Gravitational Interaction of Antimatter - Motivations For Antigravity

Motivations For Antigravity

Supporters argue that antimatter antigravity would solve several important problems in physics. Besides the already mentioned prediction of CP violation, they argue that it explains two cosmological paradoxes. The first is the apparent local lack of antimatter: by theory antimatter and matter would repel each other gravitationally, forming separate matter and antimatter galaxies. These galaxies would also tend to repel one another, thereby preventing possible collisions and annihilations. These two facts combine to imply that the universe gradually arranges itself into a gravitational dipole at the largest scale.

This same galactic repulsion is also endorsed as a potential explanation to the observation of a flatly accelerating universe. If gravity was always attractive, the expansion of the universe might be expected to decelerate and eventually contract into a big crunch. Using redshift observations, astronomers and physicists estimate that instead, the size of the universe is expanding and the rate of expansion is accelerating at an approximately constant rate. Several theories have been proposed to explain this observation within the context of an always-attractive gravity. On the other hand, supporters of antigravity argue that if mutually repulsive, equal amounts of matter and antimatter would precisely offset any attraction.

CERN physicist Dragan Slavkov Hajdukovic has proposed an explanation for the problem of galaxy rotational speeds (currently explained by dark matter models) based on antimatter antigravity. Assuming that a particle and its antiparticle have the gravitational charge of the opposite sign, the physical vacuum may be considered as a fluid of virtual gravitational dipoles. Following this hypothesis, he presents indications that dark matter may not exist at all and that the phenomena for which it was invoked might be explained by the gravitational polarization of the quantum vacuum by the known baryonic matter.