In the course
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10 videos · 3 h 22 min
Explainer · YouTube
AT&T Tech Channel
A classic classroom film made around 1961 by Educational Services Incorporated with two Bell Labs scientists: Alan Holden hosts and narrates, and Lester Germer himself re-creates the famous 1927 experiment he performed with Clinton Davisson. The perfect companion to Part 4: the experiment re-created by one of the first people ever to see electrons diffract.
Explainer · YouTube
Arvin Ash
Arvin Ash asks this section's question about a tennis ball. The lesson answers it with wavelength; he adds the second half of the answer: a big object cannot be cut off from air molecules, scattered light and its own thermal glow, any of which records its path and wipes out interference. Section 8 comes back to that idea. Keep both halves in mind: even a perfectly isolated ball would have a wavelength far too short to show fringes.
Demo · YouTube
National STEM Centre
A four-minute classroom demonstration: an electron beam passed through graphite produces diffraction rings, the same kind of ring pattern G. P. Thomson photographed in 1927. Use section 3's shortcut, λ ≈ 1.226/√V nm: a higher accelerating voltage gives a shorter wavelength, so the rings should shrink whenever the voltage goes up.
Explainer · YouTube
Physics Explained
A careful history of duality built around de Broglie. The jump lands on 'The Bohr Model revisited' and 'Explaining the allowed orbits', the standing-wave argument of this section, then runs on through 'Bragg Diffraction' and the Davisson–Germer results for section 4. Rewind to 'The French Prince' (18:35) for de Broglie himself.
Explainer · YouTube
Veritasium
Veritasium on why seeing atoms is so hard. The jump starts at 'How does an electron microscope work?', then covers the transmission electron microscope and 'Spherical Aberration', the lens flaw that, as this section explains, long kept resolution far coarser than the electron wavelength. It ends on 'Seeing atoms'. Its sources include Ruska's 1986 Nobel lecture.
Explainer · YouTube
nature video
Nature's own short report, presented by Lizzie Gibney, on the University of Vienna experiment (Pedalino et al., Nature 2026) that put a cluster of about 7,000 sodium atoms into superposition, the record that ends this section. Watch for how it frames the open question: where does the quantum world stop?
Explainer · YouTube
Looking Glass Universe
Looking Glass Universe argues that 'wave–particle duality' belongs to the old quantum theory and that the wavefunction replaces it. Chapters on momentum eigenstates and position wavefunctions show where λ = h/p lives inside ψ, and she then explains the double slit with it. This is a direct answer to 'what is waving?' and a preview of chapter 9.
Lecture · Royal Institution
The Royal Institution · Sean Carroll · 2020
Sean Carroll tells the story from Planck and Einstein through Bohr, de Broglie and Schrödinger, then argues that the measurement problem is still open and makes his case for the many-worlds interpretation. Notice where the history ends and his interpretation begins.
Explainer · MIT
MIT OpenCourseWare
Barton Zwiebach presents de Broglie's proposal at the blackboard in MIT's 8.04 Quantum Physics I (Spring 2016). Expect university-level reasoning about how the energy and momentum relations of the photon were extended to every particle; watch it after Parts 1 and 2.
Explainer · Fermilab
Fermilab · Don Lincoln
Fermilab's Don Lincoln takes on the exact puzzle of Psigor's callout: how can something with no mass carry momentum? He argues that the question comes from misusing equations; compare his resolution with the lesson's route through E² = (pc)² + (mc²)².