The Joy of Why

Maggie Miller, a mathematician at the University of Texas at Austin, explores the strange world of four-dimensional topology. She discusses knots that can untangle, spheres that can become permanently knotted, and why 4D remains mathematically mysterious. Miller also explains how topology, art, and snapshots of 3D slices help us picture higher-dimensional spaces.

Jonathan Halliwell, a theoretical physicist at Imperial College London, explores where the quantum world gives way to everyday reality. He discusses decoherence, quantum cosmology, and why consciousness is not needed for classical behavior. The conversation tackles macroscopic realism, contextuality, Leggett-Garg tests, Einstein’s moon, and how meditation can help us live with scientific mystery.

Alex Kontorovich, a Rutgers number theorist, Ravi Vakil, Stanford algebraic geometer and American Mathematical Society president, and Fields Medalist Akshay Venkatesh explore AI’s growing role in mathematics. They discuss AI-generated proofs, unexpected counterexamples, mathematical storytelling, education, access, careers, and whether human creativity, beauty and understanding can endure when machines solve harder problems.

Melanie Mitchell, cognitive and computer scientist at the Santa Fe Institute, explores AI as an alien form of intelligence. She discusses whether LLMs truly reason or just mimic reasoning. Short segments cover AI and mathematical creativity, six principles for testing machine cognition, and the Clever Hans caution about misleading signals.

Ishmail Abdus-Saboor, a neuroscientist at Columbia studying the skin–brain axis, touch, and pain. He talks about how researchers measure pain and pleasure without objective biomarkers. He explains molecular sensors like PIEZO and TRPV1, behavioral pain scales in rodents, the ethics of animal work, social and soothing touch pathways, and why naked mole rats are a surprising model.

Adam Riess, Nobel-winning astronomer and expert on cosmic distance measurements. He walks through supernovae as cosmic lighthouses and the distance ladder. He lays out the rising Hubble tension between local and early-universe measures. He previews new telescopes and why this growing mystery is both maddening and exhilarating.

David Kipping, an astronomer at Columbia who studies exoplanets and exomoons, explains why moons might hide habitable worlds. He discusses statistical frameworks for assessing habitability, surprising diversity from Kepler, the limits of biosignatures and SETI, and a birth-death model for civilizations. He stays hopeful but rigorously agnostic about detecting extraterrestrial life.

Lauren Williams, a Harvard mathematician and MacArthur Fellow known for work in algebraic combinatorics and the positive Grassmannian. She explains what the positive Grassmannian is and why its pieces reappear in traffic flow, wave models, and particle scattering. She also discusses a project testing AI on research-level proofs and what that might mean for the future of mathematical discovery.

Jennifer Doudna, Nobel-winning biochemist who co-developed CRISPR-Cas9, reflects on her RNA-driven path to a transformative gene-editing tool. She discusses how CRISPR works, its clinical breakthroughs like rapid bespoke therapies, barriers such as delivery and cost, ethical concerns around heritable edits, and future uses in medicine, agriculture, and climate innovation.

What is the future of gene editing with CRISPR? Has AI changed mathematics forever? Will we find other civilizations in the universe? What if we’ve been wrong about dark energy all along? These are just a few of the big, bold questions we’ll be exploring in the new season of The Joy of Why.Mathematician Steven Strogatz and physicist Janna Levin are back as your hosts for these and other conversations that explore the frontiers of basic science and mathematics. Each episode features an in-depth conversation in which Steven or Janna sits down with a leading scientist or mathematician to unpack one big idea or area of research. The two hosts also chat together throughout each episode, sharing their own thoughts, reactions, and questions.New episodes drop every other Thursday, kicking off on June 11 with biochemist and Nobel Laureate Jennifer Doudna, who helped revolutionize gene editing and biology as co-discoverer of the CRISPR-Cas9 system. The wide-ranging conversation explores the discovery and sudden rise of CRISPR as a tool that can modify genes in a highly precise manner, the successes and issues the work raised, and what comes next.All 12 episodes of Season 5 will be available to stream or read here, and on Apple Podcasts, Spotify, TuneIn, or wherever you listen to podcasts.