Hyperbolic World

Welcome, world explorer ! Well yeah, you are a world explorer ;-) You have your own perception of the world around you, the living environment, "what is there". No need to travel for that, you only need to be there. And then you'll notice that the railroad tracks meet on the horizon, that the hula hoop around your head appears as a straight line, and that the poster stuck on the wall of that building appears as a trapeze.

However, haven' you, maybe, taught at school that parallel lines never intersect, that circles aren' straight as lines, and that trapezes don't have right angles? Effectively, euclidean geometry doesn't really fit to the experience we have every day of visual perception (and also of other perceptions), of our environment, of the living environment.

So here you'll find a bit of refreshing non-euclidean geometry, by some blogs, and by a simulation of the Poincaré's Disc.

Image strip: hyperbolic tiling "Circle Limit 4" made by M.C.Escher
Hyperbolic World | CC-BY-4.0 2014-2019, Julien Busset.