Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas

Welcome to the October 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group them together if they are about a similar topic. Enjoy! Blog post with AMA questions and transcript: https://www.preposterousuniverse.com/podcast/2025/10/13/ama-october-2025/ Support Mindscape on Patreon. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Certain features of our universe seem unnatural to us. These include "constants of nature" such as the cosmological constant and the mass of the Higgs boson, as well as features of the initial conditions like the curvature of space and the initial entropy. But they can't truly be "unnatural" -- they are literally features of Nature itself. Some have turned to the anthropic principle and the multiverse, while others look to theism for an explanation. I talk here about my views on the various attitudes one might take toward these apparent fine-tunings, and why it is important to think about them. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/10/06/331-solo-fine-tuning-god-and-the-multiverse/ Support Mindscape on Patreon. Some readings of relevance: Fine-Tuning, Complexity, and Life in the MultiverseIn What Sense Is the Early Universe Fine-Tuned?A Reasonable Little Question: A Formulation of the Fine-Tuning ArgumentOur Improbable Existence Is No Evidence for a MultiversePuzzles of Anthropic Reasoning Resolved Using Full Non-indexical Conditioning See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

A characteristic of complex systems is that individual components combine to exhibit large-scale emergent behavior even when the components were not specifically designed for any particular purpose within the collective. Sometimes those individual components are us -- people interacting within societies or online communities. Studying the dynamics of such interactions is interesting both to better understand what is happening, and hopefully to designing better communities. I talk with Petter Törnberg about flows of information, how polarization develops, and how artificial agents can help steer things in better directions. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/09/29/330-petter-tornberg-on-the-dynamics-of-misinformation/ Support Mindscape on Patreon. Petter Törnberg received a Ph.D. in complex systems from Chalmers University of Technology. He is now an Assistant Professor at the Institute for Language, Logic and Computation at the University of Amsterdam, Associate Professor in Complex Systems at Chalmers University of Technology, NWO VENI laurate, and senior researcher at the University of Neuchâtel. Web siteUniv. Amsterdam web pageGoogle Scholar publicationsAmazon author pageBluesky See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Getting along in society requires that we mostly adhere to certainly shared norms and customs. Often it's not enough that we all know what the rules are, but also that everyone else knows the rules, and that they know that we know the rules, and so on. Philosophers and game theorists refer to this as common knowledge. In Steven Pinker's new book, When Everyone Knows That Everyone Knows..., he explores how common knowledge (or its absence) explains money, power, and a wide variety of subtextual human interactions. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/09/22/329-steven-pinker-on-rationality-and-common-knowledge/ Support Mindscape on Patreon. Steven Pinker received his Ph.D. in psychology from Harvard University. He is currently the Johnstone Family Professor of Psychology at Harvard University. He is the author of several best-selling books and recipient of several honorary doctoral degrees. Among his awards are Humanist of the Year (two different organizations) and the William James Lifetime Achievement Award from the Association for Psychological Science. Web siteHarvard web pageGoogle Scholar publicationsAmazon author pageWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Like any machine, bodies occasionally break down, and it's natural to go in search of a replacement part. Ancient societies featured simple prosthetics for teeth, noses, and limbs, while modern medicine pursues more advanced ways of replacing internal organs and microbiomes. But what is striking is not just the impressive ingenuity of our attempts to replicate human anatomy, but the surprising level of difficulty involved in doing it well. I talk with author Mary Roach about the many ways in which humans have chosen to replace bits of themselves, as told in her recent book Replaceable You: Adventures in Human Anatomy. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/09/15/328-mary-roach-on-replacing-parts-of-our-bodies/ Support Mindscape on Patreon. Mary Roach received a bachelor's degree in psychology from Wesleyan University. Her books include multiple New York Times bestsellers and have appeared on numerous best-of lists. She was a guest editor in the Best American Science and Nature Writing series, and received the Rushdie Award from the Harvard Secular Society. Web siteWikipediaBlueskyGoodreads profileAmazon author page See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Welcome to the September 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group them together if they are about a similar topic. Enjoy! Blog post with AMA questions and transcript: https://www.preposterousuniverse.com/podcast/2025/09/08/ama-september-2025/ Support Mindscape on Patreon. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

