If you are not yet familiar with this series, please review Parts 1, 2, 3, 4, and 5 before proceeding. If you have already read them, you may wish to cursorily glance at them to remind yourself of the basic concepts I am employing to generate a model of the future. In this entry, we expand the time horizon to 100,000 years (100 ky) - 10% of the total period of this diary series - and further follow humanity's Root/Spore evolutionary cycling into increasingly strange territory.
This isn't directly relevant, but it's a cool commercial rocket test worthy of seeing:
Table of Contents
(Current part in bold)
I. The Energy History of Life (Part 1)
II. The Energy History of Humanity (Part 1)
III. The Next Decade (Part 2)
IV. The Next Century (Part 3)
V. The Next Millennium (Part 4)
VI. 10,000 Years (Part 5)
VII. 100,000 Years (Part 6)
VIII. Mark: One Million Years (Part 7)
When we left Part 5 at 10 ky, the inner solar system has become a dense "soup" of heavily interacting, artificial structures along the plane of the ecliptic that rely exclusively on passive solar energy harvesting. Outer solar system civilizations, though still widely dispersed, have economically united with the Root by means of directed solar energy from gathering/focusing infrastructure close to the Sun and router networks further out, and have begun exporting their raw materials inward in exchange for trivially abundant energy at an accelerating rate. Vast populations of asteroid-based N+2 Spore migrate between the inner and outer solar system along highly elliptical "Trader" orbits, and some small fraction of them have colonized other stars within a sphere of about 10 light-years traveling at fractions of lightspeed.
Now that the entire planetary region of the solar system is Root, the boundaries that once delineated it from Spore instead mark two distinct intra-Root domains - Inner Root and Outer Root. Where exactly this boundary occurs will be entirely a matter of economics, and would be difficult to predict without highly quantitative analysis that I have no intention of attempting. Basically, this boundary would occur at the orbital region where raw materials imported from the outer solar system reach an economic "dew point," at which it makes more sense for the shippers to sell them there than to accept greater expenses and complexities to sell further inward.
An analogy for this boundary could be made with trade between the US and China: There are many islands between here and there that may take a very small fraction of the US-China exports, but for the most part cargo goes straight from the Chinese to the American Pacific coasts and vice-versa. But it makes a lot more sense, in the case of China-to-US trade, for a Chinese shipping company to entrust the land-based delivery to American trucking or rail freight than to handle it themselves, so there is a natural economic boundary at the US Pacific coast. It isn't impossible for a Chinese company to truck its own cargo within the US to customers, but it makes a lot more sense to wash their hands of it at the Port of Los Angeles. Likewise, there will be a point where it makes a lot more sense for outer solar system materials to be passed off than for the original shippers to continue inward. This is the boundary between the Outer Root and Inner Root.
The reason for this is economic density: Bulk cargo isn't suited to end-point delivery, because its advantages come from operating point-to-point across long distances with few or no major stops. As economic density increases, more and more stops have to be made to deliver smaller and smaller pieces of cargo, so there is every incentive to have that leg of the process handled by a large number of smaller carriers with shorter range but greater efficiency for that particular task. This transition can happen several times before a good reaches consumers - from large container ships to trains, from trains to large trucks, from large trucks to delivery vehicles who bring it to stores, and from there to the individual consumer who may drive home with the product in an automobile.
So, because there are many points of transition, the Inner Root will itself have internal economic structure based on density that would be strongly proportional to distance from the Sun. Where these internal boundaries occur would be pure speculation, but they would have the same economic basis as the Inner/Outer Root boundary - points where the economic density forms a natural transition point where it is more efficient to transfer trade materials on to a larger number of smaller media for further distribution.
