“Röntgen must have gone mad” 

The discovery of X-rays

Ingo Zenger
Published on November 8, 2022

The 19th century was a golden era for sensational scientific discoveries. Never before in history had so much been discovered, invented, measured, and mapped – and newspapers were reporting astonishing findings and innovative electrical devices on an almost daily basis. Toward the end of the century, the first motorized streetcars were operating in cities; streets and alleyways were lit with electric lamps; and people were using elevators, sending telegrams, having their photos taken. In an era such as this, you would be forgiven for thinking that new discoveries ought not to come as a great surprise.

Wilhelm Conrad Röntgen
Das „Schattenbild“ eines Gewichtssatzes im Inneren eines Kästchens Quelle: Röntgen-Gedächtnisstätte Würzburg

The “shadow-image” of a set of weights inside a box
Source: Röntgen Memorial, Würzburg

<p>öntgen initially kept the discovery to himself. He withdrew into his work and was barely seen for the next seven weeks. No one knew what was going on in the professor’s laboratory – his assistants found the doors locked, and his wife, Bertha, went through what she would later describe as a “dreadful time.” Röntgen came home late and in a foul mood, barely spoke as he ate, and raced back to his lab immediately afterwards. Soon, he even had his bed taken into his laboratory, and his wife sometimes didn’t see him for days on end. When Bertha asked what the matter was, she initially received no answer. It was only when she pressed him that Röntgen said if people knew what he was doing, “they would say ‘Röntgen must have gone mad.’”</p>
Der Ort der Entdeckung der X-Strahlen: Röntgens Labor an der Universität Würzburg Quelle: Deutsches Röntgen-Museum

It must have been difficult for Röntgen to convince his contemporaries of what had been going on behind the closed laboratory doors for all those weeks: As well as “X-raying” a wooden spool to produce a photograph of the wire inside it, Röntgen was able to read the direction on a compass enclosed in a metal case and – in one particularly noteworthy example of his many experiments – to look through a closed door by setting up a fluorescent screen in the room next to his lab. Take a glance at Röntgen´s laboratory und learn more about his experiments in our video “Wilhelm Conrad Röntgen“ from 1968.

Röntgens handgeschriebene erste Seite des Manuskripts zur Abhandlung „Über eine neue Art von Strahlen“. Quelle: Deutsches Röntgen-Museum
<p>The most sensational of these images was taken on December 22, 1895. By asking Bertha to place her hand on a photographic plate and “X-raying” it for 15 minutes, Röntgen took one of the most famous photos in the world: the bones of Bertha Röntgen’s hand, showing a wedding ring that appeared to be floating around her finger.<br><br>The scientific community’s initial skepticism quickly subsided – for one simple reason: In those days, virtually every physics laboratory was equipped with apparatus similar to that used by Röntgen, and his experiments could therefore be reproduced and confirmed with little effort. By mid-January 1896, the world was in the grips of “X-ray mania.” Everything imaginable was X-rayed: purses, mummies, furniture – and above all the human body.</p>
Das aufsehenerregendste der ersten Röntgenbilder: Bertha Röntgens Handknochen mit Ehering Quelle: Deutsches Röntgen-Museum
Am 10. Dezember 1901 erhält Röntgen den ersten je verliehenen Nobelpreis für Physik. Quelle: Deutsches Röntgen-MuseumAm 10. Dezember 1901 erhält Röntgen den ersten je verliehenen Nobelpreis für Physik. Quelle: Deutsches Röntgen-Museum

On December 10, 1901, Röntgen received the first ever Nobel Prize in Physics 
Source: German Röntgen Museum

Ingo Zenger
Ingo Zenger
By Ingo Zenger

Technology journalist and author at the Siemens Healthineers Historical Institute