1. History of Fridman's discovery of the nonstationary nature of the Universe 475
2. The past and the future in Fridman's theory 476
3. Elementary derivation of the law of expansion 477
4. The case of an arbitrary equation of state 479
5. The structure of the universe as a whole 480
6. The density of matter 481
7. Observational investigation of the structure. The horizon 481
8. Neutrinos and electromagnetic radiation 483
9. The metric of the expanding universe 484
10. Curvature of space, superlight speed, and the Milne model 484
11. The red shift, or aging of quanta? 485
12. The red shift. Exact formula and physical interpretation 486
13. Electric charge in the universe 488
14. Asymmetry with respect to charge 488
15. The mass of the closed world 489
16. Statement of the problem of the initial state 489
17. Types of initial conditions 490
18. Nonuniformity of density and accidental motions 491
19. Gravitational instability 492
20. Conclusion 494