Atoms as Rods and Clocks in Gravitational Field

Abstract

We consider the implications of using an atom as a rod and a clock in a constant gravitational field. One consequence of this is that the space metric of any constant gravitational field should be locally isotropic. This fixes the privileged coordinate system. In it the deflection of light at finite distances from the Sun is given by the tangent to the trajectory. In general this approach agrees with general relativity only in linear approximation and this is quite surprising.Introduction and exposition of the approach Almost 50 years ago the authors of [1] proposed to use, for example, the hydrogen atom as rod and clock in gravitational field and analyzed the consequences of this, see also [2]. The gravitational field, according to its strength, modifies the Bohr radius r b