Wilhelm Weber helped build the first electromagnetic telegraph and give light its letter c
In 1833 two Göttingen scientists strung a wire between an observatory and a physics lab and sent signals along it electrically. One was Carl Friedrich Gauss; the other was Wilhelm Weber, a physicist whose measurements later hinted that light is electromagnetic. The unit of magnetic flux, the weber, carries his name.
Weber was born in Wittenberg on 24 October 1804, the son of a theology professor, and was the middle of three brothers who all showed a gift for science. When Wittenberg's university was dissolved in 1817 the family moved to Halle, where he studied natural philosophy and rose quickly to a professorship. While still around twenty he co-wrote a well-received book on wave theory with his brother Ernst Heinrich, an anatomist, and later studied the mechanics of human walking with his younger brother Eduard.
Gauss recommended him to Göttingen, which hired him as professor of physics in 1831, when he was twenty-seven. Unusually for the time, he believed lectures were not enough and let students run their own experiments in the college laboratory at no cost. Two years later he and Gauss built their telegraph. They also worked together on magnetism, producing an atlas of geomagnetic maps, and Weber's efforts did much to establish magnetic observatories.
Politics interrupted. In December 1837 the government of Hanover dismissed him as one of the Göttingen Seven. He travelled, including to England, taught at Leipzig from 1843, and returned to Göttingen in 1849. In 1864 he published a system of absolute measurement for electric currents that became the basis of units still used.
His most far-reaching result came in 1855. With Rudolf Kohlrausch he showed that the ratio between electrostatic and electromagnetic units matched the speed of light, a clue that fed James Clerk Maxwell's idea that light is an electromagnetic wave. A paper by the pair in 1856 was the first to use the letter c for that speed. Weber died in 1891 and lies in the same Göttingen cemetery as Max Planck and Max Born.
Source: Wilhelm Eduard Weber
