**Copyright Information:**All rights reserved to Prof. Leonard Susskind, Stanford University.

### Lecture Description

Leonard Susskind focuses on classical mechanics expressed using Newton's 2nd law. The notions of phase space, momentum and energy are introduced. He also discusses some of the basic laws and ideas of modern physics. In this lecture, he focuses on some of the incorrect laws of motion that were first proposed by Aristotle. While they are invalid they provide some insight into how modern physics has developed to the state it is at today. Topics: - Aristotle incorrect laws of motion - Newton's law (the 2nd law) - Inertial reference frames - Newton's determinism and the need of position and velocity - Momentum and Newton's law - Phase space - Newton and reversibility - Newton's law and conserved quantities - Newton's 3 laws - Proof of conservation of momentum for an isolated system of particles - Potential energy - Energy conservation for a system of particles - Harmonic oscillator and energy Recorded on October 3, 2011.

### Course Index

- State diagrams and the Nature of Physical Laws
- Newton's Law, Phase Space, Momentum and Energy
- Lagrangian, Least Action & Euler-Lagrange Equations
- Symmetry and Conservation Laws
- The Hamiltonian
- Hamilton's Equations
- Liouville's Theorem & Phase Spaces
- Poisson Brackets
- Lagrangian of Static Electric and Magnetic Fields
- Particles in Static Electric and Magnetic Fields

### Course Description

This is the first course in a collection of 6 core physics courses by renowned physicist Leonard Susskind's series, The Theoretical Minimum. Our exploration of the theoretical underpinnings of modern physics begins with classical mechanics, the mathematical physics worked out by Isaac Newton (1642--1727) and later by Joseph Lagrange (1736--1813) and William Rowan Hamilton (1805--1865). We will start with a discussion of the allowable laws of physics and then delve into Newtonian mechanics. We then study three formulations of classical mechanics respectively by Lagrange, Hamiltonian and Poisson. Throughout the lectures we will focus on the relation between symmetries and conservation laws. The last two lectures are devoted to electromagnetism and the application of the equations of classical mechanics to a particle in electromagnetic fields.