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.

In thinking about nanotechnology today, what's most important is understanding where it leads, what nanotechnology will look like after we reach the assembler breakthrough.

Protein engineering is a technology of molecular machines - of molecular machines that are part of replicators - and so it comes from an area that already raises some of the issues that nanotechnology will raise.

I had been impressed by the fact that biological systems were based on molecular machines and that we were learning to design and build these sorts of things.

If you take all the factories in the world today, they could make all the parts necessary to build more factories like themselves. So, in a sense, we have a self-replicating industrial system today, but it would take a tremendous effort to copy what we already have.

In a sense, artificial intelligence will be the ultimate tool because it will help us build all possible tools.

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.

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.

...Local prohibitions cannot block advances in military and commercial technology... Democratic movements for local restraint can only restrain the world's democracies, not the world as a whole.

After realizing that we would eventually be able to build molecular machines that could arrange atoms to form virtually any pattern that we wanted, I saw that an awful lot of consequences followed from that.

But if we can manage it so people don't have things forced on them that they don't want, I think there's every reason to believe things can settle out in a situation that is recognizably better than the one we're stuck in today.

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