It's a lot easier to see, at least in some cases, what the long-term limits of the possible will be, because they depend on natural law. But it's much harder to see just what path we will follow in heading toward those limits.

An international race in the relevant technologies is getting under way at this point, not necessarily with an understanding of where that race leads in the long run, but strongly motivated by the short-term payoffs.

And that because the moving parts are a million times smaller than the ones we're familiar with, they move a million times faster, just as a smaller tuning fork produces a higher pitch than a large one.

Scientists study physical things, then describe them; engineers describe physical things, then build them.

Likewise nanotechnology will, once it gets under way, depend on the tools we have then and our ability to use them, and not on the steps that got us there.

I've encountered a lot of people who sound like critics but very few who have substantive criticisms. There is a lot of skepticism, but it seems to be more a matter of inertia than it is of people having some real reason for thinking something else.

Today we have big, crude instruments guided by intelligent surgeons, and we have little, stupid molecules of drugs that get dumped into the body, diffuse around and interfere with things as best they can. At present, medicine is unable to heal anything.