Cosmology: The Universe in evolution

There are three principal pieces of evidence which, when taken together, support the notion that the Universe as a whole is evolving. These are: (a) the Hubble velocity-distance relationship; (b) the abundance of light elements in the Universe; and (c) the three degree cosmic background radiation. The best explanation of these observations is that the Universe began, if it had a beginning, in a hot dense state and it has been expanding and cooling down ever since. In the course of that process matter came to be out of energy, galaxies and stars formed, and you and I came to exist. In this process the emergence of organic material in general, and human beings in particular, seems to have required a very fine tuning of the evolutionary process itself. We do not yet have a definitive scientific explanation of that fine tuning and, therefore, we do not yet understand the linkage of the human being to cosmic evolution. But some interesting suggestions can be made. (author). Abstract only