You wake up one day on permanent vacation. There are only so many jobs in the economy now that robotics take care of most routine tasks, from elder-care to organic farming. There are only many service industry jobs, too. You spend much of your time online, playing games, but you decide today to play tourist and see the real world with your own, mark one, eyeballs.
You live comfortably enough, a free one-room apartment with free food and utilities, including bandwidth. It's rationed, of course. If you want more than your stipend, you'll have to find a job to pay for it... but there is no real push or pull to do so. Most people dream by what used to be called TV, before it became interactive and immersive. The food isn't bad, but it's uninspired. Most families, or groups of neighbors, have an amateur cook or chef who dabbles in turning the raw ingredients into something tastier, but today you don't bother.
You plan on traveling, so you treat yourself to an old-fashioned breakfast, sausage, scrambled eggs, toast and orange juice. The sausage meat is tissue cultured pork, as are the eggs, but the juice and the bread came ultimately from local indoor hydroponic farms, either greenhouses tended by robots under the supervision of a 'farmer', or underground tunnels lit indirectly by the sun, or wind, wave, even nuclear (All that radioactive waste left over from last century is getting 'burned' up in comparatively much safer nuclear cans (after all, it will be gone, then, and not left lying around in corroding steel canisters!) with few moving parts, and mostly do it someplace far away, just like the solar power is mostly collected in the middle of a desert).
After breakfast you throw the dishes in the dishwasher, which these days cleans them and puts them away. You could have left them lying around for the apartment robotics to see to, but tidy habits die hard and make you something of a nonconformist. The place leaves your stuff alone or puts it where you designate it belongs if you just leave it, but otherwise keeps the apartment clean and safe. The place is a little sad because you have to keep things to code. It'd be different if you owned it, or won the lottery and could move someplace, own real estate...
Out the door and down the hall you take the elevator. None of these free apartments is in a small building, so you drop down twenty stories to the street, which moves. Slidewalks always used to be the stuff of science fiction, but with smart materials somebody got the idea to work. Surfaces slide over each other now if you want them to, and you step onto the moving surface and walk out to the faster band in the center. The slidewalk can slide you as well; a few kids come gliding past, skating along. The active surface helps pedestrians keep their footing by variable acceleration, so you don't stand with one foot in a faster lane and have that foot drift out from under you, or cause you to turn slowly in circles, although you can, if you want to. Since you do, you say "spin" and the slide walk responds by spinning your patch and moving it around in traffic.
It's a good, sunny day, no smog to see or smell. No large powered vehicles in sight, either. Goods get delivered to your house of business underground in a system of tunnels. People move around by foot or slidewalk, and go long distances with a faster, underground or elevated version of the same. They call it 'The Tube' because it is a version of the slidewalk which wraps up and over, and speeds you rapidly along.
You're coming up on the tube now. You slide around the spot where the tube comes out of the ground, opens up and flattens out, what seems like a big curved wall under a sun-catcher canopy, weave around people getting off the thing and into the acceleration zone. A hump of the slidewalk has bunched up and now stretches and speeds up from the crawling pace designed for universal access to over fifty miles per hour down into a well lit tunnel. Behind you an old man says "bench" and the slidewalk obliges by moving wall and floor around to gather enough layers in one place to form a curved bench that slides along smoothly behind you. He adds a destination and settles down to take a nap. The bench will make all the connections for him while he dreams of the good old days.
Your plans are for a long-distance journey, and for that you need an even faster version of the tube, stacked up on this one. Where this is fifty times faster than crawling, the 'intercity tube' is ten times faster than that. You walk up a slight hill of bunched up slidewalk to get on it and the tube diameter is a bit smaller, but the principle is just the same. Away you go, and you take a page from the old man's book as you settle down for the hours-long ride cross continent.
