
Free Daily Podcast Summary
by Steven Strogatz, Janna Levin and Quanta Magazine
The mathematician and author Steven Strogatz and the astrophysicist and author Janna Levin interview leading researchers about the great scientific and mathematical questions of our time.
The most recent episodes — sign up to get AI-powered summaries of each one.
Nothing really exists in isolation. Almost every part of our lives exists in a network. Consciousness arises from what neurons do together, life from what genes and proteins do together, society from what we do together. When researchers began mapping real-world networks in the 1990s – from the World Wide Web to Hollywood actors linked by films – they found that wildly different systems shared architectural features that their components alone could not explain. This suggested common organizing principles for how networks form and develop. In this episode, two of the pioneers of network science – Albert-László Barabási and co-host Steven Strogatz – discuss how the field took shape, the ideas that underpin it, and why this is more than graph theory under a different name. The conversation then turns to health and nutrition. Disease-related genes cluster in “network neighborhoods”, Barabási explains, which may help identify better drug targets and predict which patients will respond to which drugs. That work led him to his Foodome project, which catalogs the molecules found in the food we eat and asks what they do inside our cells. By his count, around 135,000 compounds lie outside conventional nutrition, which concerns itself mainly with energy, building blocks, and vitamins. These compounds, which he calls the “dark matter of nutrition,” and their effects on the body are only beginning to be understood.
Black holes are one of the universe’s most exotic and elusive objects. When nothing, not even light, can escape their powerful gravitational grasp, taking a picture of one seems unimaginable. But an image of a black hole, or more accurately its shadow, could offer insights that theory alone may not provide when testing predictions. So how can it be done? Harvard astrophysicist Shep Doeleman and a team of 250 researchers achieved this extraordinary feat by linking a group of radio telescopes around the world. This network, called the Event Horizon Telescope, produced the first image of a supermassive black hole in the galaxy M87, around 55 million light-years away, and the first image of the black hole at the heart of our galaxy. In this episode, Doeleman tells co-host Janna Levin how he turned the Earth into a telescope capable of seeing a black hole, the incredible level of science and collaboration that was required to achieve this, how the images have furthered our understanding of these exotic objects, and how movies of black holes may be possible by the early 2030s.
People may think of soil as just dirt, but it is anything but inert. Beneath your feet, a vast network of mycorrhizal fungi is hard at work, trading minerals with plant roots. This trading system helps enrich the soil, and it sequesters 13 billion tons of atmospheric carbon dioxide each year — roughly equivalent to one-third of the world’s fossil-fuel emissions. Scientists know that these fungi form partnerships with 80% of all plant species on Earth, a relationship that evolved some 450 million years ago. What they have not understood is how organisms with no brain or central nervous system can decide whom to trade with, and on what terms. Toby Kiers, an evolutionary biologist at Vrije Universiteit Amsterdam, has spent much of her career making this hidden world visible. Drawing on economics and game theory, and using tools that range from fluorescent quantum dots to imaging robots, her lab is probing how fungi and plants conduct their trade. The work raises new questions about soil, carbon, and even what counts as an individual organism. In this episode, Kiers tells co-host Steven Strogatz how these brainless, decentralized organisms can behave strategically — discriminating between better and worse partners and shifting resources across the network to wherever a plant will “pay” more for it — and how she has built a worldwide community of researchers
We know all about how things exist in the three dimensions of length, width, and height. Physicists often talk about time as a fourth dimension, but what if there were a fourth spatial dimension — another direction entirely? How on earth would we picture that? Mathematicians use topology to visualize abstract spaces in higher dimensions. Maggie Miller at the University of Texas at Austin explores what happens when knots encounter an extra dimension. Familiar tangled loops behave in unexpectedly complex and counterintuitive ways in 4D: Knots can always come undone, while ordinary surfaces like spheres can — surprisingly — become knotted in ways that can’t be undone. In this episode, Miller explains to co-host Janna Levin why 4D is the lowest dimension that mathematicians still don’t fully understand, how she and her collaborators resolved a question about knotted surfaces first posed by mathematician Charles Livingston in 1982, and how her interest in art has helped her develop the visual techniques she uses to picture 4D spaces.
Quantum mechanics may be one of the most precisely tested paradigms in science, but there’s still no universally accepted interpretation of what it tells us about reality. How do we get from the wave-like behavior of quantum systems to the solid, macroscopic world of objects and the universe at large? Jonathan Halliwell, a professor of theoretical physics at Imperial College London, has spent his career probing the foundations of quantum theory. In this episode, he tells Steven Strogatz why decoherence — the process by which fragile quantum behavior becomes dispersed through interactions with the surrounding environment — is key to the transition from quantum to classical behavior, and he describes the “histories” approach that he uses to understand this. Along the way, Halliwell tackles some of the field’s deepest paradoxes. He explains why the quantum-to-classical transition doesn’t require a conscious observer, and he explores Einstein’s famous question of whether the moon is really there when no one looks. The conversation ends with Halliwell explaining how yoga and meditation help him sit with the mystery of competing perspectives in science.
Mathematicians are witnessing a profound shift in their field. AI systems are now producing proofs, spotting connections between distant fields, and, in a few cases, solving problems that had stumped mathematicians for decades. The pace of progress over the past several months has raised challenging questions: What can AI systems actually do? And what happens to the more human, creative aspects of the field once machines can match – or exceed – people at problem-solving? In this special live episode of The Joy of Why, recorded at the International Congress of Mathematicians in Philadelphia on July 26, 2026, hosts Janna Levin and Steven Strogatz are joined by three mathematicians responding to the rise of AI in math: Akshay Venkatesh at the Institute for Advanced Study; Ravi Vakil at Stanford University and president of the American Mathematical Society; and Alex Kontorovich at Rutgers University. Together they discuss what recent AI-generated proofs really demonstrate, what will be gained and lost as mathematics becomes more machine-assisted at the frontier, and what this means for the next generation of mathematicians. The conversation turns to a deeper question: What do mathematicians value about doing mathematics in the first place? The answer involves grappling with what proof and understanding really mean, and with the surprising importance of storytelling.
When an LLM answers a question, is it reasoning like humans, or just producing text that looks like reasoning? The distinction isn’t just philosophical, this determines what we can trust AI to do, how closely we need to supervise it, and ultimately what its real-world impact will turn out to be. Melanie Mitchell at the Santa Fe Institute argues that we lack adequate methods for measuring machine cognition, and that AI is a form of “alien intelligence” that operates through non-human cognitive mechanisms. In this episode of The Joy of Why, Mitchell tells Steven Strogatz how methods that psychologists use to study cognition in other kinds of “alien intelligence” — babies and animals — can be adapted to probe AI, and she lays out six principles for better assessing machine cognition. Their conversation ranges from the challenge of interpreting what’s happening inside these systems, to recent AI-assisted breakthroughs in mathematics, to why a math-performing horse from the early 1900s offers a cautionary tale for how we assess intelligence.
Pain and pleasure seem like simple facts of life, but they are far from it. Neuroscientists still cannot say why physical pain differs from psychological pain, for instance, nor why a loved one’s touch soothes while a stranger’s touch repels. To explore the science behind these sensations, Janna Levin talked to Ishmail Abdus-Saboor, a neuroscientist at Columbia University’s Zuckerman Institute. Their conversation covers how pain serves an evolutionary purpose, how researchers measure pain and pleasure in the lab despite the absence of any objective biomarker, and how touch functions as a social and emotional signal, not just a sensory one. Abdus-Saboor also describes his work with naked mole rats — a species that barely feels pain, shows no signs of aging, and lives in colonies built almost entirely on touch — and the ethical trade-offs when studying sensations in animals that cannot describe what they feel.
Free AI-powered daily recaps. Key takeaways, quotes, and mentions — in a 5-minute read.
Get Free Summaries →Free forever for up to 3 podcasts. No credit card required.
Listeners also like.