"Liberalism," divorced from its particular connotations in this or that modern political context, refers broadly to a philosophy of individual rights, liberties, and responsibilities, coupled with respect for institutions and rule of law over personalized power. As Cass Sunstein construes the term, liberalism encompasses a broad tent, from Ronald Reagan and Margaret Thatcher to Martin Luther King and Franklin Roosevelt. But liberalism is being challenged both from the right and from the left, by those who think that individual liberties can go too far. We talk about the philosophical case for liberalism as well as the challenges to it in modern politics, as discussed in his new book On Liberalism: In Defense of Freedom. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/09/01/327-cass-sunstein-on-liberalism/ Support Mindscape on Patreon. Cass Sunstein received a J.D. from Harvard Law School, and worked as a clerk for Supreme Court Justice Thurgood Marshall. He is currently Robert Walmsley University Professor at Harvard. He served in several government roles during the Obama administration. He is recognized as "by far the most cited legal scholar in the United States and probably the world." Harvard web pageGoogle Scholar publicationsSubstackAmazon author pageWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

In a relatively short period of time, exoplanets (planets around stars other than our Sun) have gone from an intriguing conjecture to an active field of scientific study, with over 5,000 confirmed discoveries. The task now is to move beyond merely accumulating new examples, and embarking on systematic studies of their properties. What fraction of stars have planets, how are they distributed in size and distance, what kinds of atmospheres do they have, are any promising homes for life? I talk with Natalie Batalha about what we've learned so far, and prospects for future discoveries. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/08/25/326-natalie-batalha-on-what-we-know-and-will-learn-about-exoplanets/ Support Mindscape on Patreon. Natalie Batalha received a Ph.D. in astrophysics from the University of California, Santa Cruz. She is currently a professor of astronomy and astrophysics at UCSC. She has served as Science Team Leader, Mission Scientist, and Project Scientist for NASA's Kepler satellite observatory. She is a member of the American Academy of Arts and Sciences, and was listed as one of Time Magazine's 100 Most Influential People in the World in 2017. Web pageGoogle Scholar publicationsWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

The world is becoming pixelated. As computers and other digital devices become ubiquitous, human knowledge and communication and information is gradually being converted into, and manipulated as, strings of bits. What does that really mean, and what are the ramifications going forward? Alvy Ray Smith is a computer scientist, co-founder of Pixar, and author of A Biography of the Pixel. We go through the journey of how he helped make computer animation a reality, and the implications of what he calls the "Great Digital Convergence." Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/08/18/325-alvy-ray-smith-on-pixar-pixels-and-the-great-digital-convergence/ Support Mindscape on Patreon. Alvy Ray Smith received a Ph.D. in computer science from Stanford University. He has been a professor of electrical engineering and computer science at New York University, a member of the Computer Graphics Lab at the NY Institute of Technology, director of computer graphics at Lucasfilm, and cofounder of Pixar and Altamira. He is a member of the National Academy of Engineering and a Fellow of the America Association for the Advancement of Science as well as the American Society of Genealogists. He is the winner of two technical Academy Awards. Web siteGoogle Scholar publicationsWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

It is not manifestly obvious that universities should be where most scholarly research is performed. One could imagine systems that separated out the tasks of "teaching students" and "generating new knowledge." But it turns out that combining them yields spectacular synergies, both from letting students experience cutting-edge research and from keeping researchers inspired by interacting with bright young minds. Today we talk to Elizabeth Mynatt, Dean of Computer Sciences at Northeastern, both about her own research in "human-centered computing," and about the bigger-picture issues of why basic research is important, and why universities are such good places to do it. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/08/11/324-elizabeth-mynatt-on-universities-and-the-importance-of-basic-research/ Support Mindscape on Patreon. Elizabeth Mynatt received a Ph.D. in computer science from the Georgia Institute of Technology. She is currently Dean of the Khoury College of Computer Sciences at Northeastern University. She is a senior investigator with Emory’s Cognitive Empowerment Program and co-PI for the NSF AI-CARING Institute. She is a fellow of the Association for Computing Machinery and the American Association for the Advancement of Science, and a member of the American Academy of Arts and Sciences. She was lead author on the National Academies report, "Information Technology Innovation: Resurgence, Confluence, and Continuing Impact." Web pageGoogle Scholar publicationsWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Welcome to the August 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group them together if they are about a similar topic. Enjoy! Blog post with questions and transcript: https://www.preposterousuniverse.com/podcast/2025/08/04/ama-august-2025/ Support Mindscape on Patreon. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

The search for a foundational theory of quantum mechanics that all physicists can agree on remains active. Over the last century a number of contenders have emerged, including Many-Worlds, pilot-wave theories, and others, but all of them have aspects that many people object to. Jacob Barandes has taken up the challenge, proposing a new formulation of quantum theory in which there is no wave function, only real degrees of freedom with fundamentally stochastic dynamics. We talk about this new theory and the challenges facing it. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/07/28/323-jacob-barandes-on-indivisible-stochastic-quantum-mechanics/ Support Mindscape on Patreon. Jacob Barandes received his Ph.D. in physics from Harvard University. He is currently Senior Preceptor in Physics and Associated Faculty in Philosophy at Harvard. He teaches both physics and philosophy courses at Harvard, where he has been the recipient of several teaching awards. Web siteHarvard web pagePhilPeople profileGoogle scholar publications See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

When we think of the capacities that distinguish humans from other species, we generally turn to intelligence and its byproducts, including our technological prowess. But our intelligence is highly connected to our ability to use language, which is in turn closely related to our capacities as social creatures. Philosopher Philip Pettit would encourage us to think of those social capacities, as enabled by language, as the primary locus of what makes humans different, as discussed in his new book When Minds Converse: A Social Genealogy of the Human Soul. And that linguistic aptitude helps us understand the nature of agency, responsibility, and freedom. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/07/21/322-philip-pettit-on-language-agency-politics-and-freedom/ Support Mindscape on Patreon. Philip Pettit received his Ph.D. in philosophy from University College Belfast. He is currently Laurance S. Rockefeller University Professor of Human Values at Princeton University and Distinguished University Professor of Philosophy at Australian National University. He is a Fellow of the Academy of Social Sciences in Australia, the Australian Academy of the Humanities, the American Academy of Arts and Sciences, and the Guggenheim Foundation, among other honors. Princeton web pageGoogle Scholar publicationsWikipediaAmazon author page See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Quantum field theory is the basis for our most successful theories of fundamental physics. And yet, there are things we don't understand about it. Some of these puzzles are relatively well-known, while others are less celebrated. David Tong joins us to talk about some of the more interesting and perplexing aspects of quantum field theory. He also discusses his new project to write a series of textbooks covering (all?) important topics in theoretical physics. To date, these include Classical Mechanics, Quantum Mechanics, Fluid Mechanics, and Electromagnetism. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/07/14/321-david-tong-on-open-questions-in-quantum-field-theory/ Support Mindscape on Patreon. David Tong received his Ph.D. in theoretical physics from Swansea University. He is currently a professor of Theoretical Physics in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. He is a winner of the Adams Prize and a Simons Investigator. In addition to his books, he has written many freely-available sets of lecture notes on topics in physics. Cambridge web pageGoogle Scholar publicationsAmazon author pageWikipediaRoyal Institution lecture on quantum field theory See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Welcome to the July 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group them together if they are about a similar topic. Enjoy! Blog post with questions and transcript: https://www.preposterousuniverse.com/podcast/2025/07/07/ama-july-2025/ See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Our universe started out looking very simple: hot, dense, smooth, rapidly expanding. According to our best current model, it will end up looking simple once again: cold, dark, empty. It's in between -- now, roughly speaking -- that things look complex. I have been working to understand the stages by which complexity comes into existence, thrives, and eventually disappears. Without going into technical details, in this solo episode I give an overview of the general picture and the clues we are looking at to better understand the process of complexogenesis. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/06/30/320-solo-complexity-and-the-universe/ Support Mindscape on Patreon. The Santa Fe Institute has recently published a four-volume set of classic papers on complexity. David Krakauer provided a comprehensive introduction that has been published as a standalone book. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

