Noun
Zeeman effect (plural Zeeman effects)
(physics) The splitting of single spectral lines into three (or more) in the presence of a magnetic field.
Observations using the Zeeman effect show that prototypical sunspots come in pairs with opposite magnetic polarity. Source: Internet
These two successes, and the continuing failure of the Bohr-Sommerfeld model to explain the outstanding problem of the anomalous Zeeman effect, led Heisenberg to use the virtual oscillator model to try to calculate spectral frequencies. Source: Internet