Wilhelm Wien's best-known contribution to the investigation of thermal radiation is Wien's Displacement Law, which establishes a relation between the temperature of a Planck Black Body and the wavelength that manifests maximum radiated power. Among other uses, it serves to explain the greenhouse effect in Meteorology.
Wilhelm Carl Werner Otto Fritz Franz Wien is born on January 13, 1864, in Gaffken near Fischbach (today's Primorsk, Poland), a small town in East Prussia. In 1879, he is expelled from secondary school, due to poor academic performance. He is then taught by a private tutor, which soon enables him to continue his secondary education successfully, this time at Königsberg.
In 1882, he starts studying Mathematics and Natural Sciences in Göttingen, and in the winter semester of 1883/1884, he continues his studies in Mathematics and Physics in Berlin, with Hermann von Helmholtz, who becomes his doctoral adviser. In 1886, Wien achieves his doctoral degree, with a dissertation on "The Diffraction of Light on Photographically Reduced Lattices." In 1892, Wien habilitates at Friedrich-Wilhelms University at Berlin. From 1896 to 1899, he holds a professorship at Aachen, from 1899 to 1900, he teaches at Gießen.
In 1900, he accepts an appointment to the University of Würzburg, as the successor of Wilhelm Conrad Röntgen.
In 1911, Wilhelm Wien is awarded the Nobel Prize for Physics for his research on thermal radiation. From 1913 to 1914, he is Rector of the University of Würzburg.
In 1920, Wien moves on to Munich, once again succeeding to a position previously held by Röntgen. He also becomes Rector of the University, serving from 1925 to 1926. Completely unexpected, Wien dies on August 30, 1928, in Munich.
After 1888, Willy Wien contributed a physicist's point of view to the debate around the technological and financial issue whether gaslight or electric lighting was more economical. In this context, it appeared essential to solve the fundamental question: What is radiation? As a physicist, one had to address the question by taking measurements. A special radiation source was constructed for the purpose, the Black Body. At different temperatures of this radiator, the intensity of radiation at various wavelengths – "colors" – was measured. Wien was trying to establish a relation between maximum intensity of radiation in interdependence with radiator temperature, finally becoming able to give a mathematical expression. Then, in 1896, he succeeded in finding a formula that accurately represented a great number of the values derived from measuring. Four years later, Max Planck developed a radiation formula which exactly covered all measured values on the basis of quantum theory.
Working and Living in Würzburg
In the winter semester of 1899/1900, Wien was appointed Röntgen's successor at the University of Würzburg, accepting the position in the spring of 1900. At last, the couple, with their four children Gerda, Waltraud, Karl, and Hildegard, was able to settle down for the next twenty years. The family moved into the spacious apartment on the top floor of the Physical Institute at Röntgenring 8. Living and working in the pleasant city was comfortable and agreeable, and Würzburg's location provided many opportunities of exploring the lovely Lower Franconian countryside. Together with his assistants, Wien sometimes took delight in posing as a group of English tourists. From Würzburg, he embarked on many trips to other European countries, visiting Spain, England, Italy, and Greece. At Würzburg, he also found the time to pursue his life-long interests in History and the Arts.