Today’s xkcd comic made me laugh out loud!
Non-mathematicians who don’t know ErdÅ‘s or what an ErdÅ‘s number is should take a look at these Wikipedia articles: Paul ErdÅ‘s, ErdÅ‘s Number.
If you’d like to read more about ErdÅ‘s I recommend two books on him that I’ve read and enjoyed:
- Bruce Schechter: My Brain is Open: The Mathematical Journeys of Paul Erdős
- Paul Hoffman: The Man Who Loved Only Numbers
ErdÅ‘s also inspired a book on elegant mathematical proofs called Proofs from the Book, which is worth checking out too if you’re into that sort of books. (Disclaimer: I haven’t read this one cover to cover yet.)