Well, it had to happen. The OPERA team has identified two potential problems in their measurement of neutrino velocities. (You remember that story, right? The one where it seemed as if the neutrinos were superluminal…)
It turns out that there’s a problem with an atomic clock that they used to get start/stop times for the measurement. (The error here would tend to increase the measured time-of-flight, and thus reduce the measured speed.) There was also a problem with the optical fibre connection between the main clock and the GPS system. (Surprisingly, the error here would tend to increase the measured speed.)
The identification of these two systematic errors means that the OPERA team can no longer claim to have seen superluminal neutrinos. Further experiments later this year, both at OPERA and elsewhere, will surely put the story to bed once and for all.
What has been fascinating here, though, has been the reaction of the scientific community to the claim. I think we all knew that this result was never going to stand. But that doesn’t mean the OPERA team were wrong to publish. Their initial result caught the public imagination, and their identification of systematic errors in the experiment showed the public how science progresses in the real world.
They showed that science is sometimes messy, sometimes confusing. But they also showed that science is transparent, and eventually it gives us knowledge we can rely on. Well done OPERA.