Complex sentence: In 1949, he conducted research at Cornell University with Hans Bethe, where he also met Richard Feynman, which awoke his interest in the divergence problems of classical electrodynamics, for which he later became a leading expert.
Split into simpler sentences: In 1949, he conducted research at Cornell University with Hans Bethe. There he also met Richard Feynman, which revived his interest in the divergence problems of classical electrodynamics, for which he later became a leading expert.