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

Welcome to the July 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 transcript: https://preposterousuniverse.com/podcast/2026/07/13/ama-july-2026/ Support Mindscape on Patreon.

The cosmological constant, as discussed last episode, provides a perfectly good (thus far) explanation for why we observe the universe to be accelerating. But it might not be the right explanation, and demonstrating that would be yet another foundational discovery. In this episode I discuss what is required to invent a plausible theory of dynamical dark energy, This includes considerations from particle physics, possible experimental tests, and the option that we should modify gravity rather than adding a new source of energy to the equations. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/06/29/359-solo-theories-of-dark-energy/ Support Mindscape on Patreon.

Messenger RNA (mRNA) plays a literally central role in the functioning of life as we know it, shuttling information back and forth between the DNA where it is stored to the ribosome where it is used to produce proteins. RNA may even have been the first molecule to kick-start the origin of life. Today, scientists are learning how to manipulate mRNA to cure and prevent diseases, whether through vaccination or literally editing one's DNA. Jeff Coller explains how it all works and how mRNA is revolutionizing medicine as we know it. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2026/06/15/357-jeff-coller-on-mrna-vaccines-and-bespoke-therapeutics/ Support Mindscape on Patreon. Jeff Coller received his Ph.D. in cell and molecular biology from the University of Wisconsin-Madison. He is currently Bloomberg Distinguished Professor of Biomedical Engineering and Director of the RNA Innovation Center at Johns Hopkins University. He is co-founder of Tevard Biosciences and the Alliance for mRNA Medicines, and leads the REPAIRx consortium. He is a fellow of the American Association for the Advancement of Science. Web site Johns Hopkins web page Google Scholar publications "This May Be the Most Important Medical Story of the Decade," New York Times, April 9, 2026

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

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