Einstein can rest easy as neutrinos obey speed limit

LONDON Fri Mar 16, 2012 3:10pm EDT

Scientists stand in front of screen before the first successful collisions at full power at the Compact Muon Solenoid (CMS) experience control room of the Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) in Meyrin, near Geneva March 30, 2010. REUTERS/Denis Balibouse

Scientists stand in front of screen before the first successful collisions at full power at the Compact Muon Solenoid (CMS) experience control room of the Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) in Meyrin, near Geneva March 30, 2010.

Credit: Reuters/Denis Balibouse

Related Topics

LONDON (Reuters) - New research suggests neutrinos that appeared to break one of Einstein's fundamental theories by travelling faster than the speed of light actually keep within the universal speed limit after all.

The latest measurement of the sub-atomic particles' speed of flight from the CERN research centre in Geneva to Gran Sasso in central Italy contradicts an initial super-fast reading reported last September, which caused a scientific sensation.

Since then, more doubts have crept in about the original claims, especially after news last month that the first finding from the so-called OPERA experiment may have been distorted by faulty cabling.

The new analysis was done by researchers working on a separate experiment called ICARUS. Using independent timing data and measuring seven neutrinos in the beam sent from CERN, they found the time was exactly consistent with the speed of light.

Sandro Centro, an expert in high-energy physics and spokesman for the ICARUS experiment, said he believed the results of the new tests were conclusive.

"The speed of light and speed of neutrinos are the same," he said in a telephone interview after the team's findings were published online on Friday.

The earlier controversial OPERA study had clocked neutrinos covering the 730 km from CERN to Gran Sasso 60 nanoseconds - or 60 billionths of a second - faster than light.

"The evidence is beginning to point towards the OPERA result being an artifact of the measurement," CERN Research Director Sergio Bertolucci said in a statement.

But he added that the scientific community needed to be rigorous and further tests were planned in May using more pulsed beams from CERN to provide the final verdict.

Many scientists had been skeptical about the original measurements, which flew in the face of Albert Einstein's 1905 Special Theory of Relativity which states that nothing in the universe can travel faster than light, an assertion that underpins much of modern physics and cosmology.

The ICARUS team, working at the same Italian National Institute for Nuclear Physics (INFN) Gran Sasso laboratory, north-east of Rome, as colleagues on the OPERA project, had already queried the initial findings because the neutrinos did not appear to lose energy on their flight as would have happened if they had broken the light barrier.

"As it happens in science, someone repeats the same experiment and can come up with a different result," Fernando Ferroni, INFN's president said in a statement.

He said that after this latest results, doubts about the faster-than-light reading were "gaining more ground".

The ICARUS scientists used a vast chamber of liquid argon to detect the arrival of the neutrinos at the Gran Sasso laboratory, which is dug deep in a mountainside.

The details of the experiment were posted on the scientific website arxiv.org/abs/1203.3433 .

(Additional reporting by Kate Kelland, editing by Robin Pomeroy and Angus MacSwan)

FILED UNDER:
We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see http://blogs.reuters.com/fulldisclosure/2010/09/27/toward-a-more-thoughtful-conversation-on-stories/
Comments (7)
krm398 wrote:
OK, great we know for a fact then that nuetrinos can travel at light speed. Quit goofing off and build that engine, the Nuetrino engine that makes probes and ships travel faster than the junk we have today. If your so good to get to the bottom of this contriversy so quickly, then lets see you make something of it.

Mar 16, 2012 12:38pm EDT  --  Report as abuse
gregbrew56 wrote:
Attempts at verification should have taken place BEFORE publication. All this episode did was give science and the scientific method a black eye.

Researchers:

Stop.
Doing.
This.

Mar 16, 2012 1:39pm EDT  --  Report as abuse
..Peace..6 wrote:
can someone explain to me in layman’s terms how they track the same 7 neutrinos?

Mar 17, 2012 10:45am EDT  --  Report as abuse
This discussion is now closed. We welcome comments on our articles for a limited period after their publication.