Well, ICARUS flies even higher, and so far shows no sign of losing its wings.
Remember OPERA, the experiment that claimed neutrinos sent from the CERN lab in Switzerland to the Gran Sasso lab in Italy arrive earlier than they were expected to? And that a couple of weeks ago had to admit they’d found a couple of problems that were large enough to scrap their result for the moment, and that require additional investigation?
And remember ICARUS, OPERA’s neighbor in the same Gran Sasso lab in Italy, which measured the energies of neutrinos from the CERN neutrino beam, and showed they were not altered in flight? And thus proved that if the neutrinos really were traveling faster than light, they did not exhibit anything like the variant of Cerenkov radiation that was suggested by and calculated by Cohen and Glashow?
Now, ICARUS’s result from the fall didn’t directly refute the OPERA experiment (despite some claims, even by them) but it certainly added to the aura of extreme implausibility that surrounded the whole story.
Well, this time ICARUS refutes OPERA. Essentially, they did the same measurement as OPERA-2, as I called the short-pulse variant of OPERA’s original experiment. They took data at the same time as OPERA-2, in the same neutrino beam, in the same laboratory. It took them a while to do all the distance and timing calibrations that OPERA had done many months ago, but they’re finished now. And whereas OPERA-2 gets the same result as OPERA-1— an early arrival of 60 nanoseconds (billionths of a second) — ICARUS finds a result consistent with an on-time arrival. Same measurement, different answer. At least one experiment made a mistake; and one result is vastly more plausible than the other, so I think the consensus is pretty clear in the matter.
