Into the Impossible With Brian Keating - Sara Walker: The Origin of Life ​(#219)

Episode Date: March 16, 2022

Sara Walker is an astrobiologist and theoretical physicist interested in the origin of life and how to find life on other worlds. She is most interested in whether or not there are “laws of life’ related to how information structures the physical world that could universally describe life here on Earth and on other planets. Walker is deputy director of the pioneering Beyond Center for Fundamental Concepts in Science, which is devoted to confronting the big questions of science and philosophy.  She is Associate Director of the ASU-Santa Fe Institute Center for Biosocial Complex Systems and Assistant Professor in the School of Earth and Space Exploration. She is also Co-founder of the astrobiology-themed social website SAGANet.org, and is a member of the Board of Directors of Blue Marble Space. She is active in public engagement in science, with appearances at the World Science Festival and on "Through the Wormhole" and NPR's Science Friday. Sara’s provocative paper: Origins of Life: A Problem for Physics can be found here https://twitter.com/sara_imari https://beyond.asu.edu Join my mailing list for twice-monthly content from around the universe: http://briankeating.com/mailing_list.php  Please Visit our Sponsors: Athletic Greens, makers of AG1 which I take every day. Get an exclusive offer when you visit https://athleticgreens.com/impossible AG1 is made from the highest quality ingredients, in accordance with the strictest standards and obsessively improved based on the latest science. All 33 Chairs. My All33 Chair is the ideal chair for all of us ‘knowledge workers’ suffering through unending Zoom calls. Sitting still is bad for you. All33 chairs are my choice because they allow your pelvis to move the way it does while you walk — so all 33 vertebrae align into perfect posture. The result? Better breathing, better blood flow, and relief from pain. It’s crazy what you can do when you set your body to it. To get $100 off your order, visit https://all33.com/impossible Search for The Jordan Harbinger Show on Apple Podcasts, Spotify, wherever you listen to podcasts, or go to jordanharbinger.com/subscribe Connect with Dr. Brian Keating: 🏄‍♂️ Twitter: https://twitter.com/DrBrianKeating  🔔 Subscribe https://www.youtube.com/DrBrianKeating?sub_confirmation=1 📝 Join my mailing list; just click here http://briankeating.com/mailing_list.php  ✍️ Detailed Blog posts here: https://briankeating.com/blog.php 🎙️ Listen on audio-only platforms: https://briankeating.com/podcast.php    A production of http://imagination.ucsd.edu/ Support the podcast: https://www.patreon.com/drbriankeating  Produced by Stuart Volkow (P.G.A) and Brian Keating Edited by Stuart Volkow Music:  Yeti Tears Miguel Tully - www.facebook.com/yetitears/ Theo Ryan - http://the-omusic.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

I'm an astrobiologist and I study life. I'm interested in life here on Earth. And I'm also interested in life out there among the stars if we can find it. And that's really cool, except the problem is we don't really understand what life is. And so I'm interested in whether we actually have a theory of life, if we could find a theory of life, and what its basis would be. Hey, everybody, you're going to love this interview with Professor Sarah Walker of the Arizona State University. Sarah is a friend that I met virtually, and she is anything but virtual. She's an incredible thinker in the real world in the scientific communication space,

and you're going to hear an exclusive from Sarah today into the impossible exclusive that Sarah's writing a book about her travails and travels in the world of the origins of life. So look for that coming later on in your life and her life, and she'll be back on the show. She assures me when that is out. Today you're going to learn a massive amount of cool, interesting stuff. Sarah's one of my favorite, favorite thinkers of all time. We talked about so much today, and just a smidgen of the topics we're going to cover today involve the question of what is life?

Is that even a good question? What is time? Is that a good question? We even got into things such as the origin of biological systems as relating to the laws of physics, even cosmology. Of course, we had to touch upon intelligent design. some tough questions about that subject as well as her theory that she's developed along with past guest Lee Kronin, so-called assembly theory. You'll learn about that. What is that? How can we

detect the imprimatur of life, perhaps here on Earth, perhaps in distant solar systems, perhaps if they come and visit us through Omuamua, which we also discussed Avi Loeb and the efforts to ascertain whether or not the existence of techno signatures in the form of objects that visit us should be pursued further. We talked about that. Charles Darwin, his warm little pond, so much more, her expertise is unbounded. And it's really a great way to continue our mission into the Impossible podcast. I'm so pleased to reveal that we've been ranked number one in all of natural sciences on iTunes and the Apple podcast ecosystem, number nine in all of science. It's just incredible. I never thought when I started doing this just a couple of years ago that it would lead to such great

success and you my listeners viewers are all part of this success equation i can't do without you so please do share the podcast with your friends share the audio share the video please subscribe to the video uh as well because i put in some great b-roll production my super producer stewart bull cow member of the pga not the professional golfers association but producers guild uh just adds in a magic pixie dust to each and every video and audio episode so that's dr Brian Keating on YouTube. And so today's episode is not one to be missed. I'll talk to you at the end and give you some homework assignments. Stay tuned and now enjoy this episode with Dr. Sarah Walker of the Arizona State University. Any sufficiently advanced technology is indistinguishable from magic. Open the pod bay doors, please help. All right. Everybody, you are in for a treat on today's episode of the Into the Impossible podcast with a phenomenal thinker, a

brainiac, a deep thinker, a astrobiologist, professor, theoretical physicist. She does it all and she does it all incredibly well. I've been a huge fan of hers for a long time. And I'm just so happy that Professor Sarah Walker is joining us on the podcast today. Sarah, how are you today all the way in Arizona? I'm great. How are you? I'm doing well. So a quick intro. Professor Sarah Walker is an astrobiologist and theoretical physicist interested in the origin of life and how to find life on other worlds. And she's the deputy director of the Beyond Center for Fundamental Concepts and Science, Associate Director of the ASU Santa Fe Institute Center for Bioshocial Complex Systems and Assistant Professor in the School of Earth and Space Exploration. And that is CC, although

I see some conflicting things that you're associate professor, someplace I see your assistant It doesn't really matter once you get tenure. And if you don't have tenure, you'll get it. And we would snatch you up in a second if we had a chance here in San Diego. She does a lot of outreach, especially as I met her on Clubhouse, where I've met a lot of people in virtual space, but not in real space. And she's prolific engager of the public with scientific concepts, never dumbing things down, having multiple appearances at the World Science Festival through the wormhole, NPR Science Friday. She does it all. And Sarah, so glad to have you here.

Great to be here. I'm looking forward to it. Yeah. So we have a lot of interesting feedback from my audience, and we'll get to those later. I always take the host prerogative when my guests are prolific authors, and I ask them, you know, explain the title and origin and judgment of your cover. So I had that with Paul Davies and an interview we put out recently, judging books by their covers. You don't have a book yet, although I'm sure there will be many publishers. to get your scrivenings into the public's hand in a book.

And if not, let me be your agent. I will only charge 55%. But I want to judge your paper, the paper that caught my attention so long ago now, almost four years ago, Origins of Life, a Problem for Physics? I add the question mark. Sarah, what is the relevance of the origin of life to physics?

I mean, I could see for biophysics, but why is it a problem for physics as a whole? Yeah, so, well, I think people confuse physics with the problems that studied in the past rather than a way of thinking about the world. So the issue I see there is that because we've come to kind of a deep fundamental understanding about parts of reality, those are confused with physics as a discipline rather than thinking about this idea that physics is really predicated on trying to look for deep, abstract principles that are really explanatory and have a large breadth of explanation. And so with the origins of life, I think that's really critically important because I find it hard to believe that life doesn't have some deep fundamental explanation.

And in particular, in the field of astrobiology, when we're talking about whether there's other life out there in the universe, we really need universal principles. And therefore, when you cast it in that kind of framing, it becomes a problem for the mindset of a physicist as far as how do I abstract this problem to its essence and then how do I develop a mathematical understanding that allows me to predict features of examples of the system that I've never encountered? And I think that's actually really the program for Asherbiology is we don't want to just have aliens hit us in the head or something.

We want to actually go out in the universe and look for them and predict where we should find them. And some of the research I've seen you involved in particular in the paper is kind of straddling the interface between information and complexity as well as life problems. You know, life qua life. And I wonder, you know, I don't want to have this, I don't want to ask you this question, even though people like Lee Kronin told me to ask you this question. I kind of get sick of me asking it, although I'd love to hear your response, if you like,

but it's the famous question posed but not answered by Schrodinger, what is it life? And I just find it a little bit, you know, it's like Wonderbread or something like that. You know, it's, yes, it's technically a question, but is it a good? question? Maybe we can ask that instead of you defining for the nth time as you've done so skillfully. Is it a proper question or is it sort of like these why questions? You know, why is their life? You know, is it a different question than what is life? So what do you make of this? Well, so first off, I'm not, I'm a physicist that's not afraid of asking why questions, which is maybe why I ask a traditionally non-traditional question in physics is that I don't think that we should be scared

of those questions because I think by the practice of asking a why question, you ask things differently than if you didn't consider the why, which means your what questions are better informed because they have some deeper principles underlying them. The what is life question, I think, is ill-posed because it makes some assumptions about life as we understand it being a natural kind or being actually a category in nature. And usually when, at least if you look at the history of physics, it's not like we were asking what is gravity before we came to. up with the idea of gravity. You were asking other questions like, why do the planets have regular emotion in the night sky? Or why does this apple fall from the tree the way it does? Or why does this,

you know, ball roll down this incline plane? And then we came up with this kind of unifying explanation that we call the laws of motion and the laws of gravitation. And I think when we're approaching the life question, there's a lot of assumptions that because we are life, we know what life is. And therefore, we can just go in and define it. And what is life actually makes sense as a question? but I think as you dig down deeper into that question, it starts to make less sense to pose it that way. So the way that I like to think about the question is what are the laws of physics that would have features associated to them that explain the phenomena that we call life? And that's a little bit of a mouthful, but I think the simple way of saying it is there's something underneath the phenomena we call life. That's probably a pretty deep explanation.

and we should really be trying to derive the properties of life not to find them. Yamava Resort and Casino at San Manuel is California's number one entertainment destination for today's superstars. Catch the Jonas Brothers return to the Yamava Theater stage on April 30th, the powerful vocals of Demi Lovato on May 17th, and the signature Southern Country Rock of Eric Church on July 19th. Tickets on sale now at Yamavatheater.com, only at Yamava Resort and Casino, celebrating its 40th anniversary, U-N.

