In the latest video in the series, Numberphile (previously) speaks to Stanford University professor Persi Diaconis about the randomness of tossing a coin. Diaconis explains that while coin flips are, in a sense, deterministic, there are a good deal of different factors that ultimately influence the outcome.

Small changes in the initial conditions make for the difference in heads and tails. For most of us that’s what makes coin tosses random.