The Stephen Hawking I Knew

Most of us spend most of our lives without any sense of the imminence of our mortality. This wasn't true for Stephen Hawking. He was diagnosed with amyotrophic lateral sclerosis at age 21 and given months to live. Whenever somebody uses the expression "delaying the inevitable" in my presence, I always reply, "Why yes, I woke up this morning alive." I know someday that won't happen; none of us lives forever, so all of life is about delaying the inevitable. On Wednesday, this caught up with Stephen Hawking -- but not before he had managed to delay the inevitable by more than 50 years, a time he spent exploring the universe, with the sword of Damocles dangling above him at every moment.

I was a postdoctoral researcher with Stephen in 1983. The work I did with him focused on trying to solve fundamental questions. What are space and time? Where did the universe come from? How does quantum mechanics, which can be demonstrated in a candle flame, interact with gravity, which binds that candle to Earth? The work was fascinating, and while my later career took me far afield from these basic questions, the spirit of that inquiry stayed with me.