Fundamental physics is like an art more or less. It's completely non-practical, and you can't use it for anything. But it's about the universe and how the world came into being. It's very remote from your daily life and mine, and yet it defines us as human beings.

Facebook can be an accumulation of different intelligences.

Facebook now is mostly about people you know. In the future it could be about people you know less but are more important.

I must analyze, from what I do now, what will be the impact two or three or five years in the future. What is the statement I want to make?

It is hard to think of practical applications of the black hole. Because practical applications are so remote, many people assume we should not be interested. But this quest to understand the world is what defines us as human beings.

Big Internet companies on average are capable of generating revenue of $1 million per employee, and that compares to 10 to 20 percent of that which is normally generated by traditional offline businesses of comparable size.

It’s not about revenues: the fundamental economics in digital business is scale and margins. The top line has become the bottom line.