Thursday 22nd September 2011. This is the day that rocked the world of physics. An inconspicuously titled paper, “Measurement of the neutrino velocity with the OPERA detector in the CNGS beam” is posted by The OPERA Collaboration (a team consisting of approximately 200 physicists) on the arXiv website.
They had found experimental proof that neutrinos had travelled a distance just slightly faster than light would have! Light is the highway patrol for the universe. No one is to break its law! Or so we thought.
After a great flurry of articles, in print and online, on this topic the world now awaits patiently for these results to be peer-reviewed and thus confirmed independently.
On 29th September, another paper appeared on the arXiv website explaining what might be expected if the neutrinos were travelling faster than light (FTL). The theoretical paper was published by Andrew Cohen and Sheldon Glashow, who argue that a FTL neutrino will radiate in a particular manner that would be distinctive due its FTL speed. This however is not the only theoretical model out there, and there are other possibilities, such as the neutrinos travelling through some extra dimensions in which case one would not detect radiation as suggested by Cohen and Glashow.
On the 17th October, Imaging Cosmic and Rare Underground Signals (ICARUS) collaboration submitted a paper on arXiv website claiming that they have obtained an energy spectrum for the neutrinos that does not correspond to the theoretical predictions of Cohen and Glashow for FTL neutrinos. Though the group did not measure the speed of neutrinos directly, the energy spectrum for the neutrinos obtained didn’t correspond to them having travelled at FTL speeds.
This still does not rule out FTL neutrinos and two experiments are still to run their investigations into OPERAs results: The Main Injector Neutrino Oscillation Search (MINOS) experiment based at Fermilab in Batavia, Illinois, and the Tokai to Kamioka (T2K) experiment in Japan. Neither is likely to have results for some months, the world continues to wait.
Now, on another note, it takes normally months to make an hour-long documentary, if not years. Professor Marcus du Sautoy, presented a new programme on the question of faster than speed of light on the BBC…Check it out: