"For all our everyday experience, the geometry of space is smooth and flat. But as we examine it more closely, it must show oscillations. And still more closely, it must show foam, a foam-like structure. And that means that down at the very smallest distances, this idea of before and after really lose their meaning."

“I had the good fortune of having my first and only heart attack last January ... I call it good fortune because it taught me that there's a limited amount of time left and I better concentrate on one thing: How come existence? How come the quantum? Maybe those questions sound too philosophical, but maybe philosophy is too important to be left to the philosophers.”

“Today I think we are beginning to suspect that man is not a tiny cog that doesn’t really make much difference to the running of the huge machine, but rather that there is a much more intimate tie between man and the universe than we heretofore suspected…The physical world is in some deep sense tied to the human being.”

“The question is—what is the question?”

“The best way to learn something is to have to teach it.”

“We are participators in bringing into being not only the near and here but the far away and long ago. We are in this sense, participators in bringing about something of the universe in the distant past and if we have one explanation for what's happening in the distant past why should we need more?”

“Of all obstacles to a thoroughly penetrating account of existence, none looms up more dismayingly than “time.” Explain time? Not without explaining existence. Explain existence? Not without explaining time. To uncover the deep and hidden connection between time and existence, to close on itself our quartet of questions, is a task for the future.”