Cosmological Considerations
Section Thirty - Thirty-Two
Einstein published his cosmological application of general relativity in 1917, and the Part III is based on this paper. On this problem, our student H. Onoda is an expert. Einstein begins by pointing out the difficulties for the Newtonian Astronomy (and Gravity) as applied to cosmological considerations:
Why is this a problem? Because this does not agree with empirical observations!
All right, then, what is the situation with respect to general relativity?
Later, after E. Hubble (and A. Friedman) suggested the possibility of expanding universe, Einstein was to regret this proposal by saying that his objection (and hence the introduction of the cosmological term) against the expanding universe was "the biggest blunder of my life". However, the cosmological term has refused to die to this date! See Cosmological Term. Einstein himself refers to this problem in Appendix Four; and he points out a couple of problems of the picture of expanding universe. It should be noted that these problems gave rise to new theories of cosmology in the 20th century. See, e.g., Hawking short-short.
As Einstein suggested in the text, it is much easier to imagine a two dimensional spherical world than a three dimensional one! The man in the figure is of course a two-dimensional creature.
Last modified, May 31, 2002. (c) Soshichi Uchii
suchii@bun.kyoto-u.ac.jp
