Paul Erdős. Kevin Bacon. Black Sabbath. What do they have in common?

They’re really, really well connected.

People are fascinated by collaboration. When two or more people get together, great things happen. Be it papers on mathematics, movies, or proto-metal, these motivated individuals have been known to get around. For those that collaborate for a living, a standard gets set in their honor, placing them at the center of their field’s social network.

The most notable example is Kevin Bacon, who’s starred in dozens of movies throughout his career. The numbering system goes as such: Those who have starred in a film with Kevin Bacon have a “Bacon Number” of one. Those who co-star in a film with someone who has previous worked with Kevin Bacon have a Bacon Number of 2, and so on and so forth. Now, hold that thought for just a second.