"We can certainly go further than cats, but why should it be that our brains are somehow so suited to the universe that our brains will be able to understand the deepest workings?"

"How can a speck of a universe be physically identical to the great expanse we view in the heavens above?"

"Physicists are more like avant-garde composers, willing to bend traditional rules... Mathematicians are more like classical composers."

"Sometimes attaining the deepest familiarity with a question is our best substitute for actually having the answer."

"No matter how hard you try to teach your cat general relativity, you're going to fail."

"I have long thought that anyone who does not regularly - or ever - gaze up and see the wonder and glory of a dark night sky filled with countless stars loses a sense of their fundamental connectedness to the universe."

"The boldness of asking deep questions may require unforeseen flexibility if we are to accept the answers."

"If the theory turns out to be right, that will be tremendously thick and tasty icing on the cake."

"A unified theory would put us at the doorstep of a vast universe of things that we could finally explore with precision."