Equation (4.20) describes the propagation of light in a nonuniform medium and equation (4.21) describes the propagation of light in a gravitational field. However,
In a uniform medium, the light (electromagnetic waves) moves from one point to another in the shortest path, i.e. in a straight line.
The curvature of space-time reveals itself in the curvature of a trajectory of light beams and in the gravitational shifts of spectral lines. These effects are absent in the flat […]
Because of the fact that the inert mass of a body is identically equal to its gravitational mass, the motion of bodies in a gravitational field is similar to the […]
The equations of the general theory of relativity do not include the mass of the Universe and the density of its distribution explicitly. From this point of view the whole […]
Several effects that are observable in the gravitational field of the Sun and corroborate the general theory of relativity follow from equation (4.12). These are so-called classical relativistic gravitational effects:
In the general theory of relativity, equation (4.6) for the square of an interval is interpreted as the following.
A free moving body moves in a straight line, i.e. in the shortest path between two points. Mathematically, this statement may be written as:
A gravitational interaction has a particular importance for physical processes taking place at the scale of the Universe. At present, the general theory of relativity is the only accepted theory […]
It is suggested in the general theory of relativity, which is the generally accepted theory of gravitation, that space-time is curved in a gravitational field.