Albion College

Mathematics and Computer Science

Mathematics and Computer Science

COLLOQUIUM

Are you smarter than a 19th century mathematician?

Timothy A. Sipka

The Four Color Theorem is a simple and believable statement: at most four
colors are needed to color any map drawn in the plane or on a sphere so
that no two regions sharing a boundary receive the same color. It might
be surprising to find out that mathematicians searched for a proof of this
statement for over a century until finally finding one in 1976. In this
talk, we'll consider the "proof" given by Alfred Kempe, a proof
published in 1879 and thought to be correct until an error was found
in 1890. You're invited to look carefully at Kempe's proof and see
if you can do what many 19th century mathematicians could not do—*find the flaw*.