Pi is a 1998 American conceptual psychological thriller film written and directed by Darren Aronofsky. Pi was filmed on high-contrast black-and-white reversal film. The title refers to the mathematical constant pi. The story focuses on a mathematician with an obsession to find underlying complete order in the real world and contrasting two seemingly irreconcilable entities: the imperfect irrationality of humanity and the rigor and regularity of mathematics, specifically number theory. The film explores themes of religion, mysticism, and the relationship of the universe to mathematics.