Physics that keeps on boggling the mind

PUBLISHED : Saturday, 01 October, 2011, 12:00am
UPDATED : Saturday, 01 October, 2011, 12:00am


The Cern experiment that found a stream of subatomic particles had travelled faster than the speed of light in apparent violation of Einstein's relativity theory made news headlines everywhere. Physicists around the world are now trying to check and recheck the results, or duplicate the experiment. Many experts believe it's a false alarm. We'll find out soon enough.

But regardless of whether the Cern results are accurate, the public should know about the basic issues. At stake is nothing less than the laws of nature and how we represent them.

The Cern experiment involved neutrinos, ghostlike particles with almost no mass. They come in three flavours - as electrons and mu and tau neutrinos. One of the quirks of quantum mechanics is that we can't predict which state a neutrino is in unless we measure it. Each flavour has a slightly different mass.

Suppose the Cern scientists initially prepared a large supply of electron neutrinos, sent them from point A to point B and then measured their speed. Not a simple thing, because neutrinos travelling between A and B would manifest themselves in different flavours. Scientists not only would have to measure their velocity, but account for their different phases and the proportions of the different flavours of neutrinos when they hit detectors at B.

Yet how did the Cern scientists carry out these complicated measurements and calculations? By using equations composed of such universal constants as h (Planck's constant) and c (the speed of light)!

How can we use c in equations to invalidate the claim of c as a universal constant? The mind-boggling questions that quantum physics create about physical realities are, once again, more challenging than most sci-fi fiction.