Zeeman, Pieter, << ZAY mahn, PEE tuhr >> (1865-1943), a Dutch physicist, became known for his discoveries in spectroscopy, the study and analysis of spectra of light. In 1896, he discovered what is now called the Zeeman effect, the splitting of spectral lines by a magnetic field. The theory for this phenomenon was developed by Hendrik A. Lorentz, and Lorentz and Zeeman shared the 1902 Nobel Prize in physics for their work. Through the Zeeman effect, astronomers measure the strength of the magnetic field on the surface of stars. Zeeman was born on May 25, 1865, in Zonnemaire, in Zeeland, the Netherlands. He died on Oct. 9, 1943.
