Davy’s ‘arch’

A few years ago, the cartoonist Randall Munroe, author of the endlessly insightful cartoon series XKCD, published a book entitled ‘What If?’ which collected a series of absurd questions that he then answered by means of Fermi estimates, kooky line drawings and wacky asides. Contrary to popular belief, ‘what if’ is the fundamental question of science that makes it possible for us to eventually arrive at answers to the second question: ‘Why?’. Supreme among the exponents of the ‘What if’ school of exploration is Humphry Davy, the chemist whom many regard as being the greatest scientist of his day – quite an accolade in a crowded field.