sentences:  In 1932 Dennison and Uhlenbeck solved the two-minima "reversing umbrella" problem for the position of nitrogen in ammonia.This result predicted absorption at microwave wavelengths, which inspired Neal Williams to build a molecular microwave spectrograph, one of the first ever built.During World War 2 Dennison received a citation from the US Navy for his work with the VT radio proximity fuse.