I’ve had this idea for a sci-fi story setting kicking around the back of my head for a while, and I want to get it down somewhere. It’s not really an idea for the story so much as the just background setting, but I still think it’s pretty cool.
The background begins with a near-future Earth, where the environment has gotten worse. Temperatures have risen, ice has melted, and the West Coast has practically disappeared up to the Rockies. The Great Plains are starting to resemble a desert, but Canada is still able to pick up the slack in food production. There are no more doubters or deniers, and everyone is fervently looking for a breakthrough, with no success. Until.
It finally happens. Someone creates a cheap, clean, easy, compact, and — above all — abundant new energy source. The how/what of this new energy source don’t matter, and I’d avoid talking about it too much, except to say it involves Thermodynamics, and the total and efficient conversion of any matter into energy, where any common rock, dirt, trash, water, whatever, can be an energy source even better than plutonium.
Suddenly everyone has more energy to play with than they ever thought possible before. Use of fossil fuels for anything disappears practically overnight. New technologies that rely on this energy begin to develop. It has a profound effect on society. Space exploration is suddenly much cheaper and safer, though still (at first) too slow. Warfare begins to shift towards energy weapons, with the counter of the development of any energy shield.
And you’d better believe there is warfare. The sudden lack of steady income into certain religiously charged areas, coinciding with the simple construction of new energy weapons that put them at a level with superpowers weakened by environmental deterioration, and things really break down just as space travel has it’s own energy drive breakthrough. The energy drive is also straightforward and simple, and once explained any competent engineer can build one, just like the with the energy production, and it’s unfortunate that the war and other events disrupts more concerted and coordinated exploration efforts.
More than this, it turns out that even clean energy is not such a panacea. There’s still the fundamental laws of thermodynamics to contend with. Energy cannot be created from nothing, and neither can it be destroyed. The used energy remains; it’s merely converted to a different form. That form is heat. Global warming is worse than ever, even without fossil fuels or greenhouse gasses. The environment is failing even faster, society is approaching collapse from war, but suddenly space travel is easier than ever, if a bit blind.
It happens. Evacuation. Earth is mere decades from no longer supporting life. In order to get people off planet in quantity, mankind turns again to it’s favorite new invention. Common buildings are outfitted with an energy machine, discrete shield generator, oxygen/carbon scrubber, makeshift hydroponics area that often amounts just to raised gardening beds and sunlamp, and an energy drive, which is an offshoot of earlier weapons research with the new energy source. The shield generator is set to project fields that almost exactly match the exterior of the building, such that once in space you have, for all intents and purposes, and common building just floating there, with very little in the way of visible accommodations for the hazards of space.
When a building is ready, it just leaves. There are buildings of all types, ranging from sheds for one all the way up to skyscrapers. Mostly it’s larger buildings that are already equipped with cafeterias, exercise facilities, dormitories, and common entertainment areas, like schools, hospitals, and some hotels, but any larger building can be converted, so warehouses and factories are common, too, and some families will make a go of it in their own homes. Looking at it in space, you might just see a normal house float by.
But that doesn’t stop the fighting. There is no easy access to grow food or obtain raw materials or products. Resources are scarce. There is no government up there. Piracy is an immediate problem, and so the building-ships scatter in a great dispersion. Many are destroyed, and mankind is left with a remnant travelling the stars in their building-ships.
For a more visual story, pirates seized most the great buildings during the initial escape. A skyscraper would become a symbol of evil; a school or hospital a symbol of good.
The opening of this story would take place at least a number of years later. Long enough that many of the building ships have failed. Either the tech was botched in their building, or they were not able to establish a sustainable routine for producing food. Those that remain have reasonably reliable tech powering their building, and probably at least one person who knows how to maintain it. By now they have found a way to survive for longer periods without aid, but they are always on the verge of exhausting their resources. No one is well off.
It’s far enough along that most building-ships are scattered and isolated but no so far in the future that buildings have dwindled and spread to where encounters are statistical anomalies. Encounters with other building-ships are not common, but not rare, either. Every building hopes to encounter another friendly building; every building dreads seeing a skyscraper. There are still older people who remember Earth, and active adults where were born there but left too young and lived a different life for too long to remember how things were. The young have known nothing but space.