In 1895, while experimenting with cathode rays, physics professor Wilhelm Conrad Röntgen, asked his wife to set her hand on a photographic plate. The result was the very first human x-ray. Here's the full story of how it happened.
Wilhelm Conrad Röntgen's life is one of the great feel good stories in science.
Before sporting one of the greatest beards of his day, Wilhelm was born in the lower Rhine lands of Germany in 1845. His father was a simple cloth merchant but always had some interesting devices around. Wilhelm's father in an effort to diversify began manufacturing cloth to sell to increase his profits.
At the time, there were not many different cloths available by trade for a fair price in the heart of Germany. So the family moved to Apeldoorn in The Netherlands. Located in a trade-heavy and shipping country; the Röntgen family could pursue the cloth trade! Wilhelm was like most kids of this age, playing in nature and wandering around in forests and streams. Sometimes however, his father required his help in fixing the manufacturing machines - which Wilhelm had a gift for. He continued this skill in his leisurely time by making all kinds of small machinations even while attending the boarding school: Institute of Martinus Herman van Doorn. Wilhelm was an average student and continued his education at a technical school in Utrecht but this was short lived. Wilhelm was expelled in 1862 after being accused of drawing a caricature of a teacher, although the actual artist was a classmate of his.
By 1865 Wilhelm was off to University and chose the University of Utrecht as the best place for him. There he studied physics - though only for a short time. He heard of student's great success at the Polytechnic school in Zurich. Wilhelm couldn't transfer his credits but he could take their aptitude examination and study there. He passed with flying colors and began student life over again this time in Mechanical Engineering. There he took classes from Rudolf Clausius of the famous Clausius-Clapeyron equation. Wilhelm like most undergrads chose to gain more experience by working in a laboratory of a professor. The lab he chose was none other than August Kundt, the famous German physicist known for his work in light absorption of plants and magnetic and electrical properties of gases.
Both of these 'greats' had a huge impact on Wilhelm, he learned a lot about what he wanted to do and where he wanted to go in life. So much so that he was awarded his Ph.D. in 1869 at the University of Zurich. He did his postdoc with Kundt and worked with him on many of his experiments and traveled with him for many conferences. Wilhelm liked to work alone, when others would visit his lab, they would be amazed by the contraptions and apparati that he had built by himself.
Wilhelm began making a name for himself and several Universities began seeking him out and trying to entice him to join their faculty. In 1874 he took a position at Strasbourg University, but by 1875 he had moved on to the Academy of Agriculture - Hohenheim in Württemberg. Then in 1876 he became a Physics Professor again at Strasbourg University. Röntgen was stacking his curriculum vitae for the penultimate position of Physics Chair at the University of Giessen.
Röntgen was the physics Chair that everyone wanted. He turned down the Chair of Physics position at University of Jena, University of Utrecht, University of Leipzig, but did accept it at the University of Würzburg [finding his fellow colleagues Helmholtz and Lorenz here] and finally the University of Munich in 1900 where he remained for the rest of his career. He was only persuaded to go after the Bavarian Government sent a special request to replace the collossal physicist and mathematician Eugen Cornelius Joseph von Lommel. Wilhelm was still sought after he declined several more positions throughout his life, the average student who had been dismissed from school earlier was now one of the most desired faculty members in Europe.
What made him so desirable? His works and his experience of course!
Wilhelm's first work, published in 1870 was an offshoot of an idea he gained while working with Kundt. It dealt with the specific heats of gases, which gave him some ideas on thermal conductivity of crystals. He studied the electrical and chemical characteristics of quartz [which is used in watches], refractive indices of fluids with pressure exertions, and the modification of polarized light from the effects of electromagnets! From Clausius, Wilhelm worked on the variations and functions of temperature as well as the compressability of water and many other fluids. He even contributed to the surface tension and cascading phenomenon of oil droplets on water. He influenced so many fields of study that laid the ground work for tons of advancements in equations and everyday life!
We're missing the biggest and most visceral of his achievements. X-rays.
It all began in 1895 when he was studying phenomena of electric currents being applied to a gas at an extremely low pressure. He was standing on the shoulders of his colleagues and predecessors who had already done much work in this same field on things like Ruhmkorff's induction coil and cathode rays. So a hat tip to Plucker, Hittorf, Varley, Goldstein, Sir Crookes, Hertz, von Lenard among others.
On the night of November 8th, Wilhelm was experimenting with cathode rays. He found that if the discharge tube was enclosed in a sealed black box that blocked all light, and if he worked in the dark, he could put a paper plate coated with barium platinocyanide on one side in front of the rays. What happened was that the ray path fluoresced even 2 meters away from the discharge tube! Wilhelm toyed with objects of different thickness and put them in the path of the rays and was able to notice variations in transparency. He quickly moved to get a photographic plate and see the effects. Like a good scientist he asked his wife for help. He asked her to put her hand in front of the rays and put a photographic plate behind her hand. The result is the first x-ray image, you can see her hand above.
The technique was called a "röntgenogram." The nature of this phenomenon was unknown at the time, like a good math student he labeled his unknown variable 'X' and while he knew he was working with cathode rays, he just called it an X-ray. It wasn't until Max von Laue's team displayed that x-rays are of the same electromagnetic nature as light and the only difference is that they operate at a higher frequency than their vibration.
Needless to say, this impact of the scientific community was immense. To write out and list his various awards, titles, honorary doctorates, prizes and medals would require a couple pages of a book, although a big one is certainly the Nobel prize of 1901. He frequently gave to charity and lived a modest life, still making sure to enjoy nature and the outdoors. At his summer home, Wilhelm would take friends on hiking excursions in the Bavarian alps, never forgetting his childhood passions.