ay you're a nanotechnology expert, able to manipulate matter at the atomic level. Say you can create objects and substances which are capable of reproducing themselves in a biological manner. Say you're trying—for whatever reason—to improve the standard of living for the people of Earth. Not just the rich people, or the people of a particular region, but as many different people in as many different areas as possible. What do you do? What are humanity's most pressing needs?
The easy answer: food, shelter, clothing and storage. If you were smart, you'd devise a material which could grow rapidly, using only the energy of sunlight and the mass of air and dirt. (In practice you might need some water as well, since it's an excellent chemical solvent and also one of the best and most plentiful sources of hydrogen.) Your nanomaterial would be edible in the early stages of its growth, whereas in the intermediate stages it'd be flexible and tough—suitable for woven fabrics capable of repelling water, blocking sunlight and supporting the weight of a human being or a load of equipment. And its growth would be fast enough to see with the naked eye (though maybe just barely), so that within a few weeks, a speck of the substance would grow by tens of meters and dozens of kilograms, and would harden and expand into some standardized and very useful shape, perfectly suited to human-scale construction needs.
What shape would that be? The easy-but-wrong answer is something like a brick or LEGO block—something square, that interlocks without glue or fasteners. Wrong because on reflection, LEGO/brick structures are strong only in the vertical direction—they make good walls but lousy and very dangerous ceilings. And since the ceiling is the most important part of any shelter, your material would really have to be strong in tension, i.e., when laid down sideways and weighted. And like any modern material, it also needs to be light, maximizing its strength-to-weight ratio. For these reasons, you'd probably want your material to shape itself into long, hollow cylinders—the same shape we use for tent poles and painters' trusses, space stations and bicycle frames.
Growing a future we can live with
If they were watertight, these tubes could also be fitted together as plumbing, and would be even more useful if they were divided into segments—say, 3 to 12 inches long—with watertight but easily removable dividers. That way, a single man-sized length of it could be used as a drainpipe, or separated into six or eight little storage vessels—each about the size of a drinking glass or coffee mug.
Of course, not every useful article is shaped like a hollow cylinder, so ideally your material would be fibrous in nature: very strong but also easily cut. The coffee mugs could be split lengthwise or edgewise, or steamed and folded out, or else pulped into papery sheets or spun into rope. They'd make good roof tiles as well as support beams, and with a few drilled holes they could serve as strainers or musical instruments or shower heads. Indeed, a material like that, with a shape like that, could be formed into virtually anything human beings might need: from houses to bridges, from shovels and shaving whisks to chairs and boats, and even light bulb filaments. And finally, the material should be biodegradable when abandoned, and also rich in carbon, so that if the need arises, it can be burned as a fuel in stoves, furnaces and foundries. Maybe it's not the best fuel in the world, just as its juvenile form isn't the best food. It can't do everything well, but what the heck, in a pinch it will suffice. And since the stuff reproduces itself, springing up anywhere that space and light permit, it grows—literally—like a weed. Call it Builder's Weed.
Still, feeding the masses on this stuff is maybe not the best idea in the world. You'd probably want to invent a separate material for that: one which grew just as fast and just as easily, but was tastier and more nutritious. For convenience, it might package itself in fist-sized nodules protected by a tough outer layer, and could grow in a protected underground space, where animals would have a harder time getting at it. This would require the extension of energy-gathering solar panels at the surface, but that's OK—these would serve as handy markers: food cache buried here. To please the world, the food itself would have to be fairly versatile. Baked in a lump, it should look and taste and feel quite different than it does when boiled, or fried up in small pieces. Ideally, you would want this food to contain every single nutrient human beings require, but in practice this would slow its growth, and require a lot of extra material for processing all those different molecules. Instead, what you really need is a filling substance which grows at maximum speed, provides most of the needed nutrients, and can be supplemented with small amounts of the other foods which people are going to eat anyway. The material would also digest slowly, so that a meal of it would bleed energy into the body for many hours afterward. This implies a lot of complex carbohydrates, rather than simple sugars. Its taste would be more starchy than sweet, although a sweeter version might also be available. Call it Energy Weed.
You say potato, I say unlimited energy
What a world that would be, eh? Builder's Weed and Energy Weed growing wild in vacant lots, free for the taking by anyone with a saw or shovel?
The good news is, we already live in that world: we call its products "bamboo" and "potatoes." And what a miserable world it would be without them! Imagine: no potato chips. No french fries. No mashed potatoes and gravy, no sweet potato pie. Potatoes are such an important food that when the "late blight" fungus wiped them out in 1845-1849 Ireland, 2.5 million people starved or fled the country. The absence of bamboo is easier for most Americans to imagine, because it's less a part of our day-to-day lives. We don't even use it for umbrellas or fishing poles anymore, but a typical home in Asia or Polynesia or the wetter parts of Africa still contains dozens of bamboo artifacts. The poor rely on it very heavily, given their limited options, and even in wealthy areas it's a preferred material for many things, because it's also a very attractive plant. Imagine a "tropical paradise" movie set, and your mind's eye will conjure up Builder's Weed by the truckload. Take away the miracle of bamboo, and the tropics stop looking like paradise and start looking hot, wet and poor.
This highlights the one great flaw in bamboo's design: although it's a member of the grass family, it doesn't grow well in dry or cold areas. This is one improvement a nanotechnologist could make which would dramatically improve the world: an all-weather version of this plant, so that the plastic canteen in your closet and the aluminum stepladder in your garage might finally be replaced with high-tech bamboo equivalents. Ahh. Paradise, meet Nebraska.
This brings me to my central point: there are an infinite number of nanotech wonder plants which are just as useful as Energy Weed and Builder's Weed, but which don't exist on planet Earth. What a rip. Am I alone in my outrage? Think of all the countless products we have to live without, or have to buy from factories when they could be sprouting from our lawns. Think about how desperately poor and miserable these absences make us. You know those times when you feel bad during the course of your day? When you feel some indefinable something missing in your life? It's the wonder plants you're pining for: the health and happiness and comfort and harmonious beauty that really do grow on trees. Or should, anyway.
So the question before us is, are we going to accept this fate? Or shall we right nature's wrongs, greening the Earth with the Oz-type wonder plants it should have had all along? Before you answer, put down that french fry and consider: somewhere in a parallel universe, there's a version of you who has never seen a potato or a cane of bamboo, a blade of grass or a partridge in a pear tree. She hasn't even imagined that such things might be missing from her life. Would you trade places? No? Then I rest my case, and throw myself on the mercy of a bright nanotech future.
Wil McCarthy is a rocket guidance engineer, robot designer, science fiction author and occasional aquanaut. He has contributed to three interplanetary spacecraft, five communication and weather satellites, a line of landmine-clearing robots, and some other "really cool stuff" he can't tell us about. His short fiction has graced the pages of Analog, Asimov's, Science Fiction Age and other major publications, and his novel-length works include Aggressor Six, the New York Times notable Bloom, and The Collapsium.
