- A New Kind of Science by Stephen Wolfram
Wolfram Media, 1197 pp, £40.00, May 2002, ISBN 1 57955 008 8
One of the most intriguing of all magic tricks, the Disappearing Handkerchiefs, was presented to King Louis-Philippe at the Château St-Cloud in 1846 by the renowned French magician Robert-Houdin. An account can be found in his Memoirs:
I borrowed from my noble spectators several handkerchiefs which I made into a parcel and laid on the table. Then at my request different persons wrote on the cards the names of the places whither they desired their handkerchiefs to be invisibly transported. When this had been done, I begged the King to take three of the cards at hazard and choose from them the place he might consider most suitable.
One of the three cards picked by the King suggested that the handkerchiefs should be placed beneath the candelabra on the mantelpiece, the second that they should be transported to the dome of the Invalides, and the third that they should materialise in a chest buried under a particular orange tree in the grounds of the château. The King chose the orange tree, and sure enough a small chest smelling strongly of sulphur was found at its base. When Louis-Philippe opened it with a rusty key fastened to a turtledove, he found a piece of parchment that read: ‘This day, 6 June 1786, this iron box, containing six handkerchiefs, was placed among the roots of an orange tree by me, Balsamo, Count of Cagliostro, to serve in the performance of an act of magic, which will be executed on the same day sixty years hence before Louis-Philippe of Orléans and his family.’ ‘There is decidedly witchcraft about this,’ the King is reported to have said, on tearing open the enclosed envelope and displaying the handkerchiefs to the astonished spectators. The simple trick underlying this apparently complex performance was, of course, to predict which hiding place the King was likely to choose from the small selection offered him and then to make the necessary arrangements in advance.
The complexity of living things, both extant and extinct, was achieved by means of similar tricks: great feats, which on first inspection appear difficult or even impossible to achieve, but are nevertheless accomplished by simple means. This is the key to evolution: once the underlying mechanistic ‘tricks’ have been determined, the mystery of biological form and function is made rational and comprehensible.
That simplicity begets complexity should not be surprising – how else could life have originated in the first place? But our understanding of how evolution accomplishes its conjuring tricks continues to mature. While Darwin’s foundations were easily built on to accommodate genes and mutations, recent work has been more challenging. Stephen Jay Gould and Richard Lewontin, for example, used the spandrels of St Mark’s in Venice, which exist as a necessary by-product of the process of mounting a dome on rounded arches, as a way of illustrating the anti-adaptationist idea that certain features of organisms have arisen independently of natural selection. The spandrels reflect the constraints of building a particular type of structure in a particular type of way and are, as a result, often devoid of function.
Then there is the work of complexity theorists, who argue that there are rich seams of non-programmed, self-organising and self-assembling order in the natural world that offer natural selection a helping hand by generating complex patterns without the intervention of genes. Evolution, from this perspective, is driven by an intricate interaction between natural selection, the programmed order of genes and the non-programmed ‘order for free’, as Stuart Kauffman has called it, generated within certain types of complex system. Historical contingency, too, has a role in the new synthesis. Simon Conway Morris has argued that if the Earth hadn’t been hit by the meteorite that probably made the dinosaurs extinct, the history of life would have been quite different.