I figured out how ASMNT (aluminosilicate molecular nanotechnology) works in the mine-seed application (This is an idea I had for exploiting methane clathrates, 'fire-ice', the biggest form of hydrocarbon we don't currently use. Methane is a strong greenhouse gas, so better to burn it into CO2 and water than to let it get into atmo...). The wallsof the mine-seed are grown from the inside-out and the outside-in, as needed, and then we cut, paste and slide. I estimate a complex, 10^9 atom individual element, 100 atoms wide, about 10 nanometers (10^-8 meter), and 10^5 atoms deep, or 10^-5 m. It would take 10^9*10^-6 seconds or 1,000 seconds per element, provided that all the feedstock and fuel is there. If the mine-seed is a 10 meter cylinder with one meter hemisphere end-caps, which is 10*1*pi + 1^2*pi, or 11*pi m^2, ~11*22/7 m^2 is 242/7 is 34 4/7 m^2. Say this is 4.2 g/cc or 4,200 kg/m^3 and walls 10^-5 thick, so the mass of the mine-seed is 242/7 * 4200 * 1/10^5 is 242*600/10^5 is (1200 + 240 + 12)/1000 is 1452/1000 is 1.452 kg, about 3 pounds. It's a little over 8 tonnes of water... if we give it ballast in the form of some silicate feedstock and pump some air or O2 under pressure, which I want some anyway, for powering the mine-seed.
The mine-seed 'lands' on the seabed, and moves around seeking a methane-clathrate deposit. When it is in the right place, it grows 'roots' into the fire-ice, to harvest the methane for transport and use. The root walls can grab O2 from sea water, CH4 from the ore-body, silicates from the seabed, create more membranes for doing those things and for creating more membrane (not a universal assembler, but a programmable loom or molecular mill, fuel cells, pumps and ducted fans, solenoids and servos, circuitry, all of the things we need to build submersible tankers and freighter for transport and further resource exploration. Or the thing just spreads out under the seabed, growing a pipeline to the land, wherever we need the stuff to go...
I think we need a hundred tonnes of this stuff to go into production; development at one man-hour per atom, a billion atoms times 100 different mills, 10^11 hours divided by 10 years at 2,000 hours per, 2*10^4, so we need 5 million people working for 10 years. If the average worker is costing the effort $100,000 per year for 10 years, or $10^6, which is $5*10^12. Argh! Wages plus stuff, another order of magnitude more... call it a factor of 5, $2.5*10^13. It gives us a mature ASMNT, or the first step to one, a toddler step, as opposed to a baby step.
Also thinking how an ASMNT slidewalk would take advantage of silicate materials' natural tendency to form sheets. The moving sheets are tens of millions of atoms thick (10^7*10^-10 m is 10^-3 m) and bunch up at embarkation and disembarkation zones. The edges of the high-speed section roll up, actually sliding apart and then back together again. The system has a slight bow and is permeable, draining water and sifting light dirt below the moving surface. It bunches up, going from a millimeter to five centimeters, and 25 meters per second to 1/2, or 1.8 kilometers per hour, about 1 mph, crawling speed, and up to 90 klicks, over 50 mph. Slow for I-95, but pretty good for a pedestrian. At these speeds, the slidewalk really needs to be enclosed. The 5 meter bowed bed becomes a 10 meter enclosed tunnel. Perhaps the slidewalk is a millimeter thick and goes to 30 cm, about foot thick, in the slow zone. It rolls over a surface, in turn, which accelerates or decelerates the sheets and swaps out damaged sections as needed. The 10 m tunnel could narrow and accelerate, to 2 m and ~280 mph!
An ASMNT loom could make a new section every 10^5 seconds, a little over a day. Incidentally, the loom or molecular mill could travel inside the 10 million atom thick slidewalk segment as cargo... if the segments carry double-sided molecular mills with feedstock and fuel in the sandwich, they could be offloaded, formed up into pairs and accrete new slidewalk segment anywhere they can be resupplied.
