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.

We see an entire planet which has many limitations.

Nanotechnology is an idea that most people simply didn't believe.

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.

Because of technological limits, there is a certain amount of food that we can produce per acre. If we were to have intensive greenhouse agriculture, we could have much higher production.

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

One of the concepts essential to molecular manufacturing is that of a self-replicating manufacturing system. That concept has lagged behind in its acceptance.