[HoneyBadger]

I finally have some time to commit to this, so I thought I'd start posting a little outline of the setting I have in mind:

First of all, the "world" itself will consist of a Dyson structure of the type known as a "Matrioshka Brain". If you don't know what that is, a quick, simple definition is that it's basically a computer designed around a star, in such a way that it's various components each work at their optimal level, at the particular heat/energy level they happen to be recieving from the star they surround, at the position (distance from the star) they occupy.

So we have an enormous, hollow world, many times larger than the Earth, which happens to be approximately 1 1/2 times as thick as the Earth's diameter from North Pole to South Pole. The computer components of the Matrioshka Brain itself are made from nanobots, picobots, and femtobots, each of which-and collectively together-can form themselves into practically any substance of practically any density and complexity. They surround a middle-large sized blueish star (about 2 1/2 times the size of our sun) of unusual stability. Surrounding this nano-substance, to a depth of 250 km, is an insulating layer consisting of a circulating, heat-dampening substance (107 km thick) sandwitched between two relatively thin layers of tungsten-carbide (3 km thick each), followed by a layer of "buckyball" carbon rods (9 km thick), a layer of 95% pure gold, mixed with platinum, copper, and other precious metals (12 km thick) which is also sandwitched between 2 layers of iridium (1 km thick each), followed by a layer of nickel-iron (27 km thick), and finally a layer of mixed rock and minerals, 81 km thick, which is not unlike our own Earth's crust in consistency. This last layer contains tens of thousands of miles of human-traversible tunnels, caverns, and byways-some of which have formed semi-naturally, and others used by regulatory nano-bots for easy access.

These layers are permeated by trillions of industrial-strength regulatory nanobots, which are capable of quickly and efficiently rebuilding it, as needed. The surface is not one solid, consistent piece of rock, or even several Continental plates, but instead (from the circulating layer up) consists of hundreds of thousands of enormous rock "pegs" which can easily move, expanding and contracting fluidly with the gravitational fluctuations from the Star-which flexibility keeps the Brain from being ripped apart by solar tides, and helps it resist impact with any rogue meteorites (It should be noted that the Brain is also capable of-and does-regulate the Star's energies in such a way that it reduces the chance of it going Nova to almost 0%, and that, if necessary, it could replicate itself.). Gravity on this world is problematic, but is carefully regulated, being 1.33 G (+ or - .35) from the surface of the planet, to a height of 6 meters, but then dropping to .25 G for the next 1500 meters. Although almost all energy and light from the Star is captured by the Matrioshka Brain (to 99.997%), plenty of heat for life to flourish is provided by the Brain. Light, and supplimental energy, is provided by 4 artificial "suns"-three of which also function as artificial "moons"-which rotate around the planet in such a way that "days" are 36 of our hours long, and "years" last 729 of our days. Atmosphere contains 5% more oxygen than current totals, and airpressure is somewhat higher.

The reason this isn't (exactly) science fiction is because of the function of the Matrioshka Brain itself.

Humanity had finally reached the point of Singularity. They had altered themselves, their bodies, their culture, their place among the stars, so much, that they were moving beyond that which-for good and bad-could be called "human". It was evolution, simply and inevitably.
So, before they no longer cared to, they set up a magnificent museum to themselves-to each and every human who had ever existed-as they once were.

The Brain's original purpose was to duplicate, physically and mentally, down to the very electrons orbiting the atoms which make up the cells of our brains, every possible human being who ever lived or could have lived, at every possible point in their hypothetical lives-every cell, every memory, every life and lifetime-and then to duplicate a world in which those humans could live, at several points in time, based on their own recreated memories. It then deduced, as well as it could with limited information, which of the humans had actually lived, and at what time, but with limited information (seeing as how this is occuring atleast a thousand years in the future, and a lot of historical data has been misplaced, if not lost), some of the humans that got "recreated" had never actually existed, and the ones that had, had their own ideas and notions of how their world had actually been (for them, "myth" had been their reality)-only some of which were based on science, or fact, or a clear view of what was actually going on in the world while they lived their lives (some people just don't follow the news, especially when most means of communication hadn't been invented yet). And so, the World was built by Committee.

