The properties of materials depend on how their atoms are arranged. Rearrange the atoms in coal and you get diamonds. Rearrange the atoms in soil, water, and air, and you have grass. And since humans first made stone tools and flint knives, we have been manipulating atoms in great thundering statistical herds by casting, milling, grinding, and chipping materials. We rearrange the atoms in sand, for example, add a pinch of impurities, and we produce computer chips. We have gotten better and better at it, and can make more things at lower cost and with greater precision than ever before.

Even in our most precise work, we move atoms around in massive heaps and untidy piles-millions or billions of them at a time. Theoretical analyses make it clear, however, that we should be able to rearrange atoms and molecules one by one-with every atom in just the right place-much as we might arrange Lego blocks to create a model building or simple machine. This technology, often called nanotechnology or molecular manufacturing, will allow us to make most products lighter, stronger, smarter, cheaper, cleaner, and more precise.