Must be 21 to enter. Right. And I think maybe we could even start there by, you know, recapitulating some of the notions of emergence, which you've spoken about before. But I think my audience would get a kick out of hearing it from you. I always say, you know, life is kind of like the Supreme Court's, you know, 1950-something definition of pornography. It's like we know when we see it. But maybe we know it when we don't, or we know what it is when we don't see it, you know, more likely. But I wonder the confluence of information and life as an emergent phenomena and the concomitant, you know, question of how does consciousness emerge?

A lot of people maybe conflate, maybe erroneously, I don't know. I'm not an expert like you are. But consciousness as being a prerequisite to understand life. In other words, can you have life without consciousness? Certainly there wasn't maybe conscious life before, you know, human beings maybe or something like human beings. And yet there was life. So can you talk about this emergence? And as Morrison said, more is different.

And so first of all, what is emergence and why is it relevant potentially to the origin of life? Yeah. So emergence is this idea that you can get new properties at new scales of organization. So like if you think about, you know, reality being separated out in scales, which is really not. It's just that we do that because we have to build models of things. You know, there's the atomic scale and then atoms come together to make molecules. and then maybe when you're talking about living things, you get cells and cells come together to make multicellular organisms or people come together to make societies. And when we're looking at each of

those different spatial scales, we see fundamentally new rules emerging. And so this is one of the reasons that Anderson said more is different. It's not the same at every scale. We actually see new properties. And one of the things that's probably the most mysterious about emergence is it seems to be the case that you can describe these scales independently of having to refer back down to the lower level scales. So a lot of, so for example, we can talk about social dynamics without having to appeal to, say, QCD or something, right? So we don't need to have those theories of like how the very basic component parts work to understand something at a high level like that. And so in sort of our traditional concepts of science, that seems kind of deeply mysterious

because people think, or, well, there seems to be some conflict as far as, well, are these genuinely new properties? Or is it the case that if we really had a giant supercomputer and we could run, say, the interactions of all the elementary particles in a social system, we'd actually really recover those high-level dynamics? And of course, this gets into more issues of, like, let's say maybe something like metabolism, you know, like I'm eating. Is there a particle description of what it is for me to be eating. But then there's also the question, is there a particle description

of what it is for me to feel hungry? Because feeling hungry seems much more subjective and intrinsic to the scale of organization that I operate on. So there's some questions in biology that seem much more apparent that some kind of emergent description is actually necessary.

You can't really reduce it to the particle description. Yeah. And it's interesting because in this paper, you talk about kind of the emergence of life, but the first example that you give and, you know, in the history of life's, uh, of life's emergent properties of life is a colony, are these stromatolites, which, um, you know, seem to be these mysterious things in, in Australia, um, that, uh, or collectives.

It's not like we find some isolated, you know, protozoa somewhere by itself, at least is the earliest form of life, if I'm not mistaken. And so it seems, yeah, again, even kind of cut it, you know, breaking the egg, even more the chicken or the egg. Now it's like, which comes first to collect. or the individual in order to have a definition of life. And, you know, well, I think, I think, again, that's not the right framing of the question, because the issue is that you're looking at it as two scales.

But really, the phenomena itself is a multi-scale phenomena. So people think, you know, life emerged at like a cell scale or something and cells, you know, reproduced and then radiated out across the planet. But really, you know, there's other theories of the origin of life that it was, you know, like biochemistry emerge from geochemical cycles, and then you start thinking about it more in terms of ecosystem scale or planetary scale. And so I think this idea, this very, it's a very reductionist idea that we think life is about individuals. And it's not actually about individuals at all. It's about information propagating along lineages. So a cell, even if you think about

a cell as a structure as an individual, a cell has to constantly rebuild itself. And it's using the information imprinted in the matter that it is to reconstruct itself. And then if you think about that extended over time, the structure that you call life is actually the structure that's extended out over time, basically the pattern that keeps reproducing itself in the material substrate. So a lot of the discussions I have with colleagues, and in particular this idea comes from Michael Lachman at Santa Fe Institute, is really to think about the fundamental unit of life as a lineage of information. And we're all just these kind of bundles of intersecting information. If you think about evolution. And I think this is really related to the problems associated to emergence.

So just to, because I think people have removed time from consideration in the way we talk about both physics, because time is supposed to be an emergent property, right? Time doesn't exist at the fundamental scale. It has to emerge based on some properties of the second law or, you know, there's all these errors of time we talk about like the cosmological arrow of time, the second law, the biological arrow of time-wise biology increasing. And they all tend to point in the same direction. and that's some big mystery in current physics because there's no fundamental concept of time. But in biology, if you put time as being more primary, I think it actually takes care of some of the issues of emergence. Because when you're talking about an object that has emergent properties, what you're really saying is that object has more time in it,

where time is actually a physical attribute of the object. And this is something that we're trying to do in assembly theory because you think about like a molecule as being all the ways of assembling a molecule. which is basically looking at the structure across time. And so then you can stack, you know, that whole hierarchy I did of, you know, going from atoms to molecules to cells to multicellular things to societies as actually being about how much time exists in an object. And that brings in sort of the idea that evolution, sorry, my leg went out, actually is sort of fundamental to the way that we talk about what life is in the sense

that time actually has to be a part of the way you construct theories, that you actually think things exist across time. They're not just an individual instance that exists at that moment you're observable. Yeah. One of the questions I have about assembly theory is that it could imply if there's some end of the historical deviations from a previous state. Let's say we get to the ultimate evolution of society. You know, we become university professors. And that's the pinnacle of evolution. You know what the proof is, by the way, that we have the best job in the world, Sarah? You know what the proof of that is? What?

What did the man who achieved the highest heights literally in history, namely Neil Armstrong, walking on the moon? What did he do after he retired from walking on the moon? He became a professor. So let's stipulate that's the highest form of evolution. Now, if you then reach kind of a stasis, you know, I can agree that there's more complexity in a Darwin's warm little pond, which we'll get to, than there is in just water molecules by themselves.

So assembly theory would say there's more information, more stored memories, etc. But eventually that comes to some stasis, but time doesn't cease. So how can you reconcile those two facts? In other words, without knowing what comes next after societies, you know, then our collectives,

that time can then continue to progress in a way that the biological, psychological, cosmological, all the different hours of time, would agree that, yes, time is progressing. if you reach some maximum stasis. So I think part of the, this is a really interesting question. So one of the things I've been doing a lot of thought experiments on is what does a

clock look like in assembly theory? But I don't have like, and we and I have been debating about that. But I think one of the key points is if you think that there's an ordering of events, like I can't spontaneously fluctuate out of the vacuum, which currently the physics might say could happen. And I think is actually a logical impossibility. So sometimes, so where it gets interesting talking about life is where we have had a tendency in the past to take theories of physics and draw them to like their logical end state and then accept that that's actually a real possibility in our universe even though it's ludicrous. And then you come at it looking at from the perspective of life and you really see why it's ludicrous. So there's like this idea of Boltzmann brains or anything is possible to spontaneously fluctuate into existence. And part of the sort of argument that, we would make an assembly theory is, no, that's not possible because you actually need the

specific sequence events to make that object. There had to be causal structure in place, things that you might call constructors or however, whatever language you want to use, information in the system to actually assemble that specific object. So you can't just get a Sarah for free. You have to go through the four billion years of evolution to get to an object like me. So even if I was static and I never changed in the future, you would still have that four billion year time point. But, But part of the point is also I have to constantly reassemble myself to exist. So I'm not a static object. I'm a thing that is constantly reconstructing myself.

You're constantly reconstructing yourself right now. So even if you're just sitting there and you're not doing anything, your body is metabolizing. I'm like Madonna. I'm always reinventing myself. That's right. Material girl. I'm also a material girl. But I like Roger Penrose's perspective that he doesn't know what the,

material is and I think that's probably pretty accurate. So I think when you think about it from that perspective, I don't think that the traditional notion that things can be static in time actually even makes sense. And so part of the way we're playing with ideas is this causal structure, if you want to call it ordering in time, is the fundamental thing and that universe is constantly assembling itself into the next quote unquote state, although I don't really, I think states are kind of a weird thing that we talk about in physics for various reasons, but the next thing that exists. So the universe is constantly moving forward in time, but it exists in the current moment, right? So it's that assembled moment. So there's not really, for things to persist, right?

Like, why does something exist across time actually becomes an active process, not a static one? So I have a question from an audience member named Lee Cronin and says, is Lee right about time? Now, I don't want to make this about Lee. Lee gets enough attention and he's no, he's very shy. So, you know, it's hard for us. Yes, you know, question about Lee. He's very shy, yes. But I'm curious because we are talking about time.

When we had a conversation a week or two ago, he and I on Kurt Jiam Engels channel, Theary of Everything, which folks should check out, you know, he basically says, that time doesn't exist and because only through, you know, only chemists have a, have a true proper understanding of entropy and time is fundamentally a chemical process or entropic process

for the way of the second law. Now, given that there, and I said there's so many different definitions of entropy and my friend and maybe you know, Nicole Younger Halpern as well, she has a great book coming out. She'll be a guest next month on the podcast for Quantum Steampong. She talks about the, you know, the advice that that Van Neumann was given, I think, to Silard or somebody said,

when you don't know how to define something, just call it entropy, because nobody knows what entropy is. Right. So I like the fact that so far we haven't really preferred to entropy or the second law, but I think it is appropriate to get into that and maybe, you know, my ratings really depend on drama and battles. Oh, I see. So Lee threw down.

