Abstract

The most obvious thing about the universe in which we find ourselves is its structure. Before the scientific revolution, the instinctive reaction of thinkers to the existence of perceived structure was to find a direct reason for that structure. This is reflected above all in the Pythagorean notion of the well-ordered cosmos: the cosmos has the structure it does because that is the best structure it could have. In fact, that is what the word cosmos really means—primarily order, but also decoration, embellishment, or dress. Kepler and Galileo were no less entranced by the beauty of the world than was Pythagoras, and they formulated their ideas in the overall conceptual framework of the well-ordered cosmos. However, both studied the world so intently that they actually identified aspects of motion that fairly soon led to the complete overthrow of such a notion of cosmos. The laws of the new physics were found to determine not the actual structure of the universe, but the way in which structure changes from instant to instant. Ultimately, no explanation is provided for the currently observed structure; it is simply attributed to an initial structure that was never fashioned by the laws of nature but merely continually refashioned thereafter. The initial and boundary conditions for our universe lie outside the purview of science. But all of the structure we observe around us must ultimately be traced back to those mysterious initial and boundary conditions.