David Hilbert1862–1943
Space-filling curve
German mathematician whose work transformed geometry and analysis; the space-filling curve bearing his name maps a line through a plane recursively.
A space-filling curve of the given order. Rotation turns the square; the path always visits every cell once.
David Hilbert, 1891

A space-filling curve: a 1D index folded until it visits every cell of a 2ⁿ×2ⁿ grid. Order is how many times the U is folded; rotation turns the square. The path is always a single stroke.
Behind the mathematics
Space-filling curve
German mathematician whose work transformed geometry and analysis; the space-filling curve bearing his name maps a line through a plane recursively.