Brian Greene

In any finite region of space, matter can only arrange itself in a finite number of configurations, just as a deck of cards can be arranged in only finitely many different orders. If you shuffle the deck infinitely many times, the card orderings must necessarily repeat.

We're on this planet for the briefest of moments in cosmic terms, and I want to spend that time thinking about what I consider the deepest questions.

In my own research when I'm working with equations, I never feel like I really understand what I'm doing if I'm solely relying on the mathematics for my understanding. I need to have a visual picture in my mind. I'm constantly translating from the math to some intuitive mind's-eye picture.

Before the discovery of quantum mechanics, the framework of physics was this: If you tell me how things are now, I can then use the laws of physics to calculate, and hence predict, how things will be later.

Most scientists like to operate in the context of economy. If you don't need an explanatory principle, don't invoke it.

I like to think that Einstein would look at string theory’s journey and smile, enjoying the theory’s remarkable geometrical features while feeling kinship with fellow travelers on the long and winding road toward unification.

The revelation we've come to is that we can trust our memories of a past with lower, not higher, entropy only if the big bang - the process, event, or happening that brought the universe into existence - started off the universe in an extraordinarily special, highly ordered state of low entropy.

We are living through a remarkably privileged era when certain deep truths about the cosmos are still within reach of the human spirit of exploration.

Assessing existence while failing to embrace the insights of modern physics would be like wrestling in the dark with an unknown opponent.