I’ve been learning a lot of physics over the last year, mostly following the resources at https://www.susanrigetti.com/physics. However that guide contains only textbooks, and I much prefer video lectures, for a few reasons.
Rant
Firstly, sometimes I just don’t want to read, maybe my voice is tired, etc. Secondly, textbooks usually only contain a few, low quality images, while videos can have animations and diagrams that make things much easier to understand. Thirdly, the text in a textbook is separated far from the equations and images, and you constantly have jump to (equation 69.420) that is 3 pages past what you are reading, while in a video the equation will be shown on screen with the most important points highlighted. Finally, most textbooks cost money unless you know where to look.
However there are a lot of bad videos out there too, where either the professor spends most of the time writing and erasing the chalkboard and can barely speak english such as https://www.youtube.com/watch?v=xQFgk-nEihg or those popular clickbait videos that constantly repeat information that sounds cool but is misleading, outdated, or just wrong (did you know, if you go near a black hole there is a 1% chance that albert einstein tells you to go away)
This article contains the good resources I found after searching through the internet, hopefully someone will find it useful.
- prereq
- High school physics, calculus, finite dimensional vector spaces (or linear algebra). I was already familiar with these topics and since they are relatively common to learn, there are lots of good resources online.
- differential equations
- https://www.youtube.com/channel/UCdf2-sP9uBkJMi7OJV6SS8w?tab=playlists
- https://reddit.com/r/EngineeringStudents/comments/kjt1dg/for_those_of_you_taking_diff_eqs_next_semester/
- Personally, memorizing the various methods for solving differential equations and solving a bunch of them on a closed-book exam is not helpful for me at all, because it’s better to use a calculator, and a lot of the time these methods don’t even work. I just remember that these methods exist (see the chart linked above) and what overall form these solutions take (such as solution existence and uniqueness, and the structure of linear equations)
- classical mechanics (more advanced)
- Lagrangian Mechanics Sequence videos 1-3
- John R. Taylor - Classical Mechanics-University Science Books (2005)
- I quickly skipped through the first few chapters as it goes over high school physics, the chapters about lagrangian formalism and after are interesting
- harmonic motion and waves
- special relativity
- special relativity kinematics - Intro to Special Relativity Course
- It’s a lot easier to understand if you do not think of the classical universe with added “special effects” such as length contraction, time dilation, etc that are “corrections” to the classical theory. Instead visualize each event on the spacetime diagram shown in that video and imagine applying stretching along one light axis and compression along the other.
- When doing calculations, it is easier to work with the full 4-vectors rather than memorizing a bunch of formulas for time dilation and other correction factors (this will be introduced in the electrodynamics section)
- electrodynamics
- Griffith - Introduction to Electrodynamics
- don’t have any videos or tips for this topic, sorry
- quantum mechanics 1
- Griffith - Introduction to Quantum Mechanics
- remember that functions are an infinite dimensional vector space, and operators are the infinite dimensional version of matricies
- thermodynamics
- https://www.youtube.com/playlist?list=PLpGHT1n4-mAsJ123W3fjPzvlDHOvIhHA0
- Daniel V. Schroeder - An Introduction to Thermal Physics (1999)
- read both the book and the lecture, skip through parts you already know
- optional
- astronomy
- https://www.youtube.com/playlist?list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL
- fun and easy to understand
- more advanced, focusing on physics of processes inside stars
- https://www.youtube.com/playlist?list=PLpkegBCPWkWOuyg_JWtkANQi8cy9Q-GoO
- An Introduction to Modern Astrophysics (Bradley W. Carroll, Dale A. Ostlie)
- https://www.youtube.com/playlist?list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL
- nonlinear dynamics and chaos theory
- electronics
- https://www.youtube.com/channel/UCJ0yBou72Lz9fqeMXh9mkog - videos on transformers, diodes, operational amplifiers, logic gates
- continuum (solid)
- https://www.youtube.com/playlist?list=PLLSzlda_AXa3N5jaDART7kimBlYz1dFnX
- stopped watching around lecture 17 because it was getting boring and I didn’t care
- https://www.youtube.com/playlist?list=PLLSzlda_AXa3N5jaDART7kimBlYz1dFnX
- fluid dynamics
- astronomy
- general relativity
- understand tensors first, otherwise the notation will be impossible to follow
- introduction https://www.youtube.com/playlist?list=UUWvq4kcdNI1r1jZKFw9TiUA watch what you find interesting
- next, learn differential geometry to understand manifolds. Then learn about einstein equations and which manifold represents spacetime, depending on initial conditions. Then learn about solutions to the einstein equation for certain initial conditions.
- differential geometry
- comprehensive lecture
- From what I understand, we only have solutions for a few, very simple scenarios, such as a universe with only a single black hole that has no creation process and never changes, along with small perturbations. For more complicated scenarios, such as what if 10 black holes are arranged in a certain formation? what if a gravity wave passes by another black hole? What if you fall in a black hole right before it evaporates? I don’t know how that would be solved.
- quantum mechanics 2 and particle physics
- Introduction to Elementary Particles (David Griffiths)
- https://www.youtube.com/channel/UCogE_pJuDs_xLtDVcp4W_UA
- may be easier to understand than the textbook
- dirac equation (relativistic version of schrodinger equation)
- guage symmetry
- quantum electrodynamics, chromodynamics, electroweak unification
- Why aren’t all particles virtual?
- quantum field theory
- hard 😩