It is common to refer to philosophy as "a series of footnotes to Plato." But in the original quote, Alfred North Whitehead was more careful: he limited his characterization to "the European philosophical tradition." There are other traditions, both ancient and ongoing: Chinese philosophy, Indian philosophy, Africana philosophy, and various indigenous philosophies. For the most part, these do not get nearly as much attention in European and American schools as the European tradition does. Bryan Van Norden argues for expanding philosophy's geographical scope, to the benefit of philosophy in general. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/06/23/319-bryan-van-norden-on-philosophy-from-the-rest-of-the-world/ Support Mindscape on Patreon. Bryan Van Norden received his Ph.D. in philosophy from Stanford University. He is currently James Monroe Taylor Chair in Philosophy at Vassar College and Chair Professor in the School of Philosophy at Wuhan University. Among his books are Introduction to Classical Chinese Philosophy and Taking Back Philosophy: A Multicultural Manifesto. He is a recipient of Fulbright, National Endowment for the Humanities, and Mellon fellowships. Web siteVassar web pagePhilPeople profileWikipediaAmazon author page See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Economics is seeing an upsurge in the importance of controlled, reproducible empirical studies. One area where this has had a great impact is on development economics, which studies the economies of low- and middle-income societies. Edward Miguel has been at the forefront of both the revolution in empirical methods, and in applying those techniques to alleviating poverty in sub-Saharan Africa and elsewhere. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/06/16/318-edward-miguel-on-the-developing-practice-of-development-economics/ Support Mindscape on Patreon. Edward Miguel received his Ph.D. in economics from Harvard university. He is currently Distinguished Professor of Economics and Oxfam Professor in Environmental and Resource Economics at the University of California, Berkeley. He is also Faculty co-Director of the Center for Effective Global Action and a Faculty Research Associate of the National Bureau of Economic Research. Among his awards are the Frisch Medal of the Econometric Society, the Kenneth Arrow Prize of the International Health Economics Association, and multiple teaching awards. Web siteBerkeley web pageGoogle Scholar publicationsWikipedia See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

The human brain is extremely complicated, but decades of careful neuroscientific research have revealed quite a bit about how it works, including how certain genes affect particular brain behaviors. Nevertheless, this progress has not led to quite as much improvement in the treatment of brain disorders as we might expect. I talk with neuroscientist Nicole Rust about why this is and how to improve the situation, as discussed in her new book Elusive Cures. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/06/09/317-nicole-rust-on-why-neuroscience-hasnt-solved-brain-disorders/ Support Mindscape on Patreon. Nicole C. Rust received her Ph.D. in neuroscience from New York University. She is currently a professor of psychology at the University of Pennsylvania. She is also a contributing editor at The Transmitter and an editor at BrainFacts.org. Among her awards are the Troland Research Award from the National Academy of Sciences. Web siteUPenn web pageGoogle Scholar publicationsWikipediaBlueskySee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Welcome to the June 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group them together if they are about a similar topic. Enjoy! Blog post with AMA questions and transcript: https://www.preposterousuniverse.com/podcast/2025/06/02/ama-june-2025/ Support Mindscape on Patreon. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.