Physicists who have observed particles beating the speed of light have found similar results in an experiment rerun.
The repeat of an earlier experiment, in which neutrinos sent through the ground from Switzerland to Italy, confirmed measurements that showed the particles arriving a fraction earlier than they would have at light speed.
The Opera experiment sent neutrinos through the ground from Cern in Geneva, Switzerland, to the Gran Sasso laboratory in Italy. In September, the European particle physics laboratory Cern announced measurements that were “at odds with well-established laws of nature”.
After putting the results out for scrutiny by the scientific community, Cern repeated the experiment, and published data confirming the first test on 17 November.
Cern said in a statement on 18 November: “The [Opera] collaboration has rechecked many aspects of its analysis and taken into account valuable suggestions from a wide range of sources… This test confirms the accuracy of Opera’s timing measurement, ruling out one potential source of systematic error.”
However, Cern also stated that “the observed anomaly in the neutrinos’ time of flight from Cern to Gran Sasso still needs further scrutiny and independent measurement before it can be refuted or confirmed”.