Over the past couple of days London has been shrouded in thick fog, causing several flights to be cancelled at Heathrow and Gatwick airports. We live in an increasingly ‘hi-tech’ world, indeed, there is a planned mission to Mars. Using infra-red cameras, telescopes can see to the farthest corners of the universe. I think it is fair to say our scientists and engineers can do anything they put their minds to, so how come they cannot defeat fog? By now one would have thought all jets would be able to fly through it, and cars drive through it?