How Kevin Bacon Cured Cancer (ATOM Study Guide)

Kevin Bacon, Applied Mathematics and Cancer Research not exactly the ideas that you expect to find in the same sentence.

How on earth could anything that a hard-working Hollywood actor might do have a significant effect in medical research and, for that matter, other areas of social and scientific research?

Well, the story is both remarkable and quite entertaining. Its not so much what Bacon has done himself but the way a couple of computer students and scientists have used him. As an actor, he is not one of the greats but hes been around a long time and has a huge list of movie credits and thats the key. In 1994, he referred to his ubiquity with an off-hand comment that he thought he had appeared in a movie with just about every other actor in Hollywood, or at least someone whod worked with them. He was making a half-serious claim to be the central node of a special social network (Hollywood actors), although he probably didnt see it in those terms.

At the same time, the urban myth of Six Degrees of Separation was already popular. Its the idea that we are all related to everyone else within six links or less. A group of students at Albright College in the US began to play around with the idea that Bacon was the centre of the Universe, or at least his universe, and created a trivia game Six Degrees of Kevin Bacon. Its the sort of thing that students get into over pizza, a few beers and a collection of bad movies. To play the game, they had to think how to link an actor to Kevin Bacon, directly or indirectly, through the movies in which theyd appeared. A couple of years later another computer student, Brett Tjaden at Virginia University, followed through and wrote a computer program to calculate automatically what a mathematician would refer to as the Bacon number of any movie actor. The game Oracle of Kevin Bacon can still be played on the Internet. The Bacon number is the number of steps by which Bacons career is related to any actor in the Internet Movie Database. If they appeared in a movie with Bacon, then they have a number of one. If they appeared in a movie with someone who had worked with Bacon, then they score a two, and so on. It soon became clear that numbers over three were quite unusual although about twelve per cent of actors could not be linked at all. Finding people with numbers as high as seven or eight has become a game in itself. This was not new. It is a way of demonstrating Shortest Path Analysis algorithms, which just happens to be a lot more entertaining than the usual mathematical calculations. In fact, it had been done before with the late Paul Erd_s, a Hungarian mathematician who had a prodigious output of academic articles, most of them co-written. Given that mathematicians and scientists collaborate on projects frequently, many, many contemporary researchers and academics have an Erd_s number.

These exercises were done for fun even mathematicians have a sense of humour! But the next step was much more significant.