StarTalk Radio – "Macroscopic Quantum Tunneling" with John Martinis

Host: Neil deGrasse Tyson
Co-host: Chuck Nice
Special Guest: Prof. John Martinis (UC Santa Barbara, 2025 Nobel Laureate in Physics)
Date: January 6, 2026

Episode Overview

In this episode, Neil deGrasse Tyson and comedian Chuck Nice sit down with physicist John Martinis, celebrated for his leadership in quantum computing and his Nobel-winning work on macroscopic quantum tunneling. The discussion weaves through the wild world of quantum mechanics, the leap from micro to macroscopic quantum effects, and what it all means for technology, cryptography, and our potential quantum future. With humor, clarity, and plenty of nerdy digressions, the show connects Nobel-level physics to everyday curiosity, pop culture, and even the possibility we’re living in a simulation.

Key Discussion Points & Insights

1. What Is Macroscopic Quantum Tunneling?

• [04:52] The Nobel Prize was awarded for "the discovery of macroscopic quantum mechanical tunneling and energy quantization in an electric circuit.”
• John Martinis explains:
  • Normally, quantum mechanics is associated with the microscopic world (atoms, molecules).
  • The breakthrough: Quantum effects were observed in an electrical circuit visible to the naked eye (about the size of a dime). “It’s the current and voltages of that that obey quantum mechanics.” [05:06]
• Superconductivity vs. Macroscopic Tunneling:
  • Tyson notes that superconductivity is a macroscopic quantum effect. Martinis clarifies this is a different phenomenon, giving the analogy of how quantum mechanics at the atomic level can “build up” to macroscopic geometry (think crystals), but with macroscopic tunneling, the coherent quantum behavior occurs across a device-size system.
  • “The fact that you see what’s going on on the atom level with your eyes is kind of a magic physics phenomenon.” [07:53]

2. Quantum Tunneling - Explained for All

• Chuck Nice’s summary:
  • “Tunneling is when a particle overcomes a barrier, even though it shouldn’t… doesn’t have enough energy to do so. Right?” [09:55]
• Martinis confirms:
  • That’s correct. In their circuits, a change from superconducting (no voltage) to normal (voltage present) involves a quantum tunneling event.
• Implications:
  • Their work proved that you can build new electronic devices—quantum circuits—whose behavior is governed by quantum mechanics even at the macroscopic scale. “We actually have a bigger periodic table now… inductors, capacitors, transmission lines, Josephson junctions… a whole new class of quantum devices…” [13:10]

3. Why the Nobel Now? The Slow Revolution

• [15:01] Tyson notes the seminal research dates to 1985, so why did it take so long to be recognized?
• Martinis explains:
  • Often, “you don’t know if physics is important until you see what it develops into.” The field mushroomed, leading to thousands of physicists working on quantum computation.
  • “It’s kind of like fine wine, right? It had to sit there for a while.” [16:13]
• Personal note: Martinis began this project as a grad student; he’s just retired as professor—a lifetime from discovery to recognition.

4. Debunking: Tunneling Isn’t Instantaneous

• Tyson’s misconception:
  • “What’s said of them is that tunneling, it crosses the barrier instantly…”
• Martinis sets the record straight:
  • “This is new physics we did… It takes a little bit of time for it…” [21:21]
  • They even coined a term: “tunneling traversal time” [22:35].
  • The tunneling time depends on factors like circuit distance and the speed of signals (speed of light delays).
• Impact:
  • In complex systems, tunneling time affects device behavior and interpretation of experiments.

5. Josephson Junctions & Cooper Pairs—Foundations of Quantum Circuits

• Josephson Junction:
  • “Just two metals separated by a very thin insulating barrier…” [27:53]
  • Allows Cooper pairs (paired electrons in a superconductor) to quantum tunnel through and conduct current.
• Cooper Pairs:
  • Central to superconductivity—pairs of electrons with net-zero velocity condense into a supercurrent.
• Martinis:
  • “The Cooper pairs exist inside the superconductor… this is kind of a magic that happens in metals…” [28:40]

6. Qubits and Quantum Computing—The Nuts & Bolts

• What’s a Qubit?
  • Like a classical bit (0 or 1), but can exist in a quantum superposition—“both a 0 and a 1 at the same time.” [30:09]
• Tyson seeks clarity:
  • “Aren’t you making a statistical statement… or a statement of existence?” [31:31]
• Martinis:
  • “That’s the strange thing… it’s actually at all these different places at the same time.” [31:44]
• Quantum Advantage:
  • With 53 qubits, “that’s 10^16 states in parallel.”
  • “By the time you get to hundreds, that’s a number bigger than there are atoms in the universe.” [33:16]
• Why not break all encryption?
  • Algorithms exist (like Shor’s) that could break RSA encryption, but quantum-safe alternatives are underway.

