Astrobiology & The Physics of Life's Emergence with Sarah Walker
The Core of Life's Emergence
In this episode, Sarah Walker provides a profound exploration of astrobiology and theoretical physics as they relate to the origin of life. The conversation centers on her upcoming book, Life As No One Knows It, and redefines life not as a collection of chemicals, but as the physics of how the universe selects pathways through combinatorial space.
Moving Beyond Traditional Definitions
Walker challenges the standard definitions of life—such as "self-sustaining chemical system capable of Darwinian evolution"—arguing they are insufficient. Key insights include:
• Life as a Process: It is the mechanism by which information structures matter across time and space.
• The Role of Time: Walker posits that living objects are essentially "huge in time," carrying causal histories that allow them to exist.
• Assembly Theory: This framework quantifies complexity and history, marking a potential phase transition where objects can only exist if they are part of a self-reinforcing, selectable lineage.
The Technosphere and Universal Principles
Walker discusses the concept of the technosphere as the most complex living structure currently on Earth. She argues that technology, language, and mathematics are not separate from biology but are deep temporal structures of our biosphere. She suggests that these systems evolve to navigate vast, non-exhaustible spaces of possibilities.
"I think life is the process of how information structures matter over time and space... any individual is just a particular instance of these lineages."
Consciousness, Intelligence, and Physics
The discussion touches on the hard problem of life, suggesting that consciousness may be a manifestation of our temporal depth. Furthermore, Walker explains that:
• Life is a continuous, planetary-scale phenomenon.
• Language is a dynamic, evolutionary system that allows us to explore deeper levels of reality.
• Exploring aesthetic spaces—like fashion—is a way to understand the combinatorial complexity of human expression and identity.