Lagrangian Mechanics - A beautiful way to look at the world
Notes
光之所以会在水中发生折射，是因为这种下光的转播所需的时间最短，同时需要的 Action 最小。
All objects in the universe behave in the same way that our light beam did. https://youtu.be/dPxhTiiq-1A?t=371
At least that’s waht Richard Feynman taught A more philosophical interpretation dates back as far as 亚里士多德 as is that nature does in fact have goals. Things move in such a way to satisfy nature’s goals. The Principle of Least Action is a manifestation of this idea.