I have had a bit of fun figuring out my Erdös number. This number, if you don’t know, counts the “collaboration distance” between a particular person, such as myself, and Paul Erdös, where a “collaboration” is created when two people co-author a scientific paper. In other words, if I co-wrote a paper with Paul Erdös, my Erdös number would be 1, but if I only co-wrote a paper with somebody who co-wrote a paper with Erdös, my Erdös number would be 2, and so on.
Paul Erdös was an eccentric and famously prolific mathematician who travelled around the world co-authoring papers with people wherever he happened to be. A recent book about him received good reviews, but I have not read it.
Anyway, on to the matter at hand: my Erdös number is not greater than 6. The chain of collaborations goes like this:
6. Yours Truly with Michael Luke [paper]
5. Luke with Mark Wise [multiple papers]
4. Wise with Edward Witten [paper]
3. Witten with Ron Donagi [multiple papers]
2. Donagi with Marcel Herzog [paper]
1. Herzog with Paul Erdös [paper]
My Erdös number is not very impressive. I haven’t seen statistics on the distribution of Erdös numbers, but I expect that a large percentage of people who have published a scientific paper, especially in physics or mathematics, have an Erdös number equal to or less than mine.
Incidentally, I am dumbfounded that an automated Erdös number calculator has not been established online. (There is one for mathematicians, but what about the rest of us?) Most of the publication records for most scientific journals are now online, and it ought to be a fairly simple matter to crawl them and build a collaboration network. Then one need only apply a straightforward shortest-path algorithm to find the Erdös number (or, for that matter, the Einstein number, Feynman number, or even Burrell number) of anyone who has published a paper. Someone ought to do this.