Theoretical Physics podcasts

Fraser Cain and Pamela L. Gay examine possible futures of the universe across vastly different timescales. Topics include the Milky Way and Andromeda, cosmic isolation as expansion continues, the fading microwave background, the end of star formation and the era of stellar remnants. They discuss uncertain processes such as proton decay, black-hole evaporation through Hawking radiation, entropy and heat death, alongside alternative outcomes if dark energy evolves. These are model-dependent projections. Pamela Gay is a senior scientist at the Planetary Science Institute. Published on 21 September 2026, the episode appears in the feed as The Beginning and End of Everything, Part 2. Its original duration is 37 minutes 7 seconds.

Hosted by Fraser Cain, Pamela L. Gay

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

Jim Al-Khalili and Sean Carroll discuss the nature of time, whether it is fundamental or emergent, and how its direction relates to physical laws and human experience. Their conversation connects the arrow of time with unresolved questions in quantum mechanics, biology and cosmology.

Hosted by Sean Carroll

Vitor Cardoso discusses how observations and theory are changing black-hole physics. The conversation covers Hawking radiation, general relativity, gravitational-wave observations and the Event Horizon Telescope, asking what these measurements reveal about black holes and what future observatories could test.

Hosted by Sean Carroll

Øystein Elgarøy and Anders Kvellestad discuss unresolved problems in physics, drawing on cosmology and particle physics. Conversation in Norwegian.

Ulrich Sperhake and Seppe Staelens explain hypothetical boson stars and how researchers use mathematical modelling to investigate them. The discussion connects these unusual compact objects to black holes, gravity and gravitational-wave observations.

Sean Carroll explores explanations for cosmic acceleration beyond a constant vacuum energy. He discusses dynamical dark-energy models, their relationship to particle physics, possible changes to gravity and the observations that could help distinguish competing theories.

Hosted by Sean Carroll

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

Sean Carroll traces the cosmological constant from Einstein's equations to modern evidence for accelerated expansion. He explains why the energy of empty space is difficult to reconcile with particle physics and examines the related puzzles of its observed size and importance in today's universe.

Hosted by Sean Carroll

Sean Carroll examines quantum mechanics on its own terms and asks how the familiar everyday world emerges from its formalism. The episode explores the tension between quantum theory and classical intuition, including how competing interpretations approach measurement and physical reality.

Hosted by Sean Carroll

Daniel Harlow discusses what attempts to reconcile gravity and quantum mechanics reveal about quantum theory itself. The conversation follows black-hole radiation, information loss, the wave function of the universe, the AdS/CFT correspondence and quantum information. It then connects these developments to quantum cosmology and questions about the structure of quantum mechanics.

Hosted by Sean Carroll

Øystein Elgarøy discusses what cosmology can say about conditions preceding the conventional Big Bang account. Conversation in Norwegian.

Yang-Hui He joins Steven Strogatz to trace geometry from ancient measurement and Euclid to curved spaces, general relativity, and string theory. They discuss why geometry provides a shared language for mathematics and physics, how rigorous proof interacts with physical intuition, and how artificial intelligence might change mathematical discovery. The conversation also contrasts broad conceptual views with concentrated work on individual problems.

Hosted by Steven Strogatz, Janna Levin

Åsmund Folkestad discusses the black-hole information problem and attempts to reconcile gravitational and quantum descriptions. Conversation in Norwegian.

Steven Strogatz speaks with physicist Frank Wilczek about what clocks measure and why the passage of time seems directional. They discuss different arrows of time, irreversibility, and the relationship between physical time and human experience. Wilczek explains how Einstein changed the definition of time and considers whether time could be emergent or illusory. The conversation also explores connections between time, symmetry and ideas about dark matter.

Hosted by Steven Strogatz

Øyvind Grøn discusses gravitational waves, their detection by LIGO and what these measurements reveal about distant cosmic events. Conversation in Norwegian.

Øystein Elgarøy discusses the anthropic principle, apparent fine-tuning of physical laws and proposals involving multiple universes. Conversation in Norwegian.

Øyvind Grøn discusses black holes, their prediction by relativity and the observations used to study them. Conversation in Norwegian.

Are Raklev discusses the Standard Model and experimental searches for physical phenomena beyond it. Conversation in Norwegian.

Anders Kvellestad discusses the success of quantum theory and the unresolved questions surrounding its interpretation. Conversation in Norwegian.