Hideki Tsuiki

Professor of Mathematics and Computer Science
Graduate School of Human and Environmental Studies, Kyoto University
Kyoto, Japan
When I found H-fractal (Hexagonal bipyramid imaginary cube fractal) and T-fractal (Triangular antiprismoid imaginary cube fractal), I was attracted by their beauty, in particular, the way their projected images change. Recently, I succeeded in characterizing the directions from which these objects are projected to positively-measured fractals, and I was also moved by the beauty of this result. I wondered how I can convey this beauty to a wider audience, and I came up with the idea of making precise models of these fractals with 3D-printers, make YouTube videos of them, and link a paper in the comment of the video.
Fractal Imaginary Cubes
Fractal Imaginary Cubes
13 x 25 x 20 cm
resin
2022
These three objects are fractal imaginary cubes, which are fractal objects with square projections along three orthogonal directions. Let \(F(k,D)\) be the fractal defined as the unique fixed-point of the operator \(F(X) = \frac{X + D}{k}\) on non-empty compact subsets of \(\mathbb R^3\) for + the Minkowski sum. The green one is known as Sierpinski Tetrahedron (4096 pcs), which is \(F(2,D_S)\) for \(D_S\) the four vertices of a regular tetrahedron. The other two, T-fractal (yellow, 729 pcs) and H-fractal (red, 729 pcs) are the only two fractal imaginary cubes of the form \(F(3,D)\) for \(D\) a nine-point set in \(\mathbb R^3\). Continuously changing fractals obtained as projected images of these fractals are beautiful and interesting.