A membrane that can remove salts from water more efficiently

ALAN TURING was no slouch. He laid the mathematical groundwork for modern computing. He led the successful effort to crack Germany’s Enigma code during the second world war. And he also, though it is less well known, made an important contribution to chemistry with a paper winningly entitled “The chemical basis of morphogenesis”. In it he described how the diffusion of two chemicals that react with each other can, in certain circumstances, produce complex patterns of blobs and striations. These patterns, now called “Turing structures”, bear an uncanny resemblance to many that are found in nature: a zebra’s stripes, for example, or a ladybird’s spots.