The Heresy of Friar Travolo is now up at Daily Science Fiction.

This story combines medieval theological disputations and hyperbolic geometry. I’m quite proud of it.

The Heresy of Friar Travolo is now up at Daily Science Fiction.

This story combines medieval theological disputations and hyperbolic geometry. I’m quite proud of it.

The **cross-ratio** of four points is .

By taking we define the cross-ratio on (ordered) quadruples of points on the real line, and thereby, by interpreting the differences as signed distances, on ordered quadruples of collinear points in Euclidean space. 311 more words