Evidence receipt / belief
Published · transcript-backedSara Walker: belief
13 Jun 2024 Lex Fridman Podcast #433 – Sara Walker: Physics of Life, Time, Complexity, and Aliens
“We have ways of thinking about it in assembly theory that I think are pretty rigorous.”
Source trail
Everything needed to verify it.
- Speaker
- Sara Walker
- Attribution
- Verified speaker
- Claim type
- belief
- Recorded
- 13 Jun 2024
- Publisher
- Lex Fridman Podcast
Transcript context
…So what do you think is the origin of life on earth and how can we talk about it in a productive way? The origin of life is like this boundary that the universe can only cross if a structure that emerges can reinforce its own existence, which is self-reproduction, autocatalysis, things people traditionally talk about. But it has to be able to maintain its own existence against this sort of randomness that happens in chemistry, and this randomness that happens in the quantum world. And it’s in some sense the emergence of a deterministic structure that says, “I’m going to exist and I’m going to keep going.” But pinning that down is really hard. We have ways of thinking about it in assembly theory that I think are pretty rigorous. And one of the things I’m really excited about is trying to actually quantify in an assembly theoretic way when the origin of life happens. But the basic process I have in mind is a system that has no causal contingency, no constraints of objects, basically constraining the existence of other objects or forming or allowing the existence of other objects. And so that sounds very abstract, but you can just think of a chemical reaction can’t happen if there’s not a catalyst, for example. Or a baby can’t be born if there wasn’t a parent. So there’s a lot of causal contingency that’s necessary for certain things to happen. So you think about this sort of unconstrained random system, there’s nothing that reinforces the existence of other things. So those sort of resources just get washed out in all of these different structures and none of them exist again, or they’re not very complicated if they’re in high abundance. And some random events allow some things to start reinforcing the existence of a small subset of objects. And if they can do that, just molecules basically recognizing each other and being able to catalyze certain reactions. There’s this kind of transition point that happens where, unless you get a self-reinforcing structure, something that can maintain its own existence, it actually can’t cross this boundary to make any objects in high abundance without having this sort of past history that it’s carrying with us and maintaining the existence of that past history. And that boundary point where objects can’t exist unless they have the selection and history in them, is what we call the origin of life. ng with us and maintaining the existence of that past history. And that boundary point where objects can’t exist unless they have the selection and history in them, is what we call the origin of life. And pretty much everything beyond that boundary is holding on for dear life to all of the causation and causal structure that’s basically put it there, and it’s carving its way through this possibility space into generating more and more structure. And that’s when you get the open-ended cascade of evolution. But that boundary point is really hard to cross. And then what happens when you cross that boundary point and the way objects come into existence is also really fascinating dynamics, because as things become more complex, the assembly index increases. I can explain all these things. Sorry. You can tell me what you want to explain or what people will want to hear. This… Sorry, I have a very vivid visual in my brain and it’s really hard to articulate it.…
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