### Quantum Gravity 4.9. The Refractive Index

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,

### Quantum Gravity 4.8. The Propagation of Electromagnetic Waves

In a uniform medium, the light (electromagnetic waves) moves from one point to another in the shortest path, i.e. in a straight line.

### Quantum Gravity 4.7. Deflection of Light Beams

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 […]

### Quantum Gravity 4.6. The Equivalence Principle

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 […]

### Quantum Gravity 4.5. The Limits of Applicability of the General Theory of Relativity

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 […]

### Quantum Gravity 4.4. The Relativistic Gravitational Effects

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:

### Quantum Gravity 4.3. Distance and Time

In the general theory of relativity, equation (4.6) for the square of an interval is interpreted as the following.

### Quantum Gravity 4.2. The Curvature of the Space-Time

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:

### Quantum Gravity 4.1. The Foundation of the General Theory of Relativity

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 […]

### Quantum Gravity 4. The New Interpretation of the General Theory of Relativity

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.