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10 videos · 4 h 15 min
Lecture · YouTube
Physics Explained
A patient forty-minute derivation that covers the ground of Parts 4 to 7 of this lesson in mathematical detail: the classical calculation of the radiation in a hot cavity, the moment it diverges, and Planck's way out using discrete energies and Boltzmann's statistics. Best watched after the lesson, with a pencil and paper.
Explainer · YouTube
The Science Asylum
Nick Lucid explains why star colours run from red through white to blue but skip green and purple: a blackbody spectrum is so broad that, by the time its peak sits in the green, your eye is receiving every colour at once. A perfect companion to Part 3.
Explainer · YouTube
minutephysics
A four-minute minutephysics short on colour temperature, the topic behind this section's aside that lighting catalogues call reddish light 'warm' and bluish light 'cool', although on the blackbody scale red marks the cooler body and blue the hotter one. Watch it with that inversion in mind, then check it against this section's Draper point and tungsten-bulb figures.
Explainer · YouTube
FloatHeadPhysics
Mahesh Shenoy builds the Rayleigh-Jeans law by intuition rather than algebra, the same route as this section: standing waves (2:50), Jeans's cube of modes (5:30), the equipartition theorem (9:32), applying it to light (14:35) and counting modes in 3D (16:19). It ends with the ultraviolet catastrophe (18:24), a natural bridge into section 5; rewind to 1:11 for the motivation.
Explainer · YouTube
Physics Girl
Dianna Cowern's short, friendly account of the Rayleigh-Jeans catastrophe; the start time skips the blackbody intro (0:23) and goes straight to the 'Ultraviolet Catastrophe' chapter, and the final chapter (4:49) jumps ahead to probability clouds. If it presents Planck as setting out to cure the catastrophe, keep this section's history callout in mind: the catastrophe was clearly diagnosed only after Planck's work.
Explainer · YouTube
Kathy Loves Physics
Kathy Loves Physics tells the story of 1900 in Planck's own words, which suits this section's history: Planck and Wien's law (1:47), statistical mechanics and the second law (3:48, 4:50), Boltzmann (6:12) and the quantum of energy (8:12). Notice that her chapter on the ultraviolet catastrophe (8:48) comes after the quantum, not before, and that Einstein enters at 9:43.
Explainer · YouTube
FloatHeadPhysics
Picks up where the Rayleigh-Jeans video above leaves off, starting at the question 'which classical assumption is wrong?' (4:40). Mahesh Shenoy works out a 'new partition theorem' to replace equipartition (6:22, 8:47), shows how quantization fixes the catastrophe (11:04) and arrives at E = hf (16:23): the intuitive version of this section's freeze-out argument. The 'final challenge' at 21:46, why the peak shifts with temperature, links back to Wien's law in section 2.
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.
Demo · Harvard
Harvard Natural Sciences Lecture Demonstrations
Harvard's lecture-demonstration team illustrates this section's central claim: blackbody radiators in thermal equilibrium should all emit the same spectrum, and the demo looks inside an oven at high temperature to see it. Watch with Kirchhoff's rule in mind: once everything shares one temperature, material and surface finish stop mattering.
Lecture · MIT
MIT OpenCourseWare · Alan Guth
From MIT 8.286 The Early Universe (Fall 2013), the story behind this section's satellite callout: from 23:17 Alan Guth goes from Penzias and Wilson's single frequency to a 1987 rocket result well above the blackbody curve, then to COBE (32:12), its 1990 preprint and the standing ovation for John Mather. At 36:37 he turns to the spectrum's shape, writes it per unit frequency (38:51) and at 40:00 notes the extra factor needed per unit wavelength, section 2's warning in action; the segment ends near 42:40, and the rest of the lecture is about the cosmological constant.