A Test to Verify the Speed Change of Light in the Gravitational Field of   the Earth
  Based on the Schwarzschild solution of the Einstein equation of gravitational field, it is proved that the speed of light speed would change and isotropy of light speed would be violated in gravitational field with spherical symmetry. On the surface of the earth, the speed of light vertical to the surface is 0.2m/s less than that parallel to the surface. It is suggested to use the method of the Michelson Morley interference to verify the change of light speed and the violation of isotropy in the gravitational field of the earth. In the proposed experiment, one arm of interferometer is vertical to the earth surface while another is parallel to the surface. When two arms are turned over 90 degree, the shift of about 0.07 interference stripe would be caused which can be observed directly. So this experiment can be considered as a new verification for general relativity in the gravitational field with spherical symmetry. If the experiment shows that gravitation would change the speed of light and violate the isotropy of light speed, the result would cause great effects on foundational physics, astrophysics and cosmolo 
Mei Xiaochun