from the didn't-see-that-coming dept.
Phys.org reports that in a new paper accepted by the journal Astroparticle Physics, Robert Ehrlich, a recently retired physicist from George Mason University, claims that the electron neutrino is very likely a tachyon or faster-than-light particle. Ehrlich's new claim of faster-than-light neutrinos is based on a much more sensitive method than measuring their speed, namely by finding their mass. The result relies on tachyons having an imaginary mass, or a negative mass squared. Imaginary mass particles have the weird property that they speed up as they lose energy – the value of their imaginary mass being defined by the rate at which this occurs. According to Ehrlich, the magnitude of the neutrino's imaginary mass is 0.33 electronvolts, or 2/3 of a millionth that of an electron. He deduces this value by showing that six different observations from cosmic rays, cosmology, and particle physics all yield this same value (PDF) within their margin of error. One check on Ehrlich's claim could come from the experiment known as KATRIN, which should start taking data in 2015. In this experiment the mass of the neutrino could be revealed by looking at the shape of the spectrum in the beta decay of tritium, the heaviest isotope of hydrogen.p
But be careful. There have been many such claims, the last being in 2011 when the "OPERA" experiment measured the speed of neutrinos and claimed they travelled a tiny amount faster than light. When their speed was measured again the original result was found to be in error – the result of a loose cable no less. "Before you try designing a "tachyon telephone" to send messages back in time to your earlier self it might be prudent to see if Ehrlich's claim is corroborated by others."