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

For all that human beings spend a lot of their time thinking, it's far from obvious what that process actually entails. Part of it amounts to classical logical reasoning. But an even bigger part involves reasoning with probability and uncertainty. And some of it is governed by unavoidable limitations on time and accuracy. Psychologist and computer scientist Tom Griffiths suggests that we have thought about it enough to feel that we have come to understand some general principles, which he explains in his new book The Laws of Thought: The Quest for a Mathematical Theory of Mind. Take your personal data back with Incogni! Use code MINDSCAPE at this link and get 60% off an annual plan: https://incogni.com/mindscape #sponsore Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/02/09/343-tom-griffiths-on-the-laws-of-thought/ Support Mindscape on Patreon. Tom Griffiths received his Ph.D. in psychology from Stanford University. He is currently Professor of Psychology and Computer Science at Princeton University, Director of the Computational Cognitive Science Lab, and Director of the Princeton Laboratory for Artificial Intelligence. He is the co-author of Algorithms to Live By: The Computer Science of Human Decisions, as well as the upcoming The Rational Use of Cognitive Resources. Web site Princeton web page Google Scholar publications Wikipedia

Welcome to the February 2026 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/2026/02/02/ama-february-2026/ Note that Mindscape now has a new hosting provider, Libsyn. (Actually a return home, as that was my first host when Mindscape was launched.) Things seem to be going smoothly, but let us know if there are any technical glitches. Support Mindscape on Patreon.

Evolution with natural selection involves an intricate mix of the random and the driven. Mutations are essentially random, while selection pressures work to prefer certain outcomes over others. There is tremendous divergence of species over time, but also repeated convergence to forms and mechanisms that are unmistakably useful. We see this clearly in eyes and fins, but the basic pattern also holds for brains and forms of social organization. I talk with philosopher Rachell Powell about what these ideas mean for humans, other terrestrial species, and also for forms of life we have not yet encountered. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/01/26/342-rachell-powell-on-evolutionary-convergence-morality-and-mind/ Support Mindscape on Patreon. Rachell Powell received her Ph.D. in philosophy from Duke University. She is currently a Professor of Philosophy at Boston University. She has held fellowships at the National Humanities Center, the American Council of Learned Societies, the Konrad Lorenz Institute for Evolution and Cognition Research, the National Evolutionary Synthesis Center, the Berlin School of Mind and Brain at Humboldt University, and the Center for Genetic Engineering and Society at North Carolina State University. Boston University web page PhilPapers publications

"Things fall apart; the centre cannot hold," wrote W.B. Yeats. I don't know about the centre, but the tendency of things to fall apart is pretty universal, ultimately due to the Second Law of Thermodynamics. Anyone living in a society or involved with technology must therefore be interested in the concept of maintenance -- keeping systems working. In his book Maintenance: Of Everything, Part One, Stewart Brand looks at the challenges and rewards of this concept. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/01/19/341-stewart-brand-on-maintenance-as-an-organizing-principle/ Support Mindscape on Patreon. Stewart Brand received an undergraduate degree in biology from Stanford University. He was the founder, editor, and publisher of the Whole Earth Catalog, which won a National Book Award. He founded the journal CoEvolution Quarterly and the WELL electronic community, and was a co-founder of the Long Now Foundation. He has been called "the 20th century's top influencer." Web site Amazon author page Wikipedia

At any given moment, an uncountable number of events are happening, but only some of them matter to us. What does it mean for something to matter, and more importantly, what does it mean for us to matter -- to ourselves as well as to others? The need to matter can be motivation to do great things, but it can also be a reason for people to come into conflict. Philosopher/novelist Rebecca Newberger Goldstein explores this issue in her new book The Mattering Instinct: How Our Deepest Longing Drives Us and Divides Us. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/01/12/340-rebecca-newberger-goldstein-on-what-matters-and-why-it-matters/ Support Mindscape on Patreon. Rebecca Newberger Goldstein received her Ph.D. in philosophy from Princeton University. She is the author of several novels and works of non-fiction. Among her awards are the MacArthur and Guggenheim Fellowships, membership in the American Academy of Arts and Sciences, and the National Humanities Medal. Web site Amazon author page Wikipedia

