Faster than Light

Physicists have a stock phrase they trot out whenever someone claims to have made an astounding discovery about the universe. “Important,” they say, “if true.” It’s a tactful way of saying, “Don’t bet on it.” They’ve been saying that a lot lately.

The reason: a team of European scientists has reportedly clocked a flock of subatomic particles called neutrinos moving at a shade over the speed of light. According to Albert Einstein, that can’t be, since light, which cruises along at about 186,000 miles per second (299,000 km/sec.), is the only thing that can go that fast.

If the Europeans are right, Einstein wasn’t just wrong but almost clueless. Particles that move faster than light are essentially moving backward in time, which could make the phrase cause and effect obsolete. “Think of it as being shot before the trigger is pulled,” wrote University of Rochester astrophysicist Adam Frank on his NPR blog.

The evidence for this complete upending of modern physics and cosmic decorum comes from an experiment involving two physics installations. One is CERN, the European Center for Particle Physics, near Geneva, where a particle accelerator created a swarm of neutrinos and aimed them through the Alps (neutrinos move effortlessly through obstacles) at particle detectors 450 miles (724 km) away in the Gran Sasso Observatory, beneath Italy’s Apennine Mountains. When the two labs synchronized their watches, it appeared that the neutrinos had made the journey 0.0025% faster than a beam of light would have.

That splinter of a second isn’t much, but it’s enough to overturn a century of firmly established physics, rewrite the textbooks and throw the faculties at major universities around the world into a collective tizzy. In short, it’s really important. If true.

No one is tearing up the Einsteinian rule book just yet. As physicists well know, astonishing results often turn out to be wrong, especially when they haven’t been replicated–though in this case, the scientists painstakingly checked the calibration of their instruments and recrunched their data and came up with the same results. Still, they welcome–indeed invite–a second opinion. As physicist Antonio Ereditato, leader of the Gran Sasso, told the BBC, “My dream would be that another, independent experiment finds the same thing. Then I would be relieved.”

He may get his wish soon. A group at the Fermilab accelerator complex near Chicago says it’s gearing up for a round of studies to confirm or refute the results. As it happens, Fermilab made its own claim of faster-than-light neutrinos back in 2007. It too would have been important if true, but on closer analysis, the evidence went away. At the moment, physicists everywhere are betting the European study’s findings will do the same.

Or maybe they won’t. The history of science may be littered with claims that were ultimately proved false. But it takes only a single true one to overturn everything we think we know about the universe.