On October 23, 1852, Professor Augustus De Morgan wrote a letter to a colleague, unaware that he was once launching probably the most well-known mathematical conundrums in history--one that might confound hundreds of thousands of puzzlers for greater than a century. this can be 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 consistently coloured otherwise? This deceptively uncomplicated query was once of minimum curiosity to cartographers, who observed no use to restrict what number shades they used. however the challenge trigger a frenzy between expert mathematicians and novice 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 12 months, 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 outcome used to be eventually proven. Even then, tough questions remained, and the difficult solution--which concerned no fewer than 1,200 hours of desktop time--was greeted with as a lot dismay as enthusiasm.
Providing a transparent and chic rationalization of the matter and the facts, Robin Wilson tells how a likely harmless query baffled nice minds and prompted intriguing arithmetic with far-flung functions. this can be the exciting tale of these who didn't end up, and those that eventually did turn out, that 4 shades do certainly suffice to paint any map.
This new version positive aspects many colour illustrations. it's also a brand new foreword via Ian Stewart at the significance of the map challenge and the way it was once solved.
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