Anisotropic propagation speed of light in a uniform linear motion system relative to earth centered inertial frame

Abstract: Based on the Global Positioning System (GPS) range measurement equation whose correctness has been fully proven by GPS practices, we found that in an inertial system which is moving relative to the Earth Centered Inertial (ECI)  frame, the propagation speed of light is neither constant nor isotropic, but , where v is the velocity of the system relative to the ECI frame and is the unit vector of the direction of light propagation.  Utilizing an interferometer of two independent ultrastable lasers, a crucial experiment examining this important scientific problem with a low translational speed of the interferometer is proposed; and its comparison with an existing experiment of the generalized Sagnac effect is also presented. Besides, such an interferometer can be utilized to examine another important scientific problem: whether the speed of light is isotropic or not on rotating Earth’s surface. Because the vast majority of optical laboratories on the surface of the Earth have high linear velocities of the Earth’s rotation, only a small change of the orientation of the interferometer is sufficient.