WHAT does the king of Gothic horror, Christopher Lee, have in common with Britain's Astronomer Royal? They're both fantastically well connected, according to a new mathematical study. Its author says that applying similar techniques to our own social contacts could make successful networking much easier.
According to popular folklore, any person in the world can be connected to any other by a few acquaintances, typically around six. A similar "small-world" effect is enshrined in the Kevin Bacon game: link any film actor to Bacon through their co-stars in as few steps as possible. Most actors link to him in three steps or fewer.
Intrigued by such social networks, Mark Newman of the Santa Fe Institute in New Mexico decided to study how well scientists are connected. He extracted the names of authors on scientific articles within a particular discipline, such as the astrophysics papers put in the Los Alamos e-print archive between 1995 and 1999.
Newman worked out the "distance" between every possible pair of authors. A pair who worked together had a distance of 1, for instance, while two people who had not collaborated but had a collaborator in common had a distance of 2. The lower a person's average separation from others, the better connected they must be.
But some collaborations involve hundreds of scientists who don't know each other. When Newman weighted the measures of distance to reflect this, he found that the accolade of best-connected astrophysicist went to the Astronomer Royal, Martin Rees of Cambridge University.
Rees is modest about this honour. "I'm certainly relieved not to be the 'most disconnected astrophysicist'," he says.
Newman thinks his work could have practical benefits, such as improving software that puts people in touch. "Working out the shortest path between people could be useful," says Newman. "If you want to get in contact with some other person, you could find out if you have a friend in common, then ask for an introduction."
He adds that he got a surprise when he applied his algorithm to actors: "The best-connected person in the movie-acting world is actually not Kevin Bacon at all--it's Christopher Lee."
More at: http://arXiv.org/abs/cond-mat/0011144
