Prof. Muni Mahendra Kumar
The astronomers have tried to find out the average density of matter by astronomical observations. One of them Edwin Hubble, the eminent astronomer of Mt. Wilson Observatory, after having studied for years some specific portions of the space, has calculated the average amount of matter in unit volume of space. This number, according to him, is 0.0000000000000000000000000000001 gram per unit cubic centimeter, which can be written as
10-30 gm/cc.
Substituting the value of e in Einstein’s field-equations (equation no. iv above), the radius of curvature of the universe comes out to be
35,000,000,000 light-years.
i.e., 3.5x10-10 light-years.
Or
210,000,000,000,000,000,000,000 miles
i.e. 2.1x1023 miles.
This means that a sunbeam setting out through space at the rate of 186,000 miles per second would return to its source after having a complete round of the universe after a little more than 200 billion terrestrial years[1]
Substituting the value of Ro in equation no.(ii) above, the volume of the universe comes out to be of the order of 1071 cubic miles
These calculations were modified to some extent after the discovery of the theory of expanding universe, which we shall discuss in the next section.
