The odds have shrunk that Einstein was wrong about a fundamental law of the Universe.
Scientists at the world's biggest physics lab said on Friday they have ruled out one possible error that could have distorted startling measurements appearing to show particles travelling faster than light.
Many physicists reacted with scepticism in September when measurements by French and Italian researchers seemed to show subatomic neutrino particles breaking what Einstein considered the ultimate speed barrier.
The European Organisation for Nuclear Research said more precise testing has confirmed the accuracy of one part of the experiment. “One key test was to repeat the measurement with very short beam pulses,” said the Geneva-based organisation, known by its French acronym CERN.
The test allowed scientists to check if the starting time for the neutrinos was being measured correctly before they were fired 730 km from Geneva to a lab in Italy. The results matched those from the previous test, “ruling out one potential source of systematic error,” said CERN.
Still, scientists stressed only independent measurements by labs elsewhere would allow them to declare the results a genuine finding. “A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny,” said Fernando Ferroni, president of Italian Institute for Nuclear Physics. “The positive outcome of the test makes us more confident in the result, although a final word can only be said by analogous measurements performed elsewhere in the world.”
According to Einstein's 1905 special theory of relativity, nothing is meant to be able to go faster than the speed of light — 299,792 km per second.
But the researchers said in September that their neutrinos travelled 60 nanoseconds faster, when the margin of error in their experiment allowed for just 10 nanoseconds.