Thursday, 18 September 2008

There is no zero

You've probably heard about the LHC at CERN by now. You may have seen the LHC rap. Unfortunately, you've probably also heard about the 'end of the world via black hole'. While it is great that such an important physics experiment is now (almost?) a household name, it is a shame talk is of such nonsense, rather than the science.

There is no chance that the LHC will cause the end of the world (except via its presumably huge carbon footprint).

I believe a main reason for so many people seriously worrying about this is due to scientists communicating with 'the public' assuming that they think like scientists. And assuming that the public have some knowledge of quantum mechanics.

In physics, there is no zero. Nothing is ever just nothing. You can't be completely still (zero momentum), you can never reach a temperature of 'absolute zero', and nothing can ever have no energy. In fact you can't even have nothing. The theory behind this is quantum mechanics - I shall save the full explanation for another day - but it basically says that particles (and hence everything) behaves in a probabalistic manner. Instead of definites, you have probabilities. And nothing is ever impossible.

So when you pour your milk onto your cereal, in physics language it is possible that you will create a black hole and destroy the world. In non-science talk, you would say this is an absolutely ridiculous suggestion.

The same applies to the LHC. In physics terms, nothing is impossible; but in normal language, CERN will not destroy the earth*.

For a very entertaining introduction to the LHC, watch the LHC rap!

*And I don't mean there is a tiny chance. It is the same kind of chance as creating a black hole from a (glass) milk bottle.

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