That's a cell of physics. You and I have to speak on behalf of physics. Okay. So these chemists are doing too much. I call them chemists, by the way, to annoy them. But is it a fundamental physical concept? You know, Nicole talks about the elemental, fundamental clock, and that you could have a two-state system that's a clock,

and we use, you know, atomic clocks that are, you know, not strictly two-state systems, but could such a model in your theory have a truly set to be a complex, you know, if you make the simplest instantiation of an object, namely a two-state quantum clock, and that it exhibits and it can do certain things and has certain properties associated with Clark. In what sense could we say that that will continue to exhibit, you know,

the features of assembly theory that would lead one in your rubric to account that it has sufficient complexity to be warranted amongst the pantheon of different discussions of entropy, etc. Yeah, so this is very much a work in progress. I don't actually know exactly what you're asking because I feel like there were like 10 questions in your question. Yeah, there were probably more than that. I guess imagine just a simple two-stay clock.

Is that sufficient to account for time? And people say that time is emergent. But we all know it again, like pornography. We all know when we say it. So a simple clock, how does that fit in just a two-state business in assembly theory? Right. So I think this is one of the places that maybe Lee and I disagree, but I'm not entirely sure. Rating's gold.

It's good, yeah. Because it is like something that we're trying to develop, right? And part of the reason that you want to work with multiple people on developing a theory is where you find congruence in your ideas or when you convince another person, then you start to see that there's some really interesting stuff going on. So the one of the, so the one thing I think that we do agree on is that time is moving forward, whatever that is. And that there's, and that is a generative mechanism for the universe. So time is actually the thing that generates the universe. And then I guess when I think about time in an object, I don't think. about that linearly though, right? So when we think about a molecule existing as a, you know, a certain

amount of time or causation exists in the molecule, maybe causation is the better word than time. You can think about all the ways of assembling the molecule, which means that that molecule actually has a very complex structure in time. It's not one way that time, that causation could have a sequence of events to produce that molecule. It's all the ways. And so a simple example that I like to do as a thought experiment is just to think of a stack of Legos. So imagine, you know, I was holding a stack of 10 Legos and maybe like five were yellow and five were blue and they were arranged in a particular pattern. In order to understand the assembly structure of that stack of Legos, I actually have to take the Legos apart into the five blue and five yellow and then build up the pathways.

So the argument I would make is all of those ways of assembling that object are features of that object. But to resolve those features, you actually have to observe them across time because they're not features that exist in any one instant of time. And so, and then if you want to see them in a linear sequence of time, you have to do that over and over again. But they're all features of what could have happened if you wanted to assemble that. So time doesn't necessarily have a single strand to it. It's this very complicated causal structure embedded in an object, but the universe as a whole is constantly chugging forward in time. So a clock is kind of an interesting object because you want to ask, well, how much complex time is in a clock,

or is the clock actually tracking the motion of the universe forward in time? And I think those are two different ways of asking questions about the nature of time in a clock. Very good. So I guess we'd say maybe Lee is not quite right or maybe it's not quite complete. So that'll stimulate him. It depends on what it's on, right? So sometimes he's clearly wrong. So I wonder, you know, if we can, you know, some of the classics and walk me through the current thinking of it.

As a cosmologist, I, you know, I'm not nearly as in touch with the underlying, you know, kind of state of play of things, although it's quite fascinating to me. And yet, I feel like there hasn't been much progress in some of the actual origin of life. In certain sex, there have been, you know, extremophiles and so forth. But, you know, one of my proofs that there has been some stagnation in things like string theory is that, you know, string theory is like the best theory ever invented to describe string theory. You know, it has a lot of, has a lot of promise to describe string theory. But can it describe other things? And I think that's what gives something predictive and value. Now, if you go back to Darwin's paper, I think it was to Huxley.

It might have been a letter to Huxley or something. He said, like, you know, if life could begin in some warm little pond with mineral salts and so forth and this thing and that thing and proteins and whatever, then, you know, it could evolve. In other words, that life could sort of kick off in this warm little pond, which in my simple-minded way of looking at it is not too dissimilar from an experiment done by the namesake of our chemistry department, Harold Uri, and his student Stanley Miller here at UC San Diego. They did it in Chicago, but they were later professors here. And that was this Miller-Urie experiment. And in my mind, we haven't made much progress since those initial kinds of experiments, which were at least intellectually the air of the Warm Little Pond thought experiment of Darwin. So can you take us to where do things stand in the kind of replication of life,

not the classification, and we moved away from that, but origin of life, you know, ab initio, and then perhaps, since you said nothing's off limits, we can talk about some of the criticisms, even from the intelligent design community, if you're willing to go there. No, I'm totally going to go there. I think they have some legitimate arguments, but I don't agree with the answer they provide to the argument. So where we're at with Miller-Yuri-type experiments? Yeah, so actually, so I made a crack that Lee is sometimes wrong, but we all are. But I think the thing that he's really good about is pushing the boundaries.

And I think something he's really right about is how much intelligent design goes into current original life experiments or historically. And what he means by that is when you're designing an experiment, you purify the reagents, put them in a test tube, you know, exactly what's in there. You crank a knob for like if you want to, you know, put, change the pH or you do, you know, add a mineral. But it's all very controlled and very methodical. And so basically the way I think about it is.

you're putting agency into the system. You're constraining all the boundary conditions. So when you get a complex molecule out, like say you do produce a molecule that is implicated in life, is it because that actually is a spontaneous process or is it because you as an agent that already evolved in the universe controlled the boundary conditions so tightly that you basically predispose the system to generating that complex structure?

Not that we actually make complex things prebatically because we make really simple biomolecules. But this is sort of one of the problems. So if you buy sort of the set of arguments that life is more about the lineage and we're all just kind of these packets of information or these features of assembly space that are propagating and generating more structure, then anything you do is basically becoming part of that living structure because you're a cause for those kind of things. And so the real challenge of original life experiments is to remove our biological lineage

and all the agency that we've accumulated over four billion years from the design. of experiments. And so this is something that is one of the reasons that I really wanted to start working with Lee when we first started talking is because he was the only person that I felt recognized this issue. And the only person that was really trying to design original life experiments that could do this. And one of the ways he's doing that is through this automation, this digitization of chemistry to basically build experiments that are agnostic. They're not designers like we are. And they don't have any predisposition to what the chemistry of life needs to look like and you basically want to start from a messy soup of things and try to evolve it under all

kinds of different simulated planetary conditions. I think of it if we could scale this up, it would be like a planet simulator. And Lee and I are working on ideas about how would you actually generate an experiment at scale like you would do in particle physics. So my favorite sort of experiment to compare this to is super kamikande, which is one of my favorite experiments In Japan, looking for proton decay. So proton decay has been predicted by theories, never observed in our universe, and every time we don't observe that event, we can bound the probability. The problem with the original life is it's a chemical search problem.

Chemical space is huge. It's exponentially huge. It's beyond exponentially huge. The combinatorial possibilities of molecules you can get, even for small number of elements, it's larger than you can possibly fathom. So the question is, how would you build an experiment, large enough to simulate planetary chemistry and explore enough of the volume of the space that you would expect a high likelihood for the original life to pop out. And that's the kind of

way we need to think not as designers of the original life, but asking, how is this a process that happens in the universe and how can we bound the likelihood of it? The longer we don't observe it, the lower probability it is, just like proton decay. And we need a theory to search it, which is what we're trying to do with assembly theories. So if you put those kind of experiments together with something like assembly theory, then you have this kind of way of doing original life science, like the way that we explore the early universe in cosmology or the way we think about particle physics. So one of the things of the characteristic of superkase, A, it uses, you know, super pure reagents. It's amazing. Yeah, it's a huge volume. Sometimes they explode the photo multipliers,

and then grad students have to go on a canoe. A background footage of Super Chemia Canada here. season and my business is scaling fast. To keep the nectar flowing, I need a phone plan with top priority data speed. That's why I chose GoogleFi Wireless. My connections stay strong even when the hive is buzzing. Plus, unlimited plans start at $35 a month. Now that's a deal that doesn't stay. Explore GoogleFi Wireless plans today. Plus taxes and government fees. Google Fi Wireless is not subject to data traffic deprioritization during times of high network usage. But I wonder, you know, when you about the, you know, kind of this, this challenge, it's kind of going the opposite way of Miller Uri. They literally did it with stuff you got at the chemistry stockroom in Yuri Hall here at

UC San Diego. You could do it. And, and of course, you know, now we know that it, I mean, it wasn't like fraudulent data, but it was, you know, it was far off from what we now know about the origins. And yet, it's still, if you look at many, many, you know, kind of proposals, at least in secular books, et cetera, and even, you know, popularizations. It's always pointed to is, you know, oh, you get Miller-Yuri and, you know, some version of it. Well, it didn't exactly do it, but we're confident some of it. But no, I mean, it's not like we're saying, oh, well, Super Kamikanda, you know, hasn't seen it. And therefore, you know, but we'll have some version of super, no, all we can do is run it longer, as you say, with a larger fiducial volume. And then

with, you make up for time by having more opportunities for decay and then the properties of half-life than work in your favor. But this is kind of going the opposite way of Miller-Yuri, which is to go, instead of looking at one proton decay, you're looking, now you're, how big an experiment would you need? And would it be imposing, you know, this purity upon it? Or would you even be using physical chemicals at all? Or would it be purely simulated? No, it has to be physical, right?

