If you think the technology is infeasible, you don't worry about what it might do and what its potential is.

One of the things that we can say with confidence is that we will have much lighter, much stronger materials, and this will reduce the cost of air flight, and it will reduce the cost of rockets.

We see an entire planet which has many limitations.

Machines built by human beings they will function correctly if we provide them with a very specific environment. But if that environment is changed they won't function at all.

Today we see a human population of over 6 billion people, many of whom have serious medical conditions, which either can't be treated or cannot be treated economically.

Disease and ill health are caused largely by damage at the molecular and cellular level, yet todays surgical tools are too large to deal with that kind of problem.

There are certain things that are inherently scarce. For example, there is only a certain amount of beachfront property in California. It is going to be scarce, it is going to be expensive.