This quantum number can take non-negative integer values. The following figure illustrates the Zeeman effect. Thus, a single transition is split into 3 transitions by the magnetic field in this example. The Zeeman effect can be interpreted in terms of the precession of the orbital angular momentum vector in the magnetic field, similar to the precession of the axis of a spinning top in a gravitational field. The lines corresponding to Zeeman splitting also exhibit polarization effects .
Polarization has to do with the direction in which the electromagnetic fields are vibrating.
This in turn, can have an effect on whether the spectral light can be observed. For example, polarizing sunglasses are often effective in suppressing ambiant glare because light reflected from surfaces has a particular polarization and polarizing sunglasses are designed to not pass that polarization of light. One practical example in astronomy of such polarization effects is that in the preceding example the middle transition is polarized such that it cannot be easily be obverved from directly over a surface perpendicular to the magnetic field.