New Experiments Find Neutrinos Did Not Travel Faster Than Light
March 17, 2012

New Experiments Find Neutrinos Did Not Travel Faster Than Light

Neutrinos that appeared to travel faster than the speed of light during an experiment last year actually travelled at exactly light speed, new research from the European Organization for Nuclear Research (CERN) has revealed.

According to CNET reporter Stephen Shankland, the controversy began in September 2011, when the members of a CERN experiment team known as Opera fired neutrinos from the organization's underground particle accelerator near Geneva to the Gran Sasso National Laboratory in Italy, located at surface level a total distance of more than 450 miles away.

The experts calculated that the journey should have taken exactly 0.0024 seconds to complete, the AFP reported Friday.

However, they appeared to have arrived at their destination 0.00000006 seconds (or 60 nanoseconds) sooner than expected, which would have meant they were travelling faster than the speed of light. Realizing the repercussions of their research--namely that it would have turned Einstein's theory of relativity on its ear--the Opera team asked other physicists to conduct their own checks in order to either confirm or dispute their findings.

That challenge was taken up by another CERN team--members of an experiment known as Icarus--who used a different measuring technique, identified by the French news agency as a liquid argon time projection chamber, to double-check the travel times of the seven neutrinos studied by the Opera team. As Ben Hirschler of Reuters reports, their analysis discovered that the beam traveled at a velocity "exactly consistent with the speed of light."

"The speed of light and speed of neutrinos are the same," Icarus experiment spokesman and physics expert Sandro Centro told Hirschler. Likewise, he told BBC News science and technology reporter Jason Palmer that he had been "a little skeptical" of the Opera team's findings "since the beginning," and was now "100% sure" that the speed of light and the speed of the neutrinos were the same.

"I didn't trust the result right from the beginning - the way it was produced, the way it was managed," Centro added during his interview with Palmer. "I think they were a little bit in a hurry to publish something that was astonishing, and at the end of the day it was a wrong measurement."

Other CERN officials defended the Opera team's work. Research Director Sergio Bertolucci said in a statement that, regardless of the result, "the OPERA experiment has behaved with perfect scientific integrity in opening their measurement to broad scrutiny and inviting independent measurements. This is how science works." Likewise, Icarus project spokesman and Nobel Prize winner told AFP added that the research involved "difficult and sensitive measurements" and that they "underline the importance of the scientific process."

The Icarus team's findings have been published online at