HENDRIK ANTOON LORENTZ (1874)

Joint winner with Pieter Zeeman also of The Netherlands of the 1902 Nobel Prize for Physis for his theory of electromagnetic radiation which confirmed by findings of Zeeman gave rise to the Special Theory of Relativity of Albert Einstein.

Lorentz was appointed professor of mathematical physics at Leiden University in 1878. In his doctoral thesis (1875) he refined the electromagnetic theory of James C. Maxwell of England so that it more satisfactorily explained the reflection and refraction (bending) of light.

Although his work in physics was wide in scope, it appears that his central aim was to construct a single theory to explain the relationship of electricity, magnetism and light. Althoug according to Maxwell´s theory, electromagnetic radiation is produced by the oscillation of electric charges, the charges that produce light were unknown. Since it was generally believed that an electric current was made up of charged particles. Lorentz later theorized that the atoms of matter might also consists of charged particles and suggested that the oscillations of these charged particles inside the atom was the source of light. If this were true, then a strong magnetic field ought to have an effect on the oscillations and therefore onn the wavelength of the light thus produced.

In 1896 Zeeman a pupil of Lorentz demonstrated this phenomenon known as the Zeeman effect and in 1902 they were awarded the Nobel Prize for their efforts.

Lorentz electron theory was not successful in explaining the negative results of the Michelson-Morley experiment, an effort to measure the velocity of the Earth through space by comparing the velocities of light from different directions. In an attempt to overcome this difficulty he introduced in 1895 the idea of local time (different time rates in different locations).

Influenced by the proposal of George F. FitzGerald of England that moving bodies approaching the velocity of light contract in the direction of motion Lorentz extended his idea in 1904 and arrived at the Lorentz transformations.

These transformations are mathematical formulas that describe the increase of mass, shortening of length and dilation of time that are characteristic of a moving body and form the basis of Albert Einstein´s special theory of relativity.

In 1912 Lorentz became director of research at the Teyler Institute, Haarlem, though he remained honorary professor at Leiden where he gave weekly lectures.