This paper is based on the premise that the theory of relativity is inconsistent, not in accord with relevant experimental evidence, and must be replaced. An alternative is sought without the notion of an absolute space. This is found in an ether-theory in which the ether is compressible and probably irrotational and has no mass. The ether is the medium for the transportation of all forces. The mass of a body and the velocity of light are not constant but depend on the place in space, on the distribution of energy. All mass is electromagnetic mass and gravity is due to the variation of the velocity of light. The first calculations based on these principles, in which only motions relative to the ether are considered, not the motions of the ether itself, are very promising. The positive results of calculations based on relativity can be explained, including the bending of light and the perihelion-advance of Mercury.
