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 site
• Wikipedia
• Bluesky
• Goodreads profile
• Amazon 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 page
• Google Scholar publications
• Substack
• Amazon author page
• Wikipedia

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 page
• Google Scholar publications
• Wikipedia

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 site
• Google Scholar publications
• Wikipedia

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 page
• Google Scholar publications
• Wikipedia

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 site
• Harvard web page
• PhilPeople profile
• Google 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 page
• Google Scholar publications
• Wikipedia
• Amazon 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 page
• Google Scholar publications
• Amazon author page
• Wikipedia
• Royal 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.