Life as No One Knows It by Sara Imari Walker tackles the challenging question of defining life, a problem as complex as understanding consciousness or matter's existence. Walker argues that current definitions are inadequate for comprehending life's origins or potential extraterrestrial forms. She proposes that solving this puzzle requires revolutionary thinking and an experimentally verifiable theory. This is crucial for both creating life in laboratories and searching for it on other planets. Walker suggests a new paradigm for understanding physics and life, exploring the work of innovative scientists who are reframing fundamental questions about the universe. The book concludes with a bold theory for identifying and classifying life, applicable beyond Earth. It's a rigorous yet accessible work that celebrates life's mystery while demonstrating physics' explanatory power.

Sara Imari Walker is an astrobiologist and theoretical physicist focused on the origin and discovery of life. She's a professor at Arizona State University and deputy director of the Beyond Center. Walker is also affiliated with the Berggruen Institute and Santa Fe Institute. Her award-winning research on life's origins has gained international recognition and media attention.

Shermer and Walker explore diverse topics including defining life, self, and organisms; philosophical concepts like materialism and idealism; origins of life research; assembly theory; consciousness; free will; symbiogenesis; exoplanet biosignatures; alien civilizations; and the intersection of extraterrestrial search with religion. They discuss paradigm shifts in understanding life's origins, potential alien characteristics, and the Kardashev scale.