Stephen Hawking

When you pursue a “theory of everything” that would answer every outstanding question in physics, you’ve effectively declared war on the notion of limits. That was the brilliance of Stephen Hawking.

His physical limitations led him to mental flights of fancy, the daring theorizing that resulted in his greatest achievements—like his proposition that the gravitational sinks known as black holes do in fact emit radiation.

Hawking told people at one lecture that they too could escape from whatever black hole they were in—“There’s a way out,” he said—an example of the humanizing touch that endeared him to so many. He had the grace to make complicated topics understandable and the humility to question his own fame, shunning comparisons to the likes of Einstein.

One never knew what Hawking might do next, or where he would pop up. He flew on a jet capable of producing zero gravity so he could experience the phenomenon of weightlessness. He visited Antarctica and Easter Island. He met presidents and prime ministers. He counted among his heroes Einstein, Galileo, Darwin, and Marilyn Monroe. And when one interviewer asked him what he most thought about, the twice married-and-divorced Hawking said, “Women. They are a complete mystery.”

Hawking challenged admirers with his fierce atheism, delighted them with a puckish sense of humor that landed him on TV shows like The

Simpsons, and stirred them with a call for space exploration as a matter of practicality—humans would need another home in the event of nuclear war or global contagion.

In the end, Stephen Hawking died on Einstein’s birthday. Imagine that.