“Go big or go home” could be the mantra of astrobiologist and theoretical physicist Walker. Her new book’s title? Life as No One Knows It: The Physics of Life’s Emergence.

A professor at Arizona State University’s School of Earth and Space Exploration, Walker seeks to understand the physical nature of life, a domain rarely discussed outside the scientific community. In one chapter she theorizes that “time is actually a physical attribute, so you could think of it as a physical property, not just something that ticks on clocks. For living things, it’s information accumulated during billions of years, and it becomes an actual feature of them and provides a physical system that we might measure.”

In her book Walker explores one particular physics idea that has been hotly debated recently. Assembly theory says that complex systems are always evidence of life, whether they are living things themselves or cultural and technical artifacts created by us. Her approach could help scientists detect unfamiliar forms of life on other planets—and better understand the evolution of life on Earth.

Walker says she pushes herself to lean into bold areas of science. Her pioneering path has not gone unnoticed. In 2021 she received the Stanley L. Miller Early Career Award from the International Society of the Study of the Origin of Life. “She has shown a deep dedication to the field of the emergence of life,” says Jim Cleaves, former president of the ISSOL, “and she comes at the challenges with novel modeling approaches.”