Here the stereographic projection of the sphere to the plane is illustrated. Also a proof that the plane is not compact is shown:
Proof: Consider equally...
This video illustrates operations on open sets (symbolized by burning objects). The fire symbolizes that open sets have no border. The union of two open...
This video illustrated the construction of the fundamental Group of a topological space.
Inside a topological space (symbolized by the brown box) we consider paths. Paths...
This clip shows two non homeomorphic topological spaces (a line segment and a circle).
Proof: We have to show that there is no bi-continuos map from...
