A submission to #SoME2.
A short introduction to renormalization techniques as they appear in statistical physics, aiming to simplify the mathematics as much as possible. The goal is to explain why matter becomes simpler as you zoom out from the microscopic, and how this leads naturally to phase transitions. Text version to follow.

This is a reupload with a couple typos fixed.

00:00 Introduction
02:13 States and probabilities
03:16 The Gibbs distribution
03:56 Course-graining
05:05 Hamiltonians
06:30 Renormalization calculation
07:38 Details of calculation
09:45 Renormalized coefficients
10:44 Renormalization flow
12:18 Fixed points
13:30 Particle physics
14:09 Phase transitions
15:42 Summary
16:19 Closing

https://www.brokensymmetries.com