632nm

Craig Gidney, a Google Quantum AI researcher known for magic-state factories and tools like Stim and Crumble, joins to discuss making fault-tolerant quantum computing practical. He explains why small Shor demos mislead, how reversible arithmetic and T gates dominate costs, and how tooling and clever resource tricks drastically cut estimates for breaking cryptography.

Tom Südhof, Nobel-winning neuroscientist who uncovered the molecular machinery of synaptic transmission. He explains how action potentials trigger millisecond-fast neurotransmitter release. The conversation covers calcium-triggered vesicle fusion, the proteins that dock and prime vesicles, and how tight spatial coupling and active zone organization enable rapid signaling.

Dan Gelbart, prolific inventor and precision engineer celebrated for lasers, optics, and ultra-precision tools. He recounts Maiman’s ruby laser story and how questioning assumptions unlocks progress. Short demos show clever loopholes around supposed physical limits. Talks cover precision metrology, pragmatic workarounds in manufacturing, materials serendipity, and how small focused teams outmaneuver giants.

Mark Bear, MIT neuroscientist known for pioneering work on visual cortex and critical periods. He explains why vision is ideal for studying experience-driven brain change. Short, clear takes on monocular deprivation, how critical periods open and close, synaptic pruning, adult visual plasticity, and links to disorders like amblyopia and Fragile X.

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 beyond what conventional diffractive optics or Fresnel lenses allow. Capasso clarifies common misconceptions, contrasts metasurfaces with diffraction gratings and phased arrays, and emphasizes the importance of physical intuition and simplicity.The conversation covers metalenses, polarization optics, holography, and how these ideas moved from theory to large-scale manufacturing in semiconductor foundries, ultimately appearing in consumer devices like smartphones. Capasso also reflects on commercialization, the legacy of Bell Labs, and the blurred boundary between basic science and real-world technology.Whether you’re interested in metasurfaces, metalenses, nanophotonics, optics, or the process behind breakthrough discoveries, this episode offers a clear and insightful look at how modern optical physics becomes transformative technology.Follow us for more technical interviews with the world’s greatest scientists:Twitter: https://x.com/632nmPodcastInstagram: https://www.instagram.com/632nmpodcast?utm_source=ig_web_button_share_sheet&igsh=ZDNlZDc0MzIxNw==LinkedIn: https://www.linkedin.com/company/632nm/about/Substack: https://632nmpodcast.substack.com/Follow our hosts!Mikhail Shalaginov: https://x.com/MYShalaginovMichael Dubrovsky: https://x.com/MikeDubrovskyXinghui Yin: https://x.com/XinghuiYinSubscribe:Apple Podcasts: https://podcasts.apple.com/us/podcast/632nm/id1751170269Spotify: https://open.spotify.com/show/4aVH9vT5qp5UUUvQ6Uf6ORWebsite: [https://www.632nm.com](https://www.632nm.com/)Timestamps:00:00 - Intro01:53 - Transition from Bell Labs to Harvard09:45 - Generalized Snell's Law21:25 - Facing the Diffractive Optics Community31:07 - Benefits of Well-Rounded Education45:16 - Metalenses55:55 - Can AI do Physics?1:07:39 - Industry vs Academia1:11:44 - Nanophotonics1:14:44 - What Allowed for the First Metalenses?1:17:38 - 632nm and Other Lasers1:20:47 - Quantum applications of Metalenses1:30:14 - Quantum Entanglement Redefines Spacetime1:43:22 - Stokes Parameters1:48:28 - Limits of Metasurface Pixel Size1:55:20 - Advice for Young Scientists2:01:45 - Critique of the H Index#metasurface #metalenses #quantumphysics #materialscience #optics  #photonics

In this engaging conversation, Philip Kim, a Harvard physicist renowned for his work on low-dimensional quantum materials, shares insights into the bizarre behaviors of electrons in reduced dimensions. He discusses the revolutionary role of graphene and carbon nanotubes in advancing material science. Kim provides anecdotes from early experiments, explains the historical context of the Hall effect, and dives into the concepts of fractional quantum Hall states. He also touches on the implications of twistronics and the potential of AI in future experimental discoveries.

