ABSTRACT
It is possible to build apparent physical representations of impossible geometry, because our materials and our methods of preparing them are not perfect, especially when the medium is paper. But the validity or lack of validity of a model need not interfere with our aesthetic enjoyment of it, though it certainly prevents us from using it as an example of an object that exhibits certain theoretical properties. As a mathematician and an origamist, I am naturally curious about the validity of many origami models that I encounter.
