Wilhelm Weber (1804-1891)
Wilhelm Weber was born on October 24, 1804, in Wittenberg, Germany. He was one of 12 children and along with his brothers, Ernst Heinrich Weber and Eduard Friedrich Weber, was adept at scientific study. At various points in his life Wilhelm Weber would carry out collaborative research with his brothers, culminating in a large work on wave theory published in 1825 with Ernst and a treatise on the mechanics of walking co-written with Eduard in 1833. Their father was a theology professor, first at the University of Wittenberg, and then, after 1815, at the University of Halle. Wilhelm Weber received his earliest education from his father, but then attended a grammar school in Halle before entering the university there in 1822. He was a distinguished student of natural philosophy, and after obtaining his doctorate in 1826, he received an appointment as a professor at his alma mater.
In addition to wave theory, Weber was very interested in the phenomena of electricity and magnetism. His interest in these areas he held in common with Carl Friedrich Gauss, with whom he forged a very fruitful association when he accepted a professorship at the University of Göttingen in 1831. The pair built one of the world’s first working electrical telegraphs in 1833, the line of which stretched nearly a mile between Weber’s physics laboratory and the astronomical observatory where Gauss spent most of his time. The galvanometer, a device that Weber would later significantly improve, served as the telegraph’s receiver. Together Weber and Gauss also embarked on the study of terrestrial magnetism, coordinating measurement efforts at magnetic surveying stations around the globe and correlating their results.
Over the course of his investigations on magnetism with Gauss, Weber developed and enhanced a variety of devices for sensitively detecting and measuring magnetic fields and electrical currents. Included among these devices was the electrodynamometer, which was capable of measuring electric current, voltage or power through the interaction of the magnetic fields of two coils. Using this device, Weber experimentally validated André-Marie Ampère’s force law, but due to his sudden dismissal from the University of Göttingen in 1837 on political grounds, the publication of this research was delayed. When it finally appeared in 1846, it was accompanied by Weber’s generalized electrical law, which essentially integrated Ampère’s law with the laws of induction and the Coulomb-Poisson law.
Accurate measurements were very important to both Weber and Gauss, who realized they were crucial for verifying and developing physical laws. Both scientists would contribute much towards making such measurements possible and establishing units and definitions that could be used to consistently express concepts encountered in the study of electricity and magnetism. Gauss developed a system of magnetic units expressed in terms of length, mass and time in the early 1830s, and Weber began developing a similar system of electric units around 1840. When an official Committee on Electrical Standards was formed by the British Association for the Advancement of Science in the early 1860s, the group adopted the systems created by Gauss and Weber as the foundation to which they added new units and definitions as necessitated by ongoing developments in the field.
After his dismissal from Göttingen, Weber journeyed to England for a time. But for the most part he remained in Germany without an appointment until 1843, when he became a professor of physics at the University of Leipzig. Six years later he returned to Göttingen, where his previous academic position was restored to him. In 1855, he was temporarily installed as director of the university’s astronomical laboratory, but his main endeavors continued to be in the fields of electricity and magnetism. His work on the ratio between the electrodynamic and electrostatic units of charge, which Weber’s calculations indicated was approximately the speed of light, would later become extremely important for James Clerk Maxwell’s electromagnetic theory. In his later years, Weber also delved into the electrical structure of matter. His studies led him to speculate that atoms contain positive charges around which negative particles rotate, and that applying a voltage to a conductor results in the movement of the negative particles between atoms.
Weber’s achievements in science were recognized around the world, and he received honorary titles and awards in several countries. When he died on June 23, 1891, in Göttingen, he was 86 years old and had lived a very successful life. His name is used as a unit of magnetic flux (the weber) as a tribute to him.