There has to be much number crunching before we celebrate the light fantastic

AN EXCITING new result has been announced suggesting that neutrinos – subatomic particles with a tiny mass, much smaller than the mass of an electron – may travel at a speed that exceeds the speed of light by two parts in 10,000.

So, this result would imply that neutrinos are travelling faster than the speed of light, nature’s speed limit, the maximum speed allowed by any particle in nature according to the Theory of Relativity proposed by Albert Einstein.

This theory has been verified many, many times by experimentation.

These results arise from a very complex analysis which relies on measuring the time difference between the neutrino production at CERN and the neutrino arrival at the particle detector.

It relies on very careful global positioning system (GPS) measurements, painstaking calibration of the electronics and a very accurate measurement of the position of the distance between the detector and the production point at CERN, with an accuracy of 20 centimetres.

Does this mean that in principle, we could send messages with neutrinos that travel at faster than the speed of light? Does it mean that we could travel in time?

We have to be extremely cautious in interpreting these results. While at first sight the experiment has been performed very carefully, there is a large number of complicated corrections that might not be as accurate as the scientists estimate, and it relies on adding up the delay on many different electronic effects.

A previous experiment in the US, called MINOS, performed a similar measurement and had ten times worse accuracy than this experiment.

While the GPS measurement in this experiment is more sophisticated than that of the experiment in the US, to achieve a factor of ten improvement in the accuracy is very difficult, and it will need careful verification by the scientific community.

This is potentially an extremely exciting result, but at this point in time it is still far too early for us to say whether nature’s speed limit has been breached by these neutrinos, or more probably, whether an underestimate in the precision of the experiment is the cause for this discrepancy.

l Dr Paul Soler, reader in particle physics, school of physics and astronomy, University of Glasgow.