On a dark November evening in 1895, Wilhelm Conrad Röntgen was perplexed by a fluorescent screen in his laboratory that was glowing for no apparent reason. Röntgen's experiment on how cathode-ray tubes emit light appeared to be affecting something that was not part of the study. It took weeks spent eating and sleeping in his lab to identify the cause of this mysterious glow – a discovery with which Röntgen's name is linked for all time, and which earned him the very first Nobel Prize in Physics in 1901.
Röntgen's discovery of a new form of energy would be subsequently named after him, but he always preferred the term X-rays – from the mathematical designation for something unknown – as no one understood what these remarkable rays actually were. In a series of experiments Röntgen discovered X-rays could travel distances of metres, and could pass through materials such as cardboard, wood and aluminum unimpeded, but not denser materials such as lead and, perhaps more notably, bone.
The stark images of Röntgen's first X-ray-photographs, in particular a ghostly picture of his wife Anna Bertha's hand, with bones and a ring on her third finger clearly visible, had a profound effect worldwide. Accounts and images of Röntgen's experiments appeared in almost every newspaper and scientific publication. Doctors instantly realised this new photographic technique could help them look inside the human body without surgery, and within weeks were using X-rays to diagnose bone fractures, locate embedded bullets and identify causes of paralysis.
For a man known to be quiet and reserved, the instant global attention Röntgen and his discoveries received seems ironic, but this was thanks to another of his traits. Researchers worldwide could experiment on X-rays as Röntgen refused to patent his findings, convinced that his "inventions and discoveries belong to the world at large."