Infinite Scattering: The Future of Spacefaring Civilization?

When speculating about alien intelligence, much is made of the fact that we see a cosmos primeval rather than a cosmos being eaten away by artifice. What if, instead of proving there are no advanced spacefaring civilizations out there, it proves that some of our ideas about what an advanced spacefaring civilization would look like are wrong?

In Thomas Moynihan’s fascinating May 2020 Palladium article “Our Visions of the Future Determine Our Society Today”, which relates to ideas I explore in more depth in my post “The Coming Union of Intelligence and the Cosmos Primeval”, it is pointed out that futurists often envision an advanced civilization as a “technological cancer” sweeping the galaxy, consuming planets and even whole stars for its material and energy needs.

The presence of such a culture, if it covered much of our galaxy, would be obvious! Yet we see no sign of it. If such a culture even covered one whole galaxy in the nearby universe it would be detectable to us. Quite a few searches for such a culture have been done of thousands of galaxies near us, yet not one has been found.

The question of “If alien intelligence is common, where are they?” has been dubbed “the Fermi Paradox”, and one solution is that we are indeed alone in the universe, that our intelligence is unique. That seems very unlikely.

Firstly, the ingredients for life are common, and life formed on Earth very soon after conditions became favorable, suggesting that life arising is easy and very likely, and should be present on all the water-rich Earth-like planets we’ve discovered are common in the universe. Secondly, once life forms, complexity and intelligence tends to increase as long as the environment permits it. While it’s not inconceivable that human intelligence is unique, is there a likelier explanation?

Infinite Scattering: a Solution to the Fermi Paradox?

I believe there is. The simplest explanation by far is that advanced civilizations, at the level needed to consume all the stars of a galaxy, go down a path of technological development that gives them options better than consuming all the stars in a given galaxy. What might those options be?

I would venture forth “infinite scattering” as one explanation for how life seems like it must be common yet we see no truly large-scale machinations of advanced civilizations. Although the more advanced stages of this are very speculative, there is an earlier stage of “infinite scattering” that is based on much harder science.

The first Stage of Infinite Scattering

Whatever the population of a planet is, once its denizens expand out into the rest of its solar system, population density decreases dramatically. Our solar system contains as much surface area as ten thousand Earths, and needless to say the human population isn’t going to increase by a factor of ten thousand any time soon. As more and more of the population becomes spacefaring, the civilization becomes more dispersed and less concentrated.

By the time population expands to become ten thousand times larger, assuming that ever happens at all, slower-than-light interstellar colonization will be in full swing, further multiplying the area available for the culture’s people. We should therefore expect that as the spherical volume increases population density will decrease.

There might be only a small population in each star system; even for a civilization that has many orders of magnitude greater per capita energy consumption than we do there might not be enough population at each star system to make structures like Dyson spheres worth the effort. The wandering tribes of such a widely dispersed civilization could for all we know be within our own neighborhood of the galaxy right now.

Over long enough time periods, however, problems with this picture start to appear. At least a few civilizations should experience exponential population growth over extended periods, which will overwhelm the expanding volume and convert it to rather obvious artifice. Other factors unknown to us could be at work ensuring that any such civilizations don’t arise in the first place, don’t stay that way for long, or don’t survive over the long haul.

It could be simpler than that. There might be sources of power unknown to us that are far superior to the crude artifice of Dyson spheres, so superior that no sane civilization would use Dyson spheres for their power source.

The second Stage: Infinite Scattering through Wormholes

Wormholes are speculative structures that bend the fabric of spacetime to shorten the distance between two points. The “ER=EPR” conjecture in physics speculates that quantum entanglement and Einstein-Rosen bridges, a type of wormhole, are actually one and the same. Since quantum entanglement is commonplace, and according to an extension of this conjecture might even determine the structure of spacetime and thus gravity, it follows that wormholes are also commonplace in nature.

Einstein-Rosen wormholes are non-traversable, but it has been proposed that such wormholes could be stabilized artificially, thus permitting transit through them. If this could be accomplished, instantaneous travel to any point in the universe would become feasible.

Now that’s something that could cause infinite scattering! The current human population spread over the entirety of the visible universe yields an astonishingly low density of perhaps an octillion square miles per person. That’s over a thousand galaxies per person! A band of a hundred people would have over a hundred thousand galaxies to roam through together.

And consider that this is only the visible universe! It’s thought to be almost certain that the universe’s actual size is far larger than what we can see, at least 250 times larger by many estimates. For all we know space could be infinite.

Even with infinite space, however, the density of civilizations’ origin points puts a lower limit on how low density can go. If, for example, every galaxy contains a billion aliens, the population per galaxy cannot go below a billion per galaxy no matter how much civilizations scatter.

The only way to bring the median galaxy’s density down below that is for populations to, paradoxically, predominately concentrate in only a few galaxies, leaving most of the remainder empty. That would leave many volumes of space as large as our observable universe devoid of detectable activity. For all we know there could be galaxies covered in the far-future equivalent of urban sprawl, it’s just that they’re so rare that none of them are in the volume of space we can see.

Wormholes to Infinite Universes

It’s worth noting, however, that wormholes can just as easily connect our universe with other universes as well, not just different points within our universe. If the many-worlds interpretation of quantum mechanics is correct, each universe splits with every event that happens, producing an extremely large number of daughter universes. Some speculative theories of physics such as string theory also predict other universes are out there, albeit through different mechanisms.

Wormholes could in principle connect all these universes, providing a gateway for aliens and humans to pour into less-populated universes and continue “infinite scattering”. An infinite number of universes provides for an infinite number of unpopulated universes to colonize. Of course there would also be an infinite number of heavily populated universes, but since there’s an infinite amount of space to flee from their teeming hordes they shouldn’t present a problem.

More speculatively still, it has been proposed that “baby universes” or “basement universes” are created by black holes. If this process occurs naturally, in principle it could be replicated artificially. Especially if you have wormholes to connect them to the mother universes, why not go and create a whole new universe just for yourself?

It has sometimes been suggested that advanced civilizations might sequester themselves away in virtual realities, needing real mass and energy only for their computation needs. But why simulate a universe when you can create a physically real one instead? Why even bother with living in a virtual reality when you can grant yourself the same abilities in physical reality?

Taking my Space Opera Setting into the Far Future

One reason why I’m grappling with these questions now is that I am contemplating what would happen in my own science-fiction space opera setting in the far future. The furthest in the future I have set any story thus far is circa 2060, in “Letters from the Airy Deep”. The 21st century is more advanced in my world than it is in ours, with it being an alternate history, but the premise of “Letters from the Airy Deep” is plausible enough for the 22nd century in real life, perhaps the 23rd or at latest the 24th.

In any case the speed of technological advance is faster in my world. Instead of increasing by a one order of magnitude in the 20th century, from 0.6 to 0.7 on the Kardashev scale, primary energy consumption increases by four orders of magnitude, from 0.6 to 1.0. This is largely due to the unlocking of nuclear power, catapulting human civilization to Type I overall, equivalent to the total solar energy that falls on the Earth, though ironically with solar power representing only a small fraction of the total.

At a rate of four orders of magnitude per century, by 2100 humanity will be at 1.4, by 2200 1.8, and by 2250 a Type II civilization, equivalent to the sun’s entire output! The big problem is that nuclear fusion reactors, which by then in my timeline will be the primary energy source, can’t produce that much power, not without taking apart the sun and other nearby stars and stripping them for hydrogen at any rate, which will be somewhat beyond their abilities to say the least.

This will represent the end of a centuries-long period of rapid growth in energy consumption and the broader economy; without that tailwind of unlocking nuclear energy living standards will grow much more slowly once nuclear fusion reactors’ efficiency approaches the limits imposed by the laws of physics. Living standards will still grow, since increasing the sheer scale of mines, reactors, and explosive devices will yield gains, and technologies to more efficiently use energy should still advance.

As fusion reactors approach their limit, growth might gradually slow, perhaps starting as early as the 22nd century, and eventually level off at a much lower level than the torrid pace of “10,000 times greater in a century”. Stagnation, at least in relative terms, might set in during the 23rd and 24th centuries and later.

A new Age of Nomadism

It’s likely to be a pleasant stagnation, however, since although technology will advance only slowly compared to the heady days of the nuclear revolution, there will be plenty of room and resources for everybody. Spaceships and space habitats, the abode of most people in my setting by then, freely roam the galaxy, the resulting nomadic band society representing in many ways a return to the Paleolithic, the dawn of the first unsettled industrial-technological civilization, and the end of sedentism.

Technology will likely still advance at a pace faster than it did in the Paleolithic, but a kind of “Space Age Stasis” will set in, as mankind spreads to a plethora of new solar systems. In my setting I am planning two key breakthroughs that will bring this era to an end.

First, wormhole technology will be developed, not enough to send a manned ship through to any destination, but enough to create stable non-orientable wormholes. This will enable the orientation and charge of matter sent through to be flipped, passively turning matter into antimatter.

This will, over the course of perhaps a century or two, increase energy consumption by a hundred times. The attendant economic and energy consumption growth rates would be equal to or somewhat greater than our 19th and 20th centuries, though not as fast as this world’s 20th and 21st centuries.

A New Order for another Millennium

A whole new suite of technologies aside from antimatter production will open up with wormholes, from communicating instantly over long distances, to instantaneous travel to previously unattainable locations, to possibly accessing the interiors of black holes and parallel universes. Installations manufacturing black holes for the purpose of creating new universes artificially, or possibly using wormholes to access suitable naturally-occurring universes, are a distinct possibility.

I’m still not entirely sure about the time period I want to introduce these innovations, aside from wanting a few centuries after the nuclear revolution to have a “space age stasis” period. This takes us to at least the 27th century. I have been thinking that some time in the 30th or preferably 31st century or later might be the best time. Over a thousand years almost anything could happen to demographics and many languages would diverge and evolve substantially.

A thousand years after that would give more time for demographic and linguistic divergence before wormholes reunite the various solar systems, but almost two thousand years of Space Age Stasis might be a bit much for my taste. The sweet spot might be about a thousand years in the future. That is still subject to revision, though.


The idea of infinite scattering, although it is extremely speculative, is fruitful for both speculation about the real-world human future and worldbuilding for science fiction authors such as myself. The possibilities, particularly once the nomadic space age sets in and after wormhole technology is developed, are vast. Such a setting, in either the time of scattering before wormholes are harnessed, or the time when scattering really takes off after they are, is at least in my view a fascinating place to explore.

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