... since the universe is constantly changing, how does its observability change over its history? In short, it offers a relatively brief window of opportunity for doing cosmology, and we happen to find ourselves in that window. In the future, galaxies will be farther apart; Classical Cepheids (an important type of standard candle) will be less common; and the CBR will be fainter as a result of the continuing expansion of the universe. When the universe is a few times its present age, the evidence of the Big Bang will no longer be available for observation. With this realization in mind, Abraham Loeb recently wrote, “The accelerating universe makes the study of cosmology a transient episode… ” .Read the rest at Biologic Institute. Carl Sagan, wherever you are, check your e-mail.
Not only is this the best period in history for doing cosmology, it also seems to be the only period that can sustain living, breathing cosmologists. The early universe was a much more dangerous place, and in the future Sun-like stars and the geologically important radioisotopes will be rarer, both important requirements for intelligent life. So, it seems that the best time for observing is also the best time for observers!
But why should this be so? It isn’t easy to explain this in terms of mere coincidence because, on top of explaining why the universe seems set up for life, we now need to explain why it seems set up for discovery. The simple solution, of course, is the obvious one—that the universe was designed both for intelligent life and for discovery.
Is this idea testable?
I think it is. For instance, if additional examples of the link between life and discovery are found, this will strengthen the thesis, as would additional evidence for known examples. On the other hand, if additional study weakens the examples we have described, or shows them to be wrongly interpreted, then the thesis is weakened.
(Note: The image is from Reasons to Believe.)
This is Gonzalez's book, which expands on the theme: