An Erdös Coin for my Dad (both sides)
Originally uploaded by ruzel.
A few years back I gave my dad a book called The Man Who Loved Only Numbers, its a fantasitc book about Paul Erdos. Paul Erdös was a legendary and prolific mathematician. He wrote over 1500 papers in his time an collaborated with a large number of mathematicians. For that reason, mathematicians often discuss their Erdös number, or their degree of separation from Erdös through published papers. My brother recently read the book and became interested in the connection he may have to my dad. (our father is a mathematician) So for father's day my brother worked out his Erdos number and made him an Erdös coin (using a laser no less) that has Erdös on one side, and his Erdös number and connection on the back. Very cool. He definately wins for the best father's day gift this year, or possibly ever.