Geburtshaus (house of birth) of Wilhelm Röntgen in Lennep,Remscheid
Wilhelm Conrad Röntgen was born on 27 March 1845 in Lennep (now part ofRemscheid),Prussia,[7] the only child of Friedrich Conrad Röntgen, a merchant and cloth manufacturer, and Charlotte Constanze Frowein.[8] In 1848, he moved with his parents to the Netherlands, where his mother's family lived,[8] rendering himstateless.[9]
In 1862, Röntgen enrolled at Utrecht Technical School,[8] where he followed courses for almost two years.[10] In 1865, he was unfairly expelled from the Technical School when he was falsely accused of drawing acaricature of one of the teachers, which was actually drawn by someone else.[11]
Without a high school diploma, Röntgen could only attend university in the Netherlands as a visitor. In 1865, he tried to attendUtrecht University without having the necessary credentials required for a regular student. He then moved to Switzerland and passed theentrance examination of the Federal Polytechnic School inZurich (nowETH Zurich), where he became a mechanical engineering student. In 1869, he received hisPh.D. from theUniversity of Zurich.[8] At the University, he was the favorite student ofAugust Kundt—whom he followed to theUniversity of Wuerzburg after graduation, then to theUniversity of Strassburg in 1873.[12]
Career
In 1874, Röntgen became a lecturer at the University of Strassburg. The following year, he became a professor at theAcademy of Agriculture inHohenheim. In 1876, he returned to Strassburg as Professor of Physics, and in 1879 was appointed to the Chair of Physics at theUniversity of Giessen. In 1888, he reacquiredGerman citizenship (after being stateless for 40 years)[9] and obtained the Physics Chair at theUniversity of Wuerzburg,[13] and in 1900 at theUniversity of Munich, by special request of the Bavarian government.
Röntgen had family inIowa in the United States and planned to emigrate. He accepted an appointment atColumbia University inNew York City and bought transatlantic tickets. However, the outbreak ofWorld War I changed his plans, and he remained in Munich for the rest of his career.
Later life and death
Grave of Wilhelm Röntgen (and relatives) at Alter Friedhof (old cemetery) inGiessen
Röntgen died ofcolorectal cancer on 10 February 1923 inMunich at the age of 77.[15] In keeping with his will, his personal and scientific correspondence—with few exceptions—were destroyed upon his death.[15]: 113 [16]
In 1895, in his laboratory in the Physical Institute at theUniversity of Wuerzburg, Röntgen was investigating the external effects of passing anelectric discharge through various types of vacuum tube equipment—apparatuses fromHeinrich Hertz,Johann Hittorf,William Crookes,Nikola Tesla, andPhilipp Lenard.[14][17] In early November, he was repeating an experiment with one of Lenard's tubes in which a thinaluminium window had been added to permit thecathode rays to exit the tube but a cardboard covering was added to protect the aluminium from damage by the strong electrostatic field that produces the cathode rays. He knew that the cardboard covering prevented light from escaping, yet he observed that the invisible cathode rays caused afluorescent effect on a small cardboard screen painted withbarium platinocyanide when it was placed close to the aluminium window.[13] It occurred to Röntgen that theCrookes–Hittorf tube, which had a much thicker glass wall than the Lenard tube, might also cause this fluorescent effect.
In the late afternoon of 8 November 1895, Röntgen was determined to test his idea. He carefully constructed a black cardboard covering similar to the one he had used on the Lenard tube. He covered the Crookes–Hittorf tube with the cardboard and attached electrodes to aninduction coil to generate an electrostatic charge. Before setting up the barium platinocyanide screen to test his idea, he darkened the room to test theopacity of his cardboard cover. As he passed the induction coil charge through the tube, he determined that the cover was light-tight and turned to prepare for the next step of the experiment. It was at this point that he noticed a faint shimmering from a bench a few feet away from the tube. To be sure, he tried several more discharges and saw the same shimmering each time. Striking a match, he discovered the shimmering had come from the location of the barium platinocyanide screen he had been intending to use next.
Based on the formation of regular shadows, Röntgen termed the phenomenon "rays".[18]: 40 As 8 November was a Friday, he took advantage of the weekend to repeat his experiments and made his first notes. In the following weeks, he ate and slept in his laboratory as he investigated many properties of the new rays he temporarily termed "X-rays", using the mathematical designation ("X") for something unknown. The word for X-ray in German and some languages in Central and Eastern Europe are derived from Röntgen's name[19] (and the associatedX-ray radiograms as "Röntgenograms").
At one point, while he was investigating the ability of various materials to stop the rays, Röntgen brought a small piece of lead into position while a discharge was occurring. Röntgen thus saw the first radiographic image: his own flickering ghostly skeleton on the barium platinocyanide screen.
About six weeks after his discovery, he took a picture—aradiograph—using X-rays of his wife Anna Bertha's hand.[6] When she saw her skeleton she exclaimed "I have seen my death!"[20] He later took a better picture of his friendAlbert von Kölliker's hand at a public lecture.
