I take issue with the celebration of Paul Erdős’ 100th birthday.
Not the celebration itself, but the number. Why 100? The number 100 was chosen, of course, because 10 is the base unit of our number system: We have 10 unique symbols (0-9) that can be combined to represent any conceivable number. Ten units of 10 is 100, so it’s a nice, neat factor. If we used a base 12 system, we would have 12 unique symbols, and we’d be celebrating anniversaries of 144 years. But I can’t find any particular significance about 100 for Erdős.
Erdős was born in 1913 in Hungary to Jewish parents, both mathematics teachers. He moved to Manchester, England, in 1934 for a post-doctoral appointment, but also spent time (unofficially) working in London, Cambridge and Bristol--establishing a trend of bouncing from institute to institute that would continue for the rest of his life. Erdős did not return to Hungary until 1945, after Soviet troops liberated Budapest from the Nazis. Throughout his life he spent time living in the US, Israel and Britain, and visited Hungary often. But he had no permanent residence. He lectured, taught and worked at dozens of universities, but never held a permanent position at any of them. He died in 1996 of a heart attack while attending a conference in Warsaw.
Next year will mark Erdős’s 101st birthday, which would be better than celebrating his 100th birthday, because 101 is a prime number. You can’t divide 101 by anything but 1 and itself and still get a whole number (where 100 is the product of 2 x 2 x 5 x 5). Erdős once told his biographer, Paul Hoffman, in a somewhat beautiful and somewhat sad sentiment that prime numbers were his best friends.
A large portion of Erdős’s work involved prime numbers. The first significant theorem he ever proved, at age 17, stated that between any number and its double, there is at least one prime number. The Russian mathematical giant Pafnuty Chebyshev had already proved this theorem, called Bertrand’s conjecture, 80 years earlier, but Erdős proof was simpler and clearer. Erdős later did a similar job of simplifying the prime number theorem, which reveals how prime numbers will be distributed. Close to zero, prime numbers are common: 2,3,5,7, et cetera. As one climbs higher and higher, however, prime numbers occur more infrequently. (The prime number theorem doesn’t show how to find those numbers, which are infinitely abundant. The largest known prime number is 257,885,161 – 1, which has over 17.4 million digits).
Reducing proofs and theorems to their “elementary” state was a particular talent of Erdős’. He once wrote a simpler proof of a theorem in a paper he was supposed to be refereeing. Erdős believed that “the Supreme Fascist” (God) kept a book of mathematical proofs in their most perfect, simplified states, and it was the task of mathematicians to transcribe the pages from this book.
In some respects, zero was a rather significant number for Erdős. Along with his peripatetic proclivity, he never married, never had children, never bought a home and never had a regular job or very much money. Instead he traveled, carrying all his worldly possessions in two suitcases, making a temporary home with collaborators. This lifestyle took him throughout the U.S. and Europe. At last count, he published papers with 511 people.
Erdős’ terrible behavior as a house guest is legendary: opening a carton of tomato juice by cutting a hole in it and not bothering to clean up the mess; banging pots and pans at 4:30 in the morning to wake everyone so they could continue their work.
Despite his obnoxious behavior, Erdős was usually welcomed back, and remained friends with most of the people he visited. Reportedly, he was a radiantly happy person, a delightful collaborator, and had a gift for getting people to do mathematics to the best of their capabilities. In fact, a more fitting celebration for Erdős might be December 26, 2039, or 1,521 months after his birth: 1,521 is the total number of papers he collaborated on, which is more than any other mathematician in history.