Re-interpretation of the Two-World Background of Special Relativity as Four-World Background II

Coexisting four universes in separate four-dimensional spacetimes constitute four-world background for the special theory of relativity (SR) in each universe, as developed in previous papers. The fact that the four universes exhibit perfect symmetry of state and perfect symmetry of natural laws is shown in this paper. The many universes concept involved is entitled compartment universes. Compartment universes are coexisting symmetrical universes in different fourdimensional spacetimes of identical extents. Material particles and bodies are symmetrically distributed in spacetimes and the same natural laws take on identical forms in compartment universes. These features differentiate the compartment universes concept from the multiverse of inflationary cosmology and the parallel branes of M-theory. The compartment universes concept opens new vista for many-world interpretations of the natural laws, as demonstrated for the special theory of relativity already, and it is a potential platform for the uniform formulation of the natural laws. Investigation of the possible existence of larger number of compartment universes than four and many-world interpretations of gravitation and other natural laws in the compartment universes picture are recommended.