As materials from the Outer Root (OR) flow inward, the Inner Root (IR) would become denser, more complex, and more stratified, and the Inner/Outer boundary would gradually creep outward as well. The number of internal strata in the IR would be purely speculative - I suspect that it's virtually unbounded, and would increase with time as the IR complexified - but I have made a radically simplified little slideshow to give a visual sense of the concept:
For a long time, the increasing density and stratification of the IR would be mainly limited to within a few degrees of the ecliptic due to the economics of inclination - it costs substantially more in delta-v to achieve a highly inclined solar orbit, making it impractical for any kind of place where a lot of material trade needs to occur.
With radically increasing density, the IR in this region would effectively become a single physical system - not a solid "discworld," but a more or less continuous technological environment that maintains equilibrium through subtle means, probably involving an extreme level of computation and self-correcting balances. Even though it is not really a disk, but a thick soup of structures along the ecliptic with tendrils extending in various directions off of it, we can call this environment the IR Disk due to its large-scale shape.
Now, I do not expect the vast majority of the IR Disk to be involved in what we would recognize as "human" habitation or even biology: While I refuse to get into arguments about Singularity or machine intelligence, I would say that on a 100,000-year time horizon, things we today would recognize as being descended from us (or even being biological in nature) would account for a miniscule minority of the activity in the IR.
But at the same time, such distinctions will probably not be relevant - it is entirely likely that conscious entities and mechanical processes will exist along a smooth, continuous spectrum involving all manner of material substrates (nucleic acids, proteins, silicon, other metals, exotic materials, etc.) and information languages (genetics being only one example). So the "inhabitants" will have increasingly flexible definitions of "human" until the concept ceases to have meaning.
Nevertheless, I do not expect biology to ever be rendered obsolete - it is something that occurs in nature, and therefore demonstrates its intrinsic efficiency under some conditions. Even if there are epochs where biological life is accidentally or deliberately eradicated, what remains would, I think, decide to recreate it and salvage as much lost information as thermodynamics allows, perhaps including human history (credit goes to Charles Stross for acquainting the world with that idea). Not for sentimental reasons, of course, but because nature is endlessly useful. There will be a vast profusion of human-derived biological entities in numbers too staggering to comprehend, in addition to an even larger ecosystem of arbitrarily-designed or alternately-derived organisms, some of which might also be intelligent.
Given the economics of energy-density, biology would not be efficient in the innermost regions of the IR - it would simply cost too much in energy terms compared to using the same volume for raw computation. In other words, a biological entity or "Bio" simply couldn't afford minimum living volume within a certain distance from the Sun, and would be out-competed for it by energy-dense computational processes, some of which might be "conscious" (insofar as that means anything).
Still, there would not be an abrupt boundary between orbits occupied by Bios and those with computational infrastructure - one would blend into the other, with the proportions gradually shifting as one approaches the Sun until it's entirely non-biological information systems. And since plenty of entities would be hybridized between Bio and non-Bio functions, that shift in proportions might be reflected within individual organisms - i.e., in terms of the percentage of their mass that is organic. I doubt there would be any "rule" against Bios living closer to the Sun, but they just wouldn't have any practical way of doing it, and probably wouldn't have any motivation to try beyond a point: Why would you want to live in some tiny cubicle surrounded by nothing but billions of cubic kilometers of computational matter?
However, being closer to the Sun would carry a greater level of sociopolitical power, as the occupants of that radius receive more potent waste heat from that immediately "above" them, and therefore wield significant influence over regions "beneath" them that depend on their own subsequent output. I would speculate that waste heat from inward radii would not be the only source of energy, but by far the most economical - getting it directly from the Sun with routers on highly-inclined solar orbits seems like it would be more expensive, and fusion reactors even more so: Hardly as simple as passively harvesting energy that is already at your doorstep. So, now that the entire solar system is Root and depends on routed solar light, we can say that proximity to the Sun would carry enormous power with it - the power to leverage and control the entire solar system.
