10 December 2004 -- Perhaps you're wondering, as the Nobel Prizes are awarded today, what separates you, toiling away in your particular little garden, from one or another of the celebrated recipients. Well, if you happen to be working in more or less the same field as the awardee, the answer is about four other scientists on average, according to recent, though admittedly frivolous, research.
That's a closer connection than you are commonly thought to have with a random stranger, which is perhaps not so surprising, given the intimacy of scientific communities. Famously if somewhat apocryphally, six other people, or six degrees are thought to separate any two randomly connected individuals, but in fact the relation only holds for members of defined communities or occupations.
The notion that any two people can be connected by six intermediary acquaintances stems from a 1967 experiment by then City University of New York psychologist Stanley Milgram. In that trial, a group of people were asked to get a letter hand delivered to a particular stranger on the other side of the United States by asking friends and friends of friends to pass it along. While only a few letters actually made it through, the study turned social scientists on to the highly connected nature of the modern world. In later work the mean number of connections to get from one person to another was found to be six. And while it never proved true that everyone in the world, or even in the United States, is that closely connected, many categories of people such as actorsand mathematicians have been found to be tied together by the six-degrees rule. An ongoing study by sociologist Duncan J. Watts and colleagues at Columbia University, in New York City, is trying to discover how well the six-degrees rule holds true for the worldwide community of people with access to e-mail.
Last year, when the 2003 Nobel Prize in Physiology or Medicine honored the invention of magnetic resonance imaging, or MRI, a couple of graduate students at Johns Hopkins University, in Baltimore, happened to wonder whether they might be connected with MRI inventors Paul C. Lauterbur and Sir Peter Mansfield. As specialists in medical imaging, they naturally hoped the links would be surprisingly close.
In their experiment, the students, Luis F. Gutierrez and Guy Shechter, began by searching a popular medical literature database for all the articles with MRI or its equivalent terms in the title or abstract. Then, a computer program the pair wrote looked at all the authors and calculated the connections between them. For instance, any scientist who had coauthored an article with either of the Nobel Prize winners had one degree of separation from them. Anyone who had done a paper with one of Lauterbur or Mansfield's coauthors but not Lauterbur or Mansfield themselves had two degrees of separation from them. And so on.
The Hopkins students found that of the more than 200 000 scientists who had published medical research about MRI, almost 90 percent were connected to the Nobel Prize winners by a chain of at most 11 other scientists. A full 99 percent of those were separated by six degrees or less, but the average researcher was just four steps from fame. (The Hopkins researchers' results, ”Six Degrees of Nobelity,” were presented in October at the Biomedical Engineering Society's 2004 annual meeting in Philadelphia and are available online at )
For Shechter, now a postdoctoral fellow at Technion University, Haifa, Israel, and Gutierrez, the study was a bit of bust: they don't make the cut at all, even by six degrees. ”Neither of us is connected to the Nobelists according to the criteria we used,” they wrote in an e-mail. ”After all our work, this is probably what surprised us the most.”
This story was corrected on 10 December 2004.