Because we don't know, we don't understand what physics governs origin of life. It's not, like, you can't simulate life in a computer because you don't understand the causal structure of what life is. If we had the right physics, we could simulate life in a computer. We can simulate some projections of features of life, like evolutionary processes and things in a computer. But I think the original life we can't simulate because we don't know the principles. But just on the point about Miller-Jurie and comparing to the way the particle physics community works, say, and the way the original life community works, when you look at original life experiments globally,

it's always the case that it's like a single lab, you know, has their favorite molecule that's implicated in life. And they want to understand if they can synthesize that under quote-unquote prebiotic conditions. where prebiotic conditions is, again, some kind of pure reagents, not necessarily a mix of soup that would be present on the early earth, but some purified chemical compounds that they mix together in precise ratios. And then they subject it to whatever kinds of conditions that they want to study the particular synthesis pathway. And of course, that's an okay mentality for doing science. If you're an organic chemist and you've been trained to synthesize a purified reagent, but a molecule is not life. And producing a single molecule, a social molecule,

with life under those kind of conditions is not solving the origin of life. And then you'll get one, you know, lab, you know, maybe making amino acids over here under some kind of condition that might be presumably prebiotic. And another lab over here making a nuclear base. And another lab over here talking about the energy pumps necessary in early membranes. And there is this sort of rampant assumption in the fields that some people will really precisely articulate. So Nicolena is one of these people that if we know enough of those steps, we'll be able to just string them together. and then we'll be able to understand the mechanisms of the origin of life. But I think what that view is missing is that each step is precisely tailored to the particular

outcome that you want for that step, which means that we are putting so much agency into those experiments. I like to equate it a little bit to like verifying a number is prime. If you want to find the next prime, that's a really hard search algorithm because you don't know what you're looking for. But if you already know it's prime, it's pretty easy to develop algorithms to verify its prime. And so what prebiotic chemists are doing right now is verifying primes by looking for known molecules and doing it under very controlled conditions and they happen to be small primes because

they're not very complicated or hard to get to. And what we really want to do is try to find what's the large like what's the largest prime and like how can we predict that out of priority? It's like it's a much harder problem for origins of life than as far as it's, it's not even the same like class of search problem that we're doing right now as it should be. And right. And then getting back to this kind of controversy, which Lee said in his interview with me, although I've heard him, you know, take multiple sides of it. It's like, it's like Stephen Hawking. Penrose says, you know, you always want to make a bet with Stephen Hawking, because no matter what side you take, he'll capitulate and you'll always be right, because he always

changes mind. Now, I've heard Lee debate intelligent designers and have, you know, some very harsh upbraiding, you know, and a gentle, gentlemanly Scottish way that he has. But I've also heard him, you know, say that literally chemistry has an intelligent design problem, or biochemistry has an intelligent design problem. You mentioned that you're not afraid. What do you say to somebody, like past guest Stephen C. Meyer, or, you know, perhaps future guest I've spoken to James Tour, you know, who stipulate that, yeah, there are these problems of, you know, purity of very carefully controlled initial conditions, as you know from physics training. You know, this is an incredibly important and vital aspect of characterizing any physical system, let alone a biological

system. So, you know, is this, you know, destined to kind of always have this ambiguity, which drives human beings crazy, not being black or white? But, you know, is there a point? If you had a steel man or steel woman, the points of the ID, the intelligent designers, the Stephen C. Myers, what would you say? And then we can look at, you know, countering it, for example. What are the biggest criticisms in this field of origin of life? I think, well, I mean, I think there's a lot of them, but I guess the main one is just because we don't have a mechanistic understanding doesn't mean that we need to appeal to something outside of the universe. And I'm agnostic on sort of all issues. And I think what I always try to do is maintain an open mind that any possible explanation is possible. But I see so many roots to actually having an understanding of the origins of life being something that we can understand from physical principles within the I think the problem is that we're not asking the questions the right way. And even the way we ask the questions is actually loaded the die for intelligent design to be the

explanation because the way we talk about the origins of life is wrong. And I think we have too many preconceptions about the problem and the nature of what we are and the assumptions that we understand what we are that make it really hard to work in this area. And this is one of the reasons that, I mean, I started in. when I was a PhD student as a cosmologist, but one of the reasons I really wanted to work on origins of life is because the conceptual foundations were so poorly defined. And on some level, I don't even care if the way that I'm trying to pose the question is right,

but what I do with the problem and what I do with every problem that I try to look at is look at how people are talking about it and then just try to turn it slightly and be like there's another logically consistent narrative with all the evidence we have, over here that nobody's actually looked at yet. So why don't we explore that one and try to see where the possibility space is for that one? And then that opens up subsequent pathways. And I just think that people haven't really been poking at the original life things from the right angles yet. And we've seen that through the history of human thought that we've had major breakthroughs as soon as somebody came up with some fresh idea to something. So I think anytime that you want to

prematurely say a problem is unsolvable is really limiting the potential of what humans can do in the future. Because I also, this is sort of a bias of how I think about constructing theories, and maybe it's a very David-Doichi and kind of view. But I really think that explanations are pretty fundamental. I mean, they're fundamental to the physics of what life is. Like, my favorite kind of physics is the physics of theoretical physicists.

Talk about going back to like the pinnacle of like, you know, that's like a really egotistical way to study life. But of course, it's the example of life I'm most intimate. familiar with and also like cognitively when I do thought experiments about life, it's the one that I have the most playroom with. But it's also like a carefully constructed set of experiments because mathematical physics has done so well this idea of taking abstractions, mathematical objects and using them to describe reality and then doing incredible things with those descriptions of reality like launching satellites into space based on the laws of gravitation or building

experiments like supercaniaconda to look for the decay of proton or discovering gravitational waves, have been passing through the earth as long as life has been on this planet, but we've never made contact with that phenomenon in the universe before. We actually knew to go look for it. So I think the idea that we won't have a theory that explains us is, to me, incredibly limiting about the future potential of our planet and where we're going, because if we do understand what we are, then we have control over that phenomenon in the same way that we have an understanding of gravity and can control motion and understand how to launch rockets and things. Imagine what it would be like if we understood what life was. Right. Yeah, I would say, you know,

two things. One, you know, these nature is under no obligation to make things understandable to you on the time scale of a PhD thesis or a 10-year case. But also I say to my, you know, and I'm a practicing Jew, I, you know, attend temples and I do, you know, practice in that sense. And I do read the Torah every day. But on their hand, I tell my religiously, you know, much more predisposed colleagues and friends, you know, if you really believe in science, sorry, if you really believe in God, you should approach it through a scientific lens because it might be the only clue, you know, it might be that, you know, Yang Mills theory or, you know, Maxwell's equations or whatever are the only hints that we can ever hope to get of God talking in our language. But moreover,

if you tell your children that, you know, life started purely because of a miracle, You know, then I think it limits their ability to at least search for, you know, going back even further to primary, you know, the primary source material, if you will, if you just say everything is done by God and every single thing is controlled by some agent that you have no access to because God is not revealing himself to us in our modern age. So I think that's incredibly stunting of my religious friends and the intelligent designers beyond, you know, other challenges that I posed to them. But I think you had to, oh, go ahead. No, I just want to pick something really interesting in your point, because one of the things that I've always found at conflict that I don't understand how to resolve is that intelligent design seems to me to be a principle that limits creativity in the universe. Like, it means that creativity is not a physical thing. And the way I approached the problem, even when you said, you know, it's not, it's not necessarily the case that we should be able to learn the laws of nature on a university education timescale, right? But we can. So I use that as observational evidence for the kind of physics I want to understand. And so then you have to construct the problem, well, why is it we can comprehend reality?

And what is that as a physical process? And I think intelligent design misses the ability to even ask that question because they assume all of that just came for free. And so it's trying to explain us, but ultimately it really doesn't explain us. It sweeps any explanation for what we are as special in the universe or different in the universe under the rug. And I think the one thing that I think is really deeply intriguing is as far as we know there aren't any other physical systems like our modern technosphere and our participation in it as thinking agents that are conscious, right? And an ability to explain that, it has got to be pretty profound and really interesting as far as how we understand ourselves and our relationship to the cosmos, but also what else might be out there. And so I think your point about limiting, potentially limiting imagination is really the part that. I would want to push back on. I'm open to alternative explanations. Yeah, right. I see you as a very,

you know, non-dogmatic, very, you know, ecumenical thinker in that you're, you're not going to have an open mind so open as Carl Sagan said, your brains fall out. But on the other hand, you're willing to strengthen your position by taking an opposing perspective, which I find, you know, quite, quite the hallmark of the best scientists on Earth. I think you had a beautiful statement. I I forget where it was originally, but you said, you talked about what's called the Luca, the last universal common ancestor, and you said that it is akin to my field, the last scattering surface of the cosmic microwave. I thought that was one of the coolest analogies I've ever heard.

Explain to people, what is Luca? Who is Luca? And why is it so important to study the oldest, most primitive things as we do with C&B photons? But why is it so important in the field that you've chosen to dedicate so much of your intellectual effort to. Yeah. So I think the actually equation between Luca and the CMB came from Nigel Goldenfeld and I picked it up from him because he's awesome. Oh, I think he's my new colleague here. Yeah. Okay. Well, that's cool. Yeah. So he, you know, Matter physicists working on origins of life would come up with this kind of analogies.

But I love it. I think it's... Well, that's another hallmark for you young people, I have to say, sorry to interrupt you, Sarah. It's so interesting. But what Sarah just did is the hallmark of a true scientist. She gave proper attribution. And it's actually, in Judaism, it's considered a sin. It's called stealing thought. Like when ever hear somebody say, oh, I'm going to steal that joke, that's actually like a pretty big sin because people are going to attribute to you the credit that's owed to other people. And academia, we don't get away with that in our papers. But you could have easily gotten away with that with me. I wouldn't have known.

But it's a sign of an expert scientist to do what Sarah did. So for my young audience, I have a huge, very rabid young audience. That's a lot of EDU addresses in my mailing list, which you should all subscribe to. But I just want to point that out. Keep going, everybody. Keep going. Yeah, so go ahead. So what is this analogy? I love it.

