Gravitation as a pressure force: a scalar ether theory
Abstract
If the presence of a gravitational field breaks the Lorentz symmetry valid for special relativity, an "absolute motion" might be detectable. We summarize a scalar theory of gravity with a such "ether", which starts from a tentative interpretation of gravity as a pressure force. The theory also admits that our physical standards of space and time are affected by gravitation similarly as they are affected by a uniform motion. General motion is governed by an extension of Newton's second law to the curved spacetime which is thus obtained. Together with the scalar field equation of the theory, this leads to a true conservation equation for the total energy. The law of motion also leads to an alternative 4component equation governing the dynamics of a continuum in terms of its energymomentum tensor. That new equation implies that mass conservation is obtained as a limiting behaviour for a weak and slowly varying gravitational field and/or at a low pressure. In the presence of the Lorentz force field, the new dynamical equation gives the second group of the gravitationallymodified Maxwell equations in the investigated theory. This is consistent with the geometrical optics of the theory as governed by the proposed extension of Newton's second law. The theory has the correct Newtonian limit; it predicts Schwarzschild's exterior metric of general relativity and geodesic motion in the static situation with spherical symmetry. A postNewtonian approximation of this theory shows that no preferredframe effect occurs for photons at the (first) postNewtonian approximation. It is argued that the existence of preferredframe effects in celestial mechanics, comparable in magnitude with the "relativistic" effects, does not a priori invalidate the theory.
 Publication:

arXiv eprints
 Pub Date:
 December 2011
 arXiv:
 arXiv:1112.1875
 Bibcode:
 2011arXiv1112.1875A
 Keywords:

 Physics  General Physics
 EPrint:
 30 pages, appeared in Proc. 5th International Conference "Physical Interpretations of Relativity Theory" (London, 1996), Supplementary Papers Volume, 1998