superluminal neutrinos - not (quite) dead yet.

When historians of science look back on the whole OPERA superluminal neutrino discussion, one way or the other, there are going to be a number of lessons to draw from the experience about how science and science journalism function in the early 21st century.

Yesterday, with "BREAKING NEWS" headlines, Science magazine proclaimed: "Error Undoes Faster-Than-Light Neutrino Results". In that article, "according to sources familiar with the experiment", the whole timing discrepancy for the neutrinos is traced to a bad fiber optic connection to a GPS receiver. The claim from that article is that "After tightening the connection then remeasuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed." Since that's the critical amount by which the neutrinos allegedly arrived too soon for special relativity, that would seem to be the end of the story. Embarrassing for OPERA, but case closed, right? T

Wrong. First, on its face, this seems weird - no one is quoted by name, and the idea that a loose fiber coupling could contribute 60 ns in timing is pretty odd (since that would correspond to something like 18 m of free space optical path). At minimum, the description above must be garbled.

Moreover, the actual email from the CERN director does not say this at all. Rather, it says that OPERA has identified two outstanding issues, one involving an oscillator that provides timestamps for the GPS synch, and an optical fiber connector that brings the GPS signal to the OPERA master clock. The former issue could make the neutrino timing problem worse, in fact. Moreover, the message says explicitly that they are going to take new measurements in May to check these issues. That seems to flatly contradict the news article claiming that they've already done tests. For a detailed discussion, see Matt Strassler's excellent blog here.

Bottom line: as I've said before, the superluminal neutrino result is almost certainly wrong, but the jury is still out on how and why, despite what the Science news blurb says. Believe me, if they knew for sure how this stood, they'd end it with a definitive statement, not stretch this out 'til May.

UPDATE:  Prof. Strassler has the best write-up of this, based on detailed reporting from the European press.   Because of two different, subtle technical flaws, the uncertainty in the OPERA results is bigger than the 60 ns timing discrepancy, meaning (1) the result is not in contradiction w/ special relativity (big surprise), and (2) they need to run with fresh data and the problems rectified to make any more definitive statement.