If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.

If you aren't confused by quantum mechanics, you haven't really understood it.

One thought spectra are marvellous, but it is not possible to make progress there. Just as if you have the wing of a butterfly then certainly it is very regular with the colors and so on, but nobody thought one could get the basis of biology from the coloring of the wing of a butterfly.

Nothing exists until it is measured.

You must come to Copenhagen to work with us. We like people who can actually perform thought experiments!

When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections.

There is no hope for any speculation that does not look absurd at first glance.