Derivation of the relativistic equations from classical continuum mechanics on the basis of a macroscopic vacuum

By transforming a compressible fluid into an incompressible fluid, one can derive the Lorentz transformation from the Galilean transformation. This proves that there is a special superfluid linked to relativity, compressible in absolute space‐time theory and incompressible in relativistic space‐time theory. This special universal superfluid is just the macroscopic physical vacuum, and light is a second sound disturbance in it. The absolute and relativistic space‐time theories are two different space‐time theories in nature. A change of vacuum density in absolute space‐time theory causes a change in the actual space‐time standard, and, thus, relativistic effects occur. There are certain discrepancies and corresponding relations between these two space‐time theories.