There's no going beyond it, not with our brains apparently. Imagine, for instance, that you're at the center of a hollow sphere. The distance between you and every point on the sphere's surface is ...

For a Dyson-like hollow sphere of infinitesimally small mass, the shell-restricted three-body problem reveals similar ...

but rather than just split the sphere right down the middle, [Dave] makes two hollow C-shaped sections, like a tennis ball. This structure allows the halves to be printed in vase mode, which ...

His design was a sealed caldron of water was placed over a heat source. As the water boiled, steam rose into the pipes and into the hollow sphere. The steam escaped from two bent outlet tubes on the ...