Make a donation of any amount to help us continue exploring the world's deepest questions with new and exciting thinkers.   Astrobiologist and theoretical physicist Sara Imari Walker shares an intriguing new scientific theory that explains what life is and how it emerges. What is life? This is among the most difficult open problems in science, right up there with the nature of consciousness and the existence of matter. All the definitions we have fall short. None help us understand how life originates or the full range of possibilities for what life on other planets might look like.   Walker's latest book Life As No One Knows It: The Physics of Life's Emergence, is available for purchase now.   Sara Imari Walker is an astrobiologist and theoretical physicist interested in the origin of life and discovering alien life on other worlds. She is deputy director of the Beyond Center for Fundamental Concepts in Science and a professor in the School of Earth and Space Exploration at Arizona State University. She is also a fellow of the Berggruen Institute and a member of the external faculty at the Santa Fe Institute. She is the recipient of the Stanley L. Miller Early-Career Award for her research on the origin of life, and her research team at ASU is internationally regarded as being among the leading labs aiming to build a fundamental theory for understanding what life is.   Watch more Closer To Truth Chats here.