In this fun expository talk, I'll discuss the largest (non-infinite) numbers that humans have known how to define, from antiquity to the present -- including exponentials, Ackermann numbers, "Busy Beaver" numbers, and even larger numbers defined using set-theoretic concepts. I'll also discuss the role such enormous numbers have played in math and science.  Throughout, I'll emphasize the conceptual question of what it even *means* to define a number, and how that question leads us inevitably to profound issues in computer science and logic.  The talk will be loosely based on my essay Who Can Name The Bigger Number?, but will also include new material.

The Metcalc Science Center is located at 590 Commonwealth Avenue, at the opposite end of Cummington Street from the Mathematics and Comptuer Science Building at 111 Cummington Street. The SCI Student Lounge is across the hall from the Lecture hall room 109.

Directions to the Mathematics Department

Metcalf Science Center is at the east end of the Mathematics building