About the fundamental geometry of my universe. Part 1. on February 21, 2019 cubic geometry goniahedron polyhedron tetrahedra +
About the refraction and dispersion of light in my own universe. Part 1. on January 22, 2019 dispersion divergent sunlight refraction +
On rainbows. Part 8 (Or about what I learned from the wisdom of Yogi Berra) on January 12, 2019 Circumzenithal Arc dispersion double rainbow Ockham's razor primary rainbow rainbow raindrop refraction secondary rainbow theory of the rainbow +