don@allegra.UUCP (D. Mitchell) (05/06/84)
There is a fair amount of data that tells something about the evolution of the universe and the Big Bang. Red Shifts probably indicate the universe is expanding. There are other cosmological theorys that have extra terms in the equations that can explain this, but physicists tend to chose the simplest theory that fits the data. The 3-degree background radiation is consistent with the expansion (and cooling) of the universe. Nuclear astrophysics has a pretty good handle on the evolution of stars and nuclear processes (these things happen at fairly low energies which are well understood now). The observed ratios of abundances of elements and the statistical distribution of various types of stars are all consistent with the big bang. Elements heavier than helium (and lighter than iron) are only produced by stars, and it is believed that the big band produced only hydrogen, deuterium, and helium. A few elements are only produced by cosmic ray processes (like lithium and beryllium), and heavy elements are thought to be produced in super novae (which is why the abundance of elements beyond iron drops by many orders of magnitude). At any rate, if the universe was infinitely old, one would expect a much higher "metalicity", that is, more heavy elements. For that matter, if the universe was infinitely old, you would expect it to have reached thermodynamic equilibrium which would be pretty boring compared with what we see now. One has to make up strange mechanisms to account for a dynamic steady state. All this has been argued to death over the last few decades. I am biased of course. "Willie" Fowler taught nuclear astrophysics at my school, and charmed us all into believing in the big bang. He is one of the few really humble and informal physicists I have met, and richly deserving of the Nobel Prize which he just won.