It's become increasingly clear that the Turing Test -- determining whether human interlocutors can tell whether a conversation is being carried out by a human or a machine -- is not a good way to think about consciousness. Modern LLMs can mimic human conversation with extraordinary verisimilitude, but most people would not judge them to be conscious. What would it take? Is it even possible for a computer program to achieve consciousness, or must consciousness be fundamentally "meat-based"? Philosopher Ned Block has long argued that consciousness involves something more than simply the "functional" aspects of inputs and outputs. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/01/05/339-ned-block-on-whether-consciousness-requires-biology/ Support Mindscape on Patreon. Ned Block received his Ph.D. in philosophy from Harvard University. He is currently Silver Professor in the Department of Philosophy at New York University, with secondary appointments in Psychology and Neural Science. He is also co-director of the Center for Mind, Brain, and Consciousness. He is Past President of the Society for Philosophy and Psychology and was elected a Fellow of the American Academy of Arts & Sciences. Web site NYU web page PhilPeople profile Google Scholar publications Wikipedia

Time for the holiday message! Rounding off the year with a brief and casual reflection on some issue that doesn't quite rise to the level of a full solo podcast. And hopefully something uplifting. This year, I offer a short apologia for higher education in the liberal arts and sciences, focusing not on the down-to-earth economic/occupational benefits of a college degree, but on the very real ways in which such an education opens up possibilities for personal growth. I think all of us in academia should be loud and unapologetic about the more romantic, idealistic values of the modern university. Happy holidays all! Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/12/22/holiday-message-2025-the-romance-of-the-university/ Support Mindscape on Patreon.

Welcome to the December 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. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/12/15/ama-december-2025/ In the intro I give a plug for the Pods Fight Poverty effort organized by GiveDirectly. Please consider making a donation to help families in Rwanda! Enjoy!

The story goes that Wolfgang Pauli, who first proposed the existence of neutrinos, was embarrassed to have done so, as it was considered uncouth to hypothesize new particles that could not be detected. Modern physicists have no such scruples, of course, but more importantly neutrinos turn out to be very detectable, given sufficient resources and experimental technique. I talk with neutrino physicist Ryan Patterson about what current and upcoming experiments teach us about neutrinos themselves, as well as implications for dark matter and why there are more particles than antiparticles in the universe. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/12/08/228-ryan-patterson-on-the-physics-of-neutrinos/ Support Mindscape on Patreon. Ryan Patterson received his Ph.D. in physics from Princeton University. He is currently Professor of Physics at Caltech. His research involves a number of aspects of experimental neutrino physics, including involvement in the NOvA and DUNE experiments. Caltech web page Publications at inSpire

Game theory is a way of quantitatively describing what happens any time one thing interacts with another thing, when both things have goals and potential rewards. That's a pretty broad class of interesting events, so it is unsurprising that game theory is a useful way of thinking about everything from international relations to the evolution of peacock feathers. I talk with philosopher Kevin Zollman about what game theory is and how it gets used in biology and human interactions. We discuss how thinking in game-theoretic terms can help understand the origin of meaning and intentionality in human language. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/12/01/337-kevin-zollman-on-game-theory-signals-and-meaning/ Support Mindscape on Patreon. Kevin Zollman received his Ph.D. in philosophy from the University of California, Irvine. He is currently the Herbert A. Simon Professor of Philosophy and Social and Decision Sciences in the Department of Philosophy at Carnegie Mellon University. He is also an associate fellow at the Center for Philosophy of Science at the University of Pittsburgh, and a visiting professor at the Munich Center for Mathematical Philosophy. He serves as the Director of the Institute for Complex Social Dynamics at CMU. He is the co-author, with Paul Raeburn, of The Game Theorist's Guide to Parenting. Web site CMU web page Google Scholar publications PhilPeople profile

Machine learning using neural networks has led to a remarkable leap forward in artificial intelligence, and the technological and social ramifications have been discussed at great length. To understand the origin and nature of this progress, it is useful to dig at least a little bit into the mathematical and algorithmic structures underlying these techniques. Anil Ananthaswamy takes up this challenge in his book Why Machines Learn: The Elegant Math Behind Modern AI. In this conversation we give a brief overview of some of the basic ideas, including the curse of dimensionality, backpropagation, transformer architectures, and more. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/11/24/336-anil-ananthaswamy-on-the-mathematics-of-neural-nets-and-ai/ Support Mindscape on Patreon. Anil Ananthaswamy received a Masters degree in electrical engineering from the University of Washington, Seattle. He is currently a freelance science writer and feature editor for PNAS Front Matter. He was formerly the deputy news editor for New Scientist, a Knight Science Journalism Fellow at MIT, and journalist-in-residence at the Simon Institute for the Theory of Computing, University of California, Berkeley. He organizes an annual science journalism workshop at the National Centre for Biological Sciences at Bengaluru, India. Web site Amazon author page Wikipedia

Welcome to the November 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/2025/11/17/ama-november-2025/ In the intro I mentioned a couple of my favorite TV shows of this year. Here is a more thought-out list (no particular order): Slow Horses Murderbot The Residence Poker Face Severance Pluribus and Down Cemetery Road also look promising, but too early to tell. (There are a huge number of shows I've never seen, so feel free to add recommendations.) Support Mindscape on Patreon.

