Category Archives: Fun


My Erdos Number is 4

Related to my previous post, I now have an Erdős number of 4. Another thing I’ve always wanted! Here are the details and an explanation of Erdős numbers for those who aren’t familiar with them.

I’ve posted previously about the mathematician Paul Erdős. Among other things, Erdős was insanely prolific and published 1,475 papers with 511 collaborators. Since one of his many areas of interest was graphs, it’s not surprising that a collaboration graph of his co-authors, and their co-authors, and so on…should be of interest. Courtesy of Wikipedia:

The Erdős number…describes the “collaborative distance” between a person and mathematician Paul Erdős, as measured by authorship of mathematical papers. It was created by friends as a humorous tribute to the enormous output of Erdős, one of the most prolific modern writers of mathematical papers, and has become well-known in scientific circles as a tongue-in-cheek measurement of mathematical prominence.

The Erdős collaboration graph is too huge to visualize, sadly, but the Erdős Number Project site has some interesting facts about the graph. Unfortunately, I think this information is skewed because it is based only on papers published in mathematical journals, while the high degree of interdisciplinary collaboration means that many people outside of mathematics have finite Erdős numbers. Anyway, according to this information, about 83,642 other people have Erdős number 4 (probably a gross underestimate.)

My relationship to Erdős comes from the fact that one of my co-authors, Michael Brudno, was a collaborator with at least two authors with Erdős number 2: Serafim Batzoglou and Lior Pachter. Each of those authors is a co-author with Daniel J. Kleitman, who not only has Erdős number 1, but has the lowest known Erdős-Bacon number: 3.

It’s conceivable that through one of Mike Brudno’s other collaborators, his number could in fact be 2, making mine 3, but confirming or disconfirming that would be too laborious. I’m more than satisfied with 4, which is slightly lower than the mean–especially considering that I never dreamed I’d have an Erdős number at all!

Platonic Solids: Generative Architecture by Subdivision

We’ve all heard of generative graphics, how about generative architecture? The computational experiment Platonic Solids by Michael Hansmeyer is something you can get lost in for a good while. Especially since he’s added a 3-D anaglyph presentation. I hope you kept a pair of red-cyan 3D glasses in your junk drawer like I did!

Here’s what the project’s all about, in the artist’s words.

Genetic Programming Example in JavaScript

While researching genetic programming as one possible way to discover near-optimal solutions to the Travelling Salesman Problem (TSP), I came across this cool interactive demonstration of genetic programming using JavaScript. I found myself playing with it for a good while, enjoying watching the solutions evolve and converge under different fitness constraints.

The page itself doesn’t provide much information on what’s going on, but you can get a quick overview of genetic programming here. For deeper investigation, try, a site maintained by John Koza, one of the major figures in genetic programming research. There are links to all sorts of resources including all of Koza’s publications, many of which are available online.

Antique Cannabis

While researching migraine remedies, I came across this site on Antique Cannabis, i.e. medicinal uses pre-1937. Besides the history and the strange range of uses (anti-asthma cigarettes?), the photos of antique ads, labels, apothecary bottles, tins, production facilities etc. are very cool. Note the manufacturer on this one:


My friend and colleague Mark Petrovic pulled me into this blog-tag game, apparently started by Jeff Pulver. It’s a sort of parlour game where you tell five things most people don’t know about you and then tag more people to do the same. So here goes: five things most people don’t know about me:

  • I used to be a professional Shiatsu therapist. I also studied Traditional Chinese Medicine seriously before realizing I didn’t have what it took to be a doctor.
  • I have a Bachelor of Mathematics degree, but I can’t calculate the tip on a restaurant bill.
  • I’m a Zen Buddhist (well, more like a “lapsed” Zen Buddhist, these days).
  • I love Space Opera. Some of my favourite authors are Iain M. Banks, Peter F. Hamilton, Alastair Reynolds, Neal Asher, and of course: Isaac Asimov. I even love cheesy TV space operas: Star Trek (all of them), Stargate (both of them), Firefly, and Battlestar Galactica (the new one–I just couldn’t take Lorne Greene seriously in anything.)
  • My pet topic is the history and philosophy of science, about which I’d really, really like to write a book one day.

Ok, now I need to “tag” some more people. Hmm… how about Leigh Himel, Mathew Ingram, Jason Theodor, and Jason Ramsay-Brown