To complicate matters, humans of this time had the ability to easily and painlessly alter their bodies into new forms, and to create new lifeforms, and they often as not did this based on their own myths, legends, fantasies, heroic stories, and whatnot. And with the help of the Matrioshka Brain, those humans which in the past had been sickly, or diseased, or mentally/physically disabled, or just very unhappy with the way they looked, were allowed to reform themselves into new beings, and live new lives in what amounted to a relative paradise. Unfortunately, those humans which were mentally *disturbed* also were granted the same power, and thus were born monsters and nightmares.

Along with humans, other forms of life were created. All the animals and plants that had still existed, or evolved while humans were present on the Earth-atleast the ones the Brain still knew about-were recreated, from 7 million years in the past, to the year 3001. And to this were added many beneficial and useful creatures that had either been created by humanity, dreamed up by the confused humans and reproduced mistakenly by the Brain, or discovered among the stars-and a few alien life-forms here and there, that had somehow become stranded on the Dyson structure. And even though some of them can be argued to "not belong" in the great museum of humanity, the world is big enough-and the Brain is generous enough-to contain and provide for them all.

The Brain had also been programmed to eliminate much of our potential to destroy ourselves as a race-and in the process, destroy this "museum of humanity" that was the Dyson Brain itself, and so it eliminated our ability to create explosions greater than that of a low-power steam engine. All other energy above this was absorbed instantly back into the Brain. To compensate for this, and to provide a means for this ancient Humanity to progress, the Brain provided regulated energies that humans could create and manipulate at will-carefully monitored and controlled by the Brain, to ensure that they couldn't destroy the body of the world around them-but far more versatile-if ultimately less powerful-than an atom bomb or a fusion reactor. Only certain humans were granted this ability, to give them something to strive for. The "keys" to unlocking these powers were placed inside of repositories known as "magic gems". These "gems"-purely symbolic, but no less necessary-could be used by those with enough knowledge of the Brain's incredibly complex language (which it had also set up, specifically to *be* complex, and hard to understand, as an exercise in various mathematical and other disciplines, for their minds) to command fantastical powers of transformation, formation and manipulation of matter and energy, teleportation, even the very act of creation of other sentient beings-with personalities drawn from the Brain's almost infinite storage of possible but unrealized humanity. As an ultimate prize for the most ambitious of humankind, power unlimited by available gems, was offered-godhood, in other words. And the god-the Pantocrator-would reign for as long as the Brain felt would benefit humanity.

Although there's plenty of real-estate to occupy (1200 or so times as much liveable, interesting, relatively comfortable Earthlike land, as the entire Earth itself provides, there are also a multitude of virtual worlds, set up by the Brain to occupy the mental energies-and to provide simulated physical bodies and lives for-the vast legions of possible humans that the Brain filtered out. Each of these virtual worlds runs on it's own timeframe (at first much faster than "realtime", but gradually running more slowly as they increase in complexity, via the actions of it's residents), and may be very similar in nature-or very far removed from-the real physical Dyson Structure. Each of these can be accessed either through use of the "magic gems" (generally 1 way access, to summon a being from a virtual world, and into this one, for a limited time), or through various structures that allow interface between the worlds.

Dwelling among these virtual worlds may be found residents who embody the absolute limits of intelligence, creativity, morality, wisdom, even savagery and evil. Creatures that are closer to gods, or devils, than any that ever walked the Earth. And the Brain allows them more flexibility, when it comes to manipulating their virtual "bodies", than it does to real humans. Even aliens-ones too dangerous or too different from humans to allow to walk among them, on the physical Dyson structure, are contained here, virtually, their bodies dropped into the nearest black hole, but their essence, consciousness, and sense of self, preserved and remade-as true to form as is not a danger to the Museum's existence-as evidence of their contact with humanity. So anything can be found here.