John Kerr

Biography of John Kerr

John Kerr (1824-1907) was an alumus of the University who is associated with two important discoveries concerning the nature of light.

Born in Ardrossan in Ayrshire, he attended the University between 1841 and 1849, from 1846 taking classes with Professor William Thomson, later Lord Kelvin. He is noted as one of the first students to work with Thomson in his new physical laboratory.

An ordained minister of the Free Church, Kerr made his career teaching mathematics at the Free Church Training College in Glasgow - a post he held from 1857 to 1901.

In 1875 his discovery that the refractive index of materials changes in response to an electric field was received with great excitement. The effect became known as the Kerr Effect. The following year he discovered that the light reflected from a magnetized material has a slightly rotated plane of polarization. His early experiments, now known as Kerr Cells, are preserved in the University's Hunterian Museum. His work was used in early television apparatus as a means of modulating beams of light.

In 1868 the University awarded him the honorary degree of LLD. He was elected FRS in 1890 and received the society's royal medal in 1898. Kerr died at Glasgow on 15 August 1907.


John Kerr
Mathematician and Physicist

Born 17 December 1824, Ardrossan, Scotland.
Died 15 August 1907.
University Link: Graduate, Honorary Graduate
GU Degrees: MA, 1849; LLD, 1868;
Occupation categories: mathematicians; physicists
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Record last updated: 21st Jul 2009

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