Gustav R. Kirchhoff (1824-1887)

Kirchhoff was a German physicist. in 1845, he worked out a set of laws called Kirchhoff's laws.
These laws made it possible to work out the amount of current flowing at any point in a network of electric conductors.
He also showed that alternating current in an electric conductor with no resistance travels at the speed of light.
With the German chemist Robert Bunsen he developed the modern spectroscope.
They used the spectroscope and a prism specially designed by Kirchhoff to analyse substances.
In 1860, they showed that when metal compounds are heated in a flame, each gives off a spectrum particular to the metal.
It was by using this technique that Kirchhoff and Bunsen discovered the elements caesium and rubidium.
From laws he developed about the emission and absorption of radiation, he suggested the concept of the black body.
This was a key step in the development of the branch of physics known as quantum mechanics.

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