Wilhelm Conrad Röntgen, a German physics professor at Würzburg, discovered X-rays on 8 November 1895: working late with a cathode-ray tube, he noticed a fluorescent screen glowing across the room and realized invisible rays were passing through objects — he called them X-rays, X for the unknown. Weeks later he photographed his wife Anna's hand, wedding ring and all.
Röntgen refused to patent the discovery and declined to name the rays after himself; in 1901 he received the first Nobel Prize in Physics. Within months of his announcement, X-ray machines were imaging fractures and locating bullets — the first time doctors could see inside a living body without cutting it open.
