Explore the fascinating concept that our universe is fundamentally mathematical in this thought-provoking Royal Institution talk by MIT physics professor Max Tegmark. Delve into the spectacularly successful role of mathematics in describing the cosmos and consider the radical idea that our physical world is not just described by mathematics, but is mathematics itself. Examine key concepts such as the Doppler effect, plasma, and radio telescopes, while learning about influential figures like James Clerk Maxwell. Investigate the notion of pure numbers and mathematical structures as the foundation of reality. Contemplate the implications of this theory for our understanding of space, time, and the nature of existence. Challenge conventional thinking and gain new perspectives on the mathematical underpinnings of our universe in this 45-minute presentation that pushes the boundaries of scientific and philosophical thought.