Question:

And what if these high-powered experiments with atom smashers and bubble chambers do show that the world is made of quarks? Will we ever be able to see them in a practical way?

Feynman:

Well, for the problem of understanding the hadrons and the muons and so on, I can see at the present no practical applications at all, or virtually none. In the past many people have said that they could see no applications and then later they found applications. Many people would promise under those circumstances that something's bound to be useful. However, to be honest - I mean he looks foolish; saying there will never be anything is obviously a foolish thing to do. So I'm going to be foolish and say these damn things will never have any application, as far as I can tell. I'm too dumb to see it. All right? So why do you do it? Applications aren't the only thing in the world. It's interesting in understanding what the world is made of. It's the same interest, the curiosity of man that make him build telescopes, What is the use of discovering the age of the universe? Or what are these quasars that are exploding at long distances? I mean what's the use of all that astronomy? There isn't any. Nonetheless it's interesting. So it's the same kind of exploration of our world that I'm following and it's curiosity that I'm satisfying. If human curiosity represents a need, the attempt to satisfy curiosity, then this is practical in the sense that it is that. That's the way I would look at it at the present time. I would not put out any promise that it would be practical in some economic sense.