The discovery of the x-ray in 1895 proved to be one of the most transformative breakthroughs in the history of science. It ushered in a new era in medicine, allowing physicians and patients to peer inside the living human body, without the use of a scalpel, to assess health and diagnose diseases. The x-ray opened up the world of the very small, allowing us to determine the structure of the molecules of which we are made. It also revealed the true nature of the largest and oldest objects in the universe, including the universe itself. Today it has spawned amazing new imaging techniques, includi