The segments or scales are 1 mm thick and could easily be cubes, but let's make them 2.5 mm by 4 mm, or 1/100 of a cc. They are fairly flexible and can form tubes one cm in diameter. Ten layers would be 3 cm, just over an inch or a fingers' thickness. For manipulation of goods and cargo, we could easily form this stuff into arms and hands. Little three-fingered hands (2 fingers and a thumb) would be 7 cm tubes, short or long arms a little thicker, limbs to be built up into little tube-figures. Six to eight inches thick and maybe one or two feet tall with bland, smiling faces like something out of a manga or anime, they can be summoned from out of the slidewalk by the user, just as the slidewalk building blocks can be formed into chairs, benches, beds or desks and tables as needed. The Tube, tube-men and building blocks have a density of about 4.2 g/cc, but with lots of voids and space between layers to allow for 'softness' or at least 'give', it averages less, call it 2.8. So a 30 cm 'tubie' is more or less a flattened 15 cm tube 30 cm tall. What with the rounded edges and flattening, it is a little over half of 30 by 15^2, say 30*15*8 cc or 3600 cc, or ~10 kg, about 22 pounds. A small dog or fat cat.
Imagine wearing this stuff as powered armor!
Woops, what about speed? The classic loom is operating at 50 megahertz, 5*10^7 times a second, across 10^-8 m, or 1/2 m/s^2, per layer. That's good enough for the slidewalk, which can afford to accelerate people at those speeds, or slower. If we want more, we need only stack up moving layers; ten, or 1 cm is 5 m/s^2, and 2 cm is 10 m/s^2, about one G. We'd need to make exoskeletal battle armor out of faster stuff, but a 'tire' 3 cm thick would have 15 m/s^2 of acceleration. Build a sweet little roadster, even an off-road monster with fat wheels of slidewalk-stuff with a as many wheels as you need, or as few. A unicycle you ride inside of, maybe with outriders, an egg with two fat tank-like treads or half an ellipsoid with dozens of gimballed 7 cm tires, where you lie prone as in a high-speed motorcycle, but a quarter meter off the ground.
With enough energy and materials, I imagine the system could reproduce itself every 10^5 seconds. A week is about 6*10^5 seconds and a year is about 50 times as long, 3*10^7 seconds. Nothing is as simple as that, but change will be faster than we can react as a society, leading to the usual economic, social and general misery in the near-term, opportunity and prosperity in the long-term. If full employment in the ASMNT Project occupied 5 million people for 10 years, then it is a major sector of the national economy. I'd expect it to branch out into energy, manufacturing, transportation, etc. until it is the economy; $2.5 Trillion a year is ~17% of the US economy at present, and the US consumes a quarter of the world's stuff. It wouldn't double every year, although it could. Just to keep things comprehensible, if the ASMNT sector grows at 20% (just a bit faster than China 8-), and employs 10% more people a year, then in 10 years it will be equal to the entire US Economy and employ about 13 million people. Eight years later it will be bigger than the current world economy and employ some 28 million people.
I set this up to start 15 years from now and in 2050 the ASMNT 'Sector' is 11 times as big as the current US GDP, and employs 45 million people. It basically is the economy now; even with strong growth in the regular economy, I expect ASMNT should be more than half of it. In over twenty years it will have replaced most regular manufacturing, resource extraction, transportation, and energy production. It won't replace agriculture, probably, but it will change how farming happens. Robotics would make 'free range' and organic foods cheap. Indoor hydroponic farming would make food production local again.
By 2060, ASMNT produces over a million billion dollars worth of stuff and employees 116 million people, fourteen times as big as I guesstimate the US economy to be in early half a century of slow growth, and occupying the time and energy of over one percent of the world population. Deflation is a given, as more goods chase only so many dollars, plus people won't really need for much. With that kind of wealth, even a corporate state would find it cheaper to buy off dissent with free stuff, especially in a dystopia where corporate-funded welfare provided drugged food, slanted media, etc. I doubt it would be so monolithic, and I hope we could manage 'much more plenty' better than we have managed a little prosperity so far!