For 10 points, name this energy difference first detected in the 2s one-half and 2p one-half levels of hydrogen.
A deceleration lens system and cesium neutralization oven are components of a polarimeter built at KVI based on and named for this phenomenon. It was discovered by its namesake along with Robert Retherford in an experiment that utilized the Zeeman effect and exposed atoms to microwave radiation. Feynman stated it could be obtained from changes in zero-point energy, and it leads to the electron g-factor being slightly larger than two. Able to be explained by QED, it is caused by the self interaction of an electron, and it was calculated by Hans Bethe to be approximately 1062 megahertz. For 10 points, name this energy difference first detected in the 2s one-half and 2p one-half levels of hydrogen.
A deceleration lens system and cesium neutralization oven are components of a polarimeter built at KVI based on and named for this phenomenon.
{Lamb shift}