Wilhelm Rontgen, a German scientist, was the recipient of the first Nobel Prize in physics. Rontgen carried out research in several fields, but his main claim to fame is the discovery of X-rays.
In 1895, Rontgen was conducting an experiment by passing an electric current through a gas at extremely low pressure. He noticed that even though the room was dark, and the tube was covered with black carbon, a screen covered with fluorescent material was being lit up.
By placing a photographic plate at the other end, Rontgen was able to capture the image that was being lit up by these unknown rays. Since he did not know the nature of these rays, he called them X-rays. The first X-ray ever taken was an image of Rontgen’s wife’s hand. His discovery of X-rays ushered in a great revolution in the fields of physics and medicine.