Braids. Chapter 1 - The group structure
Channel: Ester Dalvit
Date: 2013-04-12

Chapter 1 of my movie about braids. 
Chapter 2: http://www.youtube.com/watch?v=VhryJaoJT1Q
Music by Raul Masu.
Homepage: http://matematita.science.unitn.it/braids/