Georg Simon Ohm (1789 - 1854) was a German physicist and mathematician best known for formulating Ohm's law, the fundamental relationship between voltage, current, and electrical resistance in a conductor.[1] His name was later given to the ohm, the SI unit of electrical resistance.
Early life and education
Georg Simon Ohm was born on 16 March 1789 in Erlangen, then part of the region that would become the Kingdom of Bavaria.[1] His father, a self-taught locksmith, gave Ohm and his younger brother a rigorous home education in mathematics, physics, chemistry and philosophy. Ohm attended the Gymnasium Fridericianum in Erlangen and went on to study at the University of Erlangen-Nuremberg, where he received his doctorate in 1811.
Teaching and research
After university Ohm supported himself through a succession of teaching posts, working as a mathematics instructor in Switzerland and later at schools in Bamberg and Cologne. It was while teaching at the Jesuit Gymnasium in Cologne, which had a well-equipped physics laboratory, that he began the experimental research that would define his career.
Ohm's law
During the 1820s Ohm carried out careful experiments on electric current flowing through wires of different lengths and cross-sections. He found that the current is directly proportional to the applied voltage and inversely proportional to the resistance of the conductor, a relationship now written as V = IR and known as Ohm's law.[1] He set out his results in his 1827 book Die galvanische Kette, mathematisch bearbeitet (The Galvanic Circuit Investigated Mathematically).
His work was at first met with indifference and even hostility in Germany, and the lack of recognition contributed to his resignation from his Cologne post.[2] In time, however, his conclusions were confirmed and became increasingly influential, particularly among British and French physicists.
Recognition and later career
Recognition eventually followed. In 1841 the Royal Society of London awarded Ohm its Copley Medal, and the following year he was made a foreign member of the Society.[1] He also received the Bavarian Maximilian Order for Science and Art. In 1849 he moved to Munich, becoming professor of experimental physics at the University of Munich in 1852. Beyond electricity he studied acoustics, describing what is known as Ohm's acoustic law.
Legacy
Ohm died in Munich on 6 July 1854. His law became one of the cornerstones of electrical circuit theory, and in 1881 the international scientific community named the SI unit of electrical resistance, the ohm, in his honour.[3]