At the innermost wall of the IR Disk facing the Sun - which probably would be less of a surface than a fluid "froth" of constantly-evolving, fractal structures that respond to changes in the solar flux - would be systems and machine intelligences we cannot imagine, and that it would be meaningless to try to envision in any particulars. Our Bio descendants, no matter how intelligent and sophisticated, would not understand them in the least, and we therefore have far less hope of doing so.
We cannot meaningfully speculate on the motives, values, or perceptions of such entities, except the one principle that ties this entire diary series together - they would evolve to climb their energy pathway by more efficiently harvesting solar energy. By that point they would be doing so through means too profound for us to grasp, but I do not propose anything beyond the laws of physics as we understand them - just an inhuman level of subtlety and detail in applying them.
The inscrutable decisions made by these beings/systems would propagate outward throughout the solar system in the form of changes in energy availability at any given location - constricted supply to one Outer Root location, expanded supply to another, routed energy subsidy to an IR Disk radius while the radius above it is penalized. In other words, the system would operate as the far-future version of a water empire, with bizarre non-human intelligence(s) directing the fundamental basis of existence according to their own strange agendas - if "agenda" is even the right word.
Given such power and self-reinforcing supremacy, it would not at all surprise me if Bios came to regard entities of higher radii with a kind of religious reverence - possibly literally worshipping them as gods. Because, in all honesty, they sort of would be: Not omnipotent beings in the Judeo-Christian sense, but certainly in the older pantheistic sense of being powerful, virtually immortal, and knowledgeable beyond comprehension. This might also apply in the darker sense of being heartlessly capricious, but no more so than nature already is.
I am immediately put in mind of the Hindu pantheon, with its millions upon millions of gods occupying concentric circles of heaven in order of increasing power and profundity. The Hindu religion does not posit hard distinctions between humans and gods, or even humans and animals, but depicts a spectrum of life leading from the smallest of things up to the ultimate spiritual unity - something it shares with Buddhism and a few other related faiths. This is a good way to imagine what the "civilization" of the IR Disk would be like, with the radii above one's own blending into a murky sense of things mystical, powerful, and unknowable.
Occupants of a few strata upward might merely be privileged members of your own group, followed by beings still close enough to interact with but difficult to fully grasp, and then it would just get stranger and less comprehensible from there. To say that people would be Sun-worshippers would be a vast oversimplification, but at the same time fundamentally correct: The Sun is the direction of what is sought, and the direction from which it comes; the direction of increasing power, intelligence, and wisdom, and the direction from which those things flow. It is virtually inevitable that this would create deeply reverential feelings, not to mention superstitious fears that might have all too much basis in fact.
But the people of the IR Disk would not, I think, regard themselves as oppressed - quite the contrary. Most of the people who built the pyramids probably did not regard themselves as oppressed either: They were born into a civilization that told them the ruler was the Son of Ra, akin to a god, and one designated by the gods to rule over the land and grant his blessings to the obedient. Ancient Egyptians had nothing better to compare their experiences with - the world was little more than starving barbarians and other despotic kingdoms at the time, and yet the common people of Egypt usually had bountiful food, a sense of cultural unity and purpose (namely, serving the Son of Ra), and beautiful monuments. The fact that they had a regular, reliable food supply must have seemed pretty convincing that the King had the mandate of heaven.
Likewise, the people of the IR Disk probably will not resent acknowledging the simple, objective fact that the beings of the higher levels are literally beyond their comprehension, and are responsible for most if not all of the opportunities they have. They will be grateful for it all, and rationalize or try not to think about cases where the unexplained actions of those beings kill a few quadrillion of them. I would say Spore civilizations would probably look down on these people, though, and regard them as slaves and religious sycophants, but that wouldn't stop anyone from doing business, and life in the IR Disk would perhaps be more sophisticated and refined than elsewhere.
