Poincaré Conjecture

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.Check out Brilliant (get 20% off their premium service): https://brillian...

The famed Poincaré Conjecture - the only Millennium Problem cracked thus far.

Ricci Flow (used to solve the problem): http://youtu.be/hwOCqA9Xw6A
Riemann Hypothesis: http://youtu.be/d6c6uIyieoo
Extra interview footage with Jim Isenberg: http://youtu.be/7eJleW0JcKg

Grigori Perelman's paper: http://bit.ly/perelmanpaper

Discussed here by Katie Steckles and James Isenberg.