Spectral Magnetism—The Zeeman Effect

Abstract

As kids we all played with magnets; these pieces of metal show more dramatically than anything just how a force can act across empty space. We probably all played with a compass too and perhaps like the young Albert Einstein were mystified as to how the needle kept pointing in the same direction no matter which way we turned the compass. Magnetic fields are produced by electric currents or flows of electric charge; the outer or optically active electrons in an atomconstitute tiny electric currents which generate tiny magnetic fields. If a population of these atoms find themselves in an external magnetic field their tiny magnetic fields respond to produce a wonderful phenomenon called the Zeeman effect in honour of the Dutch physicist Pieter Zeeman.