Röntgen's original paper,Ueber eine neue Art von Strahlen (On a new kind of rays), was published on 28 December 1895. On 5 January 1896, an Austrian newspaper reported his discovery of a new type of radiation. He was awarded an honoraryM.D. from the University of Wuerzburg after his discovery. He also received theRumford Medal of theRoyal Society in 1896, jointly with Philipp Lenard, who had already shown that a portion of the cathode rays could pass through a thin film of a metal such as aluminium.[13] He published a total of three papers on X-rays between 1895 and 1897.[21]
Röntgen's analysis and publications stirred enormous excitement among physicists. It ledHenri Becquerel to look for connections withphosphorescence, leading to his discovery ofspontaneous radioactivity in 1896.Marie andPierre Curie were also taken by the X-ray work but upon hearing of Becquerel findings they returned to isolating and identifying radioactive isotopes leading to the recognition that the radiation was generated at the atomic level.[22]
In 1901, Röntgen was awarded the inauguralNobel Prize in Physics "in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him."[23] Shy in public speaking, he declined to give a Nobel lecture.[18]: 39 He donated the 50,000kr prize money to research at the University of Wuerzburg. Like Marie and Pierre Curie, he refused to take out patents related to his discovery ofX-rays, as he wanted society as a whole to benefit from practical applications of the phenomenon.
Personal life
First X-ray by Röntgen of his wife Anna Bertha Ludwig's hand
Röntgen was married to Anna Bertha Ludwig[24] for 47 years until her death in 1919 at the age of 80. In 1866, they met inZurich at Anna's father's café, Zum Grünen Glas. They became engaged in 1869 and wed inApeldoorn, Netherlands, on 7 July 1872; the delay was due to Anna being six years Wilhelm's senior and his father disapproving of her age or humble background. Their marriage began with financial difficulties as family support from Röntgen had ceased. They raised one child, Josephine Bertha Ludwig, whom they adopted as a 6-year-old after her father, Anna's only brother, died in 1887.[25]
"For their investigations of the phenomena produced outside a highly exhausted tube, through which an electrical discharge is taking place" (withPhilipp Lenard)
Wall art by the house where Röntgen lived from 1863 until 1865 on Schalkwijkstraat inUtrecht. Made by Jackie Sleper in 2005.Röntgen's marble bust at theDeutsches Museum inMunich
In November 2004, theIUPAC named element number 111roentgenium (Rg) in his honor. TheIUPAP adopted the name in November 2011.
A collection of Röntgen's papers is held at the National Library of Medicine inBethesda, Maryland.[32]
Today, inRemscheid-Lennep, 40 kilometres east of Röntgen's birthplace inDüsseldorf, is the Deutsches Röntgen-Museum.[33]
InWürzburg, where Röntgen discovered X-rays, a non-profit organization maintains his laboratory and provides guided tours to theRöntgen Memorial Site.[34]
^abcd"Wilhelm Röntgen".University of Washington: Department of Radiology. 7 January 2015. Archived fromthe original on 7 October 2022. Retrieved2 September 2019.
^abNitske, Robert W.,The Life of W. C. Röntgen, Discoverer of the X-Ray, University of Arizona Press, 1971.
^abGlasser, Otto (1933).Wilhelm Conrad Röntgen and the Early History of the Roentgen Rays. London: John Bale, Sons and Danielsson, Ltd. p. 305.OCLC220696336.
^Agar, Jon (2012).Science in the Twentieth Century and Beyond. Cambridge: Polity Press. p. 18.ISBN978-0-7456-3469-2.
^abPais, Abraham (2002).Inward bound: of matter and forces in the physical world (Reprint ed.). Oxford: Clarendon Press [u.a.]ISBN978-0-19-851997-3.
^"Röntgen´s X-rays".German Patent and Trade Mark Office. Retrieved22 July 2025.
^Landwehr, Gottfried (1997). Hasse, A (ed.).Röntgen centennial: X-rays in Natural and Life Sciences. Singapore: World Scientific. pp. 7–8.ISBN981-02-3085-0.
^Wilhelm Röntgen, "Ueber eine neue Art von Strahlen. Vorläufige Mitteilung", in:Aus den Sitzungsberichten der Würzburger Physik.-medic. Gesellschaft Würzburg, pp. 137–147, 1895; Wilhelm Röntgen, "Eine neue Art von Strahlen. 2. Mitteilung", in:Aus den Sitzungsberichten der Würzburger Physik.-medic. Gesellschaft Würzburg, pp. 11–17, 1896; Wilhelm Röntgen, "Weitere Beobachtungen über die Eigenschaften der X-Strahlen", in:Mathematische und Naturwissenschaftliche Mitteilungen aus den Sitzungsberichten der Königlich Preußischen Akademie der Wissenschaften zu Berlin, pp. 392–406, 1897.
^Knecht-van Eekelen, Annemarie de (2019).Wilhelm Conrad Röntgen: The Birth of Radiology. Springer. p. 4.ISBN9783319976617.Wilhelm Conrad and his father were members of the Dutch Reformed Church, the mainstream Protestant.
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