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.

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.

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.

My work at MIT had focused on what we could build in space once we had inexpensive space transportation and industrial facilities in orbit. And this led to various sorts of work in space development.

The other advantage is that in conventional manufacturing processes, it takes a long time for a factory to produce an amount of product equal to its own weight. With molecular machines, the time required would be something more like a minute.

Any powerful technology can be abused.

But while doing that I’d been following a variety of fields in science and technology, including the work in molecular biology, genetic engineering, and so forth.

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.

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.

You can find academic and industrial groups doing some relevant work, but there isn’t a focus on building complex molecular systems. In that respect, Japan is first, Europe is second, and we’re third.

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.

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.

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.

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.

The really big difference is that what you make with a molecular machine can be completely precise, down to the tiniest degree of detail that can exist in the world.

The moral of the story: When considering an engineering problem, beware of letting related unknowns distract attention from well-understood solutions.

The Agricultural Revolution dates from prehistory, while the Industrial Revolution began to gain steam not long before yesterday. A single lifetime, however, is enough to span the whole of the Information Revolution, from its barest beginnings with racks of vacuum tubes to its role in today’s unfathomable acceleration of global change.

Within the microblock-size range, larger blocks enable faster assembly, while smaller blocks enable finer-grained customization, and there’s no reason to limit choices to a single size.

A radically unconventional future cannot be accommodated within the framework of plans made for a different world.

Standard engineering delivers artifacts; exploratory engineering delivers knowledge.