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 of quasiparticles, and the role of quantum criticality in creating universal, linear-in-temperature behavior. Sachdev walks us through the origins of the SYK model, its surprising connections to black-hole thermodynamics and holography, and how new lattice-based models may finally bridge the gap between solvable theory and real materials.Whether you’re curious about superconductivity, quantum criticality, black-hole analogies, emergent gauge fields, or the deep physics behind strongly correlated electrons, this conversation offers a rare, accessible look at how frontier theoretical work is redefining our picture of quantum matter—from the lab bench to the edge of spacetime.Follow us for more technical interviews with the world’s greatest scientists:Twitter: https://x.com/632nmPodcastInstagram: https://www.instagram.com/632nmpodcast?utm_source=ig_web_button_share_sheet&igsh=ZDNlZDc0MzIxNw==LinkedIn: https://www.linkedin.com/company/632nm/about/Substack: https://632nmpodcast.substack.com/Follow our hosts!Mikhail Shalaginov: https://x.com/MYShalaginovMichael Dubrovsky: https://x.com/MikeDubrovskyXinghui Yin: https://x.com/XinghuiYinSubscribe:Apple Podcasts: https://podcasts.apple.com/us/podcast/632nm/id1751170269Spotify: https://open.spotify.com/show/4aVH9vT5qp5UUUvQ6Uf6ORWebsite: https://www.632nm.comTimestamps:01:22 - Subir’s Path to Condensed Matter Physics06:24 - Challenges in Discovering Cuprates09:53 - History of Superconductivity20:07 - Subir's PhD work27:09 - Development of the SYK model41:09 - Strange Metals56:43 - Derivation of SYK Model1:03:53 - Signatures of Strange Metals1:09:58 - How Quantum Mechanics Affects Black Holes1:17:10 - What Brought Subir to Black Holes?1:19:43 - Black Hole Connections to SYK1:29:28 - ADS CFT Correspondence1:37:04 - Can Quantum Computers Help Advance the SYK Model?1:40:17 - Is AI Useful for Theoretical Physics?1:46:40 - How does Quantum Criticality Play into Superconductivity?1:49:11 - Derivation Quantum Criticality1:52:49 -  What is Holography?1:55:07 - Holography2:00:19 - Green’s Function2:08:46 - Green’s equation slides2:13:23 - Yukawa Model vs SYK2:17:30 - Can AI Brute Force Physics Discoveries?2:23:51 - What Would Subir Do With Unlimited Funding?2:36:33 - Dissecting the Hype of Superconductivity2:31:15 - Raising the Next Generation of Great Physicists#theoreticalphysics #quantummaterials #astrophysics #superconductivity #superconductor #blackhole #quantumphysics #quantummechanics

Austin Fowler, a pioneer in quantum error correction and former principal architect at Google Quantum AI, discusses the future of quantum computing. He argues that open-source collaboration, akin to CERN, can hasten advancements. Fowler highlights the need for millions of reliable qubits and critiques current funding models that may hamper progress. He also explores the challenges of superconducting qubits and emphasizes the importance of high-quality compilers and AI in quantum software development. A fascinating look at the dynamics of quantum technology!

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 between keeping time and *transferring* time, and the surprising challenges introduced by asymmetric delays, chromatic dispersion, and environmental noise. Levine walks us through the evolution of cesium clocks, the rise of optical clocks, and the technologies that make GPS, finance, power grids, and global communication possible.Along the way, we discuss the history of time synchronization, from railroad schedules to radio frequencies to modern satellite systems; the ongoing debate over leap seconds; and why the future of precision timing depends not just on better clocks, but on better *engineering* to deliver those clocks’ performance to the real world.Whether you’re curious about atomic clocks, relativity, fiber optics, GPS, the structure of time itself, or the hidden physics behind everyday technology, this conversation offers a rare look at how science, engineering, and careful statistical thinking keep modern civilization in sync—down to the nanosecond.Follow us for more technical interviews with the world’s greatest scientists:Twitter: https://x.com/632nmPodcastInstagram: https://www.instagram.com/632nmpodcast?utm_source=ig_web_button_share_sheet&igsh=ZDNlZDc0MzIxNw==LinkedIn: https://www.linkedin.com/company/632nm/about/Substack: https://632nmpodcast.substack.com/Follow our hosts!Michael Dubrovsky: https://x.com/MikeDubrovskyMisha Shalaginov: https://x.com/MYShalaginovXinghui Yin: https://x.com/XinghuiYinSubscribe:Apple Podcasts: https://podcasts.apple.com/us/podcast/632nm/id1751170269Spotify: https://open.spotify.com/show/4aVH9vT5qp5UUUvQ6Uf6ORWebsite: [https://www.632nm.com](https://www.632nm.com/)Timestamps:00:00 – Intro01:03 – What is UTC?05:50 – Timekeeping for Satellites07:08 – How Radio Created Better Clocks18:32 – From Astronomy to Atoms25:25 – Why are there 24 Hours in a Day?29:55 – Why Synchronizing Clocks is so Hard47:09 – How did Judah get into Clocks?53:29 – Is UTC Vulnerable to Hackers?1:06:41 – Cesium vs Optical Atomic Clocks1:11:23 – How Cesium Clocks Work1:23:35 – Why Cesium Clocks are Imperfect1:26:17 – Judah’s 3 Year Experiment1:29:30 – Statistics with Clocks1:33:40 – Is Time Real?1:36:29 – Is the Universe Slowing Down?1:40:29 – Atomic Time and General Relativity1:42:17 – What’s Left for Atomic Clocks?1:54:34 – What would Judah do with Unlimited Funding?1:58:57 – Judah's Past in Programming2:02:55 – Advice for Young Scientists

Peter Turchin, a complexity scientist and pioneer of cliodynamics, dives deep into why civilizations rise and fall. He introduces the concept of elite overproduction, explaining how an excess of ambitious elites leads to societal polarization and political turmoil. Turchin’s structural-demographic theory reveals the cyclical nature of history, how military competition enhances cooperation, and the impact of new technologies like AI and LiDAR on historical research. He advocates using computational models to predict societal breakdowns and promote policy interventions for stability.