Uploaded May 2020 | Updated September 2026, 3 weeks ago
In youtu.be/XUIYga-AfLI we simulated spherical geometry using an Euclidean engine. Here we simulate Euclidean space using hyperbolic geometry!
We start with the cubic tiling of Euclidean space, and proceed by replacing them by more and more curved hyperbolic cubes.
As the hyperbolic cubes get larger and larger, more of them (k) fit around the edge.
At k=6 (0:10) the vertices are infinitely far away (ideal vertices). At k over 6 the vertices are even further (ultra-ideal) . The largest k equals 8. For k=8, the four original cubes around every edge are repeated twice, so everything agrees.
The second half of the video shows a more regular construction in Euclidean space.
In youtu.be/XUIYga-AfLI we simulated spherical geometry using an Euclidean engine. Here we simulate Euclidean space using hyperbolic geometry!
We start with the cubic tiling of Euclidean space, and proceed by replacing them by more and more curved hyperbolic cubes.
As the hyperbolic cubes get larger and larger, more of them (k) fit around the edge.
At k=6 (0:10) the vertices are infinitely far away (ideal vertices). At k over 6 the vertices are even further (ultra-ideal) . The largest k equals 8. For k=8, the four original cubes around every edge are repeated twice, so everything agrees.
The second half of the video shows a more regular construction in Euclidean space.
![Circular Staircase and the non-Euclidean Geometry (VR video)
Viewing a circular staircase from the top (or conversely, viewing it from the bottom) creates the optical illusion of a mathematical logarithmic spiral. This is the same type of spiral that nature prefers, as it is seen in the chambered nautilus, the horns of a ram, the winds in a hurricane, the water in a whirlpool, and the stars in a spiral galaxy. [1]
An easy computation shows that the first sentence is not mathematically true (it is a hyperbolic spiral, not a logarithmic one). However, it is (asymptotically) true in hyperbolic geometry!
In this video, the curvature of the space changes with time. We start with 0 (Euclidean space), but for just a very short moment. Then we go to -0.5 (hyperbolic space), than back to 0 and up to 0.2 (elliptic space). The inner radius of the staircase is 1, and the outer radius is 2 (even though the stairs appear very narrow in the hyperbolic geometry). The distance between two subsequent levels is 2.4. The moment when the curvature becomes positive is easy to recognize a hole appears in the middle, because light rays do not hit our staircase at all!
[1] Bülent Atalay, https://www.trekearth.com/gallery/Europe/Italy/Lazio/Vatican_City/Vatican/photo831156.htm
Made with the HyperRogue engine [ http://www.roguetemple.com/z/hyper/ ]
Some static images: https://twitter.com/ZenoRogue/status/996046721804374016
This is a VR video. It can be rotated, or viewed using VR equipment, including cheap options such as mobile-based VR sets or anaglyph glasses. Circular Staircase and the non-Euclidean Geometry (VR video)](https://i.ytimg.com/vi/HZNRo6mr5pk/mqdefault.jpg)