So Lauca, what does it present? Luca is an abbreviation of last universal common ancestor. So the first sort of problem with that name is it's singular and really we should be thinking about as a population of cells on early earth. And I think one of the people that spoke about this most eloquently was Carl Woz, who co-discovered the third domain of life with George Fox. But he made a lot of arguments about collective evolution in our early. life. And this idea, so, so Luca comes from tracing phylogenetic trees. So if you look at all life

on Earth, it has shared biochemical component parts. And if we trace those histories back in time, it kind of converges in what we call the last universal common ancestor. And I guess my point of bringing up Carl Woz's ideas is a lot of people think that convergence means we're talking about a single cell that lived on early Earth and everything radiated out of it. But what he really pushed was this idea that Luca might have been itself a collective. phenomena. And this is actually really how I think about it. I don't think that when we're looking at the imprint of the information we have today on the earliest life, that it was a single cell that made everything. It's a feature of what life was doing at a planetary scale. All life on Earth

looked like at that time. And it was some collective feature, just as if we kind of zoomed out and looked at life today, there would be common biochemical component parts in every organism on earth today. And that's a phenomenon that exists across all known life. So the reason for equating it to the CMB is that because we're using genomic information to reconstruct the last universal common ancestor, it's kind of like the last surface of information that we can look at. And so going past it requires different tools in the sense that the genomic tools are not adequate. It's like the photons, you know, give us information from the CMB, but not earlier because they were scattering too much. And so we have this kind of boundary if we want to do these phylogenetic

reconstructions. So one of the things I'm really interested in scientifically, and this is something that I spent a lot of time working on with my students in postdocs, is trying to not look at genomic reconstructions of life, but look at patterns in biochemistry, like statistical patterns. So just like in statistical mechanics developed in the 1800s, we were, realize we could predict more features of engines and things by talking about temperature and pressure and work, these kind of macro scale variables that coarse grain, you know, the exact position and momentum of every particle in a gas. So far in biochemistry, we've been talking about the exact component parts. Luca had to have DNA. Luca had to have, well, we don't know if I

have DNA, but like had to have ribosomes, had to have certain metabolism, and people are trying to reconstruct the specific component parts. What we're trying to, we're trying to to do is say, Luka was a statistical pattern in print on early biochemistry, and let's reconstruct what that pattern was and try to predict chemistries and environments associated to that pattern. And we do that by using scaling laws and all kinds of other things, but we don't have to get in the technical details. But then the idea is to try to understand when life became universal in the sense that there is a shared biochemical component parts.

how do we understand the patterns in those chemistries that we can actually extrapolate further back than Luca just based on those patterns, which don't require genomic information? Excellent. So now moving out from our vantage point on Earth, I do want to talk to you about more controversial topics like aliens, extraterrestrial intelligence, UFOs. But before we get there, I understand that one of your, you know, I think it was your PhD thesis, as a matter of fact, involved what? called homo-chirality and the existence. And I'm going to probably get this wrong. Here's how I remember it, Sarah, and I'm looking to the world's expert, perhaps, on this. But I always remember that DNA is right-handed.

Is a right-handed helix? I don't know, actually. Well, because it has sugars that are dextrous, right? The sugars are right-handed. I know that. So, like, because I was working at the level of, like, small molecule symmetry breaking. I know the sugars are right-handed. And for amino acids, it's left-hand amino acids.

It's left-in-right. Actually, you know why I get confused on DNA? Why? It was wrong in some textbook. And I never remember which orientation was right because it was like, it wasn't that one. But now I have in my mind, anytime I hear which one it is, it wasn't that one. Here's how, I'm going to teach you a mnemonic to remember it. So DNA is, is.

right-handed because life finds a way to be right. Oh, I see. Okay. That's the way I remember it. But neutrinos are left-handed, ordinary news. So that's how I can, so if somebody asked me as a neutrino, right-hand or left-hand, I think DNA is the opposite of a neutrino, so therefore DNA is right-handed because life finds the right way, then neutrino. Okay.

Anyway, we'll probably have to edit this out. This is so bad. But imagine you're looking out to space and, you know, somebody tells you that, or they just returned and they've just returned and they go. got some, you know, ancient stromatolites from, you know, planet that orbits around Proxima Centauri B or whatever, right? You test it and it's has equal amounts, you know, it's heterochiral, I guess. Do you say this guy's a fraud, or, you know, this is nonsense? In other words, what is essential about the chirrality to the nature of life, if anything?

Yeah. So there are some arguments. that only homo-chiral, so one-chirality biopolymers, so like when you take those right-handed sugars, you need to link them together or amino acids, only those would be functional. But it's actually really hard to test that experimentally because synthesizing, you know, populations of heterochiro polymers is hard because all of our enzymes for synthesizing polymers were derived from biology, which has a particular orientation to it as far as, so it's easy to make like a left-handed protein, you know, left-hand amino acids, you can maybe make a right-handed one because you could imagine reversing everything, but doing something in between is actually quite hard.

So there's kind of this implicit assumption that functionality in life requires homo-chiralty. I am actually really interested in a kind of different feature of chirality more recently. So when I was a PhD student, I was working on symmetry breaking. So physicists love symmetry-breaking problems, right? So if you have two things, they're left-handed, right-handed, and these are the left-handed one, and otherwise equivalent, that's, you know, a symmetry-breaking problem. And it turns out you can make that problem kind of equivalent to, like, an icing phase transition, like when you have an up and down spin. And so I was working on models of how you get that symmetry-breaking prebiotically. But the thing that I've gotten more interested in recently is actually thinking about chirality as a system-level property.

So if you think of like a biochemical network, like the small molecule chemistry that biochemistry catalyzes, all of those molecules are either achyrol or they have some chiral orientation to them. And one of these things that we've been doing with this kind of statistical mechanics of biochemistry is looking at patterns in life's use of chiral molecules versus achyro molecules. It turns out there's very statistically rigorous scaling laws. Like if you look at a biochemical system and you look at the size, it's increase in size. so number of molecules that that organism uses in its biochemistry, there's a scaling law of how many of those are chiral versus achyrol.

And the reason to me that's really interesting is one, it doesn't require appealing to these large macro molecules to talk about chirality is an interesting feature because this is a small molecule chemistry, so this is getting at the original life scale, that somehow chirality is actually playing a role in the structure of networks that become living. And if I want to get to the deeper physics of that,

I think that's actually deeply associated to what we're doing in assembly theory and also thinking about time like we were talking about earlier. Because if you think about a chiral molecule and you have these two-handednesses, basically it's like a symmetry breaking in time if you choose one over the other because now you're talking about not just that molecule, but all the assembly pathways for making that molecule and all the ways that it interacts with things in the future. So chirality, I think, is playing this really interesting way about funneling biological systems. down specific kinds of trajectories in assembly spaces are in time. And that's some theory I'm trying to work on that's motivated. Right now we're working, we have these patterns in biochemistry that we've elucidated, and we're writing a paper on that now. But in the long term, I'd really like to think about a more fundamental theory for chirality.

Sort of like how chirality was brought into like QFT and all these other things at some point. Like, you know, chirality always comes up as interesting in physics. And I think about it more like a physicist because I'm more interested in like, in those kind of questions. And I don't think we've gotten to the point where we can ask those yet, but I can see hints of where there's really, really interesting physics happening with chirality. Right. Yeah, exactly.

So, and I think, yeah, that maybe connects back to where we were in the very beginning, but at least in the context of cosmic analogies, what we want to do is look out and see gravity, see the forces of nature when they were in, you know, what's called the linear regime. And I'm, you know, my simple minding way of thinking about it is, Like, what's the analog of the biological linear regime, you know, about which we can do perturbation? But maybe that's not the right way to think about it. No, no, that's interesting.

I like that. I will dwell on it. Okay. Don't steal it without it. I want to steal it. I'll catch you right-handed, Sarah. So you spoke in this paper very presciently, also the original life problem for physics, about the James Webb Space Telescope, which recently not only launched but made it to the L2 orbit and also assembled itself like,

origami or some living, you know, structure. You talk about that in the paper and what we could see and so forth with planets, you know, maybe going in front of these stars. And I wonder, you know, could we really see, you know, evidence? You're probably familiar of this discovery, this announcement, you know, touted so highly recently by past Sarah guest on the podcast, Sarah Seeger and other colleagues, Jane Greaves and others, the phosphine on Venus. I don't know how pertinent that is to your particular research, but at least the James Webb Space Telescope prospects for detecting life on other skies. You linked that in sort of a Bayesian framework.

I wonder, could you talk about what excites you about the Webb Telescope and what do you think we're likely to learn and how much could we really shrink the Bayesian confidence intervals by discovery from Webb alone? Your summer starts now with Memorial Day deals at the Home Depot. It's time to fire up summer cookouts with the next grill, four-burner gas grill, on special buy for only $199. And entertain all season with the Hampton Bay West Grove seven-piece outdoor dining set for only $499. This Memorial Day get low prices guaranteed at the Home Depot.

While supplies, price-in-valid May 14th or May 27th, U.S. only exclusions apply. See Home Depot.com slash price match for details. Yeah, these are great questions. So I have thought a lot about exoplanet biosignature science, and in particular, using Bayesian approaches where, and part of the whole set of arguments there is if you're assessing the significance of a biosignature, so biosignatures are, you know, things that we can associate to life, but they tend to be for exoplanets really simple molecules like phosphine is an example on Venus, but phosphine was developed as a biosignature for exoplanets because they're remotely detectable. So other examples are things like oxygen and meth, And this becomes very problematic as it did in the case of Venus because there's a lot of possibilities of false positives. We can't exhaustively get rid of all the possible abiotic explanations for those kind of biosignatures. So this kind of bothers me on a few levels.

One of them is that I really am interested in trying to encourage the astrobiology community to move more toward having motivating theory. we're not looking for a biosignature, we're looking for life. And if you can't connect that signature of life to a fundamental understanding of what life is, and you're not learning something new about life by testing some hypothesis about what life is on an alien world and getting some feedback about that phenomena that you're looking at, I don't think that it's quite the kind of science astrobiology should be doing yet. So I think the way we're doing biosignature science right now is by analogy to life on Earth.

So we're taking molecules that metabolism produced on Earth and looking for those in exoplanets. And we don't know the mechanisms of how they could be produced biotically or biologically on those planets. And it's a little analogy I like to make is like we don't take geological maps from Mars and expect them to apply to Earth or vice versa. Right. So we don't take, you know, the Grand Canyon and expect it to explain the morphology of Valis Marinera. However, how is that pronounced? Mara. Marinar.

Marinar. Yeah. I was having Maranara. And I'm like, Maranara's true. Not the Marinerra. That's right. I'm getting hungry.

You talked about metabolism. Right. So, but there's this implicit assumption. We can take the chemical map from Earth for biochemistry and apply it to a different planet. And I think that's really a mistake. But if you want to do that, there are rigorous ways of thinking about it. And you can ask, well, what is the likelihood of an abiotic mechanism generating that versus a biological mechanism?

