Quantum Tunnelling with Jim Al Khalili #shorts #science #quantumphysicsexplained #quantumphysics

Royal Institution
Royal InstitutionMar 16, 2026

Why It Matters

Quantum tunneling underpins the Sun’s energy output and informs fusion research, making it a cornerstone of both astrophysical theory and future energy technologies.

Key Takeaways

  • Sun's energy relies on quantum tunneling in hydrogen fusion.
  • Particles can cross energy barriers without sufficient classical energy.
  • Quantum tunneling enables nuclear reactions at temperatures below expected thresholds.
  • The phenomenon was recognized with a recent Nobel Prize.
  • Tunneling illustrates counterintuitive behavior absent in everyday macroscopic world.

Summary

The short video explains quantum tunneling, a counter‑intuitive quantum‑mechanical effect that allows particles to pass through energy barriers, and highlights its role in powering the Sun.

Using a ball‑and‑hill analogy, the narrator shows that unlike a classical ball, an electron or proton can “disappear” halfway up a barrier and reappear on the other side with a finite probability, effectively crossing the wall without the required kinetic energy.

He notes that hydrogen nuclei tunnel together in the first step of the proton‑proton chain, enabling thermonuclear fusion that produces the Sun’s light and heat, and points out that the discovery earned a recent Nobel Prize.

Understanding tunneling is crucial for astrophysics, nuclear fusion research, and emerging technologies such as semiconductor devices, because it governs processes that would otherwise be impossible at observable temperatures.

Original Description

Jim Al-Khalili explores emerging technologies powering the future of quantum, and looks at how we got here.
This Discourse was recorded at the Ri on 7 November 2025, in partnership with the Institute of Physics.

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Physicist and renowned broadcaster Jim Al-Khalili takes a look back at a century of quantum mechanics, the strangest yet most successful theory in all of science, and how it has shaped our world. He also looks forward to the exciting new world of Quantum 2.0 and how a deeper understanding of such counterintuitive concepts as quantum superposition and quantum entanglement is leading to the development of entirely new technologies, from quantum computers and quantum sensors to quantum cryptography and the quantum internet.
Jim Al-Khalili CBE FRS is a quantum physicist, author, broadcaster and well-known science communicator. He is currently Distinguished Emeritus Professor of Physics at the University of Surrey where he continues his research in the foundations of quantum mechanics and quantum biology. He has written fifteen books, between them translated into over twenty-six languages. He is also a regular presenter of many TV science documentaries, but is probably best-known in the UK for his long-running BBC Radio 4 programme, The Life Scientific.

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