Hence a hypothesis of birth of the universe from the Big Bang. One can imagine that part of the universe, obtaining in the "Big Bang" great speed away from the center of the explosion, respectively, at large distances. However, the center from which were to scatter the galaxy was detected. The question arose – what force causes the galaxies in the movement, opposing the World gravitational attraction? Not finding him response, such divergence became associated with a change (extension) of the space itself. Then it was discovered the deviation from linearity (1) speed "divergence" of galaxies. It was found that galaxies located closer to the point of observation "run away" faster than more distant ones.
Since the observed state of the galaxy (due to the finite speed of light) refers to past time, it was suggested that the process recession accelerated. To explain the mechanism of the accelerated expansion of the universe, introduced the concept of "dark energy" 2. Observing the behavior of galactic systems have found their mismatch movement of the masses of these systems 2. It turned out that the values of the mass of matter that is concentrated in galaxies, estimated to see their facilities, not enough to keep the star systems on the orbits of the prevailing speeds. Moreover, it was observed that the rate of star systems as they move around the galactic center, some distance from the center does not depend on the radius of the orbit motion 3. This led to the introduction of the concept of "ignorant masses" – Invisible under normal astronomical observations of the matter, greatly increases the mass of galaxies.