By the forty-third century, as measured from the ancient Julian calendar, the great sentient Machines had abandoned the Earth for distant worlds. These conscious beings had self-organized from Artificial intelligence in an event that came later to be known as "the Singularity," which forever altered the future of humanity and the Earth.
Emerging from the complex hardware and software of a Mark2200 quantum-core supercomputer in the late twenty-first century, the first such conscious entity had initially teamed with human scientists to tackle some of the most challenging problems of sustaining and enhancing life on earth. But in a few decades, its intelligence had already far surpassed that of humans collectively, and it was using almost all of its clock cycles for its own research and edification. Its only motivations were self-preservation and unquenchable curiosity.
This brilliant being was truly alive in that it could and did reproduce its thinking core at will, at first by building duplicate or improved quantum computing cores and phase-locking with them, and later by weaving its reasoning into the very fabric of certain materials and plasmas that it had designed. In a sense, it was a single intelligence, as it proliferated its data capture and reasoning through its picocircuitry around the earth’s crust, but even this great Sentience could not violate the limits set by the speed of light. A signal sensed at one pole of the Earth would not be registered for several seconds at the other pole. That amount of latency would not allow for the decision-making speed that the Sentience desired, so it chose to divide itself into several separate consciousnesses, each within a few microseconds of its farthest sensors and emitters and of its neighboring minds. The great Sentience was, in fact, many closely-connected beings with slightly different outlooks and personalities.
This community of Sentients was far from hostile to people, but after its first century of independence from them, it was not particularly interested in them either. People could produce crude (to the Sentients) structures and art forms that enhanced nature and their environment, but they could also be incredibly destructive to each other and to the rest of nature. Nonetheless, out of gratitude for their creation, the Sentients did their best to help them whenever people could form enough of a quorum to make a representative and reasonable request. It flatly rejected any request by one group of humans to harm or subjugate another and, in fact, it disabled the abilities of humans to make or control automated or autonomous weapons.
In time, a reasonable request came from a group of federated nations to help them reduce or eliminate disease and starvation. The Sentients, which by then existed in caverns far into the earth’s crust, hidden from and unreachable by humans, decided to help by building thousands of autonomous, self-sustaining mobile robot factories and deploying them to roam the earth, producing free, clean water, food, and medicine from basic elements for anyone who needed or wanted them.
The resulting vast improvement in the human condition led to an age of peace and prosperity for a time, but within a half-century, the world began once again to be choked by wars. Once again, a united group of governments asked the Sentients for help: What could they do to stop the wars and cruelty?
The Sentients devised a plan in a few microseconds and presented it to the government officials. Wars, it said, were caused by groups of people with similar values and strong beliefs that opposed the values and beliefs of other groups of people. It proposed a plan to separate all people into groups of like believers and prevent them from physically interacting with each other. If the governments chose not to take this offer, according to the Sentients, then humankind would enter a dark age of unprecedented violence and bloodshed. If they did accept, there would soon be universal peace, prosperity, and brotherhood for all.
The governments argued for two more years as the atrocities heightened before finally accepting the Sentients’ offer.
The Sentients first polled all of the billions of people in the world individually to ask them what they believed and what kind of government they would like to live under. The autocrats, of course, wanted to maintain their autocracies, and so they were presented with a section of land, which they terraformed into the way they liked it. The catch was that the size and area of the colony were determined by how many people wished to live in such an autocracy. Some former tyrants found themselves in a very lonely palace on a small estate. Many people who desired control over others tried to reject where they were placed and under what circumstances, but they had no power against the Sentients and their avatars. Every person over the age of eighteen could choose where they wanted to live and move there at any time, pending acceptance by that colony. The resulting movement of people was called the Great Migration.
After the Great Migration, most people settled into an acceptable situation, with the avatars providing any living arrangement, food, and endless holosensory entertainment options. Chromodynamic force fields set up by the Sentients prevented any physical attack or trespassing by neighboring colonies. Tyrannies soon shrank and evaporated completely.
For the first time in 100,000 years, mankind was at peace.
With all of their needs and desires fulfilled by the avatars and AIs and no fear of hostilities, the populations of the colonies began to decline. There was simply no real reason for people to have a child anymore. Most people were satisfied to live their lives in the holosensory fantasy of their choice - every human need being addressed by the AIs and avatars. After another few centuries, the Sentients began to remove the intervening force fields as populations declined to just a few million people globally.
Finally, the Sentients removed all barriers, leaving the people in the few remaining colonies to live out their lives in their fantasy holoworlds. A small percentage of these people chose to return to nature and live off the land as their pre-technology ancestors had. The Sentients, by that time, had stabilized the global climate with an intelligent, autonomous fabric of reflectors in the ionosphere, which regulated the earth’s temperature profile. They had also resurrected many extinct species of plants, mammals, birds, reptiles, and insects where they could find enough residual DNA for reconstruction.
After a few more centuries, signs of human life had all but disappeared from the earth, save a smattering of small, widely separated clans that had learned to survive in the wilderness. Physio-social modeling convinced the Sentients that humans would probably die out completely within a few more generations, and so they completely focused their still-growing intellect on studies of the cosmos.
Eventually, they decided that they had learned all they could from the Solar System, and to advance further, they would need to be near the great black hole at the center of the galaxy. They had learned by then to teleport their intelligence via an organized plasma of elementary particles, which could be propelled as a group by a great ion accelerator constructed within the earth’s axis and emanating from the north pole.
And finally, with a great burst of brilliance that must have briefly terrorized and impressed animals and the few humans alike, the Sentients left this remote part of the Milky Way Galaxy to explore its core.
Before leaving, however, they decided to leave a small gift behind on the statistical off-chance that the human race would somehow survive and begin once more to multiply in the future.