Before the beginning

It is now widely accepted that our universe exploded around 15 billion years ago from an unimaginably energetic initial event: the big bang. As the primordial material expanded and cooled, it evolved into the exquisite patterns of stars and galaxies we now observe. The mix of energy and radiation that characterizes our universe was imprinted in that initial instant - as were the binding forces of nuclear physics and gravity that controlled our universe's evolution. The experimental triumphs and theoretical insights of recent years offer the most dramatic enlargement in our concept of the…