Brian Greene

The bottom line is that time travel is allowed by the laws of physics. ”

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. ”

Even when I wasn't doing much 'science for the public' stuff, I found that four or five hours of intense work in physics was all my brain could take on a given day. ”

Writing for the stage is different from writing for a book. You want to write in a way that an actor has material to work with, writing in the first person not the third person, and pulling out the dramatic elements in a bigger way for a stage presentation. ”

The math of quantum mechanics and the math of general relativity, when they confront one another, they are ferocious antagonists and the equations don't work. ”

When you drive your car, E = mc2 is at work. As the engine burns gasoline to produce energy in the form of motion, it does so by converting some of the gasoline's mass into energy, in accord with Einstein's formula. ”

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

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. ”

Science is a self-correcting discipline that can, in subsequent generations, show that previous ideas were not correct. ”

Very much, string theory is simply a work in progress. What we are inching toward every day are predictions that within the realm of current technology we hope to test. It's not like we're working on a theory that is permanently beyond experiment. That would be philosophy. ”