Richard Feynman

If you're not confused, you're not paying attention.

It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.

I don't have to know an answer. I don't feel frightened by not knowing things, by being lost in a mysterious universe without any purpose, which is the way it really is as far as I can tell.

The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

The world looks so different after learning science. For example, trees are made of air, primarily.

You have no responsibility to live up to what other people think you ought to accomplish. I have no responsibility to be like they expect me to be. It's their mistake, not my failing.

Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle. Permit us to question—to doubt—to not be sure.

The only way to do something in a new way is to not know how it was done before.

We are at the very beginning of time for the human race. There is no limit to the possibilities of human development.

The game of science is to find out how the world works, not to find out how to make it work the way you want it to.

The great thing about science is that it's true whether or not you believe in it.

You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird. You'll only know about humans in different places and what they call the bird. So let's look at the bird and see what it's doing—that's what counts.

Why are the laws of physics what they are? I don't know. I don't think that's a good question to ask.

It is a great adventure to contemplate the universe, beyond man, to contemplate the universe as it really is.

The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

I don't believe I can really do anything useful in science unless I realize that the universe is not a computer in a box.

The real glory of science is that we can find out how it works.

You can't just say, 'I'm going to do this and that.' You have to be able to do it.

The purpose of computing is insight, not numbers.

If we are going to have a science at all, it must be based on experiment.