Systems of synchronization occur throughout the animate and inanimate world. The regular beating of the human heart, the swaying and near collapse of the Millennium Bridge, the simultaneous flashing of gangs of fireflies in Southeast Asia: these varied phenomena all share the property of spontaneous synchronization. This unit shows how synchronization can be analyzed, studied and modeled via the mathematics of differential equations, an outgrowth of calculus, and the application of these ideas toward understanding the workings of the heart. Mathematics Illuminated is a 13-part multimedia learning resource for adult learners and high school teachers in math and other disciplines. The series explores major themes in the field of mathematics, from mankind's earliest study of prime numbers to the cutting edge mathematics used to reveal the shape of the universe. Rather than a series of problems to be solved, mathematics is presented as play we engage in to answer deep questions that are relevant in our world today. Mathematics also provides us with a powerful language for uncovering and describing phenomena in the world around us. The groundbreaking videos, interactive Web exploration, text materials, and group activities included in Mathematics Illuminated reveal the secrets and hidden delights of the ever-evolving world of mathematics.