You know the old joke, “The speed of light: it’s not only the limit, it’s the law.” I used to think the joke was really lame, because if the speed of light were like a human law, then it could be changed. But the speed of light is a universal constant, invariant, and one of the foundations of modern physics. Perhaps you also heard, unless the din of other distractions prevailed, that scientists at the Gran Sasso Laboratory in Italy announced the measurement of a group of neutrinos moving faster than light.
Specifically: Neutrinos produced by the Super Proton Synchrotron at CERN in Geneva Switzerland were directed toward the Gran Sasso facility deep within the mountain of the same name, a distance of some 730km (455 mi). All other nuclear particles won’t go that far, but among the many weird particles in physics, neutrinos take the prize. In this case, the relevant fact is that neutrinos pass through matter – rock, metal, water – like matter doesn’t exist. So, 0.0024 seconds after the neutrinos are produced in Switzerland, they show up passing through bricks of photographic film in Italy. The interesting part, gathered from the OPERA experiment, is that at least some of the neutrinos show up 60 nanoseconds faster than if they were travelling at the speed of light. That’s 0.00000006 of a second faster. The results are published at arXiv [22 September 2011, Measurement of the neutrino velocity with the OPERA detector in the CNGS beam].
If the experimental results are correct, this is…like…awesome. I’m being deliberately obtuse. I know the number is very small; but that is absolutely and relatively not the point. If the speed of light can indeed be broken, a whole lot of physics needs to be re-thought and Einstein probably needs to be reburied. At the moment the implications of the discovery seem to be driving much of the coverage, but it’s way too early for anything other than thought experiments. Real science needs to do its thing. Discoveries of this magnitude must be verified, repeated, challenged and confirmed or not confirmed. The scientists involved are, obviously, no dummies. They are well aware of the burden of proof. They did what they could to check, re-check, examine and criticize their methods and results. Now they have released the information, which they consider preliminary, to the rest of the scientific community. Have at it! Which indeed they will because as Carl Sagan was fond of saying: Extraordinary claims require extraordinary evidence. Besides, nothing gets scientists engaged so much as something that threatens to destroy their work.
If you polled 100 physicists this morning, probably 98 of them would say something like, “What interesting results! No doubt wrong, of course.” The probabilities are that’s correct. Equipment calibration, measurement error, unidentified forces – there are many ways an experiment of such delicacy and precision can go wrong. However, the original scientists did their homework; they established a six-sigma level of confidence in their results. Five sigma would normally suffice to get attention.
However, don’t hold your breath waiting for a resolution. It will take years to play out. New experiments to recreate the measurements will need to be put in place; that alone could take months to years. Undoubtedly there will be some new theoretical modeling. There will be controversy. So be patient; there should be a number of interesting moments yet to come.