On October 23, 1852, Professor Augustus De Morgan wrote a letter to a colleague, unaware that he used to be launching essentially the most recognized mathematical conundrums in history--one that may confound hundreds of thousands of puzzlers for greater than a century. this is often the superb tale of the way the "map challenge" used to be solved.
The challenge posed within the letter got here from a former pupil: what's the least attainable variety of colours had to fill in any map (real or invented) in order that neighboring counties are continually coloured otherwise? This deceptively basic query used to be of minimum curiosity to cartographers, who observed no use to restrict what percentage shades they used. however the challenge trigger a frenzy between specialist mathematicians and beginner challenge solvers, between them Lewis Carroll, an astronomer, a botanist, an obsessive golfer, the Bishop of London, a guy who set his watch just once a yr, a California site visitors cop, and a bridegroom who spent his honeymoon coloring maps. of their pursuit of the answer, mathematicians painted maps on doughnuts and horseshoes and performed with patterned football balls and the good rhombicuboctahedron.
it'd be multiple hundred years (and numerous coloured maps) later sooner than the end result was once ultimately tested. Even then, tricky questions remained, and the complicated solution--which concerned no fewer than 1,200 hours of machine time--was greeted with as a lot dismay as enthusiasm.
Providing a transparent and chic clarification of the matter and the evidence, Robin Wilson tells how a likely harmless query baffled nice minds and inspired interesting arithmetic with far-flung functions. this can be the wonderful tale of these who did not end up, and those that finally did end up, that 4 colours do certainly suffice to paint any map.
This new version positive aspects many colour illustrations. additionally it is a brand new foreword by means of Ian Stewart at the value of the map challenge and the way it was once solved.