And the problem is that we don't, and then you could kind of plug those likelihoods into a Bayesian framework. And if you had to, a prior model for the original life on that planet, you could actually get some probability of assigning that as a biosignature. And so it gives kind of a framework for asking questions about, you know, am I really detecting life or not? That's quantitative and statistically rigorous. The challenge we have is we don't know what the abiotic probabilities are or the biological

ones or the prior for most biosignatures. So I think James Webb will help a lot because it's going to give us a lot more of a basis. of what planets are like beyond our solar system and give more detailed, um, uh, detailed observations. But I think the kind of thing that I'm more excited about is like, um, uh, you know, there's this whole proposal for a little bar have X and they're doing these more statistical types of surveys of planets. And I think that's really what we need to do. We need to have a better baseline of what exoplanet properties are. Um, and we need to build better theories. And this is one of the reasons I do this, um, for predicting, um, non-ambiguous

biosignatures. Because if you look at like Bay's equation for detecting life and you have like some probability that the signature you're looking at is actually attributed to life, there's a couple terms that matter. One is, is it possible to be produced abiotically? If it is, you have a false positive scenario. And then you need a really strong mechanism for the origin of life. You need a really, really big prior. You really have to be really confident that it's actually produced by life. Or you have to have a really strong biosignature that's not subject to false positives. And so that's that's the reason that I think assembly theory is very promising because if you have a high assembly object, the structure of that is such that we don't expect there to be false positives.

And so if you don't know the prior for the original life and you want to go survey the universe for life without knowing that prior, then you have to have some kind of signature for life that has that structure. It doesn't have to be assembly, but right now I think that's the only candidate we have. And is assembly going to potentially be the Drake equation of biochemistry and alien in a biolic chemistry? The Drake equation is a way of organizing ignorance, right? So the Drake equation is supposed to be filled in by other science, right? And so a lot of people still want to use it to make estimates because we have a lot,

you know, that was proposed in, what, 1963 by Frank Drake? So if you think about, you know, how many discoveries we've made since then, we know the likelihood of planet formation. We kind of have some bounds on the likelihood of Earth-like planets. But that probability for the original life term is completely unconstrained. because we don't know the mechanism for the origin life. Right. So I think what Assembly will give us is if we could go, say,

if you could go and survey a bunch of planets and say, did the original life happen on this planet, then you could bound that FSABEL, right? And that's the way astrobiologists should be thinking about it, I think, is how do we actually infer the likelihood of life from the data sets we're given, not having an aha moment where we're going to immediately, at least see some signatures and it's going to just be life. That's not how science works.

Yeah, I often point that out, you know, just riffing on what you just said. You know, science is not about like getting the answer and then just submitting the answer. You know, there's, you know, 2,000 planets in our, you know, galactic spiral arm. No, no, I want to know the uncertainty on it. And the problem with the Drake equation is that it's always presented as here's the number and there's never error analysis associated with it. So is that true of assembly theory too? Is it just going to give you a number, you know, probability?

or is it going to give you some bounded error bars and some Bayesian interval confidence in a Oh, no. So, yeah. So one of the things with the whole like Bayesian approach to biosigniture science is it allows you to invent new kinds of biosignatures that fit in that formalism. And assembly theory is structured that way because it's a, it's a theory that naturally accommodates probabilistic assessment. So the whole idea is like with this, so empirically, you know, Lee's lab identified that if you have more than 15 steps to produce, a molecule in the shortest assembly pathway, then it's exponentially unlikely to be produced. And if we see it, then it becomes a signature of life. And that was like empirically validated against experiments. And right now we have some theory that corroborates why there's a threshold

value that we're working on now in the current paper. So the theory would predict there should be a crossover point where you wouldn't expect this by a non-biological process, basically, or a process that didn't undergo selection. Or it didn't have any. kind of information or causation in the system. So if you buy that sort of argument, basically what it's saying is above 15, it's exponentially unlikely to ever observe those molecules. And there's a two-part argument to it. It's not just it's 15 steps. But when you see a molecule and you observe it with your instrument, like a mass spec, you have to have multiple copies of it. And so you might argue, say, based on the Boltzman brain argument, and people do this,

they're like, well, geochemistry can make anything. And I'm always like, well, Geochemistry can't make a cell phone. Where do you go out of the line? I mean, the line has to be somewhere. Otherwise, you're arguing for intelligent design. And I think people really don't understand this. It's either biological agents or the designers or the universe has some kind of intrinsic design-based laws. And since I'm looking for the situation where we can explain that physics internal to the universe and don't have to appeal external, then it's not that you can get certain objects for free. It's that there have to be specific pathways constructed to make those objects. And so with that argument, it means that when you find one cell phone, you don't find just one cell phone, you find that everybody on the planet has a cell phone. It's not an isolated occurrence like people.

You know, you never expect a single person to appear in the universe. You would expect a population of people. You would never expect a single copy of a molecule to appear in the universe. It needs to be in a population of molecules if it's part of a process that's reliable to produce that molecule, and it's not a statistical fluke. And it's actually part of an evolutionary product. Now, there might be some smearing of the distribution. not all people are identical. Not all molecules need to buy identical, but they need to be somewhere related in the assembly space. And we have ways of accounting for that. Then the idea is if you find

these molecules that are past that threshold, then you've found evidence that there had to be some kind of causal mechanisms producing them or some kind of selection or what, or information, or what all these words, emergence, complexity, you know, whatever word you want to associate to life, but it's evidence of life. So it's agnostic as to, you know, what type of chemistry could produce it? You know, could you have silicon-based life? Could you have, you know, in other words, are there biases or, you know, confirmation errors that might be imposed? There are, so one of the things that I think is of interest is trying to understand the assembly structure of different kinds of physical systems. So it might be that silicon doesn't, you would never expect to see high assembly things in silicon just because of the way the assembly look.

in silicon chemistry. But my anticipation is that probably, yes, you would still expect it. Now, one thing is that depending on the structure of the system that you're looking at, you might expect the threshold value to be different. So we can predict features based on the causal structure of the assembly space of where that transition should be, where it's necessary to have some kind of informational system produce that object. But we expect that transition to happen in any kind of assembly space.

And that transition happens just because you're talking about a system that is combinatorially huge. So the number of ways of making that object grows exponentially with the size of the object. And so there's this kind of transition where the number of pathways resembling it is too large for you to expect it to form by chance. And that's a fundamental feature of any combinatorial system where you impose a causal structure on it. So that's sort of the underlying premise of assembly theory is basically saying when you see things past that boundary for that particular assembly, that particular kind of causal structure combinatorial space, that's evidence of life. Or that's evidence of the physics underlying life. I see. And then one thing that we've talked about, maybe on Clubhouse a longer time ago, you know, is kind of this notion that I again was brought up with Lee and,

and I incurred, which was, you know, that are the properties of life encoded in the big bang in some sense? And before I get to that, I want to ask, you know, can assembly theory discard like irrelevant or low value information? For example, people talk about water, you know, oh, we found water, you know, and on Mars and there's evidence of what. I'm like, of course, you know, hydrogen is the most common element. Oxygen is like the fourth most common. Of course you're going to find a lot of water. you know so in other words is that you know finding water is that is that is that dispositive is that in any way or is can you just exclude it because it's so abundant it's it's it's almost like a nuisance parameter yeah so um so assembly theory is falsifiable like if you found a high assembly thing and you couldn't

associate it to life you can falsify the theory but i think one of the things is it's trying to get rid of all those kind of details um and the water argument is more of one of habitability than life Right. So there has been traditionally also in astrobiology this confusion between talking about the components of life as life. Right. So that's like, you know, these single molecules become like oxygen. Oxygen is not life. Oxygen could be a signature of life with a whole set of other assumptions. And DNA is not life either. DNA is evidence of life because it's high assembly object. It requires a lot of design and evolution. Oxygen is kind of so you can see where those fall on in sort of an assembly. structure. But things like water are preconditions for life, right? Assumed preconditions based on what we know of life on earth. So life on earth requires water. Therefore, we go look for environments with water because we assume that life couldn't exist in the environments that don't have water. So it's kind of like we're trying to screen out the search space and focus it in. But assembly theory is kind of agnostic to that because it just says you need to have an environment that life could emerge, whatever

environment that is and and that um and life could build complex things and then you would look for those complex things now it might be that some environments life doesn't build complex things and they're below the assembly threshold um but there are also ways that we can detect features of selection or light of information processing below that that we're still developing. Interesting. Um, and then what if you make of this, uh, this conjecture by, uh, by Avi Lowe. that the universe was once, you know, at age, you know, at a red shift of 100, the universe was approximately room temperature, meaning that you could have a liquid water

and actually a wide variety of timescales. And so liquid water was perhaps abundant in the, you know, just ambient universe. Does that play a role, you know, cosmic connect? I'm trying to push back the last, what I want to do is push the last common luca back to the last scattering surface. So I just don't see the utility. I mean, what does that give you? It gives you an interesting thing to say.

I think it's curious. I think there could be something there. But do I follow the chain of logic to say, oh, I have observational signatures of life living in that period of the universe? And I haven't seen anybody actually go that far. So, I mean, I can spend all day making wild conjectures about what life, what could be life and where it could be in the universe. I have a million ideas a day about it.

But I think the thing is, like, if you really want to discover aliens and some of us really do, I mean, a lot of us do, Abby included, right? Like, then we have to sit down and we have to really think rigorously about the problem and develop theories that we can test and things that we can do in the lab, observations we can make with telescopes and theory that we can build. And those three things have to work together, just like they do in physics. But astrobiology hasn't transitioned because it's not a mature science yet. It's a really new field. And it's bringing together a lot of areas of science that haven't worked together before. We don't know how to ask a question of life. We make a lot of assumptions that we know what we are.

And I'll know it when I see it is so pervasive. I'm glad that you brought that up earlier. It's funny, but it's true because people assume we're life. We know it when we see it. But yeah, so I think, yes. It might be correlated but not causative. Yeah, so I think it's fun to talk about the water in the early universe and could it have been the case that life could have emerged really early in the universe.

