New toy! Fritz Obermeyer’s Jenn makes stereographic projections of most of the convex uniform tilings of the hypersphere; of the 64 Conway-Guy polychora only four (whose construction is somewhat anomalous) are missing.
I downloaded the generic Unix version and easily built it on my Mac.
The author has responded cheerfully to my comments.
when grown-ups play with blocks
I’ve redone the Wikipedia page on convex uniform tilings of Euclidean 3-space.
It occurs to me that one could enumerate the convex uniform tilings of flat, spherical and hyperbolic 3-spaces by an approach similar to what I’ve used to find fullerenes. First make a list of the vertex figures of convex uniform polyhedra: these are polygons which share the property that their corners lie on a circle. Then use a spiral search to build irregular polyhedra from these polygons. Whenever such a polyhedron’s vertices all lie on a sphere, you have the vertex figure of a candidate solution (some of which will fail for other reasons). The size of the sphere tells you whether and which way the relevant space is curved.
Has this been done?
noitulovE, a quick recap (in reverse) of the last few hundred million years of life; gorgeous animation (Quicktime). Cited in povray.off-topic by Gilles Tran.
Someone mounted a camera on the back seat of a convertible to shoot a compressed record of a trip from Los Angeles to New York.
I downloaded this two years ago but never watched it before: animation of US airline movements around the clock
It’s surprising that I had not heard before of the mathematical sculptor Rinus Roelofs. His Möbius-double could be seen as a metaphor for half-spin particles.