In the course
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10 videos · 3 h 15 min
Explainer · YouTube
3Blue1Brown
Grant Sanderson shows why e^(iθ) walks around a circle, which is exactly the rotating-arrow picture behind the phasors in Part 7. Four minutes that make Euler's formula feel inevitable.
Explainer · YouTube
Veritasium
Derek Muller tells the story of the experiment that, just over two hundred years ago, made the case that light is a wave, and recreates it with sunlight and household materials: the beginner's version of this section in eight minutes. Keep it classical for now; the same experiment with single particles is chapter 7's story.
Explainer · YouTube
Looking Glass Universe
Mithuna Yoganathan's short introduction to the Born rule, with chapters on complex numbers as vectors (1:00) and standard complex notation (2:58). It is this section's 'seed of the Born rule' callout in its quantum form, and a preview of section 7's complex arrows.
Explainer · YouTube
The Science Asylum
Nick Lucid's video is about alternating current, but the start time jumps to its 'Complex Plane' and 'Phasors' chapters (5:01 and 6:18), followed by 'Phase Angle' at 7:33: this section's spinning-arrow trick at work in circuits. Rewind to 'Why Rotation?' (0:32) if you want the motivation.
Explainer · YouTube
Khan Academy Physics
Khan Academy's David SantoPietro explains how and why standing waves form on a string and how to find the wavelengths that fit: the ladder λₙ = 2L/n behind this section. Hold on to it; chapter 11 turns the same ladder into energy levels.
Lecture · MIT
MIT OpenCourseWare
A full lecture from MIT's 8.03SC Physics III: Vibrations and Waves (Fall 2016). Prof. Yen-Jie Lee adds two electromagnetic waves on the blackboard, shows how the resulting intensity depends on their phase difference, then uses path difference and the phase flip on reflection to explain the colours of a soap film. Best watched after the lesson.
Demo · Bell Telephone Laboratories
AT&T Tech Channel · J. N. Shive
A 1959 Bell Labs teaching film in which J. N. Shive demonstrates wave behaviour on the wave machine named after him: watch any one rod as a pulse passes, and see it only twist about the central spine while the pattern runs the length of the machine. The start skips to the 'Wave Behavior' chapter (1:42); 'Superposition Behavior' (7:09) previews section 4, and the later chapters on impedance and partial reflection are optional.
Lecture · Royal Institution
Ri Archives · Sir Lawrence Bragg
From the Royal Institution's own film archive: the Nobel laureate Sir Lawrence Bragg, the Ri's director from 1954 to 1966, explains electromagnetic waves with models and a reconstruction of Faraday's induction experiment, surveys their range, and experiments with a klystron. He then measures wavelengths with standing waves and finishes by sending electromagnetic waves through Young's pinholes, so it previews sections 5 and 8 as well.
Demo · Utah State University
Physics Demos · Boyd F. Edwards
This section's two-loudspeaker example made real, from Boyd F. Edwards' Utah State University demonstration series: two speakers play the same 2,000 Hz tone (a wavelength of about 17 cm in air) and set up an interference pattern in the room. Check each loud and quiet spot against the rule: whole wavelengths of path difference reinforce, odd half-wavelengths cancel.
Lecture · Royal Institution
Ri Archives · Sir Lawrence Bragg
Bragg sets out the contest between the particle and wave theories of light, builds up interference (2:26), reaches Young's experiment (9:52), then turns to sharp shadows and light bending round edges (13:15 onwards). A companion to this section's history from the institution where Young himself lectured.