Replication of OPERA results is the key

Published in The Hindu on November 23, 2011


What makes science so very different from religion? Quite simple — every theory, law and observation in science will be continuously challenged and put to test almost every day. In short, unlike religion, science is not dogmatic.


As the OPERA team involved in measuring the speed of neutrinos has already shown, the early arrival was cross-checked for six months and by measuring the speed of more than 15,000 neutrinos before the results were announced.

When a possible source of error concerning the longer duration (10.5 microseconds) of the proton pulses was raised, the OPERA team repeated the experiment by producing shorter-duration pulses. And the results were identical — neutrinos travelled 60 nanoseconds faster than light.

Optical fibre to be used

Another possible source of error pointed out by scientists concerns the synchronisation of the clocks located at the point of generation of neutrinos (CERN) and at the detector (Gran Sasso). The clocks were synchronised using GPS signals from a single satellite. The use of GPS for this purpose has never been attempted before in the field of high-energy particle physics.

OPERA scientists will soon be cross-checking this by using optical fibre to correctly synchronise the clocks.

The litmus test for any law/theory in science lies in replicating the results. In other words, any scientists from any part of the world following the correct procedures should be able to get the same results.

Hence the results obtained by the OPERA team should be reproducible at other accelerators. The Minnesota based Main Injector Neutrino Oscillation Search (MINOS) will be running a preliminary check next year to confirm OPERA’s results.

In the meanwhile, MINOS is upgrading its timing system to “match OPERA’s precision.” It will take a year for this to be completed.

In fact, MINOS had in 2007 observed a similar early arrival of neutrinos. But the scientists downplayed it as the results lacked high levels of confidence.

The other one is Japan’s T2K accelerator which can send neutrinos 295 km from Tokai to the Super-Kamiokande detector in Kamioka. But it was shut down after the Fukushima accident, and it is not sure when this accelerator will be able to experimentally check the results.

In the meanwhile, scientists at both these facilities are having a relook at their data.

Reanalysing the existing data should not take time. Rob Plunkett, co-spokesperson for the MINOS was quoted as saying in Nature that “the MINOS group might have an answer within a few months.”