Thursday, September 29, 2011

"No Cause to Dispute Einstein"

This is the best response I've seen about those wayward faster-than-light neutrinos, from physicist Victor Stenger:
"...If the observation is confirmed, it may be the most important discovery in science in the last 100 years.

Supernova 1987a
"However, a big fly in the ointment is the supernova in the Large Magellanic Cloud, which sits just outside our galaxy 168,000 light-years from Earth. It was first seen by the naked eye on February 24, 1987. Three hours before the visible light reached Earth, a handful of neutrinos were detected in three independent underground detectors. If the CERN result is correct, they should have arrived in 1982. So, if I were a wagering man, I would bet the effect will go away because of some systematic error no one has yet been able to think of."
The 1987 neutrinos arrived slightly ahead of light not because they traveled faster than light, but because they got out of the supernova more quickly--light interacts more strongly with matter than do neutrinos, so it got held up in all the mess. Neutrinos hardly interact with matter at all--a neutrino can travel through more than a light-year of solid lead, on average, before it interacts with a lead atom. And a light year is almost 1016 meters!

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