It is tribute to how far we have come in theoretical physics that it now takes enormous machines and a great deal of money to perform experiments whose results we can not predict.

I am damned if I'm going to die before I have unraveled more of the universe

What is important is that we have the ability to create.

If you understand how the universe operates, you control it in a way.

So next time someone complains that you have made a mistake, tell him that may be a good thing. Because without imperfection, neither you nor I would exist.

I don't have much positive to say about motor neuron disease, but it taught me not to pity myself because others were worse off, and to get on with what I still could do. I'm happier now than before I developed the condition.

I think the human race has no future if it doesn't go into space.