In this lesson, Ludwig Schlafli, a 19th century mathematician, discusses objects in the fourth dimension and introduces a series of 4-dimensional polyhedra. He explains how a point in each dimension is described by a certain amount of numbers, and proceeds to create 4-dimensional objects by analogy to 2-dimensional and 3-dimensional shapes. Schlafli shows how these shapes can be projected onto our 3-dimensional space to see their shadows and highlights some of his most impressive discoveries, including the 120 cell and the 600 cell, which have 120 and 600 faces respectively.
19th century mathematician Ludwig Schlafli discusses objects in the fourth dimension including a series of 4-dimensional polyhedra.