When I was growing up, an unusual houseguest would show up at our door every few years. With steeply-arched eyebrows, a mile-wide grin, gigantic ears that looked like they could flap in the wind, and a wild tousle of white hair, he seemed to my 8-year-old self to resemble nothing less than an oversized hamster or rabbit. In a distinctive, nasal-whiney voice he would utter words in some unintelligible language that nevertheless seemed related to English. He called me and my brother “epsilons” and spoke of a mysterious food called “pea-napple-uppsheed-did-doven-tosh.” After a couple of weeks, he would disappear as suddenly as he had shown up.
Only years later, as an adult, did I learn that this man was one of the most famous mathematicians in the world: Paul Erdős. Born in Hungary, he published over 1,500 mathematical papers, many of them groundbreaking proofs that nobody else could solve. Even more remarkably, he was homeless: for most of his life he had no permanent address, and all his possessions fit in a suitcase. Traveling the world constantly, he stayed with mathematicians for a few weeks at a time while he collaborated on solving problems and writing articles. My father was also a mathematician, and that’s why Erdős would visit us. So renowned and prolific was Erdős that mathematicians are now assigned an “Erdős number” based on whether they co-authored a paper with him. Kind of like “six degrees of separation” for mathematics, people who wrote an article with him (such as my father) are designated with an Erdős number of one, while those who wrote an article with one of his co-authors get the number two, and so on.
The unusual-sounding words Erdős spoke to us were part of a private vocabulary that he invented, an amalgam of Hungarian, English, and mathematical terms: “epsilon” (a Greek letter used to represent a small mathematical quantity) was Erdős’ word for “child”. And “pea-napple-uppsheed-did-doven-tosh” was his rendering of “pineapple upside-down cake”. I learned much more about this fascinating man—and you can too!—by reading two excellent biographies from The Seattle Public Library: The Man Who Loved Only Numbers: The Story of Paul Erdős and the Search for Mathematical Truth and My Brain Is Open: The Mathematical Journeys of Paul Erdős. The library also has a wonderful documentary available through our Kanopy streaming service: N Is A Number: A Portrait of Paul Erdős. There’s even a children’s book about him: The Boy Who Loved Math: The Improbable Life of Paul Erdős. How I wish I could have read that book when I was a child and this unusual, charming man would show up on our doorstep!
Although the type of homelessness that Paul Erdős experienced is quite different from that currently affecting many people in Seattle (and other cities around the country), Erdős’ life serves as an important reminder: Homelessness takes many forms, there are many different life stories behind houseless individuals, and you might be surprised to learn who in your life is insecurely-housed.
~posted by Chris