The doctor who diagnosed me with ALS, or motor neuron disease, told me that it would kill me in two or three years.

Chaos, when left alone, tends to multiply.

Some individuals are better able than others to draw the right conclusions about the world about them and act accordingly. These individuals will be more likely to survive and reproduce so their pattern of behaviour and thought will become dominant

There is a very real danger that we will kill everything on this planet now that we have the technological power to do so.

If I have questions about the universe on my mind when I go to bed, I can't turn off. I dream equations all night.

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.

The large-scale homogeneity of the universe makes it very difficult to believe that the structure of the universe is determined by anything so peripheral as some complicated molecular structure on a minor planet orbiting a very average star in the outer suburbs of a fairly typical galaxy.