More evidence that neutrinos are NOT faster than light

Just in case there was any doubt that our current understanding of physics remains unimpeached, those OPERA boffins probably definitely didn't prove that neutrinos can go faster than the speed of light.

More boffins, this time involved in the ICARUS experiment between CERN and the Gran Sasso lab in Italy, reported a new measurement of the flight of neutrinos zooming between the two today and, no, they didn't travel faster than light and prove Einstein and the last eighty years of physics wrong.

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

"But it's important to be rigorous, and the Gran Sasso experiments, BOREXINO, ICARUS, LVD and OPERA will be making new measurements with pulsed beams from CERN in May to give us the final verdict. In addition, cross-checks are underway at Gran Sasso to compare the timings of cosmic ray particles between the two experiments, OPERA and LVD. "

The OPERA physicists caused a stir last year when they reported findings that suggested that neutrinos zipping along quite happily between CERN and Gran Sasso 60 nanoseconds faster than light could have done, a finding that would interfere with the widely accepted maxim derived from Einstein's theory of general relativity that nothing can travel faster than light.

The initial reaction from many was to declare that "Einstein was wrong!" and "Laws of physics broken", which was probably not entirely fair since Einstein was wrong/changed-his-mind-about-things a few times in his career, as do most scientists, and there's a reason it's called a "theory" of relativity, it's not really the law.

(But then headlines screaming "Einstein could possibly have been wrong with one of the implications of his theory of general relativity, which nevertheless remains a bastion of modern science and one of the reasons your smartphone works, and anyway we're not sure yet because the results will have to be repeated a good few times before we can begin to formulate any theories" might not have been quite as enticing.)

Regardless of the degree of certainty, the results were certainly exciting since they implied (to sci-fi fans at least) that time travel was more strongly possible. However, the fun was short-lived as other boffins immediately began to test the findings and discover they couldn't repeat it.

"Whatever the result, the OPERA experiment has behaved with perfect scientific integrity in opening their measurement to broad scrutiny, and inviting independent measurements," Bertolucci pointed out. "This is how science works."

The ICARUS experiment has its own method of timing the neutrinos making the journey from CERN to Gran Sasso and saw seven neutrinos come in at the speed of light and no more.

"These are difficult and sensitive measurements to make and they underline the importance of the scientific process," Carlo Rubbia, Nobel Prize winner and spokesperson of the ICARUS experiment, said.

"The ICARUS Liquid Argon Time Projection Chamber is a novel detector which allows an accurate reconstruction of the neutrino interactions comparable with the old bubble chambers with fully electronics acquisition systems.

The fast associated scintillation pulse provides the precise timing of each event, and has been exploited for the neutrino time-of-flight measurement. This technique is now recognised worldwide as the most appropriate for future large volume neutrino detectors." ®