Weber, Wilhelm Eduard (physicist)


(1804-1891) German Experimentalist (Classical Electromagnetism)

Wilhelm Eduard Weber was an ingenious experimentalist who made vital contributions to elec-tromagnetism. With the highly sensitive apparatus he developed he found new ways to measure electricity and magnetism and to define electric and magnetic units. He is also remembered as the first physicist to propose that electricity consists of charged particles.

He was born in Wittenberg, Saxony (now Germany), on October 24, 1804, into a distinguished family. His father was professor of theology at the University of Wittenberg; his older brother, Ernst, would become a seminal figure in developing the physiology of perception. When Wilhelm was 10, the family moved to Halle, where he would enter the university eight years later. After receiving his doctorate in 1826, he stayed on at Halle, at first as a lecturer and later, from 1828 to 1831, as an assistant professor. He then accepted a position as full professor at the University of Gottingen, where he met the mathematician and physicist johann carl friedrich gauss. Their collaboration marked the beginning of Weber’s work on magnetism.

Gauss and Weber created absolute units of magnetism, defined in terms of length, mass, and time. Working on his own, Weber built highly sensitive magnetometers, as well as a 3-km telegraph to connect his physics laboratory to Gauss’s at the astronomical observatory. In Gauss’s and Weber’s hands, this first working telegraph was used for scientific, rather than commercial, purposes: to connect a network of observation stations in order to correlate measurements of terrestrial magnetism made in different parts of the world.

Political events disrupted Weber’s academic life. In 1837, when Queen Victoria came to power, her uncle became the new ruler of Hanover and promptly suspended the constitution. Weber was one of seven professors who formally protested the action, all of whom were fired. He stayed in Gottingen, pursuing his research, until he was offered a professorship in Leipzig. Under these circumstances, he branched out into the measurement of electricity, defining an electromagnetic unit for electric current that was applied to measurements of current made by the deflection of a galvanometer.

Eventually, in 1849, he regained his position in Gottingen; he would remain there until his retirement in the 1870s. His later work there focused on electrodynamics and the electrical structure of matter.

In 1855, Weber studied the ratio between the electrodynamic and electrostatic units of charge. Weber calculated this ratio as 3.1074 X 108 m/s; however, he did not understand the physical implications of the fact that this ratio was close to the speed of light. It would fall to james clerk maxwell, in creating his electromagnetic theory of light, to realize that this implied that light waves were time-dependent electromagnetic fields traveling through space at a speed equal to the ratio Weber had found.

During his later years, Weber focused on research in electrodynamics and the electrical structure of matter. After his death in Gottingen on June 23, 1891, Weber’s name was given to the standard international unit of magnetic flux density, the weber, in recognition of his pioneering work in electromagnetism.

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