Zeeman Effect
The splitting of atomic spectral lines into multiple closely spaced components in the presence of an external static magnetic field.
Governing formula
ΔE = g_L μ_B m_j B
SI unit
eV (Energy Shift)
In depth
An external magnetic field interacts with the atom's orbital and spin magnetic dipole moments, removing energy level degeneracy. In the normal Zeeman effect, lines split into triplets; the anomalous Zeeman effect includes electron spin contributions.
Examples in the real world
Solar astronomers measuring Zeeman splitting in sunspot spectral lines to calculate solar magnetic field strengths.