http://oracleofbacon.org/

The Six degrees of separation refers to the idea that, if a person is one step away from each person he or she knows and two steps away from each person that their first person knows, then everyone is an average of six steps away from each person on Earth. This phenomena was pioneered by Guglielmo Marconi. Marconi attempted to compute how many radio relay stations were required to cover the globe. He came up with an average of 5.83.

The University of Virginia wanted to test the six degrees of separation theory by determining whether any actor can be linked through his or her film roles to actor Kevin Bacon. In the early 1990’s this became a very popular game on college campuses across the country. This type of game has also been created in the mathematical world but instead of actors having bacon numbers, mathematicians get an Erdos number depending on how many papers they wrote with Paul Erdos