Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
In November 1895, the German physicist Wilhelm Conrad Röntgen made a discovery that changed science and medicine. While working with a Lenard discharge tube in his laboratory at the University of Würzburg, he noticed something very strange. Although the room was completely dark and the tube was covered with black cardboard, a screen coated with barium platinocyanide began to glow. Röntgen realized that invisible rays were coming from the tube and passing through the cardboard. Instead of spending a long time on theories, he focused on practical experiments. He is often quoted as saying, “I did not think; I experimented.” He closed himself in the laboratory for seven weeks and soon discovered that these rays could pass through many materials, such as wood and paper, but were blocked by denser materials, such as lead and bone.
The most famous moment in this story happened on December 22, 1895, when Röntgen took the first medical X-ray image. For this experiment, he used the hand of his wife, Bertha Röntgen. When the image was developed, it clearly showed the bones of her hand and her wedding ring. According to a well-known story, when Bertha saw the picture, she was shocked and said, “I have seen my death!” because she was looking at her own skeleton. Although, like many women in the 19th century, Bertha was largely an invisible supporter of her husband’s career, this image made her famous. Through the picture of her hand, she became part of the history of science and medicine.
Röntgen quickly shared his results by sending copies of his paper "Ueber eine neue Art von Strahlen" (On a new kind of rays) [1], and photographs to scientists around the world on New Year’s Day in 1896. News of this “sensational discovery” spread around the world very quickly. The Viennese newspaper Die Presse was informed by Dr. Lecher, a physicist from Charles University, and on January 5, 1896, it published an article with the headline “Eine sensationelle Entdeckung” (“A Sensational Discovery”). Within days, the story was reported by The Daily Chronicle on January 6 and The Standard on January 7.
People were fascinated by the idea of “seeing the invisible.” Because Röntgen chose not to patent his discovery, doctors and scientists everywhere could begin using X-rays almost immediately. In the United States, the first medical X-ray was taken at Dartmouth College only a few weeks after the news arrived. Interestingly, the first recorded medical use of X-rays in Australia dates to early 1896, when William Henry Bragg, then a professor at the University of Adelaide, used home-made equipment to produce an X-ray photograph of his six-year-old son’s arm after a tricycle accident. Years later, the father and son collaborated to study how X-rays interact with crystals. They formulated Bragg’s Law, which explains how X-rays are diffracted by the planes of atoms, effectively founding the field of X-ray crystallography. In 1915, they were jointly awarded the Nobel Prize in Physics for their work. At age 25, Lawrence Bragg became, and remains, the youngest ever Nobel laureate in Physics.
Other well-known inventors, including Thomas Edison, also began developing X-ray devices such as the fluoroscope. However, this early period also revealed the dangers of radiation, including the tragic death of Edison’s assistant, Clarence Dally, from radiation exposure.
Röntgen’s work was so important that he received the first Nobel Prize in Physics in 1901. Today, 130 years later, X-rays are used every day in hospitals for diagnosis, in airports for security, and in laboratories for structural biology.
This lecture is designed for a general audience and aims to make Röntgen’s discovery accessible, engaging, and easy to understand. It connects the history of science with theatre and live demonstration, showing how one unexpected observation in a laboratory became one of the most important tools in modern medicine. The lecture will be accompanied by a practical demonstration using props from the theatre play Berta RTG, written by Pavlína Øezáèová and performed by the non-professional theatre group Scéna Kralupy nad Vltavou. The play premiered on November 8, 2025, to honour the 130th anniversary of Röntgen’s discovery.