A torus is a surface that can be constructed taking a square and making the opposite edges coincide. Mathematicians call this operation "quotient".
A punctured surface is a surface with a point removed. This is topologically the same as removing a disc or a square, etc.
A punctured torus is the same as two closed bands transversally glued together.
This short movie shows a torus as a quotient a square surface and the punctured torus as a quotient of two bands glued together.
Made with POV-Ray and MEncoder.
Cooles Video Ester!
LG aus TÜ
Visionary83 1 year ago