But I don't think it's helpful. to any discussion about actually solving any of the problems that we're dealing with. Okay. Well, remaining on the Avilob Banwagon for a second. So he's had, you know, kind of a lot of maybe dissonant conflicts with the astronomy community, but primarily, you know, what he's advocating for is that we spend all this money on, you know, kind of wasteful science, string theory and, you know, bigger and bigger accelerators and so forth. But we really should be studying is not even spending it on SETI, which is like information,

looking for techno signatures in the radio wave or light waves. And as I mentioned before, they really pivoted from the pure core mission that they had from Drake's time until Morrison until today, which is looking for extremophiles and all sorts of other, you know, life on earth at Redshift Zero. But what do you make of his claims is sort of, you know, we should be looking for physical, you know, techno signatures like this little chunk of a muamua that I captured not too long ago going across my But tell me, what are your thoughts about this? You should make that into an NFT.

That's right. I have been, actually, I did get approached by somebody who does is making NFT meteorites. And I'm just like, all right. No, don't look down. Don't look down. Well, tell me, what do you think about a muamua? I don't think I've asked you this before.

Yeah. So I think some of the features of being open-minded and realizing that aliens could be right in front of us and it might just pass us by are really, good about the way that Avi is approaching some of these questions. But I think in the case of I'm a, I can never pronounce this one either. Amo. Muwa. Muwa. It's not Maranara. I was going to make it this one like you could run the whole Bayesian thing we just talked about. And there are really good models, actually including developed by one of my colleagues here, Steve Dasha, ASU, that explain Amuomua in terms of completely natural explanation, including some of the anomalies

that Abby talked about in his book. Like they've been basically like all of these sort of features. So I think there's a lot of evidence that, you know, suggests it could have a natural origin and it's not an anomaly. Now, the real issue, I think, is not Amu or Amuah in the debate around that, but the whole issue of our anomalies adequate to assign alien as the explanation. And we do this everywhere. We do it in UFO science.

We can't explain it as aliens. Amuamua, we can't explain it, it's aliens. Biosignature science, phosphine on Venus, we can't explain it abiotically, it's aliens. Saucers. Yeah, saucers. I think culturally, and this is ubiquitous, a kind of scientist, members of the public, everyone, aliens right now are the other. They're the explanation for things we can't explain.

And I just don't feel like that's adequate. I don't, I think if we don't understand what something is, we should say it's an anomaly. if we have a mechanism and we can explain it and that mechanism happens to be associated to the phenomena we call life, and we can say this as an example of life that's not us, then we use the alien hypothesis. Right. It's not science if I'm just saying everything that I don't understand is alien. What about your former colleague and, you know, Paul Davies and current colleague also? Yeah.

Talks about the shadow bias fear. On the other side of the whole. Oh, right. Yeah. I could knock on the door. Yeah. the shadow biosphere and these lurkers in our solar system. And as he wrote about it, I pointed out to him, you know, we've done multiple interviews.

One was on the Erie Silence on the 10th anniversary of its publication, which was itself on the 50th anniversary of the SETI program kicking off. Yeah, the silence has only grown more deafening in that realm. So his theory of shadow biospheres and so forth, what do you make of that? Isn't that just kind of saucers by another name? Other by another name? Well, I think the shadow biosphere was intended to be a hypothesis to be tested, right? So the idea was if life is not a singular event in the universe and it's common and it's common on Earth-like planets, the most Earth-like planet is Earth. And we know the old life happened once here, so maybe it happened twice and we just haven't actually recognized that yet.

And actually, there's a lot of historical precedent for this because we have discovered alien life on Earth that we didn't know about. It just happened that we found out later it was related to us. So, for example, for most of human history, we didn't know microbes existed. We had to develop the technology of microscopes to actually literally see that there were these organisms basically living in our bread and, you know, on the tabletop and pretty much everywhere around us. But that was a completely hidden, quote, unquote, shadow biosphere for most of human history. And so the argument is if it's not DNA-based life and we're only combing the seas, like in Craig

Venters, things, you know, going through the ocean, combing up life and detecting it based on DNA sequences, what are we missing? So Paul's very adamant that it's cheaper to look for life on Earth than it is to go look for life on Mars. So why don't we just have a concerted effort to look for an alien example of life on Earth that isn't actually alien to Earth? It's just alien to us because it's also originating on Earth. And my personal perspective on it is that's a well-posed scientific question, and we should

be doing that. I think from the philosophical sign of how I approach the science and what's consistent with the kind of theories I do and the kind of. kind of work that my group has been doing, thinking about the global organization of biochemistry and patterns in biochemistry, I don't think that you can have more than one example of life per planet. And because I think life becomes a globally integrated system pretty quickly, and it's actually like a planetary scale process. And you can think about that, even with modern technology and the global internet and how we're all increasingly connected. I just, I don't see, you think about

life as information propagating and the kind of structure of it, I don't see the possibility of having more than one way on the planet. but from the perspective of is it a well-posed scientific question? Yes, it absolutely is. And I didn't mean to imply that like the whole set of biosignatures from UFOs to phosphine are not well-posed. I just don't want, like you need to have a conjecture there, like about why is this life and actual like a theoretical support. Other way, like I just, I don't understand the mentality and maybe I'm just missing something, but I feel like there's more rigorous ways of approaching the problem that people have just shied away.

from historically because the life problem is so hard. Yeah, absolutely. So if you'll indulge me for another 10 minutes, maybe, we have some audience questions. Is that going to work? Yes, that sounds great. Good. So first question comes from Dylan Graham Hussman on my YouTube channel, comment community section. It's Dr. Brian Keating on YouTube. Dylan asks, given the non-ergodic nature of life and the vastness of genetic search space. Do you think mutation, and thus evolution, is purely random? Or do you think there's a set of principles that constrain the space of mutations to places more likely to produce adaptive change? So is this kind of evolution being pre-patterned for certain adaptions? Yeah, is it purely random, or is it, or is it, you know, traceable to some sort of,

you know, set of principles, maybe design? Yeah. Yeah. I mean, I, I, I don't know where I stand on that. So some days I think that there's some intrinsic randomness in the universe. And other days I think it's totally deterministic. So I'm personally deeply intrigued by this. I think that there definitely is some contingency in, you know, what mutations happen and the ways they're adaptive. And certainly there's been experiments done to show certain features of that kind of contingency.

So it doesn't seem that they're all totally random, like certain parts of the genome are more biased toward mutation than others is a simple example. And then you can ask questions about why, and there's tons of people that are way more qualified to talk about those kinds of specific genomic questions than I am. I think the question of whether the universe requires some kind of underlying stochasticity or randomness in order for life to exist is a really deeply intriguing one.

Yeah. Great. Next question comes from a audience member named Rust in Peace, which was coincidentally the name for my first daughter. No, no, I'm just kidding. And he or she asked, could it be that a living organism doesn't require a cell wall or some kind of container? I think there's certainly a – so I don't think life has boundaries in the traditional sense. I do think that you need bounded structures. I don't think like, you know, the container is the thing that's important. So as I mentioned before,

like a cell reconstructs itself and is part of a lineage. And the lineage is really what we need to think about with life. So the boundary plays a role in terms of saying this is a packet of information that's reproducing itself in a particular structure. But then, you know, organisms can exchange genes with each other or even now like we're exchanging knowledge. So the boundaries are not as important as sort of the flow of information on the system. So I think it's kind of a secondary feature. And in fact, some things that, you know, individuality, the idea of like bounded individuals might have emerged late in the original life and that you might have just had much more collective or like system level properties early on. And I, I resonate with those kind of ideas. I think they're really intriguing.

So maybe, you know, really primitive life is not bounded, but maybe once you get into this kind of Darwinian well-defined information, a lineage is it becomes bounded. Mm-hmm. Good. Next question from Vorador. What is your opinion regarding the chances to find life fun, let's say he or she asked about Europa specifically, but what about other places in our solar system? I think it's possible for life to be a lot of places in our solar system and that we just really haven't figured out how to identify it. Yeah, I think Europa's hard mission-wise because you have to drill through the ice shell. And so getting a sample is really challenging. So for that reason, I'm much more on team Enceladus, so to say. I'm very enthusiastic about sending missions to

Enceladus because Enceladus is very similar to Europa. Another icy moon, you know, has a liquid ocean under its shell, but it actually has active jets of material being spewed into space. You can imagine flying, you know, a robot through the plume and taking samples. So you don't have to worry about the drilling problem. And from a habitability perspective of like, you know, are the ingredients for life present on these icy moons? I think Enceladus is just a strong candidate as Europa.

So that just becomes an accessibility issue. Great. Another frequent guest on my channel, the memes of destruction, our audience member. That's another good name. Yeah. These are all great band memes. I know. There's another one, Chimbrazo.

We'll get to that. He asked, are stars alive? I'm going to change that to, you know, what's the minimum, you know, kind of astrophysical entity that you could say is alive or features life? Could you have a dark cloud like Arthur C. Clark or, you know, what's the minimum comment? an ancestor, you know, stellar astrophysical prerequisite? Yeah, so this is not the way I would ask that question. So I'm going to ask you. I would say it, yeah.

Yeah, so because it's kind of like the what is life question and then what are other examples of like this is what we would canonically think. And I just don't think that's the right way of framing it. What I would think is clearly we exist in the universe as life, which means that the laws of physics are structured for life to exist. And I'm interested in those laws that specifically explain life, which, which my claim is, are not the laws of physics as we know them now. They're different kind of law of physics.

And they have very different, the laws of physics that explain life have very different properties. For example, they're not cast in this kind of initial state, fixed law of motion kind of framework, which we didn't talk about. But like, that's an aside. But anyway, just imagine, you know, there is some structure to the universe, causal structure. The universe is a causal graph, so to speak, an assembly space. Then everything has that property, just like everything has the property of existence. in space and time in gravity, right? Like there's a space-time manifold that defines the properties of the universe. And then some physical systems like us are very high assembly. And you can think of

them, like in the gravitational analogy, as being objects that have very strong gravitational potential wells like planetary systems, galaxies, or black holes are good examples to study gravitational physics, things that are good examples to study causal structure in the universe or this kind of feature of information being causal or whatever you want to call it are living things. Now, is that apparent in other examples like stars or other kinds of systems we could study? Of course, it should be because it's a future of our universe. But the question is, to what degree? And so I wouldn't really call things alive unless they're very high assembly objects, like the kind that we talk about in terms of molecular assembly theory, but assembly is supposed to be

general and applied anything. And so I don't think stars have crossed. that threshold. But I think that stars have, you know, like you can think about the contingency in stellar generations and the kind of elemental distributions they have, they do have a clear, this population of stars had to come before this population of stars. Otherwise, there's no reason for this elemental distribution. So they have a causal structure associated to them. But it would be a very simple assembly space. Right. Okay. Next question comes from Chimbrazo, who asked a lot of questions. A long-anticipated question. Yes, that's right. You said, This place was steps from the water.

