Wilhelm Conrad Röntgen won the 1901 Nobel Prize in Physics for the discovery of X-rays.
Röntgen observed the unknown radiation on 8 November 1895 while experimenting with cathode-ray tubes. The rays passed through materials that blocked visible light and produced images on photographic plates. He called them “X-rays,” using X to indicate their unknown nature.
His famous image of his wife Anna Bertha’s hand revealed bones and a wedding ring, demonstrating the medical potential of the discovery. X-rays are electromagnetic radiation with shorter wavelengths and higher energy than ultraviolet light.
A common mix-up is crediting Röntgen with inventing the X-ray machine. He discovered the radiation; later researchers developed improved tubes, detectors and medical imaging methods. Röntgen donated his Nobel Prize money to his university.