Sara Walker: Physics of Life, Time, Complexity, and Aliens | Lex Fridman Podcast #433
Sara Walker argues life is a physics problem — not a biology one — and that the technosphere may be undergoing a second origin-of-life event right now.
- Walker defines life as ‘the process by which information structures matter over time’ — rejecting all standard biology-textbook definitions as too narrow.
- She argues living objects are among the largest structures in the universe, not in space but in time — causal history is the true size of an organism.
- The modern technosphere (integrated human + technological system) is, in Walker’s view, the largest object in time currently known to exist.
- Walker claims a second origin-of-life event is happening now: the technosphere is crossing the same boundary chemistry crossed 4 billion years ago.
- Assembly theory rejects fixed dynamical laws as insufficient — the universe selects what gets to exist via historically contingent, memory-laden construction.
- Consciousness, in this framework, emerges because organisms are temporally extended objects with vast inner causal structure, not because of special substrate.
- Walker estimates humans understand roughly 1% of the big important questions — and believes the frontier has no discoverable bottom.
Guests: Sara Walker, astrobiologist and theoretical physicist, Arizona State University; author of ‘Life as No One Knows It: The Physics of Life’s Emergence’ · 2024-06-13 · Watch on YouTube
