In appreciation of Joshua Goldberg (1925 -- 2020)

Joshua Goldberg was a seminal contributor to relativity theory, both through his own original work and his function as an administrator of US Air Force research funding. He is perhaps best known for his work on algebraically special solutions of Einstein's equations, yet he also helped pave the way to our understanding of the generation and propagation of gravitational waves. He was in addition a leader in the exploration of the use of null surfaces and the description of asymptotic fields. I will give a brief overview of this work, frequently citing Josh's own comments in a series of interviews I recorded with him.