Poincaré Disk

In geometry, the Poincaré disk model, also called the conformal disk model, is a model of 2-dimensional hyperbolic geometry in which all points are inside the unit disk, and straight lines are either circular arcs contained within the disk that are orthogonal to the unit circle or diameters of the unit circle.

How to interact: Drag points around to see how distances and angles behave differently than in normal Euclidean geometry.

Key properties:

• Straight lines appear as circular arcs perpendicular to the boundary
• Distance to the boundary is infinite - you can never reach the edge
• Objects appear smaller as they move toward the boundary
• This geometry appears in Einstein's theory of relativity and M.C. Escher's art

The model was developed by Henri Poincaré to visualize hyperbolic space, where the normal rules of geometry don't apply.