What is life, and where does it come from? These are two of the deepest, most vexing, and persistent questions in science, and their enduring mystery and allure is complicated by the fact that scientists approach them from a myriad of different angles, hard to reconcile. Whatever else one might identify as universal features of all living systems, most scholars would agree life is a physical phenomenon unfolding in time. And yet current physics is notorious for its inadequacy with respect to time. Life appears to hinge on information transfer — but, again, what do we mean by “information,” and what it is relationship to energy and matter? If humankind can’t settle fundamental issues with these theoretical investigations, we might be missing other kinds of life (and mind) — not just in outer space, but here on Earth, right beneath our noses. But new models that suggest a vastly wider definition of life offer hope that we might — soon! — not only learn to recognize the biospheres and technospheres of other living worlds, but notice other “aliens” at home, and even find our place amidst a living cosmos.Welcome to COMPLEXITY, the official podcast of the Santa Fe Institute. I’m your host, Michael Garfield, and every other week we’ll bring you with us for far-ranging conversations with our worldwide network of rigorous researchers developing new frameworks to explain the deepest mysteries of the universe.This week on the show, we speak with SFI External Professor Sara Walker (Twitter, Google Scholar), Deputy Director of The Beyond Center at ASU, where she acts as Associate Professor in half a dozen different programs. In this conversation, we discuss her pioneering research in the origins of life and the profound and diverse implications of Assembly Theory — a new kind of physics she’s developing with chemist Leroy Cronin and a team of SFI and NASA scholars. Sara likes to speculate out loud in public conversation, so strap in for an unusually enthusiastic, animated, and free-roaming conversation at the very bleeding edge of science. And be sure to check out our extensive show notes with links to all our references at complexity.simplecast.com.If you value our research and communication efforts, please subscribe, rate and review us at Apple Podcasts or Spotify, and consider making a donation — or finding other ways to engage with us — at santafe.edu/engage.Thank you for listening!Join our Facebook discussion group to meet like minds and talk about each episode.Podcast theme music by Mitch Mignano.Follow us on social media:Twitter • YouTube • Facebook • Instagram • LinkedInMentioned Papers:Intelligence as a planetary scale processby Adam Frank, David Grinspoon & Sara WalkerThe Algorithmic Origins of Lifeby Sara Imari Walker & Paul C. W. DaviesBeyond prebiotic chemistry: What dynamic network properties allow the emergence of life?by Leroy Cronin & Sara WalkerIdentifying molecules as biosignatures with assembly theory and mass spectrometryby Stuart Marshall, Cole Mathis, Emma Carrick, Graham Keenan, Geoffrey Cooper, Heather Graham, Matthew Craven, Piotr Gromski, Douglas Moore, Sara Walker & Leroy CroninAssembly Theory Explains and Quantifies the Emergence of Selection and Evolutionby Abhishek Sharma, Dániel Czégel, Michael Lachmann, Christopher Kempes, Sara Walker, Leroy CroninQuantum Non-Barking Dogsby Sara Imari Walker, Paul C. W. Davies, Prasant Samantray, Yakir AharonovThe Multiple Paths to Multiple Lifeby Christopher P. Kempes & David C. Krakauer Other Related Videos & Writing:SFI Seminar - Why Black Holes Eat Informationby Vijay BalasubramanianMajor Transitions in Planetary Evolutionby Hikaru Furukawa and Sara Imari Walker2022 Community Lecture: “Recognizing The Alien in Us”by Sara WalkerSara Walker and Lee Cronin: The Alien Debateon The Lex Fridman ShowIf Cancer Were Easy, Every Cell Would Do ItSFI Press Release on work by Michael LachmannThe Ministry for The Futureby Kim Stanley RobinsonRe: Wheeler’s delayed choice experimentWikipediaOn the SFI “Exploring Life’s Origins” Research ProjectComplexity Explorer’s Origins of Life Free Open Online CourseChiara Marletto on Constructor TheorySimon Saunders, Philosopher of Physics at OxfordRelated SFI Podcast Episodes:Complexity 2 - The Origins of Life: David Krakauer, Sarah Maurer, and Chris Kempes at InterPlanetary Festival 2019Complexity 8 - Olivia Judson on Major Energy Transitions in Evolutionary HistoryComplexity 17 - Chris Kempes on The Physical Constraints on Life & EvolutionComplexity 40 - The Information Theory of Biology & Origins of Life with Sara Imari Walker (Big Biology Podcast Crossover)Complexity 41 - Natalie Grefenstette on Agnostic Biosignature DetectionComplexity 68 - W. Brian Arthur on Economics in Nouns & Verbs (Part 1)Complexity 80 - Mingzhen Lu on The Evolution of Root Systems & Biogeochemical CyclingAlien Crash Site 015 - Cole MathisAlien Crash Site 019 - Heather GrahamAlien Crash Site 020 - Chris KempesAlien Crash Site 021 - Natalie Grefenstette