Louis Pasteur was born on December 27, 1822, in Dole, located in the Jura region of France. He grew up in the town of Arbois, and his father, Jean-Joseph Pasteur, was a tanner and a sergeant major decorated with the Legion of Honor during the Napoleonic Wars. An average student, Pasteur was skilled at drawing and painting. He earned his bachelor of arts degree (1840) and a bachelor of science degree (1842) at the Royal College of Besançon and a doctorate (1847) from the École Normale in Paris.

Pasteur then spent several years researching and teaching at Dijon Lycée. In 1848, he became a professor of chemistry at the University of Strasbourg, where he met Marie Laurent, the daughter of the university's rector. They wed on May 29, 1849, and had five children, though only two survived childhood.

First Major Contribution in Chemistry

In 1849, Pasteur was attempting to resolve a problem concerning the nature of tartaric acid — a chemical found in the sediments of fermenting wine. Scientists were using the rotation of polarized light as a means for studying crystals. When polarized light is passed through a solution of dissolved tartaric acid, the angle of the plane of light is rotated. Pasteur observed that another compound called paratartaric acid, also found in wine sediments, had the same composition as tartaric acid. Most scientists assumed the two compounds were identical. However, Pasteur observed that paratartaric acid did not rotate plane-polarized light. He deduced that although the two compounds had the same chemical composition, they must somehow have different structures. 

Looking at the paratartaric acid under a microscope, Pasteur observed there were two different types of tiny crystals. Though they looked almost identical, the two were actually mirror images of each other. He separated the two types of crystals into two piles and made solutions of each. When polarized light was passed through each, he discovered that both solutions rotated, but in opposite directions. When the two crystals were together in the solution the effect of polarized light was canceled. This experiment established that just studying the composition is not enough to understand how a chemical behaves. The structure and shape is also important and led to the field of stereochemistry. 

Commercial Achievements

In 1854, Pasteur was appointed professor of chemistry and dean of the science faculty at the University of Lille. There, he worked on finding solutions to the problems with the manufacture of alcoholic drinks. Working with the germ theory, which Pasteur did not invent but further developed through experiments and eventually convinced most of Europe of its truth, he demonstrated that organisms such as bacteria were responsible for souring wine, beer and even milk. He then invented a process where bacteria could be removed by boiling and then cooling liquid. He completed the first test on April 20, 1862. Today the process is known as pasteurization.

Returning to Turkey, he taught mathematics at Galatasaray High School. In 1933 he joined the Mathematics Department of Istanbul University. In 1937 he went to Göttingen, where he received his PhD from the University of Göttingen and he worked with Helmut Hasse and Josue Cruz de Munoz. He returned to Istanbul University and worked there until his involvement with the foundation work of Scientific and Technological Research Council (TÜBİTAK) upon President Cemal Gürsel's appointment in 1962. After serving as the founding director of the council in 1963, he joined the Mathematics Department of Robert College in Istanbul. Arf spent the period of 1964–1966 working at the Institute for Advanced Study in Princeton, New Jersey.^[2] He later visited University of California, Berkeley for one year.

Upon his final return to Turkey, he joined the Mathematics Department of the Middle East Technical University and continued his studies there until his retirement in 1980. Arf received numerous awards for his contributions to mathematics, among them are: İnönü Award in 1948, Scientific and Technological Research Council of Turkey (TÜBİTAK) Science Award in 1974, and Commandeur des Palmes Academiques (France) in 1994. Arf was a member of the Mainz Academy and the Turkish Academy of Sciences. He was the president of the Turkish Mathematical Society from 1985 until 1989. Arf died on December 26, 1997 in Bebek, Istanbul, at the age of 87. His collected works were published, in 1988, by the Turkish Mathematical Society.

Cahit Arf was born on 11 October 1910^[1] in Selanik(Thessaloniki), which was then a part of the Ottoman Empire. His family migrated to Istanbul with the outbreak of the Balkan War in 1912. The family finally settled in İzmir where Cahit Arf received his primary education. Upon receiving a scholarship from the Turkish Ministry of Education he continued his education in Paris and graduated from École Normale Supérieure.

Returning to Turkey, he taught mathematics at Galatasaray High School. In 1933 he joined the Mathematics Department of Istanbul University. In 1937 he went to Göttingen, where he received his PhD from the University of Göttingen and he worked with Helmut Hasse and Josue Cruz de Munoz. He returned to Istanbul University and worked there until his involvement with the foundation work of Scientific and Technological Research Council (TÜBİTAK) upon President Cemal Gürsel's appointment in 1962. After serving as the founding director of the council in 1963, he joined the Mathematics Department of Robert College in Istanbul. Arf spent the period of 1964–1966 working at the Institute for Advanced Study in Princeton, New Jersey.^[2] He later visited University of California, Berkeley for one year.

Upon his final return to Turkey, he joined the Mathematics Department of the Middle East Technical University and continued his studies there until his retirement in 1980. Arf received numerous awards for his contributions to mathematics, among them are: İnönü Award in 1948, Scientific and Technological Research Council of Turkey (TÜBİTAK) Science Award in 1974, and Commandeur des Palmes Academiques (France) in 1994. Arf was a member of the Mainz Academy and the Turkish Academy of Sciences. He was the president of the Turkish Mathematical Society from 1985 until 1989. Arf died on December 26, 1997 in Bebek, Istanbul, at the age of 87. His collected works were published, in 1988, by the Turkish Mathematical Society.