## On beyond Erdős

I recently learned from Geoff Nunberg that there's a small-world step beyond the Erdős number — the Erdős–Bacon number. Geoff tells me that mine is 8, or maybe 9.According to the Wikipedia,

A person's Erdős–Bacon number is [..] the sum of one's Erdős number—which measures the "collaborative distance" in authoring mathematical papers between that individual and Hungarian mathematician Paul Erdős—and one's Bacon number—which represents the number of links, through roles in films, by which the individual is separated from American actor Kevin Bacon.

My Erdős number is 3 [J. B. Kruskal and M. Y. Liberman, 1983: "The symmetric time-warping problem: From continuous to discrete", in D. Sankoff and J.B. Kruskal (eds.), Time Warps, String Edits and Macromolecules, Addison-Wesley; A. J. Hoffman and J. B. Kruskal, 1956: "Integral boundary points of convex polyhedra", Annals of Mathematics Study 38:223-241; P. Erdős, S. Fajtlowicz and A. J. Hoffman, 1980: "Maximum degree in graphs of diameter 2", Networks 10:87-96.] And apparently Geoff's Bacon number is 4, which might entitle me to a Bacon number of 5 or 6,  depending on which activities are counted as the right kind of graph edge.

It's actually possible that my Bacon number is lower, since I've been interviewed on radio (does that count?) and television over the years by personalities whose Bacon number might well be lower than 5. And while it's unlikely that I'll lower my Erdős number in the future, I certainly might lower my Bacon number. Something to look forward to…

1. ### grackle said,

July 17, 2009 @ 2:53 pm

Hank Aaron is my favorite: at end of the Wikipedia article, it says, "Hank Aaron, a baseball player, is sometimes also considered to have an Erdős–Bacon number of 3, as he and Erdős both autographed the same baseball (for which he is jokingly referred to as having Erdős number of 1),[49] and he also appeared in Summer Catch with Susan Gardner, who was in In The Cut with Bacon."

Seems legit to me.

2. ### Faldone said,

July 17, 2009 @ 3:19 pm

How many baseballs did Paul Erdős sign?

3. ### Bryn LaFollette said,

July 17, 2009 @ 3:35 pm

Is that baseball listed on Google Scholars?

4. ### Skullturf Q. Beavispants said,

July 17, 2009 @ 4:58 pm

Wikipedia's article on "Erdos-Bacon number" mentions that mathematician Daniel Kleitman, who had a bit part in "Good Will Hunting", has an Erdos-Bacon number of 3.

The article amusingly details the various conceivable ways in which a lower Erdos-Bacon number could be achieved by somebody.

http://en.wikipedia.org/wiki/Erd%C5%91s-Bacon_number

5. ### dr pepper said,

July 17, 2009 @ 6:52 pm

Awww. When i saw the title of the post i thought it was going to be about combining one's distance from Erdos (is it "Erdoes" without the umlats?) with once distance from Roger Bacon. Or maybe Francis, but Roger would make more sense.

Personally i hate how this idea got stuck on Kevin Bacon when it was already a well known pop culture game with more interesting people.

6. ### Charles said,

July 17, 2009 @ 8:03 pm

I have published exactly one physical chemistry paper in Molecular Physics, and I'm sure that I *must* have some far-flung connection to the pure math world that would give me an Erdős number. Unfortunately no matter how much I search manually, I am having trouble finding a link that bridges me outside of the phys-chem world and into a pure math journal. Unlike the math world, I don't have an engine quite like MathSciNet that would make it easy.

I *do* know that I have a Bacon number of 2. I appeared as an extra in an episode of The L Word ("Lifecycle", season 5), in which Mia Kirshner plays Jenny. Kirshner once starred in a film with Bacon.

So I absolutely have an Erdős-Bacon number… I just haven't yet managed to figure out the Erdős part of it. Any ideas on how I might carry out a more automated search?

7. ### Dan T. said,

July 17, 2009 @ 10:29 pm

The L Word made a big deal about the interconnected network of people, though in that case the network focused not on what movies they appeared together on or who they authored papers with, but on who had slept with whom.

8. ### Nathan said,

July 18, 2009 @ 12:41 am

@dr pepper: You can't use the oe trick with Erdős, because that diacritic isn't actually an umlaut. It's called a double acute accent, and signals a long front rounded vowel.

9. ### Dan T. said,

July 18, 2009 @ 12:53 am

Does Homer Simpson's "D'Oh" have a long front rounded vowel?

10. ### peter said,

July 18, 2009 @ 6:29 am

dr pepper said (July 17, 2009 @ 6:52 pm)

"Personally i hate how this idea got stuck on Kevin Bacon when it was already a well known pop culture game with more interesting people."

Surely the first well-known pop culture game involved the actor Kevin Bacon, not other, deservedly more obscure, people with the same surname!

11. ### Nick Lamb said,

July 18, 2009 @ 8:53 pm

peter, the Kevin Bacon game had previously been played with other more famous (non-Bacon surnamed) actors and was modestly popular in these forms among people who enjoy movie trivia. There's no good reason why the Kevin Bacon version has achieved memetic dominance. I don't think there's ever been a popular small world game involving Francis Bacon.

12. ### dr pepper said,

July 18, 2009 @ 10:47 pm

It was played with people who weren't actors as well.

13. ### Eyebrows McGee said,

July 20, 2009 @ 11:16 am

"had previously been played with other more famous (non-Bacon surnamed) actors and was modestly popular in these forms among people who enjoy movie trivia."

I had movie-buff friends in school who played it and they always referred to it as "the ultimate dork game." I was surprised some years later when I heard other people playing it and calling it "the Kevin Bacon game."

14. ### Zubon said,

July 20, 2009 @ 1:19 pm

There's no good reason why the Kevin Bacon version has achieved memetic dominance.

Quite appropriately for this blog, the supposed history traces it back to a word replacement error: "six degrees of Kevin Bacon (separation)."