The hyperbolic space was projected to a 3D sphere, which was cut in half,
so the inside can bee seen:
2006.03.19
And this is a stereographic 4D projection into 3D space of the icosian
group. It is also cut in half; this time so you can see the inner
foam.
2003.10.14
Nice triple symmetric cut:
Same cut, seen straight into:
Inner grid in a glass block: