Wilhelm Röntgen
1845 – 1923 · Germany
Known for: German physicist who discovered X-rays in 1895 and left the discovery unpatented
“He gave the world a way of seeing through it, and asked nothing in return.”
Biography
Wilhelm Conrad Röntgen was born on 27 March 1845 in Lennep in Prussia, the only child of a cloth manufacturer. The family moved to the Netherlands when he was three, leaving him without citizenship for the next four decades. In 1865 he was expelled from the Utrecht Technical School after being blamed for a caricature of a teacher drawn by another pupil, and without a diploma he could attend university only as a visitor. He passed instead the entrance examination of the Federal Polytechnic School in Zurich, studied mechanical engineering there, and took his doctorate at the University of Zurich in 1869 under the physicist August Kundt, whom he followed to Würzburg and then Strasbourg.
Chairs of physics at Giessen and, from 1888, at Würzburg followed. In the Würzburg laboratory, on the evening of 8 November 1895, he covered a Crookes-Hittorf discharge tube in black cardboard to confirm that no light escaped, and noticed a faint shimmer on a bench some feet away. It came from a small screen coated with barium platinocyanide, struck by something invisible that had passed through the cardboard. For weeks he ate and slept beside the apparatus, calling the unknown agent X-rays, and he saw his own bones outlined on the screen while holding a piece of lead in the beam. Six weeks after the discovery he made a radiograph of his wife Anna Bertha's hand; on seeing her skeleton she said she had seen her death. His paper On a New Kind of Rays appeared on 28 December 1895, and the news reached the newspapers within days.
He published only three papers on the rays and refused to patent them, and in 1901 he became the first recipient of the Nobel Prize in Physics. He took the Munich chair in 1900 and had accepted a post at Columbia University in New York when the First World War intervened, keeping him in Germany. Postwar inflation ruined him financially, and he spent his last years at his country house in Weilheim, dying of colorectal cancer in Munich on 10 February 1923 at the age of 77. His will ordered nearly all his correspondence destroyed and left bequests to his birthplace and to the physics institute at Würzburg. X-ray imaging had by then become routine in medicine, and element 111 was later named roentgenium in his honour.