# Overview

In the article Orbital Rings and Planet Building, we tackled quite a lot of different topics; but the main goal of that article was to describe how, by using orbital rings, we could colonize the solar system, or more generally other solar systems as well. In the last two articles, Preliminary Interstellar Missions and Spaceship Comets and Highways Through Space, we talked about leaving the solar system. But those two articles primarily only discussed the prospects of spacecraft and robots leaving the solar system and venturing outward into the interstellar expanse. But in this article, we’re finally going to discuss how large numbers of people could leave this solar system and colonize other star systems in the Milky Way galaxy as well as the star systems in galaxies beyond the Milky Way. In the video on Shkadov thrusters we discussed what humanity would do after colonizing the galaxies—namely, they would merge those galaxies together using Shkadov thrusters. And, in the article on orbital rings and planet building, we discussed what we’d want to do after merging those galaxies together—namely, we’d proceed to deconstruct those galaxies and construct Birch planets. What they would do after that is something which we’ll discuss in detail in the next article, String Theory and Colonizing the Multiverse; and, later on, in Super Intelligence and Machine Rebellion, we’ll discuss in greater detail the use of shell worlds (such as the Birch Planet) to create enormous supercomputers which could also run super intelligent AGIs. In this article, we’ll cover another intermediate step—namely, how would we humans (not just self-replicating machines) actually colonize galaxies and spread our species and biosphere across whole galaxies. To do that, we need to use star lifting to manufacture billions or more interstellar generation ships; those great vessels would traverse the interstellar expanse by utilizing methods which we have discussed before; namely, we could use an interstellar highway to speed up and to slow down those arc ships as they travel from one star system to another, and vice versa.

Also, something which we discussed before, we could build mass drivers on myriad comets dispersed throughout two Oort clouds in adjacent star systems as well as comets dispersed throughout interstellar space (in other words, build mass drivers where the laser stations are) which would launch pellets of cargo containing fuel, life support, and other volatiles which would eventually be intercepted by the crew departing in their interstellar arc ships. And we also discussed how orbital rings built around the gas giant planets could be used to launch pellets contain helium-3 and deuterium (that is, the fuel) out into interstellar space where it would eventually rendezvous with those interstellar spacecraft and be used to refuel them. Those ideas of sending pellets containing cargo which would intercept with interstellar spacecraft have been mentioned by the engineer Robert Zubrin as well as recommended by the physicist Cliff Sing, A very similar approach would be used to cross the intergalactic abyss to reach other galaxies beyond the Milky Way: in between the galaxies, there are star systems containing both stars and planets which are liberally strewn across intergalactic space. We could either find such intergalactic star systems which are already in a roughly straight line in between two galaxies or, by using Shkadov thrusters, we could move intergalactic star system to positions where they do form a roughly straight line in between two galaxies—and doing that should be possible using artificial intelligence, robots, and spacecraft. Using orbital rings as launch systems, we could launch pellets containing cargo to intergalactic arc ships leaving the galaxy. And, also, laser stations could be built on moons or asteroids out there in intergalactic space; this would allow us to create a kind of intergalactic highway between both galaxies. This strategy ultimately depends on star lifting to build all of those arc ships, orbital rings and/or launch loops to transport cargo to the ships, and laser stations dispersed on bodies between the beginning point and the destination to be used for speeding up and slowing down your ships. And it is precisely this strategy of getting ships to other star systems and galaxies which will be the primary focus of this article. In the previous article, Spaceship Comets and Highways Through Space, our discussion was still somewhat close to home and we basically discussed how we humans could leave our solar system and meander to another; but in this article, I’m going to try my best to gradually move outward by discussing how humanity could colonize many star systems, the entire galaxy, and eventually other galaxies by using arc ships and other methods.

# Arc Ships

This brings us to the third method that humans could use to colonize other star systems. They would build gargantuan arc ships like the O'Neil cylinder or an artificial planet and use that as a spaceship to reach another star system. As we discussed in the previous article in this series entitled, Orbital Rings and Planet Building, by star lifting the Sun they could obtain enough materials to manufacture billions of interstellar arc ships. We also discussed using (to borrow the nomenclature which Paul Birch used in his original papers on orbital rings) suprajupiter, suprasaturn, suprauranus, and supraneptune as fuel depots for those interstellar vessels. Gas giant refineries would be connected to shell worlds englobing those Jovian planets (and, indeed, other gas giant planets created from material extracted from the Sun); those gas giant refineries would then be used to extract helium-3 and deuterium from those gas giants atmospheres which would be used as fuel for the interstellar arcships.

