Hendrik Antoon Lorentz (18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the transformation equations subsequently used by Albert Einstein to describe space and time.
Zeeman Effect - The Zeeman Effect refers to the splitting of the visible spectrum via magnets. This is only part of the exhibit; you had to look through a special lens to see the effect. On display at the Exploratorium in San Francisco, California.