..an Erdős–Bacon number. Paul Erdős was a mathematician who published some 1,500 papers with 509 different collaborators, in some way paralleling the prolific career of Kevin Bacon. As with the Six Degrees of Kevin Bacon game that gives actors a Bacon number according to the number of co-stars required to link them to Mr Bacon, published academics can be assigned an Erdős number.
Still with me? Then here’s the cool bit. There are a number of academics who have made small cameo appearances in movies, mostly in recognition of advice they have given. But there are a small number of ‘proper’ actors/actresses who have also co-authored academic papers. The two most notable are Natalie Portman and Danica McKellar. In case you’re stuck, McKellar was Winnie Cooper in The Wonder Years. She was rather attractive then; in fact if you are male and currently aged between 30 and 40 I’d hazard that you either had a crush on her or you didn’t have a TV. And now…well let’s just say that it doesn’t matter if you’re male or female, she’s smoking hot. She’s also the McKellar of the Chayes-McKellar-Winn Theorem