I think the next [21st] century will be the century of complexity. We have already discovered the basic laws that govern matter and understand all the normal situations. We don't know how the laws fit together, and what happens under extreme conditions. But I expect we will find a complete unified theory sometime this century. The is no limit to the complexity that we can build using those basic laws.

People won't have time for you if you are always angry or complaining.

Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity.

My expectations were reduced to zero when I was 21. Everything since then has been a bonus.

Latest survey shows that 3 out of 4 people make up 75% of the world's population.

Do you ever wonder how much deeper the ocean would be without sponges?

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