Wilhelm Conrad Röntgen

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    For the discovery of X-rays.

Wilhelm Conrad Röntgen was born in 1845, at Lennep in the Lower Rhine Province of Germany. In 1869, he completed his Ph.D. at the University of Zurich. In 1874, he qualified as Lecturer at Strasbourg University and in 1875 he was appointed Professor in the Academy of Agriculture at Hohenheim in Wurtemberg. In 1876 he returned to Strasbourg as Professor of Physics, but three years later he accepted the invitation to the Chair of Physics in the University of Giessen. Following Giessen, he moved to the University of Wurzburg (1888), and in 1900 he accepted the Chair of Physics at the University of Munich, by special request of the Bavarian government, where he remained for the rest of his career.

Röntgen is best known for his discovery of X-rays. In 1895 he was studying the phenomena accompanying the passage of an electric current through a gas of extremely low pressure. Röntgen's work on these cathode rays led him, however, to the discovery of X-rays. On November 8, 1895, he found that, if the discharge tube is enclosed in a sealed, thick black carton to exclude all light, and if he worked in a dark room, a paper plate covered on one side with barium platinocyanide placed in the path of the rays became fluorescent even when it was as far as two metres from the discharge tube. During subsequent experiments he found that objects of different thicknesses interposed in the path of the rays showed variable transparency to them when recorded on a photographic plate. He also discovered that he could see the shadow of bone through flesh when a hand was held in the path of the rays. This was the first "rontgenogram" ever taken. In further experiments, Röntgen showed that the new rays are produced by the impact of cathode rays on a material object. Because their nature was then unknown, he gave them the name X-rays.

Röntgen received the first Nobel Prize in physics in 1901.

Information as of 1897