We just haven't found the steps yet. How much did we save? Enough. Enough to get lost. Or you could book a stay with Hilton. Welcome to your ocean front room. Just steps from the water. The Hilton sale is on now.

Book on Hilton.com or the Hilton app and save up to 20% to get the stay you expected. When you want savings, not surprises. It matters where you stay. Hilton, for the stay. So he asked a bunch of questions. One is about humans and aliens interacting. How would we communicate with them?

You could answer that question. He also asked, why does a grand unified theory have to be beautiful? I guess my question to you would be, you know, what about these, you know, your love of physics, your love of cosmology, your kind of OG historical legacy? What interests you most and what do you find most interesting about the searches that are kind of layered upon them is this? this question of beauty and propriety, if you will, in the laws of nature. We talked about symmetry earlier. What do you make of that? Is that baggage?

Is that a shibboleth? What's going on with that? No. So on the question of beauty, I think, you know, a lot of people think that's problematic for physics. And I think it can because I think, you know, there are obvious areas where maybe we get romanticized by certain ideas and then we lose track of, you know, where's the scientific rigor. But I also think that our attraction to beauty and the way we explain the world is probably a signature also of the physics of what we are and is not just like an ad hoc feature added onto it. But I think it just depends on what your aesthetic is.

And for me, I think the aesthetic is, is it explanatory? I don't, and how much does it explain? And I'm also deeply interested in theories that are empowering. And what I mean by that is because I think theories actually are causal and they matter to how the world we live in locally on our planet works because the theories become the reality we live in. It is important to try to pick ones that maximize kind of potential for humanity. So it's not like an aesthetic choice, but it's more of a – well, it is an aesthetic choice, but it's an aesthetic choice informed by thinking about theories as physical objects and like what they do. So I guess I don't have any problem with people choosing aesthetic choices, but I think that I guess my point is we need to be very cognizant about why we're making those choices, how it's related to the physics that we're developing, and where the biases are coming in. And so one thing I always try to do is try to understand what my own biases are.

And my biggest bias is I'm trained as a theoretical physicist, so I tend to think like one, and we have a lot of baggage that we go with. And I'm okay with that, but it might not be the right way of even out. asking the life problem, right? It could be like, you know, this is completely irrelevant. But I don't think that's true, but it's entirely possible. Good. So now I'll move to Twitter to the Twitter space where you maybe have seen some of the questions posed to you. The first one will choose from Caitlin McShea, Santa Fe McShay. And by the way, you should all follow Sarah at Sarah underscore Emari. I am. We should follow Caitlin too. She's amazing. Follow Caitlin. You just got a shout out Caitlin. Hope you're watching and listening.

I'm a huge fan of Kate. one. She asked you, what's your favorite philosophical textbook or book? Oh, this is a hard one. I think I should have looked at these ahead. It would be. I think it's always nice to kind of know the early ideas of how people think. So I'm not a philosopher by training.

I took one philosophy class and it happened to be when I was at community college. And I've always had an interest in philosophy, but it's kind of like one of these things that now that I'm a middle-aged physicist, I'm. starting to read more philosophy because I need help. But when I was a student, I think I really was, I was so struck by two things. One was in my physics class, the fact that we could predict magnetic monopoles and we couldn't know we could look for them. Sorry, I don't know where my light's and they're not coming about. Oh, there they are. And the other one was Thomas Aquinas' arguments for the existence of God, which I thought were so clever. And so I really enjoyed reading that. I don't know.

Really, I think both of those together really gave me some insight into the power of human thought and how far we could push it. And since I became a physicist, that was always the thing I was romanticized by is the fact, again, it goes back to like, why is reality comprehensible and why are our brain structured to even reason about these kind of problems? And look how far we can actually push that reasoning, both in the sort of abstract philosophical arguments that we might want to run through or in the sense that we can. predict features of the universe and actually go and look and verify if they're true or not. And I think those two things are just really important features. So I guess that's kind of a half-assed answer. I like it very much. Next question, also coming from Twitter, there's about 50 from one person, Sandy Pichaldi.

But I'll just ask one of it. He says, basically, what does it even mean that time can flip? in any other direction than before to after, i.e. what we call forward. I don't know, because I think time only flows forward. I don't know why people think it could go backward. So I'm with you on that question. Please someone explain to me why it could go backward. All right. Well, you're going to, I think sort of just like I think, you know, yeah, never mind. We'll just leave about that. That's good. And then Brian Woe Times asked, what does fine tuning of initial condition? have to do with free will.

Okay. I think I might have made this argument on Twitter at one point. Which you should all follow because she's hilarious, prolific, philosophical, brilliant on Twitter. Thank you. Masterful. So there's this whole sort of conception in current physics that in order to explain the complexity now, like, you know, the fact that we're sitting here on this podcast

talking and you guys are listening, was a feature, like, like, like can be traced back deterministically to like the initial state of the universe. So so then this becomes a fine-tuning argument because in order to explain all the variation and all the structure we have in the universe, it had to be some minor fluctuations in the initial condition of the universe and the initial condition had to be fairly ordered to explain why disorder hasn't ranged. So there's all these kind of criteria on the initial state of the universe that are imposed by the features that we observe now.

And if you trace that chain of logic, basically it means that sort of every action, that you're doing now was already pre-imprinted in the initial state of the universe. So there's sort of a conflict between current physics and free will at a cosmological scale because it's not really, it goes back to the intelligent design versus creativity discussion we were having earlier, that these questions are actually deeply buried in the logic of how we talk about physics. And it goes back to this idea that sort of the laws exist outside the universe and the only thing you need to specify what happens in the universe is basically the initial condition. So once you

set that in motion, everything is predetermined. And I don't think that's the right paradigm for talking about life, mind, free will, or any of the problems that, you know, you hit up against when you're talking about what happens in biology versus what happens in physics. And it's not that physics as we know it is wrong. It's just that the kind of structure of the equations that we study in physics are not the right kind of structure of the equations for those kind of problems. I got it. And then the last question before we wrap up with closing arguments is from Stur Devant, who asks, how often are my cells created in origins experiments and in nature? How important is a lipid bilayer to first life? It's interesting that a my cell is used to protect plasmids in GMOs as well as

MR and A vaccines. Is that essential? Do you know what these my cells are? Can you define them? So a lot of people talk in origins of life about forming vesicles. So like if you have fatty acids, they basically self-organized into spherical structures. So you can have, so there's some hypotheses about cells before life that you had, you know, these my cells or vesicles forming, and then some molecules got in them. And they learned to co-replicate. And then that was sort of the way you jumpstarted life. So those are usually considered to be proto-cell models. I don't know how frequently they occur. My understanding is you just have some fatty acids. They just self-assembly. this way. So then the question becomes, how do you synthesize enough fatty acids to be able to do this?

And I'm by no means a membrane expert or knowing those things. So I would not be the person to ask about sort of the details of the chemistry on that, but I always find those things deeply intriguing too. Well, Sarah, is there anything that we haven't covered today that you'd be interested in touching on in this? We've had a nice over an hour and a half conversation, but is there anything else that I forgot or didn't have neglected to ask. I don't think so. What's next for you? Do you have any big talks coming?

Any thoughts about book? Anything fun for my audience? Well, I think I'm actually writing a book. You are? Yeah. Oh, awesome. A popular book or a text book? Yeah, yeah, it's a popular book.

And it's on life and what life is. Awesome. Yeah. That's an exclusive and into the impossible exclusive. Yeah, yeah. I haven't talked about it much because I'm like, it's mostly written, but I still And also it's hard to write a book about a theory that's a work in progress. So there's a lot of like, what is it?

I'm not perfectly. Don't ask the strength theorists, though. They would disagree with that. Yeah, I know, right? But I think part of the thing that I'm interested in is how hard it is to work at the frontier. And the fact that we're not doing that alone, right? You can't, especially nowadays, you can't really work on the frontier of knowledge without interacting with other people. other people. And I think the alien conversation is particularly interesting because it's one that I, since all of us are

the phenomenon of life, all of us should be able to engage in, in this problem, right? Like all of us have an intimate connection to the physics we're trying to understand. And everyone has a clue. It's just like, how do we stitch all those clues together to figure out what we are? Right. Right. Exactly. Well, Sarah, this has been so much fun. I can't wait for that book to come out. You'll have to come back on the show when it is out. this has been just a fascinating conversation with a deep thinker. And I'm so glad that you share your ideas with not only with me, but with the universe, the multiverse of minds that you've connected to. And especially with me and my audience today.

Thank you, Sarah, so much. Yeah, thanks. Thanks for having me. Any sufficiently advanced technology is indistinguishable from magic. Well, that's a wrap. I hope you enjoyed this phenomenal episode with Sarah Walker. She's such a brilliant mind. Follow her on Twitter at Sarah underscore Amari.

I am a r I. We ask questions of the guests. Subscribe on YouTube and Dr. Brian Keating channel and you'll be able to ask questions there and also on Twitter. Follow me there, Dr. Brian Keating. I usually will solicit questions from you, my beloved audience family members. And also soliciting as your homework assignment as promised, I want to beseech you to leave a review, a rating. You can do it on Spotify now.

You can do it on Audible now. And on iTunes, you can leave an actual review, a written review, which could be a couple sentences. And I just got a wonderful one from a listener by the name of, he's got a wonderful one from Ardalv. And he said, Keating does a phenomenal job at this podcast. He invites amazing individuals and knows how to bring out the best in his guests to his interviews. Yes, there are plenty of Nobel laureates, but don't miss out on the men. any other scientists, authors, entrepreneurs, and students who make each episode special in its own way. I'm not sure where he finds a time, but please, I sure hope he keeps it going. And I will,

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