Discrete symmetry

For example, a square possesses discrete rotational symmetry, as only rotations by multiples of right angles will preserve the square's original appearance.Discrete symmetries sometimes involve some type of 'swapping', these swaps usually being called reflections or interchanges.It manifests itself in various elementary physical quantum systems, such as quantum harmonic oscillator, electron orbitals of Hydrogen-like atoms by forcing wavefunctions to be even or odd.This in turn gives rise to selection rules that determine which transition lines are visible in atomic absorption spectra.You can help Wikipedia by expanding it.This group theory-related article is a stub.
symmetryrotational symmetrytheoretical physicsdiscrete grouptopological groupdiscrete topologycountable setparity symmetryselection rulesabsorption spectrageometry-relatedgroup theory