Lamb and Retherford measure a small energy separation between two atomic orbitals of hydrogen that wasn’t predicted by Dirac’s theory. Bethe attributes this “Lamb shift” to interactions between the atom’s electrons and vacuum fluctuations. Within months, he describes the effect with a new “renormalization” approach that lays the foundation for quantum electrodynamics.
What is Lamb Shift:
In physics, the Lamb shift, named after Willis Lamb, is a difference in energy between two energy levels 2S1/2 and 2P1/2 (in term symbol notation) of the hydrogen atom which was not predicted by the Dirac equation, according to which these states should have the same energy.
And what is quantum electrodynamics:
