The King Prawn started a conversation about this earlier, but it attracted only six comments and didn't make it to the Main Feed, so let me try again. Here is my idiosyncratic take on the CERN announcement that results from CERN's OPERA experiment provide evidence that neutrinos propagate faster than the speed of light.
Since the 1990s there have been tantalising hints that the mass squared of the neutrino might be negative based upon studies of the endpoint of the energy spectrum of the decay of tritium. Here is the 1998 paper which first caused my ears to perk up about this.
Now, if the mass squared of a particle is negative, Einstein's equations predict that it is a “tachyon” of imaginary rest mass—a particle which always travels faster than light and cannot travel slower, just as a positive mass particle cannot ever reach or exceed the speed of light. There is nothing in this which implies “Einstein was wrong”, just that at the time he wrote down his equations in 1905 nobody imagined there would be particles with imaginary rest mass. If neutrinos have a very small imaginary mass, then it's perfectly consistent with special relativity that they travel faster than light.
http://motls.blogspot.com/2011/09/italian-out-of-tune-superluminal.html
shows that almost certainly the work is simply a faulty interpretation of the data.
Motl's blog notes:
"Anna has suggested that their GPS-based timing device may have
neglected that the electromagnetic waves are moving slower than c
through the atmosphere: if the collaboration did an error in this
subtlety, they get an error of exactly the same magnitude to explain
the "signal". The index of refraction of the air is 1.0003, so light
needs to penetrate a 10-km layer of the atmosphere as it would need
to get through 10.003 km of the vacuum which would exactly produce
the 3-meter delay. Make the atmosphere a bit thicker because the
satellites are not right above your head; add the delays from both
directions and you may already produce those 18 meters of error (or
most of it)."
I am betting that some mundane explanation like the above will prove correct and that Einstein's relativity will pass yet another test. - Jack Sarfatti