Wilhelm Conrad Röntgen. Photograph: Wikipedia
Wilhelm Röntgen (27 March 1845 -10 February 1923) was a German physicist, who is known for his discovery of a type of electromagnetic radiation in a wavelength range, known today as the x-ray. This discovery earned him the first Nobel Prize in Physics in 1901. The radioactive element 111, Roentgenium, which has multiple unstable isotopes, is named after him.
Röntgen was brought up in a Catholic family from Lennep, Germany. In 1848, his family moved to Apeldoorn, and so Wilhelm was brought up in the Netherlands. After attending the Institute of Martinus Herman van Doorn, Wilhelm went to school in Utrecht. Here he was expelled for refusing to identify a classmate who had drawn an unflattering portrait of their teacher. And because of this expulsion, he was unable to attend a Dutch or German gymnasium. He tried to attend the University of Utercht, without the correct requirements for regular students, but instead, he began his studies as a mechanical engineering student at the Federal Polytechnic Institute in Zurich. He graduated with a Ph.D in 1869 from the University of Zurich. He then became a lecturer at the University of Strassburg.
In November 1895, Röntgen was repeating an experiment he had been doing with one of Philipp von Lenard's tubes. It was during this experiment that Röntgen wondered what was causing the fluroscent effect. So he decided to test this idea on the 8 Novemeber 1895. Röntgen constructed a black cardboard covering. He covered a Hittorf-Crookes tube with the cardboard and attached electrodes to a Ruhmkorff coil to generate an electrostatic charge. Before setting up the barium platinocyanide screen, Röntgen darkened the room to test the cardboard cover's opacity. As the Ruhmkorff coil charge passed through the tube, he determined that the cover was light-tight and proceeded to prepare the next step of the experiment. It was at this point that Röntgen noticed a faint shimmering from a nearby bench. Being the experimental scientist he was, he tried several more discharges and saw the same shimmering each time. Striking a match, he discovered the shimmering had come from the location of the barium platinocyanide screen he had been intending to use next.
Röntgen's original paper, "On A New Kind Of Rays" (Über eine neue Art von Strahlen), was published on 28 December 1895. Röntgen was awarded an honorary Doctor of Medicine degree from the University of Würzburg after his discovery. He published a total of three papers on X-rays between 1895 and 1897.
Today, Röntgen is considered the father of diagnostic radiology, the medical specialty which uses imaging to diagnose disease.