The Joy of x
A mathematician explores the lives and ideas of leading scientists through in-depth conversations.

The Quanta Podcast
A weekly discussion on groundbreaking science and math stories with Quanta's editorial team.

Inquiring Minds
Explores the intersection of science and society through critical thinking and in-depth analysis.

The Rest Is Science
Hannah Fry and Michael Stevens explore puzzling scientific questions that challenge everyday assumptions about reality.

Theories of Everything with Curt Jaimungal
A deep, rigorous exploration of theories uniting physics, consciousness, AI, and metaphysics through analytical and unconventional thinking.

Off The Beaten Math
Explore mathematical constants and concepts through their history and significance with hosts Eric and Allora Novak.

Math & Physics Podcast
Two University of Toronto students discuss topics in math and physics.

Into the Impossible With Brian Keating
Brian Keating explores profound scientific and philosophical questions with leading thinkers in physics, technology, and beyond.

Stuff To Blow Your Mind
Explores the strange edges of science, consciousness, and reality through neuroscience, cosmology, evolution, and emerging technology.

The World, the Universe and Us
Explores big scientific questions about life, consciousness, climate, and the cosmos with expert scientists and New Scientist journalists.

Science Magazine Podcast
Weekly episodes covering original scientific research, global science news, and expert commentary.

Relatively Prime: Stories from the Mathematical Domain
A podcast featuring stories from the world of mathematics.
The mathematician and author Steven Strogatz and the astrophysicist and author Janna Levin interview leading researchers about the great scientific and mathematical questions of our time.
AI-powered recaps with compact key takeaways, quotes, and insights.
Get key takeaways from The Joy of Why in a 5-minute read.
Stay current on your favorite podcasts without falling behind.
It's a free AI-powered email that summarizes new episodes of The Joy of Why as soon as they're published. You get the key takeaways, notable quotes, and links & mentions — all in a quick read.
When a new episode drops, our AI transcribes and analyzes it, then generates a personalized summary tailored to your interests and profession. It's delivered to your inbox every morning.
No. Podzilla is an independent service that summarizes publicly available podcast content. We're not affiliated with or endorsed by Steven Strogatz, Janna Levin and Quanta Magazine.
Absolutely! The free plan covers up to 3 podcasts, any in the catalog. Basic raises that to 15, Pro to 40 and Max to 100. Browse our full catalog at /podcasts.
The Joy of Why publishes biweekly. Our AI generates a summary within hours of each new episode.
The Joy of Why covers topics including Science, Life Sciences. Our AI identifies the specific themes in each episode and highlights what matters most to you.
Free forever for up to 3 podcasts. No credit card required.
Free forever for up to 3 podcasts. No credit card required.