17 March 2009

Reality bites

If the upheavals of the recent economic downturn have made you question the very nature of reality, there is good news this week: reality does exist. It has been officially proved by two teams of scientists working independently, who have proved that things do exist even when no-one is watching them. And it's all down to resolving something called Hardy's Paradox (bear with me - it does get exciting).

Hardy's Paradox, as you will no doubt remember, centres on the interaction between matter and antimatter - that when a particle meets its antiparticle, the pair will always annihilate each other in a burst of energy - positing that in some unobserved cases the particle and antiparticle could survive. But since they are unobserved, we'd never know - so far, so Stephen Hawking.

This week, Osaka University in Japan demonstrated what observing an unobserved phenomenon looks like, by achieving the impossible: probing reality without disturbing it, which is the quantum equivalent of not really looking at something. By pooling data on a series of partial results of encounters between two photons, they could get a glimpse of the whole - and they discovered reality is not quite what we thought it was.

The outcome of all this sub-atomic fiddling was the distribution of photons was not what was expected. In some cases, the number of photons was less than zero. Given the present state of world finances, that does indeed sound like a version of reality that everyone can understand: when no-one was looking there was lots of it - as soon as we looked, it turned out there was less than we thought there was.

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