Physics is really nothing more than a search for ultimate simplicity, but so far all we have is a kind of elegant messiness. - Bill Bryson

If a potato can produce vitamin C, why can't we? Within the animal kingdom only humans and guinea pigs are unable to synthesize vitamin C in their own bodies. Why us and guinea pigs? No point asking. Nobody knows.

As we parted at the Natural History Museum in London, I asked Richard Fortey how science ensures that when one person goes there's someone ready to take his place.

He chuckled rather heartily at my naiveté. 'I'm afraid it's not as if we have substitutes sitting on the bench somewhere waiting to be called in to play. When a specialist retires or, even more unfortunately, dies, that can bring a stop to things in that field, sometimes for a very long while.'

And I suppose that's why you value someone who spends forty-two years studying a single species of plant, even if it doesn't produce anything terribly new?'

'Precisely,' he said, 'precisely.' And he really seemed to mean it.

The pleasant fact is that the British are not much good at violent crime except in fiction, which is of course as it should be.