Who discovered X-rays?
Quick answer
German physicist Wilhelm Conrad Röntgen discovered X-rays on November 8, 1895, in his lab at the University of Würzburg. He called them “X” rays because their nature was unknown. In 1901, he received the first-ever Nobel Prize in Physics for the discovery.
How he found them
Röntgen was experimenting with a cathode-ray tube, a glass tube with electricity running through it, covered in black cardboard. He noticed that a fluorescent screen across the room started to glow, even though no visible light could escape the tube. Some invisible ray was passing through the cardboard and the air.
He spent weeks testing the rays and found they could pass through paper, wood and flesh, but were blocked by bone and metal.
The famous first X-ray
On December 22, 1895, Röntgen made an X-ray image of his wife Anna Bertha’s hand, clearly showing her bones and wedding ring. On seeing it, she reportedly said, “I have seen my death.” The image amazed the world.
Rapid impact
| Year | Development |
|---|---|
| 1896 | Doctors around the world use X-rays to find bullets and broken bones within months |
| 1896 | Early radiation injuries are reported, as dangers weren’t yet understood |
| 1901 | Röntgen wins the first Nobel Prize in Physics |
| 1910s | X-rays are used in World War I field hospitals, helped by Marie Curie’s mobile units |
Röntgen refused to patent his discovery, believing it should benefit everyone. He donated his Nobel Prize money to his university.
How X-rays work
X-rays are a form of electromagnetic radiation, like light but with much more energy and shorter wavelengths. Dense materials like bone absorb more X-rays, so they appear white on images, while soft tissue lets more pass through and appears darker.
Uses today
- Medical imaging, including CT scans and dental X-rays
- Airport security scanners
- Studying the structure of crystals and DNA
- Astronomy, through X-ray telescopes
In many languages, including German, X-rays are still called “Röntgen rays.” For another pioneer of radiation research, see Marie Curie. The smallest bones show up clearly on X-rays; see the smallest bone in the body.
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