抄録
Gravitational forces are calculated for a planet moving with the sun in the Milky Way galaxy, using the linearized Einstein theory. Two terms are found to be anisotropic: one may be called a “gravitomagnetic force”, and the other is expressed as an anisotropic effective mass of a planet experiencing the Newtonian gravitational force exerted by the sun. In the direction of constellation Cygnus the effective mass of a planet of intrinsic mass m is m(1+(1⁄2)P), and it is m(1−(1⁄2)P) in the other directions. The polarization P is the anisotropy of space and has magnitude of 1.0×10−12 (M. Mizushima: J. Phys. Soc. Jpn. 61 (1992) 1125). Because of this “anisotropic-mass effect” the equilibrium orientation of planetary orbits is in the plane perpendicular to the direction of Cygnus. The gravitomagnetic force shifts the equilibrium orientation of the planetary orbital plane to the direction perpendicular to constellation Lyra. Thus, the present orientation of the planetary orbital plane is understood as the equilibrium orientation due to these two anisotropic effects.
