Science is very good at answering the 'how' questions. 'How did the universe evolve to the form that we see?' But it is woefully inadequate in addressing the 'why' questions. 'Why is there a universe at all?' These are the meaning questions, which many people think religion is particularly good at dealing with.

The universe is incredibly wondrous, incredibly beautiful, and it fills me with a sense that there is some underlying explanation that we have yet to fully understand. If someone wants to place the word 'God' on those collections of words, it's OK with me.

It's hard to teach passionately about something that you don't have a passion for.

I think the relationship between memory and time is a very deep and tricky one, to tell you the truth. I don't consider memory another sense. I do consider memory that which allows us to think that time flows.

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.

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

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.

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.

Over the centuries, monumental upheavals in science have emerged time and again from following the leads set out by mathematics.

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.

Many different planets are many different distances from their host star; we find ourselves at this distance because if we were closer or farther away, the temperature would be hotter or colder, eliminating liquid water, an essential ingredient for our survival.

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.

String theory is the most developed theory with the capacity to unite general relativity and quantum mechanics in a consistent manner. I do believe the universe is consistent, and therefore I do believe that general relativity and quantum mechanics should be put together in a manner that makes sense.

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.

The number of e-mails and letters that I get from choreographers, from sculptors, from composers who are being inspired by science is huge.

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.

The absolute worst thing that you ever can do, in my opinion, in bringing science to the general public, is be condescending or judgmental. It is so opposite to the way science needs to be brought forth.

Art makes us human, music makes us human, and I deeply feel that science makes us human.

The fact that I don't have any particular need for religion doesn't mean that I have a need to cast religion aside the way some of my colleagues do.

For me it's been very exciting to contribute to the public's understanding of how rich and wondrous science is.

When we benefit from CT scanners, M.R.I. devices, pacemakers and arterial stents, we can immediately appreciate how science affects the quality of our lives.

Science is a way of life. Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that's precise, predictive and reliable - a transformation, for those lucky enough to experience it, that is empowering and emotional.

As every parent knows, children begin life as uninhibited, unabashed explorers of the unknown. From the time we can walk and talk, we want to know what things are and how they work - we begin life as little scientists.

Science is the greatest of all adventure stories, one that's been unfolding for thousands of years as we have sought to understand ourselves and our surroundings.

My view is that you don't tell the universe what to do. The universe is how it is, and it's our job to figure it out.

When general relativity was first put forward in 1915, the math was very unfamiliar to most physicists. Now we teach general relativity to advanced high school students.

One of the wonders of science is that it is completely universal. It crosses national boundaries with total ease.

Relativity challenges your basic intuitions that you've built up from everyday experience. It says your experience of time is not what you think it is, that time is malleable. Your experience of space is not what you think it is; it can stretch and shrink.

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.

For most people, the major hurdle in grasping modern insights into the nature of the universe is that these developments are usually phrased using mathematics.

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.

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.

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.

I like 'The Simpsons' quite a lot. I love the irreverent character of the whole show. It's great.

The main challenge that television presents is that I have a tendency to say things with a great deal of precision and accuracy. Often a description of that sort, which will work in a book because people can read it slowly - they can turn the pages back and so on - doesn't really work on TV because it interrupts the flow of the moving image.

I love it when real science finds a home in a fictional setting, where you take some real core idea of science and weave it through a fictional narrative in order to bring it to life, the way stories can. That's my favorite thing.

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.

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.

There may be many Big Bangs that happened at various and far-flung locations, each creating its own swelling, spatial expanse, each creating a universe - our universe being the result of only one of those Big Bangs.

I can't stand clutter. I can't stand piles of stuff. And whenever I see it, I basically just throw the stuff away.

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.

I think math is a hugely creative field, because there are some very well-defined operations that you have to work within. You are, in a sense, straightjacketed by the rules of the mathematics. But within that constrained environment, it's up to you what you do with the symbols.

The central idea of string theory is quite straightforward. If you examine any piece of matter ever more finely, at first you'll find molecules, atoms, sub-atomic particles. Probe the smaller particles, you'll find something else, a tiny vibrating filament of energy, a little tiny vibrating string.

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.

I've seen children's eyes light up when I tell them about black holes and the Big Bang.

I believe we owe our young an education that captures the exhilarating drama of science.

I believe the process of going from confusion to understanding is a precious, even emotional, experience that can be the foundation of self-confidence.

Nature's patterns sometimes reflect two intertwined features: fundamental physical laws and environmental influences. It's nature's version of nature versus nurture.

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.