Georg simon ohm, a German physicist. Ohm discovered the proportional relationship between current and voltage in resistance, that is, the famous ohm's law; He also proved that the resistance of a conductor is directly proportional to its length and inversely proportional to its cross-sectional area and conductivity. In the case of stable current, the charge moves not only on the surface of the conductor, but also on the whole cross section of the conductor. The international system of units "ohm" of resistance is named after him. August 2 1 day-French mathematician Cauchy was born in Paris.
On September 9th, William Bond, an American astronomer and the first director of the Observatory of Harvard University, was born.
65438+10.3-Sir Peter Tancha, the first governor of Hong Kong, was born. (1843 The first governor of Hong Kong; 1856 died)
Louis Jacques Mande Daguerre was a French inventor, artist and chemist. He was originally a stage background painter, and later he invented the silver plate photography, also known as silver plate photography. 1839 On August 9th, the French Academy of Science and Art purchased its patent on photography, and announced it to the world, announcing the birth of photography.