Sean Carroll’s Mindscape Podcast: Jordan Ellenberg on the Mathematics of Political Boundaries

Sean Carroll in Preposterous Universe:

Any system in which politicians represent geographical districts with boundaries chosen by the politicians themselves is vulnerable to gerrymandering: carving up districts to increase the amount of seats that a given party is expected to win. But even fairly-drawn boundaries can end up quite complex, so how do we know that a given map is unfairly skewed? Math comes to the rescue. We can ask whether the likely outcome of a given map is very unusual within the set of all possible reasonable maps. That’s a hard math problem, however — the set of all possible maps is pretty big — so we have to be clever to solve it. I talk with geometer Jordan Ellenberg about how ideas like random walks and Markov chains help us judge the fairness of political boundaries.

More here.