Let $X$ be a topological space. If $X$ is nice enough, then we can think of the data of the “homotopy type” of $X$ as follows:

While in graduate school I’ve spent a while wrestling with the question,

I have a number of books on the shelves above my desk which were left there by previous residents of my office. Recently I was thinking about symplectic ball packing and feeling a little bit unhappy about mathematics. In an attempt to find some solace, I decided to leaf through one of the books on my shelf which looked as unrelated to my work as possible.

For about a year and a half now, I’ve been told at least monthly by someone new that I should have a blog. I guess people think that I have something to say. Well,