It’s amazing to see the anti-science spins some people attached to the headlines last fall that physicists had observed faster-than-light travel. The alleged speed limit violators were invisible particles called neutrinos that CERN physicists sent in a beam 646 miles through the ground. The particles appeared to travel that distance 60 nanoseconds faster than the speed of light.
Neutrinos are a very hard-to-observe form of matter, first postulated by Enrico Fermi in the 1930s to explain why a small amount of mass seemed to be carried away from nuclear reactions. The first neutrinos were detected in the 1950s.
They’re generated in the sun and other stars in enormous quantities - 100 billion neutrinos zoom through a spot the size of your thumbnail every second. At night, they stream through the Earth and come out the other side. They’re not only invisible but they tend to pass through matter without leaving a sign.
Some commentators, such as Charles Krauthammer, reported that physicists were upset, even devastated by this result and reluctant to accept the idea because it violated special relativity and they revere Einstein.
This is hardly the case. Scientists were skeptical because it was a single, unconfirmed result that involved complicated equipment and indirect measurements. Indeed, the latest press release from CERN suggests some mechanical glitches that might have fooled the physicists into thinking they’d detected faster-than-light travel. A mistake is what most physicists suspected all along:
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.
It's true that the initial results would have violated Einstein’s 1905 theory of special relativity, which showed that the speed of light is constant (in a vacuum), while time and space can expand and contract. According to Einstein, faster-than-light travel allows reversals of cause and effect. It would be possible, for example, to see a crime scene in which the victim collapsed from a bullet wound before the shooter fired.
The result also contradicted measurements scientists have made of neutrinos travelling a much longer distance, from a supernova that exploded in 1987. Those neutrinos travelled 168,000 light years and arrived no faster than expected.
Penn physicist Gene Beier said other labs in the United States and Japan are already gearing up to try to confirm the original result. They may continue their experiments, and everything will eventually get sorted out. Yes, physicists were reluctant to embrace the initial result, but they were willing to put in the effort to get a more definitive answer. “I think most scientists are quite open-minded and are prepared to deal with any deviation from what might be the current orthodoxy,” he said, “but it has to be supported by experiments and those experiments have to be believable.
If the neutrino result is wrong, it should serve as a cautionary note about other single studies, especially those involving health or human behavior. Single studies with counter-intuitive results are often trumpeted by press releases, and these days press releases go directly to the public rather than getting investigated by journalists.
In the unlikely event the original result is correct and neutrinos really did violate the speed limit, Einstein’s legacy will be fine. Relativity works under most circumstances – the GPS in your phone wouldn’t work if it was completely wrong. But if the faster-than-light neutrinos were real, they might lead physicists to a bigger, more all-encompassing theory. There are already known discrepancies between Einstein’s theory and quantum mechanics, which describes matter at a sub-atomic level. So we know there’s something more out there. Physics isn’t finished describing the universe yet. Einstein would almost certainly be pleased.