Monthly Archives: July 2014

Golden mutation…?

The argument I’ve always heard for why leaves or branches grow by rotating around a stem/trunk one golden angle at a time is that this is an optimal mutation. I’ve even heard this as an explanation for why clovers typically have three leaves. I’m not sure I understand how the thinking applies, since it seems to be about getting the most sunlight without completely overshadowing earlier growth, and this clearly isn’t a factor for a single clover. I haven’t sat down with a collection of clovers and a protractor, either. So I’m basically saying I’m riddled with doubts here.

Anyway, nevertheless, I wonder about the Fibonacci/golden angle/n-leaf-ness aspect of four leaf clovers often. If we planted a patch of 4 leaf clovers, would a 3 leaf mutation really be optimal “enough” to eventually win out? This is an empirical question, so I hope someone will take the charge and design a long-term controlled study!

What the wha? Bernoulli’s theorem, applied. 1

Today, as part of the AGAM camp, the girls had a mini course on aerodynamics. And then we flew in tiny airplanes.


I wish I could say that this post was going to contain some math, but really, I’m just going to post pictures.


I got to steer the plane, to everyone’s dismay.


But despite my lack off subtlety and grace, no high schoolers were harmed this evening. And now, I think I’ll look into flight schools!

All Girls/All Math

All Girls/All Math 2014

All Girls/All Math 2014

This week, I’m teaching one of the parallel “Codes and Cryptography” classes at the All Girls/All Math camp at University of Nebraska-Lincoln. It’s so much fun to be in a room full of budding mathematicians from all over the country, and it reminds me of what it felt like to love the idea of math before getting too deep into any particular specialization.

I’ve made a few resources for the class, which I’ll drop in this post as the week continues.

Obviously, the rock climbing links come first…:
Bouldering vs. Top-Roping (vs. Lead-Climbing)
Rock climbing and teaching math

And here are some relevant math links:

The Bletchley Circle on PBS:

A quick review of the symmetric cryptography systems we talked about on Day 1:

Here’s an article about a new kind of space race — the race to bounce perfectly secret codes off low-orbit satellites using quantum cryptography:

For encrypting and decrypting messages, you can play with the web apps at

And after the jump, there’s an except lifted from a blog post by Cathy O’Neil at


Undercover at an Algebraic Combinatorics Conference

Before I went to graduate school and became a commutative algebraist, I did a little work in graph theory. It was fun! I proved theorems! My mentor/coauthor Josh Laison provided a wonderful introduction to the fun inherent in doing research.

Well, roughly a decade later, I found myself at an Algebraic Combinatorics conference in honor of Chris Godsil’s 65th birthday (whose book with Royle was my introduction to Algebraic Graph Theory almost *exactly* 10 years ago). It’s exciting to see that some of the work we did is still relevant.


It’s also a lovely drive to get to U. Waterloo from Hamilton College. In fact, on the way home, I spent a night camping on Nairne Island at the Upper Canada Migratory Bird Sanctuary. It was the maiden voyage for my new solo tent, and I had plenty of math to think about in the peace and quiet!



Sometimes when I say I’m going to work at a coffee shop, I realize that it sounds like I’m changing careers. But today is the first time I’ve been mistaken for an actual employee at an actual coffee shop. My latest, greatest thought was just interrupted by someone earnestly claiming to be one of my customers. I was very confused until we both realized what was happening.

I guess I’m a natural. Good to know there are options if I don’t like being a math prof!