Complex sentence: He was a graduate student of Willis Lamb at Columbia Radiation Laboratory and both performed the famous experiment revealing Lamb shift in the fine structure of hydrogen, a decisive experimental step toward a new understanding of quantum electrodynamics.
Split into simpler sentences: He was a graduate student of Willis Lamb at Columbia Radiation Laboratory. Retherford and Lamb performed the famous experiment revealing Lamb shift in the fine structure of hydrogen, a decisive experimental step toward a new understanding of quantum electrodynamics.