Episode notes
Why is syncing atomic clocks still one of the hardest problems in physics and engineering? In this episode, we speak with Judah Levine—legendary NIST physicist and one of the key architects of modern timekeeping—about the invisible systems that hold the digital world together. Levine explains why synchronizing atomic clocks across the planet is far more complex than the clocks themselves, and why seemingly simple ideas like “round-trip delay” break down in real-world media such as fiber optics and the internet. We explore how UTC is built from hundreds of atomic clocks, the difference…
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632nm
Misha Shalaginov, Michael Dubrovsky, Xinghui Yin · Tech & Science · English
Technical interviews with the greatest scientists in the world.
More from 632nm All episodes →
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E47 · 3 Feb 2026 · 1 hr 56 min
How Visual Experience Rewires the Brain | Mark Bear on Neuroplasticity
How does experience rewire the brain—and why is vision the ideal system for understanding neuroplasticity? In this episode, we speak with Mark Bear, MIT neuroscientist and a pioneer in the study of experience-dependent plasticity. Bear explains how the visual cortex became a model system for uncovering the synaptic mechanisms that allow the brain to change, adapt, and learn, especially during early development. We explore how visual experience shapes neural circuits, why the brain undergoes critical periods of heightened plasticity, and what classic experiments in visual deprivation revealed…
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E46 · 20 Jan 2026 · 2 hr 13 min
Snell's Law, Metasurfaces, and Metalenses | Federico Capasso
How can flat surfaces shape light as powerfully as bulky lenses? In this episode, we speak with Federico Capasso, Harvard physicist and pioneer of metasurfaces, metalenses, and nanophotonics. Capasso traces the path from his work at Bell Labs on quantum cascade lasers to the invention of metasurface optics, showing how a practical challenge—collimating light without traditional lenses—sparked a new way to control light. We explore the physics behind metasurfaces and generalized Snell’s law, explaining how subwavelength structures enable precise control of wavefronts, phase, and polarization…
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E45 · 6 Jan 2026 · 2 hr 47 min
Graphene, Nanotubes, and Quantum Hall Physics | Philip Kim
How do electrons behave when they’re confined to a single layer, and why do entirely new laws of physics emerge when dimensions shrink? Papers discussed in this episode: Experimental observation of the quantum Hall effect and Berry's phase in graphene: https://www.nature.com/articles/nature04235 Tunable Fractional Quantum Hall Phases in Bilayer Graphene: https://arxiv.org/abs/1403.2112 Room-Temperature Quantum Hall Effect in Graphene: https://arxiv.org/abs/cond-mat/0702408 In this episode, we speak with Philip Kim, Harvard physicist and a leading experimentalist in low-dimensional quantum…
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E44 · 23 Dec 2025 · 2 hr 35 min
Quantum Matter, Super-conductors, and Black Holes | Subir Sachdev on the SYK Model
What makes high-temperature superconductors and “strange metals” some of the most perplexing systems in modern physics? In this episode, we speak with Dr. Subir Sachdev: Harvard physicist and one of the leading architects of today’s understanding of quantum matter. Sachdev explains why strange metals refuse to behave like ordinary conductors, how quantum entanglement reshapes the landscape of many-body physics, and why the quest to understand cuprate superconductors continues to push both theory and experiment to their limits. We explore the physics of the cuprate phase diagram, the collapse…
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E43 · 9 Dec 2025 · 1 hr 50 min
How to Build Fault-Tolerant Quantum Computers | Austin Fowler on Surface Codes + TQEC
Would we get a quantum computer sooner if everything was open source? In this episode, we speak with Austin Fowler, one of the architects of quantum error correction and a pioneer of the surface code used in today’s leading quantum computers. Fowler helped lay the groundwork for scalable, fault-tolerant computation at Google Quantum AI, before leaving to advocate for a more open and collaborative model of research. He explains why building a useful quantum computer will require millions of reliable qubits, why no known algorithm yet clearly outperforms classical computation, and why the…
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E41 · 4 Nov 2025 · 1 hr 18 min
Can We Predict History Like the Weather? | Peter Turchin on Cliodynamics
Why do civilizations rise, prosper, and then collapse? Here's what the math tells us. In this episode, we sit down with Peter Turchin, complexity scientist and founder of the field of cliodynamics, which uses data and mathematical models to study the long-term cycles of history. Turchin explains his theory of elite overproduction, how societies generate too many ambitious, educated elites competing for too few positions, and why this dynamic reliably leads to polarization, inequality, and political turmoil. We explore how his structural-demographic theory maps the recurring “boom and bust”…
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E40 · 21 Oct 2025 · 1 hr 1 min
Why Do Quantum Computers Make So Many Mistakes? | Mikhail Lukin on Quantum Error Correction
You can’t copy a qubit. So how do quantum computers remember anything? In this episode, we sit down with Mikhail Lukin, Harvard physicist and co-director of the Harvard Quantum Initiative, whose lab is building quantum computers from arrays of individually trapped atoms. Lukin explains the paradox of quantum error correction—how you can safeguard quantum information even though it can’t be copied or measured directly—and why this breakthrough may be the key to making large-scale quantum computers possible. We dive into the strange logic of superposition, entanglement, and “small cat states,”…
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E39 · 9 Oct 2025 · 1 hr 6 min
We Interviewed the Winners of the Ig Nobel Prize | Ig Nobel 2025
The scientific stories behind this year's research that made people LAUGH, then THINK. Watch the 2025 Ig Nobel Ceremony here: https://youtu.be/z1cP4xKd_L4 In this episode, we bring together three of this year’s Ig Nobel winners whose research spans psychology, food science and human biology. You’ll hear how a team of psychologists devised a counter-intuitive way to boost a narcissist’s self-confidence; how two physicists uncovered the “mozzarella phase” of pecorino cheese while perfecting cacio e pepe; and how a group studying lactation discovered that garlic changes breast-milk’s aroma and…
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E38 · 7 Oct 2025 · 1 hr 41 min
What Science can Learn from Startups | Adam Marblestone on Focused Research Organizations
Science has stalled. And Adam Marblestone thinks he knows why. Check out the Research Gap Map here: https://www.gap-map.org/?sort=rank In this episode, we sit down with Adam Marblestone, neuroscientist, nanotechnologist, and founder of Convergent Research, to explore how new “Focused Research Organizations” (FROs) could reignite scientific progress. From DNA “ticker-tape” neural recording to optical connectomics and Neuralink, Marblestone explains how emerging neurotechnologies reveal both the brilliance and the bottlenecks of today’s research system. We discuss why traditional funding often…
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E34 · 23 Sep 2025 · 1 hr 53 min
What Optical Atomic Clocks Tell Us About Space-Time | Jun Ye
Times have changed. And cesium clocks can't keep up. In this episode, we sit down with Jun Ye, Joint Institute for Laboratory Astrophysics (JILA) Fellow and pioneer of optical lattice clocks, whose work has pushed timekeeping far beyond traditional cesium atomic clocks. Ye explains how combining ultra-stable lasers, frequency combs, and ultra-cold atoms produces clocks more than 100× more precise than today’s standards: so sensitive they can detect gravitational time dilation across the width of a human hair. We explore how this next generation of atomic clocks may open windows onto…
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