Georg Simon Ohm

Georg Simon Ohm was born on March 16, 1789 in Erlangen, a city in Bavaria, Germany. He was the eldest of three children who survived to adulthood. His father was a locksmith who had taught himself mathematics and physics, and his mother was the daughter of a tailor. Ohm received his early education from his father, who instilled in him a love for science and philosophy. He attended the Erlangen Gymnasium from age 11 to 15, where he received little scientific training. In 1805, Ohm went to Switzerland to work as a mathematics teacher in a school near Bern. He later moved to another school in Neuchâtel, where he continued his self-study of mathematics and physics. He read the works of Euler, Laplace, Lacroix and other eminent mathematicians and physicists of his time. He also experimented with electricity using a voltaic pile, a device that produces electric current from chemical reactions. In 1811, Ohm returned to Germany and enrolled in the University of Erlangen, where he obtained his doctorate in mathematics in 1817. He then became a professor of mathematics and physics at the Jesuit Gymnasium of Cologne. There he conducted his famous experiments on electrical circuits, using wires of different lengths and diameters, and measuring the voltage and current with a galvanometer. He found that the current was proportional to the voltage and inversely proportional to the resistance of the wire. He formulated this relation as a mathematical equation, which is now known as Ohm's law. Ohm published his findings in 1827 in a book titled The Galvanic Circuit Investigated Mathematically. However, his work was not well received by the scientific community at first. Some critics doubted his experimental methods and results, while others rejected his mathematical approach as too abstract and complex. Ohm was also denied a promotion at his school because of his controversial publication. Ohm did not give up on his research, though. He continued to investigate other aspects of electricity, such as the relationship between current and magnetic fields, the effect of temperature on resistance, and the propagation of sound waves in solids. He also developed the concepts of electrical potential and electromotive force. He discovered that the phase difference between the voltage and current in an alternating current circuit depends on the capacitance and inductance of the circuit elements. This is known as Ohm's phase law. He also derived a formula for the intensity of sound produced by a vibrating body in a medium. This is known as Ohm's acoustic law. In 1833, Ohm moved to Nuremberg, where he became a professor of physics at the Polytechnic School. There he received more recognition and support for his work. He was awarded the Copley Medal by the Royal Society of London in 1841 for his contributions to electrical science. He also became a member of several prestigious scientific societies in Germany and abroad. Ohm died on July 6, 1854 in Munich, where he had been appointed as a curator of the Bavarian Academy of Sciences. He suffered a stroke and was buried in the Alter Südfriedhof cemetery. His name is commemorated by the ohm (Ω), the SI unit of electrical resistance, which was adopted in 1861 by an international congress of electricians.