Ever wanted to know how music affects your brain, what quantum mechanics really is, or how black holes work? Do you wonder why you get emotional each time you see a certain movie, or how on earth video games are designed? Then you've come to the right place. Each week, Sean Carroll will host conversations with some of the most interesting thinkers in the world. From neuroscientists and engineers to authors and television producers, Sean and his guests talk about the biggest ideas in science, philosophy, culture and much more.
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This episode explores why people hold false beliefs, introducing psychologist Gordon Pennycook's concept of "unthinkingness" as a primary cause—a lack of cognitive effort rather than strong motivation to be wrong. It delves into research on pseudo-profound bullshit, the two-system mind, and the significant role of overconfidence in believing conspiracy theories. Surprisingly, AI chatbots are presented as a powerful tool for combating misinformation, effectively changing long-held beliefs by patiently presenting evidence, with effects lasting over time.
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 soun...
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: ...
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 atti...
This episode explores the application of complex systems thinking and computational social science to understand social media. Guest Petter Törnberg details how agent-based models, even with AI agents, spontaneously generate problematic outcomes like echo chambers, attention inequality, and polarization. The discussion highlights that these issues often arise from platform structures and human interaction dynamics rather than solely algorithms, posing challenges for simple interventions and profoundly reshaping politics and identity.
Steven Pinker explores the concept of common knowledge, distinguishing it from mere shared information, and shows its profound impact on human behavior. From the subtle nuances of language and plausible deniability to the dynamics of financial bubbles and collective action, this discussion reveals how our understanding of what others know fundamentally shapes society and individual rationality.
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 whi...
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...
Sean Carroll and Cass Sunstein delve into a comprehensive definition of liberalism, distinguishing it from specific modern political connotations to encompass a wide range of thinkers and leaders from FDR to Ronald Reagan. They discuss liberalism's foundational principles, including individual rights, rule of law, and pluralism, while addressing the significant challenges and critiques it faces from both conservative and progressive viewpoints. The conversation also explores the impact of technology on societal polarization and the vital role of "experiments in living" for a flourishing liberal society, concluding with an optimistic outlook on liberalism's future.
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 wit...
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 c...
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 a...
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...
Sean Carroll and Jacob Barandes delve into the foundations of quantum mechanics, addressing why physicists still grapple with its meaning despite its predictive power. Barandes proposes a radical new theory: indivisible stochastic quantum mechanics, which posits only real degrees of freedom with fundamentally stochastic dynamics, eliminating the need for a wave function. They discuss the theory's implications for concepts like measurement, decoherence, and even the nature of causality, offering a fresh perspective on the universe's underlying reality.
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 ...
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 Mech...
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:/...
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 lo...
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 V...
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-ed...
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.p...
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: htt...
Cosmologists Niayesh Afshordi and Phil Halper discuss their book "Battle of the Big Bang," which explores various theories about what happened at or before the universe's beginning, challenging the classical Big Bang singularity. They cover models like inflation, string theory, bouncing cosmologies, and cyclic universes, explaining their pros, cons, and the search for observational evidence like primordial gravitational waves and galaxy surveys to distinguish between these competing ideas.
Sean Carroll and philosopher Branden Fitelson explore the logic and use of probability, particularly in the context of science and epistemology. They discuss the nature of inductive reasoning, the problems with traditional frequency theories, and the distinction between objective probabilities found in scientific theories and the epistemic probabilities used to evaluate and compare those theories. The conversation delves into the concept of confirmation, illustrating how evidence raises the probability of a hypothesis and introducing a two-dimensional theory of argument strength involving both probability and relevance (Bayes factor), which helps explain common reasoning fallacies.
There are living creatures dwelling deep below the surface of the Earth, as deep as we are able to drill. These hearty microorganisms are related to more familiar life forms on land and under water, but the operate and survive in ways that are quite different from what we're familiar with. They live off of nutrients that have penetrated from the surface, or sometimes off of pure electrons. Karen Lloyd is a scientist who has traveled around the world studying these organisms, as she explains in h...
Eric Topol discusses AI's role in medicine, including diagnostics and image interpretation, highlighting both its potential and challenges. He also explores evidence-based approaches to longevity, emphasizing the importance of lifestyle, diet, and understanding age-related diseases like cancer, heart disease, and Alzheimer's, along with the role of the immune system and inflammation. The episode also debunks anti-aging myths and discusses societal and individual strategies for healthier living.
Welcome to the May 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: http...
Thomas Levenson discusses the history of germ theory, from the first observations of microbes to the development of vaccines and antibiotics. The episode explores why it took so long for germ theory to be accepted, the social and cultural factors that influenced its acceptance, and the lessons that can be learned from the past to address current challenges in infectious disease. It also touches on vaccine hesitancy and the importance of public health measures.
Questions about consciousness range from the precise and empirical -- what neurons fire when I have some particular experience -- to the deeply profound -- does consciousness emerge from matter, or does matter emerge from consciousness? While it might be straightforward to think that consciousness arises from the collective behavior of atoms in the brain, Annaka Harris and others argue that consciousness could be the fundamental stuff from which matter arises. She talks with a variety of experts...
Welcome to the April 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:...
