Both theories had strengths and weaknesses. For example, the big bang successfully accounted for the known abundances of hydrogen and helium in the universe but posited an embarrassing beginning that could not be explained. The steady state theory avoided the stumbling block of a universe that seemed to come from nowhere but replaced it with many little unexplained beginnings (those particles of matter appearing continuously from nothing). Yet the big bang theory made one prediction that was testable: if the universe began in a blaze of luminosity, a degraded remnant of that radiation should still permeate the cosmos, and the precise spectral distribution of this microwave-frequency background could be calculated.
Then, that very year I started teaching, the cosmic microwave background radiation was serendipitously discovered by Arno Penzias and Robert Wilson, with precisely the predicted spectrum, a triumph of comprehensibility. The universe -- space and time -- had an apparent beginning! For some people, this extraordinary development re-opened the door to a creator God, whose intelligence is the source for the intelligibility of the world. Koyré may have anticipated this. In his final paragraph he wrote:
The infinite Universe of the New Cosmology, infinite in Duration as well as in Extension, in which eternal matter in accordance with external and necessary laws moves endlessly and aimlessly in eternal space, inherited all the ontological attributes of Divinity. Yet only those -- all the others the departed God took away with Him.What others? Personhood. Love. Justice. And intelligence. Intelligence that is the source of the intelligibility of the world.
But for Einstein, and many of us here, the mathematical singularity which is the big bang is an opaque barrier. To say the universe is created by God conveys no more information than to say it is created by X. We learned to live without Koyré's Dieu fainéant, the lazybones God who had nothing to do, and see no reason to bring him out of retirement.
So why is the universe comprehensible? A few more thoughts tomorrow.
(P.S. Responding to Paul's cogent remarks yesterday about the incomprehensibility of consciousness is above my pay scale. But I am not as pessimistic (optimistic?) as he. I'll say why on Friday.)