Wilhelm Conrad Röntgen discovered X-rays in 1895 while experimenting with cathode-ray tubes in Würzburg, Germany, and he called them “X-rays” to denote their unknown nature at the time.
What happened
While testing covered discharge tubes, Röntgen noticed a fluorescent screen glowing across the room, revealing a new penetrating radiation passing through materials that blocked visible light, which he termed X-rays due to their initially mysterious properties. He soon produced iconic images, including the radiograph of his wife Anna Bertha Ludwig’s left hand showing her bones and ring, demonstrating the medical potential immediately.
Key dates
Röntgen observed the phenomenon on November 8, 1895, during laboratory experiments at the University of Würzburg, marking the discovery event most historians cite. Early public demonstrations and prints of the first medical X-rays were circulated by late 1895 and early 1896, helping the discovery spread rapidly through science and medicine.