Today riches and honours have been lavished on me, but one gift has been lacking, the most important one of all, the only one that matters, the gift of youth.

In my solitude, many miles from men and houses, I am in a childishly happy and carefree state of mind, which you are incapable of understanding unless someone explains it to you.

In old age we are like a batch of letters that someone has sent. We are no longer in the past, we have arrived.

There is nothing like being left alone again, to walk peacefully with oneself in the woods. To boil one's coffee and fill one's pipe, and to think idly and slowly as one does it.

He gave us the lakes for our Northern boundary, and the rivers stretching to the seas upon whose waters floats our commerce to the nations of the world; while man has done all that can be done by science to bind us together.

I think, however, that so long as our present economic and national systems continue, scientific research has little to fear.

Today the function of the artist is to bring imagination to science and science to imagination, where they meet, in the myth.

There is good science you can do in space. There is stuff there you cannot do on Earth and we can gain understanding from it.