Physics
An assortment of topics from physics
How are holograms possible?Holograms store 3d scenes on 2d film, here we explore how, with a lesson on diffraction along way.
Terence Tao on the cosmic distance ladderThe Cosmic Distance Ladder, how we learned distances in the heavens.
Terence Tao continuing history’s cleverest cosmological measurementsHow we know the distances to the planets, stars, and faraway galaxies.
This tests your understanding of light | The barber pole effectHow shining polarized light through sugar water results in colored diagonal stripes
How wiggling charges give rise to lightHow light can be described by a force due to the delayed effect of an accelerating charge, and how it can be used to explain the demo from the previous lesson.
But why would light "slow down"? | Visualizing Feynman's lecture on the refractive indexThe origins of the index of refraction, and why it depends on color
Answering viewer questions about refractionAnswering a few viewer questions about the refractive index.
Some light quantum mechanics (with minutephysics)An introduction to the quantum behavior of light, specifically the polarization of light. The emphasis is on how many ideas that seem "quantumly weird" are actually just wave mechanics, applicable in a lot of classical physics.
The more general uncertainty principle, beyond quantumThe general uncertainty principle, about the concentration of a wave vs the concentration of its fourier transform, applied to two non-quantum examples before showing what it means for the Heisenberg uncertainty principle.
Feynman's Lost Lecture (ft. 3Blue1Brown)This video recounts a lecture by Richard Feynman giving an elementary demonstration of why planets orbit in ellipses. See the excellent book by Judith and David Goodstein, "Feynman's lost lecture”, for the full story behind this lecture, and a deeper dive into its content.
Why 5/3 is a fundamental constant for turbulenceA look at what turbulence is (in fluid flow), and a result by Kolmogorov regarding the energy cascade of turbulence.
The Brachistochrone, with Steven StrogatzA classic problem that Johann Bernoulli posed to famous mathematicians of his time, such as Newton, and how Bernoulli found an incredibly clever solution using properties of light.
Snell's law proof using springsA clever mechanical proof of Snell's law.