Since the apparent discovery of neutrinos that are moving at superluminal speeds, scientists have been trying to come up with explanations for these findings. The most obvious and likely explanation is measurement error.
Among the most recent ideas is a paper invoking Einstein’s supposedly challenged theory of relativity. The OPERA team used GPS satellites to accurately measure the 730-km distance between their detector and the CERN beam where the neutrinos were produced. Yet, according to special relativity, calculations will be slightly different when two observers are moving relative to one another.
Since the satellites were zipping around the Earth, the positions of the neutrino source and the detector changed. According to the paper, the movement would account for a 64 nanoseconds discrepancy, nearly exactly what the OPERA team observes.
A less likely explanation is that Einstein’s Theory of Relativity is wrong. In fact, both the theories of Special and General Relativity have been amply proved by experiments and observations. There is at least one good reason to suspect that neutrinos do not regularly travel faster than light.
One of the earliest objections to the faster-than-light interpretation came from an astrophysical observation. In 1987, a powerful supernova showered Earth with light and neutrinos. While neutrino detectors observed neutrinos arriving about three hours before the light, this was due to the lightweight particles getting a head start. Neutrinos, which hardly interact with matter, escaped the exploding stellar core with relative ease while photons, absorbed and re-emitted by the various elements, took longer to flee. If the effect from OPERA were as large as observed, scientists have calculated that the neutrinos should have arrived more than four years in advance of the light.
And we know that electrons do not travel faster than light.
Theoretical physicist Matt Strassler also noted on his blog that the Standard Model’s properties suggest that making neutrinos go faster than light requires electrons to do the same. But if electron neutrinos moved at the speed suggested by the OPERA experiment, then electrons should also travel faster than the speed of light by at least one part in 1,000,000,000, or one billionth. Experiments have established theoretical limits that electrons remain subluminal at a precision down to more than 5 part in a thousand trillion, effectively ruling this scenario out.
So, what is going on? We don’t know, yet. My opinion, which really isn’t worth much, is that if the observations are verified, than superluminal travel will be due to some unique property of the nutrinos, which are odd little particles anyway.
- Game Over for Faster-Than-Light Neutrinos? [Starts With A Bang] (scienceblogs.com)
- Einstein Wins Again (the1955hudson.com)
- Slow Down: Error Produced Faster Than Light Neutrinos (lezgetreal.com)
I suppose the consensus is measurement error. Too bad. No warp drive yet.