timed travelling between two research centres in Europe.
After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed. Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos.
Later Wednesday, researchers at OPERA began circulating a statement acknowledging two possible problems with the experiment, Nature reported:
First, the passage of time on the clocks between the arrival of the synchronizing signal has to be interpolated and OPERA now says this may not have been done correctly. Second, there was a possible faulty connection between the GPS signal and the OPERA master clock.
Our own Nick Kohler wrote about the initial experiments in this magazine in November. It’s worth going back and reading his entire story, but just to give you a sense of how revolutionary these results would have been if confirmed, here’s a chunk:
(S)cientists working on the so-called OPERA experiment at the European Organization for Nuclear Research (CERN) outside Geneva generated blasts of neutrinos and sent them south, through the rocky subterranean precincts beneath the Alps, then high into Italy’s Apennines mountains, where, near the city of L’Aquila, they popped up in a neutrino detector at the underground Gran Sasso National Laboratory—a distance, all told, of some 730 km. The latest OPERA findings appear to back those earlier results—the neutrinos arrived a shocking 60 billionths of a second or so faster than a beam of light.
Should that result hold up, physicists will either have to scrap Einstein’s theory of special relativity or accept a range of phenomena now confined to science fiction—for example, that an observer travelling past a swift-flying neutrino would witness the particle hurtling backwards in time and appear at its destination before beginning its journey. The confirmation, made by scientists working on the collaborative OPERA experiment, generated enormous international chatter among physicists, who remain skeptical of the results but who must nevertheless contemplate what it would mean if a faster-than-light, or “superluminal,” neutrino proves real. Such a development would upend everything we know about the concept of “causality,” opening up the possibility of time travel at the subatomic level, and even suggesting the existence of new, hitherto unknown dimensions. More than that, it might require us to contemplate the possibility of wormhole portals connecting a Geneva suburb with the mountains of central Italy.
Thursday, February 23, 2012