Clifford torus
A torus in four dimensions, seen through a three-dimensional projection. A close relative of the Hopf fibration, with a woven surface that changes shape as the fourth dimension turns.
Inside the mathematics
Two circles of radius 1/√2 lie in perpendicular planes in ℝ⁴. We rotate the x–w plane, then stereographically project to ℝ³.
(x,y,z,w) = (cos u, sin u, cos v, sin v) / √2
P = (x,y,z) / (1 − w)