George Field, brilliant theoretical astrophysicist and truly great human being, passed away on the morning of July 31. He was my Ph.D. thesis advisor and one of my favorite people in the world. I often tell my own students that the two most important people in your life who you will (consensually) choose are your spouse and your Ph.D. advisor. With George, I got incredibly lucky.

I am not the person to recount George’s many accomplishments as a scientist and a scientific citizen. He was a...