Book excerpt: Humans have always viewed the heavens with wonder and awe. The skies have inspired reflection on the vastness of space, the wonder of creation, and humankind's role in the universe. In just over one hundred years, science has moved from almost total ignorance about the actual distances to the stars and earth's place in the galaxy to our present knowledge about the enormous size, mass, and age of the universe. We are reaching the limits of observation, and therefore the limits of human understanding. Beyond lies only our imagination, seeded by the theories of physics. In Measuring the Cosmos, science writers David and Matthew Clark tell the stories of both the well-known and the unsung heroes who played key roles in these discoveries. These true accounts reveal ambitions, conflicts, failures, as well as successes, as the astonishing scale and age of the universe were finally established. Few areas of scientific research have witnessed such drama in the form of ego clashes, priority claims, or failed (or even falsified) theories as that resulting from attempts to measure the universe. Besides giving credit where long overdue, Measuring the Cosmos explains the science behind these achievements in accessible language sure to appeal to astronomers, science buffs, and historians.