Roentgen anniversary: 125 years of new insights - Part 1

Wilhelm Konrad Röntgen, a world-renowned researcher and awardee of the first Nobel Prize in physics. How did he manage to go to university without a high school diploma? Why didn't he protect his method of x-ray generation with a patent? And why did he deny Prince Regent Leutbold of Bavaria's offer to ennoble him? March the 27th, 1845. Röntgen is born in the small German town of Lennep, close to Remscheid in North Rhine-Westphalia. He's the only child of the cloth merchant Friedrich Conrad Röntgen and his wife Charlotte Constanze. The family later moves to the Netherlands, which is the mother's country of origin. At the age of 18, Wilhelm's school education there comes to a sudden end due to a caricature of his class teacher, which is falsely attributed to him. Because he refuses to name the actual perpetrator, he gets expelled from school without a diploma. A scientific career seems impossible. But Röntgen is not willing to give up just yet. Even though he's not enrolled, he takes classes at the University of Utrecht. Later, he visits the Federal Polytechnic Institute in Zürich, known today as ETH, where he's allowed to study without a high school diploma thanks to his exceptional skills. At the age of 23, he graduates with a degree in mechanical engineering. One year later, he receives his doctorate for the investigation of the volumes and temperatures of gases. In 1869, Röntgen comes to Würzburg for the first time as an unpaid assistant and habilitation candidate. The attempt to achieve this formal qualification for professorship fails due to the missing high school diploma. In private life, he's a bit more lucky and marries Anna Berta Ludwig, whom he met at her father's restaurant in Zürich, a place he used to visit often as a student. When Röntgen moves to Strasbourg as a lecturer, the tide is also turning for him professionally. Upon special request, he finally achieves his habilitation. Following a few other positions, he ends up in Gießen in 1879. After some time-consuming and tedious experiments, he succeeds in confirming a theory by James Clark Maxwell. By demonstrating the existence of a so-called displacement current, he achieves a milestone in electrodynamics and receives worldwide attention as a renowned physicist. This same year, he decides to move back to Würzburg because the lab in Gießen wasn't The Institute of Physics at the University of Würzburg. Röntgen returns to a modern laboratory with world-class facilities, much different than those during his years as an assistant. Supplemented with some of his own devices, the equipment will soon enable some of his groundbreaking observations. However, his greatest discovery is, next to Röntgen's tenacity, owed to a coincidence, as is often the case in science. On November 8, 1895, the physicist works late. It is the time of rapid industrialization in Europe. The railroad industry is booming and towns are equipped with electricity. Modern communication is established, such as the telephone. This progress comes at a high cost. People work an average of 70 hours per week, and rooms frequently have up to five or more occupants due to a lack of housing. In his lab, Röntgen is investigating the properties of gas discharge with cathode ray tubes. It is known that this phenomenon causes the tube to light up inside. Röntgen tries out different tubes, materials and voltages. During this experiment on November 8, 1895, he sees something shimmering outside the vacuum tube on a fluorescent screen at increased voltage. He systematically goes into the matter, turning off all the visible light in the lab and covering the tube with black cardboard. The fluorescence on the platinum cyanide screen remains, no matter where it is placed with respect to the tube. From this phenomenon, Röntgen concludes that there must be an unknown kind of radiation, which he calls X-rays, one of the finest hours of science. But what happened? In those vacuum tubes, electrons are accelerated from cathode to anode by a high voltage. During their passage, they excite gas molecules in the tube to give light. But when reaching the anode, the fast electrons are suddenly decelerated and deflected, forcing them to release energy in the form of then unknown radiation, which can penetrate materials. Wilhelm Conrad Röntgen immediately realizes the far-reaching consequences of his observations. He doesn't tell anyone, hides out in his lab for weeks to scrutinize the properties of this radiation. Bulky books, metal foil, wood, nothing can stop the mysterious X-rays, not even the human body. The oldest documented X-ray image is a picture of Röntgen's wife's hand, which was exposed for 15 minutes. When Röntgen is finally confident enough in his observations, the associated publication can't come quick enough. He sends special prints of his article, on a new kind of rays, to colleagues and friends, and soon newspapers from Berlin, Vienna and around the globe report on his groundbreaking discovery. The emerging interest in his person makes Röntgen feel increasingly uncomfortable. In the beginning of 1896, he holds his first and only oral presentation of the new radiation. Afterwards, the anatomist, Professor Albert Kölliker, who is present as one of the listeners, suggests to call the X-rays Röntgen radiation. The audience applauds this proposal with standing ovations. In private life, however, Röntgen is indeed a social type. Whenever work allows, he leaves his lab in order to go on vacation with friends for hiking or hunting. Luxury, in contrast, is not for him. He hesitates to enter expensive hotels and will only do it for the sake of his wife, whose health is not at its best. Also, as a professional, Röntgen is humble. He does not apply for a patent for the generation of X-ray radiation. He wants everybody to benefit from his discovery. Some react with mockery and incomprehension, such as the inventor and businessman Thomas Edison. Likewise, Röntgen isn't flattered by honors and medals, culminating in the denial of being ennobled by the Prince Regent Leutpold, which evokes astonishment and also resentment at the Ministry in Munich. However, there is one honor that Röntgen appreciates and accepts. In 1901, he is awarded the first Nobel Prize in Physics. The ceremony requires a trip to Stockholm. Röntgen is rather unexcited. In his request to leave, he writes, On the day after the awards ceremony, Röntgen already makes his trip back, without giving the customary ceremonial address. Today, we don't know what was behind his apparent shyness. Röntgen had most of his documentation destroyed after he died, so many things remain unknown or mysterious. For example, it's still unclear why he soon stopped committing himself to a closer investigation of X-ray radiation. In any case, Wilhelm Conrad Röntgen's discovery changed the world. To this day, generations of researchers have developed a multitude of X-ray applications and their innovations have permeated all aspects of our everyday life.