Closing
Space
Solid
objects, described as 3D, are in fact 4D as they require a fourth
plane to close the space and thus limit an object from one perspective.
Diagram 1: Closing an object
4D
Space
4D
space can then be defined as 4 planes which enclosed a space. This
gives is the familiar tetrahedron.
Diagram 2: 4D "Tetra Grid"
This gives us the tetrahedronal axis f(w,x,y,z):
image courtesy
Josef Hasslberger
