Two weeks has elapsed since scientists at CERN announced the dramatic finding that the heavy muon neutrino was observed to travel faster than the speed of light. Since then scientists have been furiously investigating the results and seeking to explain why or, perhaps more importantly, why not.
The experiment involved firing a beam of heavy mass neutrinos generated by the CERN CNGS beam at the OPERA detector located 730 km away at Gran Sasso, Italy. Based on the details released in the paper, the neutrinos arrived earlier than it would have taken light to travel the same path by about 60 nanoseconds. Accordingly there is an implication that the average neutrino speed has exceed the speed of light and contravened the known laws of physics.
Opinion, as might be expected, is sharply divided. Many seek to pour scorn on the early release of the result and question whether the scientists were somewhat premature. Such a response is similar to the outcry in the early 1990's when Fleischmann and Pons believed they has observed cold fusion while carrying out an electrochemical experiment. Scientists quickly evaluated their result and the failure to reproduce anything remotely comparably led to swift rebuttal from the community. (Note - whatever Fleischmann and Pons observed, and they did observe something unexpected, it was not cold fusion, but neither has their result even been satisfactorily explained either.)
The problem in this case is slightly different. Firstly, the experiment is not easily reproduced and secondly, the data is based on several year's worth of data it is not a single result. Many, most notably Nobel laureate Sheldon Glasgow, have sought to explain how the result is not possible in the context of known physics. Others have begun to look into the details of the findings and questioned elements surrounding the timing of the events.
Many more, however, have taken the opportunity to seek new theories to justify the result by invoking some logical explanation such as through extra dimensions or bypassing Euclidian space, to the seemingly bizarre possibility that neutrinos move faster through the Earth than through space or the result hinges on the time of day!
Perhaps the most telling result is from one of the few positive identifications of neutrinos and that is with the burst observed from supernova 1987A. At the time a neutrino burst was observed to arrive a few hours before the light. This was correctly attributed to the opacity of the stellar remnant inhibiting the passage of optical photons, but not neutrinos. If the CERN result is correct there should be a corresponding burst - about 4 years before the visible event. Analysis of the data has revealed no similar result - although one should note that the neutrinos here are of much lower energy. This observation, while not a categoric disproof of the CERN result, certainly places constraints on the possible interpretations allowed on the result.
I am sure in time that the result will be explained within the current laws of physics and that the quicker time will be attributed to some systematic error in measurement. Why? Because the simplest explanation is usually the correct one. Part of me, however, wants to believe, like Sherlock Holmes, that: "We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth."
Faster than light neutrinos are highly improbable, but they might yet turn out to be true.