Yes, there was a particular event that played a significant role in Richard Feynman's breakthrough in quantum electrodynamics (QED) theory. The event was a conference held in Pocono Manor, Pennsylvania in 1948, known as the "Pocono Conference" or the "Shelter Island Conference."
During the conference, Feynman presented his new approach to understanding quantum electrodynamics, which later became known as Feynman diagrams. These diagrams provided a visual representation of particle interactions in terms of space and time. Feynman's diagrams allowed for a more intuitive and calculable way to describe and calculate quantum processes.
Feynman's presentation and his diagrams received a mixed response from the other participants, including prominent physicists such as Julian Schwinger and Sin-Itiro Tomonaga, who were working on their own versions of QED. However, Feynman's approach ultimately proved to be revolutionary and became widely accepted.
Feynman's breakthrough in QED theory, aided by the development of Feynman diagrams, significantly contributed to his later achievements and recognition, including his Nobel Prize in Physics in 1965, which he shared with Schwinger and Tomonaga for their independent work on quantum electrodynamics.