logicbutton

So last semester, I took a class called Modern Geometries, which was about proving various things about spaces and shapes and lines and points in the different geometries mathematicians use: Euclidean geometry, which is the one you learned in high school, hyperbolic geometry, which is the one Einstein was working in when he developed his Theory of Relativity, and projective geometry (aka elliptic geometry), my personal favorite. Projective geometry's big identifying feature is that there is no such thing as a set of parallel lines; the idea is that all lines will meet eventually, if you just go far enough (and by "far enough," I mean an infinite distance).

As a math major with a special interest in pure math (the abstract, theoretical stuff), and as a tutor for intro-level classes, I've heard plenty of people express doubt that the subject I'd like to devote my life to has any relevance in the real world. Well, some of the things I'm interested in often do seem like just math for math's sake, but projective geometry is an exception, in that it is what makes possible things like this sidewalk chalk drawing:

I don't know what this guy's math background is like, but even if he doesn't realize it, he has a seriously hardcore understanding of projective geometry. The rest of his stuff (which is amazing) can be found here.