At any rate, there would come a time when the IR Disk approaches optimum density at a given radius, and it becomes economical to begin extending connected structures out of the plane of the ecliptic. This poses major difficulties due to stresses of orbital mechanics, but without trying to conjure some technological voodoo to describe solutions envisioned by a superhuman intelligence, suffice it to say that such solutions are conceivable, do not violate the laws of physics, and would make economic/thermodynamic sense, ergo they would be implemented.
The end-product of this process, however long it takes, would be Dyson Spheres - continuous structures that completely envelope a star at a given radius. Put together, the concentric Dyson Spheres would comprise a Matrioshka Brain - a largely computational construct that harnesses the entire power of a star. Charles Stross wrote fascinating science fiction involving a Matrioshka Brain in his novel Accelerando, but unlike in his story, I do not consider these structures to be dead-ends, as I will explain in Part 7.
Evolution of the Matrioshka Brain and its constituent Dyson Spheres would occur over tens of thousands of years, with a continuous infall of raw materials from the Outer Root in exchange for routed solar energy, but I do not expect them to be anywhere near complete at 100 ky. Well before the IR Disk begins extending into the makings of Dyson Spheres, there would be no Earth, Moon, Mars, Venus, Mercury, or Main Asteroid Belt - they would have been completely strip-mined to nothing, and if anyone remembered that there used to be a planet at the 93 million mile radius, let alone that everything they knew sprang from there, it's unlikely they would care. Would you care what specific pebble in the ocean bore the first living organism? It might have been a nice pebble, but it was just a pebble. And Earth would simply have been a pebble eroded to nothing in the ocean that is the IR Disk.
The gas giant planets would take much longer to harvest to depletion, and I don't think that Saturn or Jupiter would be exhausted within a 100 ky time horizon, but I will speculate that Neptune, Uranus, and all of the Moons and easily-accessible (non-settled) asteroids associated with the gas giants would have dwindled to nothing under the incessant demand for raw material from the IR Disk and its successor structures. Outer Root (OR) civilizations that encountered depletion would either relocate to the IR or turn Spore and emigrate to relatively untapped nearby star systems.
If the structure of the IR is initially disk-like and extending into spherical, then the OR is a web interconnected by the network of light routers delivering solar power from the IR. While the OR is also primarily within the plane of the ecliptic due to most of the mass being there, we can expect there would also be a profusion of Trader asteroids with highly inclined orbits that would also be connected to the OR Web. This network, as mentioned in Part 5, would be both power system and communications infrastructure, so every civilization connected to it would become extremely dependent on it even if they could theoretically cut ties to it at extreme up-front cost to their standards of living (i.e., billions of their people would starve to death while their economy transitioned).
People of the OR Web would be conscious of their subordination to the IR Disk, but probably would not resent it as a foreign oppressor - rather, I believe they would look on it much as Dark Age Europeans saw Constantinople: The center of the universe, where the richest of the rich, wisest of the wise, and holiest of the holy live. The OR, by contrast, would be the "countryside" - comparatively simple, rustic, and lacking in urgency or sophistication. Of course, this is all relative: Boise, Idaho is more sophisticated than 1st century Rome, so it's not difficult to understand that the dankest OR backwater would outshine 21st century Tokyo. But people from parts inward might go there to relax and unwind.
Only civilizations in the Kuiper Belt who had never bothered to put themselves in Trader orbits, and were too distant to join the OR Web as energy consumers would tend to be highly suspicious of and alienated from the Root. In contrast to the Root, where energy is so abundant that computational processes and entities overwhelmingly dominate society, those states who retain fully independent energy capability would have a much more equitable balance: Biological processes would account for a much greater proportion than in the IR, and beings dependent on biology in part or in whole would have substantially more influence on both the pace and character of events. Still, they would not really be in control - the machines would just be a lot less alien.