Science has an incredibly impressive track record of uncovering nonintuitive ideas about the universe that turn out to be surprisingly accurate. It can be tempting to think of scientific discoveries as being carefully constructed atop a rock-solid foundation. In reality, scientific progress is tentative and fallible. Scientists propose models, assign them probabilities, and run tests to see whether they succeed or fail. In cosmologist Andrew Jaffe's new book, The Random Universe, he illustrates how models and probability help us make sense of the cosmos. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/11/10/335-andrew-jaffe-on-models-probability-and-the-universe/ Support Mindscape on Patreon. Andrew Jaffe received his Ph.D. in physics from the University of Chicago. He is currently a professor of astrophysics and cosmology and Director of the Imperial Centre for Inference and Cosmology at Imperial College, London. His research lies at the intersection of theoretical and observational cosmology, including the Planck Surveyor, Euclid, LISA, and Simons Observatory collaborations. Web site Imperial web page Google Scholar publications Amazon author page

The universe as revealed by physics is objective: it's out there, existing and behaving in ways that are completely independent of human thought. But the process by which we learn about the universe, and the language with which we talk about it, is extremely human-dependent. Does that mean that aliens would do science differently, and even think differently about physics, even if we all live in the same universe? Physicist Daniel Whiteson has teamed with cartoonist Andy Warner to investigate these questions in their new book Do Aliens Speak Physics? Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/11/03/334-daniel-whiteson-on-the-physics-of-and-by-aliens/ Support Mindscape on Patreon. Daniel Whiteson received his Ph.D. in physics from the University of California at Berkeley. He is currently a professor of physics at the University of California, Irvine. He is a Fellow of the American Physical Society and recipient of an Emmy nomination. He is the author of several books, often with co-author Jorge Cham. He is the co-host (with Kelly Weinersmith) of the podcast Daniel and Kelly's Extraordinary Universe. UCI web page Google Scholar publications Amazon author page Wikipedia

Why are people wrong all the time, anyway? Is it because we human beings are too good at being irrational, using our biases and motivated reasoning to convince ourselves of something that isn't quite accurate? Or is it something different -- unmotivated reasoning, or "unthinkingness," an unwillingness to do the cognitive work that most of us are actually up to if we try? Gordon Pennycook wants to argue for the latter, and this simple shift has important consequences, including for strategies for getting people to be less susceptible to misinformation and conspiracies. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/10/27/333-gordon-pennycook-on-unthinkingness-conspiracies-and-what-to-do-about-them/ Support Mindscape on Patreon. Gordon Pennycook received his Ph.D. in psychology from the University of Waterloo. He is currently an associate professor of psychology and Dorothy and Ariz Mehta Faculty Leadership Fellow at Cornell University as well as an Adjunct Professor at University of Regina's Hill/Levene Schools of Business. He is a member of the Royal Society of Canada's College of New Scholars, Artists, and Scientists, and a 2016 winner of the IgNobel Prize for Peace. Web site Cornell web page Google Scholar publications Wikipedia IgNobel Prize citation

Music is math that you can dance to. The fact that certain notes sound good when played together, or in succession, is related to the mathematical properties of the frequencies to which they correspond, an idea that goes back as far as Pythagoras himself. These days we have a much more intricate understanding of these relationships and how to manipulate them. I talk to composer and music theorist Dmitri Tymoczko about how different musical scales are constructed and the math underlying what sounds good. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/10/20/332-dmitri-tymoczko-on-the-mathematics-behind-music/ Support Mindscape on Patreon. Dmitri Tymoczko received a Ph.D. in music composition from the University of California, Berkeley. He is currently a professor of music at Princeton University as well as a composer and performer. He has been the recipient of Rhodes and Guggenheim fellowships. As a composer, his works have been performed by multiple groups, and recorded on several albums. Personal web site Princeton web page Mad Musical Science Spiral diagrams: rock music, classical music Google Scholar publications Amazon author page Wikipedia William Sethares's Tuning Timbre Spectrum Scale

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.

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: Livio and Rees, Fine-Tuning, Complexity, and Life in the Multiverse Carroll, In What Sense Is the Early Universe Fine-Tuned? Barnes, A Reasonable Little Question: A Formulation of the Fine-Tuning Argument Goff, Our Improbable Existence Is No Evidence for a Multiverse Neal, Puzzles of Anthropic Reasoning Resolved Using Full Non-indexical Conditioning

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 site Univ. Amsterdam web page Google Scholar publications Amazon author page Bluesky

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 site Harvard web page Google Scholar publications Amazon author page Wikipedia