To tell you the truth, I've never met anybody who can envision more than three dimensions. There are some who claim they can, and maybe they can; it's hard to say.

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

The idea that there could be other universes out there is really one that stretches the mind in a great way.

When kids look up to great scientists the way they do to great musicians and actors, civilization will jump to the next level

The tantalizing discomfort of perplexity is what inspires otherwise ordinary men and women to extraordinary feats of ingenuity and creativity; nothing quite focuses the mind like dissonant details awaiting harmonious resolution.

There's a picture of my dorm room in the college yearbook as the most messy, most disgusting room on the Harvard campus, where I was an undergraduate.

Most people don’t question the practice of eating meat. Many of these people care about animals and the environment, some deeply. But for some reason-force of habit, cultural norms, resistance to change-there is a fundamental disconnect whereby these feelings don’t translate into changes of behavior.