Beyond the solar system, two additional Spore iterations will be born - perhaps from the Kuiper Belt, but I think more likely from accelerated N+2 Spore who have settled a nearby star system: N+3 Spore civilizations will be sufficiently complex, self-sustaining, and far-sighted to move cyclically between two or a few nearby star systems, carrying people and whatever other material goods make economic sense to transfer over such vast distances. Unlike the N+2 iteration, which is only equipped to move in one direction as a colony ship to settle one nearby star, the N+3 will be Interstellar Traders whose entire societies are fashioned around that purpose. They may also shepherd N+2 Spore going one way, or even fission into N+2 Spore themselves.
It is difficult to imagine trade goods worth transporting over interstellar distances at sublight speeds, but we can say that such things would probably be advanced, proprietary technologies from highly complex economies - i.e., things whose designs they would rather keep confidential and sell the products rather than transmitting the specs for other star systems to build themselves. You can grow a tomato in your back yard rather than buying one, fair enough, but you must rely on a much larger and more complex economy than your own household to get a microprocessor - and so it would be at any scale. The technologies of the Sol IR would be beyond the capabilities of a Root around another star that had only a fraction of its information density, so it could develop things that others could not without investing more than the cost of interstellar shipping.
Then there would be the N+4 iteration, which would be so large and self-contained that it would effectively involve entire wandering worlds: These Spore might stay in the local neighborhood, but the far more interesting among them would serve as the Johnny Appleseeds of the galaxy, going out to new stars and staying just long enough to seed them with lower Spore iterations before replenishing their resources and moving on. So to recap the active Spore iterations, the N+2 either trade within a solar system or make one-way trips to settle others; the N+3 cycle between nearby stars; and the N+4 are indefinitely outward-bound civilizations that seed new stars with lower iterations without themselves stopping to settle.
Here is a totally inaccurate, not-to-scale visual representation whose sole purpose is to aid in understanding:
However, while there may not be a conscious design in this, it will likely shape up that "humanity" (the quotes are necessary at this point) expands by default in certain directions due to the relative abundances of stars - particularly, toward and along the spiral arms of the galaxy rather than just haphazardly in all directions. There is a much higher density of stars in the arms than in the gaps, so expansion will occur faster along the arms than in less dense regions: Each new star settled will, after a time, spawn its own Spore that expand further, so in a dense stellar region a "cascade" effect occurs over a sufficiently long time horizon.
The first arm of the galaxy to be fully settled will be the Orion Spur - obviously the one in which the Sun is located, which is a discontinuous arm that only extends for a few tens of degrees. The Orion Spur does not reach the galactic core, so expansion will continue along the Perseus and Sagittarius arms once they are reached sometime in the next 100 ky (Orion is 10,000 light-years long, so it's a matter of speculation how long it would take for waves of sublight settlement to traverse it). This image is not a photograph, since we can't see the Milky Way from above, but a computer visualization based on data:
As with the plane of the ecliptic in the solar system, we can expect that interstellar settlement would tend to be heavily concentrated in the galactic plane due to the higher density of stars. There would, of course, be elements who might deliberately seek to settle isolated stars that are relatively distant from others, but they are likely to be very small in number and relatively lacking in resources.
Meanwhile, other star systems would be settled and form Roots of their own much more quickly than the original took to develop. At first they would be entirely Spore, settling and exploiting outer system resources with no intention of becoming Sun-centered, but the economics of it are inexorable: Eventually, passively harvesting and directing readily-available energy from the environment becomes easier than the alternatives. The innovations made in some of these systems would make the Sol IR look rustic by comparison, although the technological "gods" that run them might be kind enough to share their progress with their counterparts around the Sun.
Particularly, any system with a much more powerful star than Sol and a lot more raw materials to work with would probably allow its technological core to evolve more quickly and perform more calculations per unit time and unit volume. This is another reason that settlement would selectively favor the spiral arms by default - more powerful stars. Still, there would be a counterbalance in the fact that the hottest stars are often so violent that they have nothing of consequence orbiting them, having either gobbled, ejected, or smashed everything that comes within its vicinity to smithereens. Stars like this would be relatively unattractive.
END OF PART 6.