John Archibald Wheeler
According to some sources, Peter Gabriel Bergmann brought Rainich's suggestion that algebraic topology (and knot theory in particular) should play a role in physics to the attention of John Archibald Wheeler, which shortly led to the Ph.D. thesis of Charles W. Misner. Another version of this tale replaces Bergmann with Hugh Everett, who was a fellow student of Misner at the time.