100 - What is Light? A Journey from Ancient Philosophy to Quantum Physics
Summary
Host Dan Hooper traces the history of light theories from ancient Greek philosophers like Empedocles and Euclid to Newton’s particle model and Huygens’ wave theory. He covers pivotal experiments by Young, Maxwell’s electromagnetic unification, and the Michelson-Morley null result. The episode concludes with quantum mechanics, explaining how Einstein and Compton proved light is both a wave and a particle.
Topics discussed
Introduction to the history of light theories
Empedocles and Plato's emission theory of vision
Euclid's geometric approach to light and reflection
Ancient debate: Particle vs. Wave theories (Aristotle vs. Atomists)
Ptolemy's experiments on refraction and optics
Descartes' mechanical theory and incorrect speed assumptions
Newton's particle theory and dominance in the 18th century
Polarization, Iceland Spar, and Newton's interpretation
Newton's color theory and early wave proponents (Hooke, Huygens)
Thomas Young's double-slit experiment proving wave nature
Faraday and Maxwell: Light as electromagnetic waves
Measuring the speed of light and Maxwell's calculation
The Michelson-Morley experiment and the demise of the ether
Quantum mechanics: Planck, Einstein, and the photon
Conclusion: Wave-particle duality and quantum reality
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