Explore the fascinating world of number theory in this colloquium talk by Toby Gee from Imperial College London, hosted by the University of Chicago Department of Mathematics. Delve into the intricacies of the Ramanujan conjecture for modular forms, gaining insights into its historical significance and recent developments. Learn about Gee's collaborative work with George Boxer, Frank Calegari, and James Newton, which proves the Ramanujan conjecture for Bianchi modular forms. Designed for a broad audience, this one-hour talk requires no prior knowledge of the subject, making it accessible to mathematics enthusiasts of all levels.