An astonishing concept has entered mainstream cosmological thought: physical reality could be hugely more extensive than the patch of space and time traditionally called “the universe.” We’ve learnt that we live in a solar system that is just one planetary system among billions, in one galaxy among billions. But there are signs that a further Copernican demotion confronts us. The entire panorama that astronomers can observe could be a tiny part of the aftermath of our Big Bang, which is itself just one bang among a potentially infinite ensemble. In this grander perspective, what we’ve traditionally called the laws of nature may be no more than parochial bylaws—local manifestations of “bedrock” laws that must be sought at a still deeper level. Astronomers might seem the most helpless of all scientists. They can’t do experiments on stars and galaxies, and human lives are far too short for us to watch most cosmic objects evolve. But there are some compensating advantages. There are huge numbers of objects in the sky, and one can infer the life-cycle of stars, just as one can infer how trees have grown and will die from one day’s wandering in a forest.
more from Martin Rees at Prospect Magazine here.