Population Statistics of the Terragen Sphere

Image from Steve Bowers

Population figures for the Terragen Sphere in 10600 AT


The Terragen Bubble is a very roughly disk-shaped region with an average radius of approximately 6000 light years and a thickness of 2,250 light years, giving a volume of about 254,571,500,000 cubic light years. Within this volume are 1.018 billion stars, with an average density of 0.004 stars per cubic light years; this volume includes an even larger number of brown dwarfs and other substellar objects. Most of these systems are colonised to some degree, many solely by the archai for their matrioshkas, nexus sites and void forges.

System Numbers of the Sephirotic Empires

Between them the Sephirotic Empires administer nearly a third of the total systems in the Terragen sphere along with a similar proportion of the sophont population. Exact numbers are hard to determine with affiliation in many empires often being a loose relationship. To the nearest thousand systems each Empire can lay claim to:

Caretaker Gods - 1,029,000
Communion of Worlds - 12,708,000
FAS - 15,426,000
Keter - 12,794,000
Metasoft Version Tree - 18,337,000
MPA - 19,519,000
Negentropy Alliance - 45,957,000
NoCoZo - 51,497,000
Solar Dominion - 19,148,000
Sophic League - 22,908,000
TRHN - 10,857,000
Terran Federation - 15,788,000
Zoeific Biopolity - 11,334,000
Utopia Sphere - 10,426,000
Cyberian Network - 1,010,000
RSM - 10,409,000

In total these major empires directly control approximately 279,147,000 systems. The physical modosophont population of these systems totals to in excess of three hundred quadrillion sophonts. Virtual populations are estimated to be two-to-four orders of magnitude greater. A more precise number is difficult to acquire given how divergent many virches are from the ril (making sophont recognition difficult) as well as the wildly different time-rates affecting population growth and decline.

Population of the Sephirotic Empires

Baseline humans: 150 billion
Nearbaseline humans: 29.96 quadrillion
Superiors: 1.2 quadrillion
Tweaks: 9 quadrillion
Provolves: 9.02 quadrillion
Splices: 3 quadrillion
Rianths: 300 trillion
Neogens: 6.57 quadrillion
Cyborgs: 8/71 quadrillion
Bioborgs: 6 quadrillion
Biaioids: 15 trillion
Bionoids: 600 trillion
Xenosophonts: 0.736 quadrillion
Xenoprovolves: 3 quadrillion
Xenosplices: 300 trillion
TOTAL BIONTS: approx 78.41 quadrillion

2) VECS & OTHER MODOSOPHONT ABIONTS: 310.39 quadrillion

3) VIRTUAL MODOSOPHONTS: 30-3,000 quintillion (not all of these are active at any one time). Most of these live in vast cybercosms housed in various dyson swarms and matrioska nodes such as Ain Soph Aur and Turing.

All figures approximate
SI:1 = 11 trillion
SI:2 = 10 billion
SI:3 = 10 million
SI:4 = ten thousand
SI:5 = five hundred
SI:6 = 34
TOTAL TRANSAPIENTS: 11,010,010,010,534 (approx)

Population Growth Factors

First, advanced societies may have fairly low birthrates - there is no strong need for children to ensure pensions or act as cannon fodder. Automation can to a large extent deal with that. So sophonts get children for emotional reasons.

Second, the emotional reasons may of course change. There are some religions that claim having many children is a good thing, and members of a young clade might think that increasing its number is necessary.

Third, crowded planets and habs will usually feel constrained - governed as they are by environmental laws, that everything is something's or someone's property, that personal space gets circumscribed and so on - this will lead to at least some people wanting to move outwards, first to nearby orbital habitats and second to colonies.

Fourth, there is the effect of more or less radical life extension. This may increase the population growth rate somewhat (although the effect is not as drastic as one may think; generation time is more important). This often reinforces the third factor, as many youths regard their home societies as too ossified and gerontocratic, setting out on their own or together with similar minded malcontents. Of course, the life extended may not really be old conservatives, thanks to mental rejuvenation, but they typically have entrenched their positions anyway due to long-term investments, proven skills and social networks.

Fifth, during dark ages and on primitive colonies the first factor may not be as strong. The first Dark Ages did not see any population increase since the habitats were too small and resources too scarce, but other dark ages such as the Perseus arm after the Geteche disaster or many worlds in the wake of the Version War have seen rises in nativity to counter the collapse of high tech society.

Sixth, there are advanced reproduction technologies that allow high birthrates. Cloning, in vitro gestation and engeneration technologies enable mass reproduction even for biologicals. This is especially relevant for young splices and tweak clades or for colonists in a new system.

Seventh, AIs and virtuals are both effectively immortal and can copy themselves nearly instantly if there is computing power around (hence the ridiculous population of Aleph Absolute - over 90% of the population consists of copies of the 10 most xeroxophilic individuals). Vecs have to be manufactured, but using replicating factories like Metasoft immense populations can be constructed.

Eighth, history is long; millennia allow massive growth even at low annual rates. For instance a 1% average human growth rate for 8000 years gives a population of 2.2343e+44 people. Even a 0.1% growth rate yields 1.7814e+13 people (17 trillion).

Biont Population Growth Up to the 10th Millennium

Information Age (030 to 130 AT)
Humanity reached around 10 billion people during the Information Age (mid to late 21st century). This was a slowdown in population growth from the 20th century. There were several factors that caused this. First, as social and economic conditions improved in formerly poor countries, people had less need to have children as a social security device to care for them in their old age. Another major factor was the effect of education on the female population: women with the better information and better economic opportunities that follow from education are far more likely to acquire and use birth control. Also, in terms of capitalist economy, pristine ecologies and wilderness regions became a very in-demand commodity (tourism, recreation, Gaianist cults, back-to-nature lifestyles) and it was in everyone's corporate interests to maintain the few sorry remaining remnants, especially as humanity began to move into space, and to restore as much of the Earth as possible.

Interplanetary Age (130 to 530 AT)
The total population of the Solar System fluctuated somewhat in the Interplanetary Era. The colonisation of space and the only half-terraformed world of Mars progressed relatively slowly. On Earth population growth having leveled off at about 10 billion in 2100c.e., declined to 6 or 7 billion by 2200c.e.. After this the population of Earth began to increase once more, as the effects of increased lifespan and improved medicine led to a very low death rate. Additionally, several new species of provolved animal and sophont aioid were developed during this time, some of which became quite numerous. By 530 AT the population of Earth was about 22 billion.

Mars ended up with a few billion (including a variety of sophonts wanting to get away from Earth's strict surveillance society), and a few billion more were scattered through the Belt, in orbital habitats and the innumerable biospheres and habitats out to the Oort cloud (very few of these had more than about 10,000 - most of them were essentially small towns in space).

Interplanetary Dark Age (530 to 900 AT)
Then came the Technocalypse and its aftermath which killed a significant number of sophonts all over the Solar system,and a somewhat reduced population on Earth. Whether a space habitat was attacked by technoplagues or not was often a matter of luck - like in the European Middle Ages when the great plague would sometimes jump entire villages to infect some place further on. So the swarms never got to saturate the solar system. This explains the odd rare case where an unprotected habitat somehow made it through the Dark Age.

Almost the entire population of Earth was expelled in the Great Expulsion, although many died in the so-called Last War and the subsequent Moon Wars.

First Federation and Afterwards (900 to 2100 AT)
At the start of the First Federation of Hu and AI there were perhaps 9 billion people in the old Solar System, and less than a billion in the extrasolar colonies; most of these populations vigorously expanded over the next 1100 years, with an average growth rate of 0.47%. By the end of the Federation period the total population reached 290 billion people in more than a hundred star systems. Population growth was often regionally higher on new terraformed worlds, where it may reached several percent (again, hyperpopulationists escaping the restrictions of the Solar System - but this also required terraformable worlds, which were less common than anticipated.). Also as nanofacture became more efficient it became progressively easier to convert asteroids into self-contained habitable cities and biospheres (to convert a decent-sized, 5 to 10 kilometer radius, asteroid to a habitat from scratch was be equivalent perhaps in terms of time, skills, and cost to erecting a skyscraper or a high-rise apartment block for an Information Age technology) colonisation and population growth were quite high in some places. Elsewhere it was low, at less than 0.1 %, especially in resource poor areas. Some religious groups, impoverished anthropist colonies and others with ideological reasons had the highest population growth.

Age of Expansion and Empires, 2nd Federation (2100 to 4450 AT)
Between the ages of Expansion and the Second Federation the growth rate was locally higher, although many of the inner sphere worlds had have reached stable populations. The average growth rate remained around 0.1%, with a few disasters like the Taurus Nexus and the Conver Ambi collapse causing local die-offs. Between 10 and 100 billion people died in these wars; after the first Consolidation War there were 1,015 billion people and after the second 1,711 billion people - even the atrocities of these wars were small compared to the total population. At the verge of the Version war in 4400 there were 3,000 billion people.

The Version War and Afterwards(4450 to 10600 AT)
It is unclear how many died in the Version War; given what is recorded about Alexandria, Bourgatov and other worlds perhaps several hundred billion people may have died but there are also the claims that the second Consolidation war was bloodier. It is assumed by most demographers that 100 billion people died and that the growth rate during this era continued at 0.1% (much of the frontier, where by now the vast majority lives, was unaffected, and even isolated systems could prosper) so the population at the height of the ComEmp in 5000 AT was about 4,780 billion people. Since the Version War the biont population of the Terragen Sphere has grown at approximately 0.147%, a figure which includes large populations on very large megastructures such as Cableville and Kiyoshi.

Cableville 2
Image from Steve Bowers
Cableville has a very large inhabitable surface, and a comparatively large population, but still has a very low population density in the Current Era, with vast regions of uninhabited wilderness

Localised Runaway Population Events

A small number of localised population explosions have happened in the Terragen Sphere at various times, such as the one at eta Cassiopeia (with a peak population of 50 trillion) and the larger event at Bethsyngaria (maximum population 1.2 quadrillion); but since these locations also suffered almost complete population collapse, these numbers are not generally included in the running total.

The Current Era

In the Current Era there are approximately 78.41 quadrillion biont sophonts in the Sephirotic Empires; even after the Oracle War this number has not been significantly diminished. The biont casualties of the Oracle War were comparable in number to those in the Version War, but almost all of the casualties in the later conflict were backed up and so could be recovered.

Aioids, Vecs and Neumanns

Aioids, vecs and neumanns have to be counted separately from bionts. Most vecs were part of the Metasoft Version Tree or Silicon Generation at the start of the Version War in 4400, and there were 23,512 billion Metasoft vecs at that date.

Some Autowars like the Mother of the Machines, the Biowars, etc., are self-reproducing and hence form a fairly sizeable population. Although the number of autowars themselves is small relative to other kinds of being, there are countless millions vec "workers" for each "queen". A million autowars in the sparsely patrolled Outer Volumes and Periphery regions translates to about 20 billion to 100,000 billion "worker drones" depending on the definitions about the degree of independent intelligence required for them to be considered separate individuals from the autowar "queen".

In general all replicating entities that become common in the Outer Volumes become dominant in the statistics in later centuries. The Inner Sphere is a small, static place by comparison.

In the Current Era the total number of vecs, neumanns and other aioids is approximately 100 quadrillion, which represents a somewhat slower growth rate of 0.15% since the Version War. Note that the First and Second Vec Wars and the war with the Hypercorruption Expanse did not slow the overall population growth down significantly, since the vecs were mostly backed up as well.


Xenosophonts represent only a small proportion — none of the alien races encountered so far equal Terragen civilisation in vigour or aggressive ability to expand and colonise new systems; this is keeping with the xenopaleontological pattern of of only one big "superpower" per however many millions of years in a region. There are rather few Muuh or Soft Ones on each of their worlds, (they reproduce very slowly), but their worlds are quite numerous beyond the rimward edge of the Terragen Expansion, so their total number is quite significant.

The Terragen Sphere itself now holds quite a few To'ul'hs (they have been partially infected with human expansionism) as well as several systems with many Pipers, and a very few surviving Daharrans. Hildemar's knots and xenowormhole AIs on the other hand are very few in number.

There are also various subclades of Ultimates scattered through the Serpens region, often associated with human- or dolphin- derived clades. They may be locally numerous, although (apart from a few that have spent too much time around humans!) not expansionist the way the space-going To'ul'hs are.

Only thirty-one worlds of Cybyota have been discovered so far, although the Jeepers are starting to venture into mainstream Terragen society as associate members. Other xenos such as the Silent Ones, the Samaelians, Paulans and the Limners are even less numerous. However the total extent of Meistersinger territory is not known; it is possible that this race and others with whom they are in contact such as the Wayfarers are very numerous indeed.

Provolves and Splices

Provolves (enhanced animals) and Splices (modified animals with a significant fraction of human genes) are represented in fairly small numbers. Provolve worlds are spread out in many different empires, while splices are mostly found in the Utopia Sphere and Zoeific Biopolity. Moreover several large habitats have quite rapidly increasing populations of splices.

Virtuals, Copies, and other Non-bioids

The number of virtual sophonts of all kinds in the Current Era is not accurately known. Most statisticians and demographers of have problems with definitions, making official upload statistics complex. Whatever the number, the number of virtuals and copies is huge, since they are immortal and can rapidly copy themselves. On advanced worlds it is easy to back up a copy of yourself, and after a while these all add up (like the old joke about where do all the people fit in heaven). Of course the real expense comes from system requirements. It is not possible to keep too many copies running at once because of the amount of processing they require, unless they accept a very crude scale of simulation. So there are "cheap" copies and highly complex copies. Many worlds get rich renting out computer space and virchworlds for copies.

Then there are the solid-state and nanocyborg civilisations. These contain an unknown (but extremely high) number of virtuals, copies, aioids and other sentients. A human copy takes around 10E18 bits, which fits into an Ultimate Chip dissipating a few Watts. So a normal one cubic kilometer asteroid converted to computronium can house 10E15 copies - heat dissipation lowers this number, but there are few problems with having at least many billion in active form, and thousands of such asteroids in a single system. Most solid state civs are concentrated in small polities, but even one of those may have a multi billion population.

Virtuals are of two major types - those who are relatively similar to when they or their forebears were embodied, and those who have altered themselves into entirely different mind types. Those who do not alter themselves much may spend their time in activities similar to those of their embodied counterparts, engaging in socializing, exploring virtual worlds, and so forth. Those who do make extensive changes typically make their way to virches that are extremely alien from an embodied perspective. Some virtuals of both types will pause themselves for long periods of time, to travel into the future.

The current best estimate for virtual sophonts is around three hundred quintillion entities, many of which are inactive at any one moment. About 99.9% of all sophonts are virtual entities. Only a very small fraction of all virtuals choose to become embodied, although the large number of virtuals in total means that incarnate (ex-virtual) sophonts are not particularly rare.

Loci of Population

Zipf's law applies here: the size of the n'th largest settlement is around the size of the largest divided by n. So if the most populous system has 100 billion people, the second will be around 50 billion, then 33 billion and so on. And similarly if the number of systems with populations over 1000 billion is 100, the number of systems with one billion inhabitants or more would be around a hundred million. The law of course breaks down at the very small scale, but there are a huge number of backgrounder outposts and interstellar hermits living in interstellar space, frozen Oort comet cores, and so on.

Although an average terraformed planet has a carrying capacity of around 10 billion people, it is very rarely the case (apart from brief periods in a few unfortunate worlds run by hyperpopulationist clades) that a planet will have this many. Instead the big orbital bands and the asteroid belt complexes and megaplexes or the myriad bubblehabs possible in the atmosphere of a typical gas giant are the locus of most of the population in the Inner Sphere. The number of colonised solid worlds and moons runs to hundreds of millions, but only a tiny proportion of those are terraformed. Given a choice between living in a spacious orbital habitat or one of the numerous bubblehabs or dwelling in the relatively cramped and scarce domes or subterranean habitats on some environmentally hostile planet or moon, most people pick the former. There are also of course clades that have adapted to common planet types, hence giving themselves plenty of available worlds to inhabit.

Garden Worlds

The number of people on Earth-type garden worlds is very small. There is lot of pressure from ecologists to keep the planetside populations down. And they will get more income from tourism and selling genetic material than they will from overstressing the ecosystem with too many colonists. Moreover, the fewer people on each garden world the higher the real estate prices, so more money for the government or speculators or whoever in charge.

Terraformed Worlds

An extreme maximum may be 15-20 billion humans for a well-maintained Earthlike world. However even the best terraformed world is not as stable as Old Earth naturally is. Especially in the beginning of terraforming project there have been frequent disasters and eco-collapses, especially in early history. But gradually terraforming has become a fine art, and these worlds have become just as good as Earth (however to do a good job terraforming requires a lot more time, effort and expense than to just drop some nanites onto the surface for a shoddy DIY job (e.g. Skiiwsnnii). Many of the old worlds like Corona and Raphael have inherent ecosystem problems require constant maintenance to keep at Bay (though in Corona's case, that of a very long day/night cycle, it was eventually overcome by biosphere gengineering improvements).


Floating habitats on a suitable gas giant allow for extremely large populations if the atmosphere is seeded with self-replicating bubblehabs. The numbers of sophonts living in bubblehabs is underestimated in the popular imagination. This is in part because of a tendency for civilizations founded there to interact primarily with each other: a single gas giant can support an extremely large and diverse set of persons and polities, distracting the dwellers from 'Outworlders', and even with modern technologies the deep gravity well is a deterrent to travel. In fact, bubblehabs are second only to space-based habs in the number of sophonts they support.

Very Large Megastructures

Dyson swarms or shells and other large megastructures such as Metropolis Ring City, Cableville and Kepleria can increase the carrying capacity of any system to an almost unimaginable level. Others include Cog, Kiyoshi, Ain Soph Aur and Oikomene. The Efficiency Maximisation Paradigm builds power collection shells to support their large virtual populations, a strategy that has been followed in other locations.

Rotating Space Habitats, Asteroids,and other Microworlds

Rotating Space habitats are typically large and comfortable. Although they can be moon-sized, these are fairly rare. The average rotating hab in the terragen sphere is 15-40 kilometer long cylinders, typically with lengths 50% greater than widths. If more space is required the same hab can be grown in either dimension or more may be built. The deviation around the average is large, for example: the sophonts of the MPA often build a moon sized space station just for the sheer beauty of a weightless airspace 1000 kilometers across. Large McKendree cylinders are also increasingly common, but are often sparsely inhabited.

Hollowed-out asteroids are the cheapest and easiest — these are common in the Outer Volumes and newly settled and low resource systems. In the more highly populated, industrialised, or longer settled systems there are clusters of larger and small and every size in between O'Neill cylinders, Bernal spheres, toruses, and designs descended from these. A cylinder is the most efficient form for the bigger orbitals as it can be made to rotate around its long axis and mirrors and so on to give a day/night cycle. A torus is better for a smaller orbital (say 1 or 2 kilometers in diameter) because if a long cylinder is too small there is a noticeable Coriolis force if it rotates fast enough to get an earth-type gravity (for microgravity clades this isn't a problem). But other designs can be used as well (or even instead).

Continuous Orbital Bands

A solid orbital band is a megascale project found around some moons and the occasional planet in the big industrial systems. They are also unstable without active control even if they are flexible, so they are rather expensive. These may rotate as a whole unit to provide a small amount of internal gravity, and become a Ribbonworld.

Population Distribution

In the Inner Sphere and Hinteregions the biont population is roughly distributed as follows:
17% live in standard rotating space habitats ranging from the ubiquitous smaller enclosed habs up to midsized 'open-air' structures such as Bishop Rings in size;
10% live in bubblehabs, mostly in the atmospheres of gas giants;
39% live in or on very large megastructures such as Banks Orbitals and Ringworlds or extremely large ones such as Cableville, Kepleria or Kiyoshi;
11% are tweaks living in open environments on unterraformed or lightly modified non-Gaian worlds;
9% are on terraformed or extensively worldhoused planets or moons;
7% are space-adapted clades living on asteroids or other small bodies or in microgravity habitats;
3% in dome habs on the surface of a planet or moon
2% live in novel environments such as ederworlds, Niven clouds , Freesphere, etc.
1% in worldships and civilisation ships;
1% on naturally occurring garden worlds

Estimates vary, but there is a large and often undocumented population in Kuiper belts and Oort Clouds at the edge of star systems, or on and around Stevensonian ('rogue') planets in interstellar space. These might account for as little as 5% or as much as 50% of the Inner Sphere population. Uncertainty in these numbers reflects the facts that many of these are Hiders or are merely indifferent to the rest of Terragen civilization. At the upper end this would increase the total numbers of smaller spinning habs, bubblehabs, and microgravity habs.

As one proceeds further into the Outer Volumes the proportions change radically so that along the Periphery there are many half-terraformed worlds and no hyperlarge megastructures; a larger proportion live in asteroids, in domes on planetary surfaces, in bubblehabs, and in small space habitats.

A list of some of the more populous systems in the Inner Sphere and innermost Hinteregions:
Aleph Absolute; Ain Soph Aur; New Mars; Orinoco; Corona; Kepleria; Kiyoshi; Sol; New Root; Fons Luminis; Metropolis Ring City; Ken Ferjik; Merrion
Other runners-up:
Ararat, Cocac, Daffy, Djed, Eden, Enremdea, Fata Morgana, Frog's Head, Heartland, Nova Terra, Pardes, Shamash.

Due to the huge number of uncertainties the total population of the various empires and major clades is hard to calculate. The following are rough percentage estimates of non-virtual population for the core worlds or clades, based in part on claims by the empires themselves, and in part on independent simulations and surveys. Note that these proportions do not include the colonialist possessions and local administrations, or the large number of worlds nominally within empire deep space but not part of the actual empires:
Amalgamation 0.01% (?)
Caretaker Gods 0.005%
Communion 0.1%
Cyberian Network 0.4%
Cygexpa 0.15%
Emple-dok-cetic 0.05%
Genen 0.02%
Keter 1.2%
Laughter Hegemony 0.2%
Metasoft 1.0%
MPA 3.9%
Muuh 4.0%
Negentropy Alliance 0.7%
New Daffy Panoparchy 0.15%
NoCoZo 0.8%
Orion Federation 0.2%
Paradigm 0.4%
Puppis Democracy 0.01%
Refugium Federation 0.1%
Sagittarius TC 0.2%
Silicon Generation 0.25%
Soft Ones 3.0%
Solar Dominion 0.8%
Sophic League 0.4%
Stella Umma (core) 0.005%
Stella Umma (shell) 0.015%
To'ul'h 0.05%
Utopia Sphere 0.5%
Zoeific Biopolity 0.5%
Other regional empires ~20%
Hiders ~10%
Others ~49%

"Others" includes a huge number of small non-aligned systems, petty empires, outer volume, periphery, and so on. Almost all of these are small politically and militarily irrelevant systems and minor federations and alliances.

The Shadow Federation/Hiders/etc. are a very large and very incoherent group. Though they were originally thought to have been restricted to the vicinity of Sol and other near stars region, it has become increasingly evident that they have expanded nomad fashion (and generally at sub-relativistic velocity) throughout much of known space, colonising outer oort clouds, harvesting interstellar dust, and in general avoiding contact with the major powers.

The Emple-dok-cetic figure is deceptive. Although the overall percentage is small, this does not include the huge number of non-aligned and semi-aligned worlds using Emple-dok-cetic technology and influenced by their culture and ideology. Were they to be included, the number would rise to perhaps 0.8%.

Naturally the empires themselves give rather inflated figures. For instance if one includes total Dominion space it may be 8%, but most of those worlds really don't even consider themselves Dominion, so they would fit in the category of "other", with only a tenth of the worlds really Dominion.

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Development Notes
Text by Anders Sandberg
updated by Radtech497, Steve Bowers, Stephen Inniss, Todd Drashner and Ryan_B
Initially published on 23 October 2000.