Source: wikibot/lamb-shift
= Lamb shift
{wiki=Lamb_shift}
The Lamb shift is a small difference in energy levels of hydrogen-like atoms, specifically in the electron energy levels of these atoms, that is a result of quantum electrodynamics (QED) effects. More specifically, it refers to the splitting between the 2s and 2p energy levels in hydrogen, which was first observed experimentally by Willis Lamb and Robert Retherford in 1947.