The most important single thing about string theory is that it's a highly mathematical theory, and the mathematics holds together in a very tight and consistent way. It contains in its basic structure both quantum mechanics and the theory of gravity....
There are two godheads: the world and my independent I. I am either happy or unhappy, that is all. It can be said: good or evil do not exist. A man who is happy must have no fear. Not even in the face of death. Only a man who lives not in time but in...
I am sitting with a philosopher in the garden. He says again and again, “I know that that’s a tree,” pointing to a tree that is near us. Someone else arrives and hears this, and I tell them, “This fellow isn’t insane. We are only doing phil...
I think one of the things you and I have to learn is that we have to live without the consolation of belonging to a Church.... Of one thing I am certain. The religion of the future will have to be extremely ascetic, and by that I don't mean just goin...
I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician, he is also a child place before natural phenomenon, which impress him like a fairy tale.
If our local, observable universe is embedded in a larger structure, a multiverse, then there's other places in this larger structure that have denizens in them that call their local environs the universe. And conditions in those other places could b...
All it takes is a small change in Newton's laws, or the rules of atomic physics, and poof - life would either be instantly extinguished or would never have formed. It seems that our guardian angel not only provided us with a very benign planet to liv...
No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.
Several times in Earth's history, rapid global warming occurred, apparently spurred by amplifying feedbacks. In each case, more than half of plant and animal species became extinct. New species came into being over tens and hundreds of thousands of y...
I don't want to give advice to people about their religious beliefs, but I do think that it's not smart to bet against the power of science to figure out the natural world. It used to be, a thousand years ago, that if you wanted to explain why the mo...
It's not as though we can keep burning coal in our power plants. Coal is a finite resource, too. We must find alternatives, and it's a better idea to find alternatives sooner then wait until we run out of coal, and in the meantime, put God knows how ...
Life can be less mysterious than we make it out to be when we try to think about how it would be on other planets. And if we remove the mystery of life, then I think it is a little bit easier for us to think about how we live, and how perhaps we're n...
The fact that you can remember yesterday but not tomorrow is because of entropy. The fact that you're always born young and then you grow older, and not the other way around like Benjamin Button - it's all because of entropy. So I think that entropy ...
I should be able to pick which applications I use for managing my life, I should be able to pick which content I look at, and I should be able to pick which device I use, which company I use for supplying my internet, and I'd like those to be indepen...
Technically you need the extra dimensions. At first people didn't like them too much, but they've got a big benefit, which is that the ability of string theory to describe all the elementary particles and their forces along with gravity depends on us...
I just think too many nice things have happened in string theory for it to be all wrong. Humans do not understand it very well, but I just don't believe there is a big cosmic conspiracy that created this incredible thing that has nothing to do with t...
Instead of explaining the sober facts of mechanics and electricity, I want to say a few words about the debt which we owe to youth; and with your permission I shall consider you as representing here not only the academic youth of Sweden nor even of E...
From a scientific point of view, our mission is to seek answers to the fundamental questions about the universe. Many are open - we don't know about dark matter, which accounts for a quarter of the universe's matter, nor do we know why there's antima...
We owe a huge debt to Galileo for emancipating us all from the stupid belief in an Earth-centered or man-centered (let alone God-centered) system. He quite literally taught us our place and allowed us to go on to make extraordinary advances in knowle...
To an observer situated on the moon or on one of the planets, the most noticeable feature on the surface of our globe would no doubt be the large areas covered by oceanic water. The sunlit face of the earth would appear to shine by the light diffused...
I was always looking ahead. I used to do all kinds of things for entertainment. When I was young, we had no radio, no TV. We were 30 miles from the public library, out in the sticks in Western Kansas, and so I'd do arithmetic exercises.
