Röntgen Discovers X Rays: 8 November 1895
1895 · event
On the evening of 8 November 1895, in a darkened laboratory in Wurzburg, a physicist noticed something that should not have been there. Wilhelm Conrad Röntgen was passing an electric discharge through a glass tube that he had wrapped in black cardboard, and a small screen coated with a fluorescent salt, lying on a bench nearby, began to glow. Something was leaving the tube, passing through the cardboard and crossing the room. He did not know what it was and called it X radiation, using the letter that mathematics reserves for the unknown.
He worked almost without a break for the next six weeks, testing what the rays would pass through, and on 22 December he asked his wife Anna Bertha to hold her hand in the beam for a long exposure. The photographic plate showed the bones of her hand and the ring on her finger. It is the first radiograph of a human body, and she is said to have found it deeply unsettling.
Röntgen published his findings on 28 December and refused to patent them, arguing that the discovery belonged to humanity. Within weeks the technique was being used by doctors in Europe and North America to locate fractures and swallowed objects, and within a year it was being taken into military field hospitals.
The first Nobel Prize in Physics was awarded to him in 1901. The dangers of the rays took longer to understand, and many early operators and enthusiasts suffered burns, injuries and cancers before shielding and dose limits became standard. Everything from dentistry and airport security to the imaging of ancient manuscripts and the structure of proteins traces back to a screen glowing on a bench in a dark room.