The European Organization for Nuclear Research (CERN) has confirmed that scientists have found errors in a physics experiment that recorded particles traveling 60 nanoseconds faster than the speed of light in late 2011. But now, the agency says that one of the errors means the particles could have been traveling faster than that!
However, the other error — a loose cable, seriously — reported by scientists working at the CERN experiment, called OPERA, means that the particles could have been traveling much slower than the initial results, calling into question the original findings that rocked the scientific world when they were first reported in September 2011.
At the time, the OPERA team reported firing a beam of uncharged particles called neutrinos from CERN’s facilities underground near Geneva, Switzerland, toward a detector 454 miles away, located near Assergi, Italy. The OPERA team said that the beam took only 2.39994 milliseconds (0.00239994 seconds) to travel the distance. That’s 60 billionths of a second, 0.00000006 seconds, faster than the speed of light (approximately 186,000 miles per second).
But the results were quickly called into question by science writers, as nothing in the known universe should be capable of traveling faster than light in a vacuum, according to Albert Einstein’s special theory of relativity.
Still, the OPERA team insisted that they had carefully double-checked their work, even repeating the experiment using shorter particle bursts in November 2011, only to uncover the same result.
Then, on Wednesday, Science Insider broke the news that OPERA scientists has discovered that the results might have been the result of a “bad connection between a GPS unit and a computer,” caused by a fiber optic cable connecting a GPS device used to track the particle beam and a computer card.
A CERN spokesperson confirmed to the The Associated Press shortly thereafter that the OPERA team had found “two separate issues,” with the experiment, including issues that “may have affected measurements,” either overestimating or underestimating the time it took the neutrinos to travel the 454 miles between the two instruments.
CERN on early Thursday finally put out its own release doubling down on this assessment of the errors, and explaining that OPERA scientists had fixed the errors and would re-run the experiment in May.
As CERN explained:
The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino’s time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May.
Cutting through the technical jargon, what CERN states is that either of the two errors could have disrupted the measurements of the actual time it took the neutrinos to travel, so the particles could have been traveling faster than initially reported, slower, or perhaps even the same speed.
That ambiguous result is unlikely to satisfy those in the particle physics community, but for now it seems, Einstein’s theory stands strong, at least until May, when the experiment is repeated using shorter beams of neutrinos. Let’s hope that OPERA scientists make sure that all the cables are tightly connected in that one.