Once upon a time, the only thing that traveled faster than the speed of light was gossip.

Thanks to the Internet, the whole physics world was watching on Friday when Dario Autiero, of the Institut de Physique Nucléaire de Lyon in France, in front of a palpably skeptical roomful of physicists, put a whole new category of speed demons on the table, namely the shadowy subatomic particles known as neutrinos. He was describing a recent experiment in which neutrinos were clocked going faster than the speed of light, the cosmic speed limit set by Albert Einstein in his theory of relativity back in 1905.

According to Dr. Autiero’s team, neutrinos emanating from a particle accelerator at CERN, outside Geneva, had raced to a cavern underneath Gran Sasso in Italy — a distance of 454 miles — about 60 nanoseconds faster than it would take a light beam. That amounts to a speed greater than light by about 25 parts in a million.

“We cannot explain the observed effect in terms of systematic uncertainties,” Dr. Autiero told the physicists at CERN, the European organization for nuclear research. “Therefore, the measurement indicates a neutrino velocity higher than the speed of light.”

Dr. Autiero said his group had spent six months trying to explain away the result, but could not do it. Given the stakes for physics, he said, it would not be proper to attempt any sort of theoretical interpretation of the results. “We present to you this discrepancy or anomaly today,” he said.