Amazon.com description: Product Description: More than 90 percent of the Universe is unseen, unknown. Ordinary telescopes cannot detect it - nor can radio antennas. Yet there is convincing evidence that it exists - as something called "dark matter". At the same time, recent discoveries about the structure of the Universe are challenging accepted views about its very origins. Michael Riordan and David Schramm explore a scientific mystery: What is this dark matter? What does it have to-do with the structure of the universe - the uncountable galaxies and clusters of galaxies that constitute the firmament? What does it tell us about the birth of our universe? Riordan and Schramm explore these questions, as they describe efforts underway at observatories, laboratories and particle colliders to determine the nature of dark matter. "The Shadows of Creation" is an account of the complicated puzzles that challenge today's physicists and cosmologists.