Softcover

ISBN 10: 014100908X ISBN 13: 9780141009087

Publisher: Penguin Books Ltd, 2003

A book to celebrate the 150th anniversary of the solution to one of the world's most puzzling mathematical problems. The four-colour theorem states that every map in the world can be coloured with just four colours in such a way that neighbouring countries have different colours. One of the simplest problems to state, one of the hardest to solve, which took a century for mathematicians to prove. This book introduces the mathematicians behind the mathematics, among them a bishop, an astronomer, a botanist, an obsessive golfer and a bridegroom who spend his honeymoon colouring maps.

Review:

At first glance Four Colours Suffice seems like such an easy thing to prove. However big and complicated the map, four colours are enough to distinguish each country from its neighbours. How do we prove that only four colours are needed? Once we realise that, if four countries all share borders with each other, then one country must be enclosed by the other three (try it), we seem to be most of the way there. But things turned out to be not quite so simple. Robin Wilson might balk at the idea that his sardonic and lively account of the problem and its solution is in any way farcical--as, indeed, might the dedicated mathematicians and keen amateurs whose 150 years of work he describes. But if the way an apparently simple problem throws out poisoned blossoms of complication, confusion and embarrassment is your definition of farce, then this story surely fits the bill. Proving the four-colour conjecture turned out to be heinously difficult, and has at last been achieved--and that in the ugliest way imaginable--only with the aid of a computer.

This, we can see now, was a landmark moment in mathematics: the moment we realised that there are proofs out there so complicated, that publishing them in full is impractical, working through them by hand is impossible, and explaining them to the public requires writers of a very special stamp indeed. (Robin Wilson, I should add, is most definitely one of them.) The publishers, in deciding to make a black-and-white book out of a colour problem, have not only done justice to Wilson's illustrations, but have also created one of the most visually arresting science books around. --Simon Ings

About the Author:

Robin Wilson is Senior Lecturer in Mathematics at the Open University and Fellow of Keble College, Oxford.