When you buy a jacket, you pick the size to ensure it fits. Similarly, we live in a universe in which the amount of dark energy fits our biological make-up. If the amount of dark energy were substantially different from what we've measured, the environmental conditions would be inhospitable to our form of life.

Far from being accidental details, the properties of nature's basic building blocks are deeply entwined with the fabric of space and time.

I've had various experiences where I've been called by Hollywood studios to look at a script or comment on various scientific ideas that they're trying to inject into a story.

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.

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.

But, as Einstein once said, “For we convinced physicists, the distinction between past, present, and future is only an illusion, however persistent.”5

Physics grapples with the largest questions the universe presents. Where did the totality of reality come from? Did time have a beginning?