7. Quantum Computing: Security & Societal Impacts

• From Patreon Fan Q&A [37:40]:
  • Question: Should quantum computing be as tightly controlled as atomic energy?
• Martinis:
  • Quantum is behind AI, but as it matures, we can apply lessons from current AI/tech regulation; “I think we already have the things in place, and we should… learn from that…”
  • “Would you put a ban on AI research and then have other countries or adversaries…?” [39:49]

8. Challenges and the Future of Quantum Hardware

• Maintaining the Quantum State:
  • Qubits are fragile—decoherence and signal loss are major hurdles. Keeping quantum computers cool (superconducting) and well-engineered is critical.
  • “We’ve spent decades now understanding this problem and figuring out how to engineer so that we don’t lose the quantum energy.” [41:34]
• When will quantum computers be commonplace?
  • Terminal access to quantum computers will likely precede personal quantum hardware, just as mainframes preceded smartphones.
  • “It’ll be remote… unless you’re worried about security…” [44:21]
  • Jokes about “the moon’s butthole” as the next cold computing site. [45:02]

9. Quantum Computers + AI = ???

• Fan Q (Dan Brown reference):
  • How might quantum computing “change humanity’s trajectory,” possibly linked to AI and even consciousness?
• Martinis:
  • In Google’s “Quantum AI” lab, people are thinking about quantum computing powering key AI breakthroughs—solving scientific problems with quantum complexity.
• Consciousness:
  • “I think people talk about that it’s a possibility, but I’m more a practical person… I’m working on building a quantum computer and not what’s going to happen in 20 years from now…” [50:13]

10. Applications and Practical Limits

• How many qubits are enough?
  • Still up for debate. Some applications might require thousands; others, millions.
  • “There’s still a lot of debate… but as soon as you see useful problems solved… then all these ideas come out.” [55:08]
• Weather prediction, brain mapping:
  • Quantum computing could tackle problems with immense complexity, from atmospheric modeling to simulating neural networks.

11. Are We Living in a Quantum Simulation?

• Tyson wonders:
  • “Could the complexity of our world be sort of a trivial calculation on a willow chip in some alien kid’s basement?” [59:23]
• Martinis:
  • “If you believe in simulation theory, whatever is doing the simulation has to have a big quantum computer.” [60:05]
• Tyson:
  • “It’s quantum all the way down.” [60:38]

Notable Quotes & Moments

• Martinis on the public and quantum physics:
  • “The fact that you see what’s going on on the atom level with your eyes is kind of a magic physics phenomenon.” [07:53]
• Tyson (on Nobel Prize timing):
  • “So what’s up with the Nobel committee?… They’re slow readers.” [15:10]
• Martinis (on tunneling myths):
  • “You’ve been misinformed your whole life… that a particle that tunnels moves through instantaneously…” [21:49]
• Tyson on quantum computing's power:
  • “You could become God.” [33:28]
• Chuck Nice on the future of jobs:
  • “Physics and engineers. That’s it. There’s going to be no other jobs.” [59:01]
• Martinis on simulation theory:
  • “Whatever is doing the simulation has to have a big quantum computer.” [60:05]
• Tyson (joking):
  • “It’s quantum all the way down.” [60:38]

Memorable Segment Timestamps

• Intro to Macroscopic Quantum Tunneling: [04:52]
• Quantum Tunneling Analogy: [09:55]
• Role of Josephson Junctions / Cooper Pairs: [27:53]
• Explaining Qubits: [30:09]
• Quantum Computing & Encryption: [33:28]
• Fan Q&A: Security/Regulation: [37:40]
• Fragility of Qubits (Hardware): [41:34]
• Quantum + AI + Consciousness: [47:25]
• Quantum Simulations: [59:23]

Tone & Atmosphere

Casual, witty, and deeply curious. Dr. Tyson dispenses with jargon when possible; Chuck Nice brings comic relief; Martinis is engaging, humble, and unafraid to explain the limits of both knowledge and technology. The episode sparkles with both scientific rigor and pop culture references—from Superman’s Phantom Zone to the "moon’s butthole" as a computer site.

Summary Takeaways

• Quantum tunneling isn’t just for atoms—under the right conditions, it manifests in electronic devices you can hold in your hand.
• The line between quantum and classical is not as clear as we think. The macroscopic world sometimes dances to quantum rules.
• Quantum computing is both an engineering marvel and a work in progress.
• Fears about quantum-powered codebreakers are real but manageable; new algorithms are being developed.
• Quantum + AI might one day change everything—even the facts of daily life or our understanding of mind.
• The biggest computational problems—modeling weather, brains, or even universes—may become possible to tackle, one (quantum) leap at a time.

StarTalk’s Quantum Edition:
From Nobel-winning physics and the weirdness of quantum tunneling to real-world tech and existential questions, Neil deGrasse Tyson and team make the quantum universe both understandable and unforgettable.