Quotes from Brian Greene

I think the appropriate response for a physicist is: 'I do not find the concept of God very interesting, because I cannot test it.'

I think it's too fast to say that all sci-fi ultimately winds up having some place in science. On the other hand, imaginative minds working outside of science as storytellers certainly have come upon ideas that, with the passing decades, have either materialized of come close to materializing.

I wouldn't say that 'The Fabric of the Cosmos' is a book on cosmology. Cosmology certainly plays a big part, but the major theme is our ever-evolving understanding of space and time, and what it all means for our sense of reality.

I'd say many features of string theory don't mesh with what we observe in everyday life.

Quantum mechanics broke the mold of the previous framework, classical mechanics, by establishing that the predictions of science are necessarily probabilistic.

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.

Black holes provide theoreticians with an important theoretical laboratory to test ideas. Conditions within a black hole are so extreme, that by analyzing aspects of black holes we see space and time in an exotic environment, one that has shed important, and sometimes perplexing, new light on their fundamental nature.

Einstein's theory of relativity does a fantastic job for explaining big things. Quantum mechanics is fantastic for the other end of the spectrum - for small things.

I can assure you that no string theorist would be interested in working on string theory if it were somehow permanently beyond testability. That would no longer be doing science.

The funny thing is, I sometimes get the impression that some people outside of the field think that there's some element of security that we have in working on a theory that hasn't made any predictions that can be proven false. In a sense, we're working on something unfalsifiable.

Supersymmetry is a theory which stipulates that for every known particle there should be a partner particle. For instance, the electron should be paired with a supersymmetric 'selectron,' quarks ought to have 'squark' partners, and so on.

Falsifiability for a theory is great, but a theory can still be respectable even if it is not falsifiable, as long as it is verifiable.

The full name of string theory is really superstring theory. The 'super' stands for this feature called supersymmetry, which, without getting into any details, predicts that for every known particle in the world, there should be a partner particle, the so-called supersymmetric partner.

String theory is not the only theory that can accommodate extra dimensions, but it certainly is the one that really demands and requires it.

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.

Every moment is as real as every other. Every 'now,' when you say, 'This is the real moment,' is as real as every other 'now' - and therefore all the moments are just out there. Just as every location in space is out there, I think every moment in time is out there, too.

Oftentimes, if you're talking to a seasoned interviewer who asks you a question, they may do a follow-up if they didn't quite get it. It's rare that they'll do a third or fourth or fifth or sixth follow-up, because there's an implicit, agreed-upon decorum that they move on. Kids don't necessarily move on if they don't get it.

By dimension, we simply mean an independent direction in which, in principle, you can move; in which motion can take place. In an everyday world, we have left-right as one dimension; we have back-forth as a second one; and we have up-down as a third.

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.

I enjoy reading blogs, but am not interested in having my spurious thoughts out there.

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.

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

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

My mom says: 'Why aren't you a doctor?' and I'm like, 'I am a doctor!' and she's all, 'No, I mean a real doctor.' She reads my books, but she says they give her a headache.