Giuseppe Peano (1858–1932) discovered this space-filling curve in 1890. Each iteration subdivides the square into a 3 by 3 grid, and placing a copy of the current curve in each smaller square. The curve obtained in the limit of this process is called the Peano curve. This function maps the unit interval onto the unit square. Furthermore, the final curve is also continuous yet nowhere differentiable.
- Bridges Finland Art Exhibition Catalog, p. 111, Edited by Conan Chadbourne, Robert Fathauer, Katie McCallum, and Nathan Selikoff, ISBN: 978-1-938664-20-5, Tessellations Publishing, 2016.