Möbius Strip (*) 
Introduction
- Build some models using your paper (or other material), scissors, glue and paints; those models will make it easier to follow what is proposed. However, the consideration of paper models for the Möbius strip - or any other surface - raises the need to clarify some important conventions; without clear ideas about what the "points" of the surface represented by the model are, some of the questions discussed cannot be understood.
- Try to discover what there is in common between the various models you constructed and what distinguishes them. The precise mathematical formulation of some of the differences is a somewhat subtle question.
- In the scope of some pages on the non-orientability of the Möbius strip, some animations with "disorienting" paths were added on some of the surfaces.
Translated for Atractor by Gabriela Chaves, from its original version in Portuguese. Atractor is grateful for her cooperation.
(*) Since many browsers are blocking Java nowadays, it was decided to convert to Javascript the original applets of this section. This conversion was carried out within the scope of a support received from FCT - Fundação para a Ciência e a Tecnologia, through FACC (Fundo de Apoio à Comunidade Científica).
Difficulty level: University
