addition

I just want to add some facts about cubes. You probably know the triangle of Pascal.Each number is the sum of two close numbers in the preceeding row.
The third row represents a cube, which contains eight points. It is also called "hexahedron". Of course this can be extended to any level. The obstacle is not the fourth dimension, but the first. If we accept this as "real", we must accept the rest. This is euclidean geometry. It is a method of your mind, rather than a description of an objective reality.