The Joy of Why

Mathematician Maggie Miller of the University of Texas at Austin joins Janna Levin and Steven Strogatz to explore knots, surfaces and four-dimensional topology. They discuss why loops can untangle in four spatial dimensions while two-dimensional surfaces can remain knotted, how three-dimensional snapshots help visualize 4D spaces, and Miller and collaborators’ resolution of a knotted-surface question posed by Charles Livingston in 1982. The conversation also connects visual techniques from art with mathematical reasoning.

Hosted by Janna Levin, Steven Strogatz

Theoretical physicist Jonathan Halliwell joins Steven Strogatz and Janna Levin to discuss how quantum decoherence helps explain the transition from wave-like quantum systems to the classical macroscopic world. The conversation covers quantum cosmology, decoherent histories, the measurement problem, macroscopic realism and why the quantum-to-classical transition does not require a conscious observer.

Hosted by Steven Strogatz, Janna Levin

Recorded live at the International Congress of Mathematicians in Philadelphia, this episode brings hosts Janna Levin and Steven Strogatz together with Akshay Venkatesh, Ravi Vakil and Alex Kontorovich. They examine what recent AI-generated proofs demonstrate, how machine assistance may change mathematical research, and what proof, creativity, understanding and storytelling contribute to the discipline. The recording took place on 26 July 2026; Quanta published the episode on 3 September 2026.

Hosted by Janna Levin, Steven Strogatz

Ishmail Abdus-Saboor explores why touch can feel painful or pleasurable and how scientists study those experiences. The conversation connects sensory pathways to social behavior and evolution, including work with unusual animal models and the challenge of interpreting subjective experience through experiments.

Hosted by Janna Levin

Adam Riess explains how astronomers measure the universe's expansion and why different methods give conflicting results. He revisits the evidence for accelerated expansion and examines what the Hubble tension might reveal about measurement techniques or missing ingredients in cosmological models.

Hosted by Steven Strogatz

David Kipping considers how to reason about extraterrestrial life when evidence is scarce. The discussion covers promising places to search, the interpretation of possible biosignatures and the role of statistical inference, alongside questions about habitable worlds and moons beyond our solar system.

Hosted by Janna Levin

Lauren Williams introduces the positive Grassmannian and the surprising connections it creates across mathematics and physics. She explains links to waves, traffic and particle scattering, and discusses how research-level mathematical problems can help assess what artificial intelligence is capable of proving.

Hosted by Steven Strogatz

Jennifer Doudna discusses how CRISPR changed gene editing and what might come next. The conversation examines emerging applications, technical limitations and the ethical choices involved in altering genetic material, including how scientific progress can be paired with responsible use.

Hosted by Janna Levin