What is a hole?
9:45
The derivative isn't what you think it is.
7:13
The unsolvable problem that launched a revolution in set theory
13:19
Topology is Impossible Without These 7 Things
9:50
A Hole in a Hole in a Hole - Numberphile
13:54
The shocking connection between complex numbers and geometry.
27:26
This open problem taught me what topology is
11:50
What is algebraic geometry?
10:19