If it [the universe] was expanding fairly slowly, the force of gravity would cause it eventually to stop expanding and then to start contracting. However, if it was expanding at more than a certain critical rate, gravity would never be strong enough to stop it, and the universe would continue to expand forever.

Not only that God does play dice, but that He sometimes confuses us by throwing them where they can't be seen.

Science is not only a disciple of reason but, also, one of romance and passion.

Every man should marry. After all, happiness is not the only thing in life.

Disorder increases with time because we measure time in the direction in which disorder increases.

Life on Earth is at the ever-increasing risk of being wiped out by a disaster, such as sudden global warming, nuclear war, a genetically engineered virus or other dangers. I think the human race has no future if it doesn't go into space. I therefore want to encourage public interest in space.

Chaos, when left alone, tends to multiply.