Invisibility? X-ray vision? At one time or another, it's likely most people have wished for one of these abilities. This entry in the Science of Superpowers series (6 titles) explores the history, present, and future of each. The power to be invisible has appeared in literature from ancient myths to current books and movies. Scirri explains how scientists are experimenting with metamaterials to create such an illusion, but, so far, they haven't created a cloak large enough for a person. X-rays have been around for two centuries, and X-ray machines are continually becoming smaller, simpler, and more sophisticated. Combining an easy-to-read font, color and black-and-white photos, diagrams, and fact boxes, this will appeal to curious readers. However, a lack of source notes and a publisher disclaimer make this better recreational than report reading.