In addition to formulating laws of electrical currents and thermal radiation, Gustav Kirchhoff developed a spectroscope with Robert Bunsen, and the pair pioneered the field of analytical spectroscopy the study of the emission and absorption of light and other radiation by matter in terms of their relationship to the wavelength of the radiation. Prior to that time, other scientists had postulated that each element had a unique spectrum, but impurities in their samples impeded the discovery since they resulted in the appearance of multiple spectra simultaneously.
Equipped with this knowledge, Kirchhoff and Bunsen discovered the elements cesium and rubidium, analyzed the chemical composition of the sun, and explained the dark lines in the solar spectrum generally referred to as Fraunhofer lines, an achievement often considered an important turning point in astronomical studies. Visit the Molecular Expressions Website. Photo Gallery. Silicon Zoo. Chip Shots. Screen Savers. Web Resources. Java Microscopy.
Win Wallpaper. University professors were civil servants in Prussia at this time and so to be a university professor, Gustav's parents believed, represented the right position where someone of high academic abilities could serve Prussia. Given Gustav's academic abilities at school, his future career followed naturally. Kirchhoff attended the Neumann - Jacobi seminar from to Now was the year in which Jacobi became unwell, so it was Neumann who influenced Kirchhoff in a very positive way. In fact Neumann published the first of his two major papers on electrical induction in while Kirchhoff was studying with him.
It was while he was studying with Neumann that Kirchhoff made his first outstanding research contribution which related to electrical currents. Kirchhoff's laws, which he announced in , allowed calculation of currents, voltages and resistances in electrical circuits with multiple loops, extending the work of Ohm.
Kirchhoff considered an electrical network consisting of circuits joined at nodes of the network and gave laws which reduce the calculation of the currents in each loop to the solution of algebraic equations. The first law states that the sum of the currents into a given node equals the sum of the currents out of that node. The second law states that the sum of electromotive forces in a loop in the network equals the sum of potential drops, or voltages across each of the resistances, in the loop.
Kirchhoff's laws followed from applying Ohm 's law but the way in which he was able to generalise the results showed great mathematical skills. At this stage Kirchhoff was unaware that Ohm 's analogy between the flow of heat and the flow of electricity, which formed the accepted understanding of electrical currents at that time, led to an incorrect understanding of electrical currents. Since no heat flowed in a body at a uniform temperature, it was believed that a static current could exist in a conductor.
Kirchhoff's work would, a couple of years later, lead to him to realise this error and to give a correct understanding of how the theory of electric currents and electrostatics should be combined. The year was an eventful one for Kirchhoff. Unemployment and crop failures had led to discontent and disturbances, and trouble was sparked by the news that Louis-Philippe had been overthrown by an uprising in Paris in February There were revolutions in many German states and fighting in Berlin.
Republican and socialist feelings meant that the monarchy was in trouble, but Kirchhoff was in a privileged position and was unaffected by events around him as he pressed forward with his career.
He taught at Berlin in an unpaid post from to , and it was while he was working in Berlin that he corrected the accepted understanding of electric currents and electrostatics which we referred to above. He left Berlin for Breslau in when he was appointed as extraordinary professor there. In the year that he arrived in Breslau, Kirchhoff solved a problem concerning the deformation of elastic plates.
Because atoms and molecules produce their own unique spectra, these laws allow for the identification of atoms and molecules found in the object being studied. This law states that the emissivity ability to emit energy as radiation and absorbance ability to absorb radiation of an object or surface are equal at any wavelength and temperature, if the object or surface is at static thermal equilibrium. In , he became an associate professor at Breslau University and in a professor of physics at Heidelberg University.
In the s, Kirchhoff and Bunsen showed that each element could be identified with a unique spectral pattern , establishing that spectroscopy could be used to experimentally analyze the elements. The pair would discover the elements cesium and rubidium while investigating the elements in the sun using spectroscopy. In addition to his work in spectroscopy, Kirchhoff would also study blackbody radiation, coining the term in His work is considered fundamental to the development of quantum mechanics.
In , Kirchhoff became the chair of mathematical physics at Berlin. He later retired in Kirchhoff died on October 17, in Berlin, Germany at the age of He is remembered for his contributions to the field of physics as well as his influential teaching career.
His Kirchhoff's laws for electrical circuits are now taught as part of introductory physics courses on electromagnetism. Actively scan device characteristics for identification.
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