Artist’s depiction of gas giant refineries used to extract materials such as helium-3 and deuterium from the atmosphere of one of the Jovian planets. Artwork by Neil Blevins at Artstation.

But a question which we didn't really address in much detail in that previous article is how the fuel would get to the interstellar arc ship. At first, the answer to this question might seem obvious: just land the arc ship on the shell world and fuel up the arc ship right there on the spot. We wouldn't actually do this because there would be many problems with this approach: first, you'd have to overcome a lot of gravity and, second, you'd have to accelerate all of the fuel up into space. The latter means that you'd be having all of the same problems that you'd have with the chemical rockets.

To avoid the problem of having to accelerate a ridiculous amount of fuel in addition to the large clunky spaceship, we could employ an idea proposed by the Princeton scientist Cliff Sing which would involve launching a stream of pellots; each pellot would consist of useful cargo for the interstellar travelers including water, hydrogen for either radiation shield or raw mass to generate gravity or both, nitrogen and oxygen for an atmosphere, and most importantly helium-3 and dueterium which would be the fuel for the interstellar spaceship. Those payloads could be sent both before and after the interstellar arc ship began its journey to the stars; in either case, whether the payloads were sent before or after, those payloads would eventually randezvous with the arcship. This method is how we'd provide fuel and life support for the humans and biospheres on board those arc ships during its passage from one star system to another. (This is true whether or not we're talking about arc ships passing from the Sun to Proxima Centuari or from a star at the galactic edge of the Milky Way to a star in intergalactic space that doesn't even belong to a galaxy; but we'll discuss that in greater detail later on.)

In the previous article in this series, we echoed a discussion in the phycisist David Criswell's paper on star lifting that star lifted hydrogen and helium could be stored in great big spheres which orbit the Sun at great distances. Those spheres would be gas giant planets in there own right, In the previous article, we only discussed one way to build a planet: by surrounding a planet with many orbital rings which could be used to support a surface. That surface would be engineered to resemble the Earth's geosphere, hydrosphere, biosphere, as well as the man-made cities and infrastructure on Earth. These wouldn't be "real" planets, but rather artificial ones. Later on in this article, we'll discuss two other ways to make a planet. One other way, which I'll mention now, would just involve smashing a whole lot of material together until you ended up with so much mass that that object would become round, spherical, and fairly smooth. Now that's somewhat of an oversimplification, but it does get the basic idea across. More specifically, you would want to replicate, more or less, the exact conditions and natural process which would lead to a planet's formation in an accretion disk in a newly born solar system. This would be yet another example of biomimickery; where our industrial processes and engineering endeavors mimic nature and processes and designs which are natural and the result of spontaneous processes which unfold according to the laws of science. But, as I said previously, what you'd be doing is smashing a bunch of atoms and material together until, eventually, you ended up with a planet. Now this would be less like an artificial planet and it would be more or less identical to the "real" planets which we actually observe in nature. Now, I imagine that there are certain kinds of planets which would be easy to make. For example, to make a gas giant planet comprised of Sun-lifted hydrogen and helium, you simply bunch together hydrogen and helium at an appropriate distance away from the Sun and you keep bunching more and more hydrogen and helium together until you end up with a planet with an appropriate mass which is comparable to that of a real gas giant.

One question that you'd might be asking yourself is how exactly would we launch that material once it is extracted using gas giant refineries. The answer is by using an orbital ring. I'm going to include a discussion later on where we talk about how an orbital ring can be used as a lunch system. We'll not only discuss using an orbital ring to launch materials rom the Jovian planets, but we could also use an orbital ring around the Sun to launch star lifted material. We'll go through all the numbers and, after doing so, it'll be pretty self-evident that we'd end up with so much hydrogen, helium and other resources that we wouldn't be able to use it up all at once. For this reason, Criswell imagined storing the hydrogen and helium (comprising roughly 98% of the mass of the Sun) in immense spheres at great distances from the Sun. Those Sun-lifted materials would be launched away from the Sun by using an orbital ring which surrounds the Sun. After those planets are formed we would, as we just discussed a little bit ago, launch materials from those gas giant planets (that we created) into interstellar space where they would eventually be intercepted by interstellar arc ships.

As much of a pain as it might sound like having to refuel your ships in this way, it is preferable (for aforementioned reasons) to having your ships hauling along vast amounts of fuel. I have just outlined three different ways humans could venture to the stars: first, by sending small fast ships; second, by hopping from world to world until you reach the nearest star; and third, by using star lifted materials to build giant arc ships which would take you and much of the Earth's biosphere to another star system. The next three sections of this article will explain each of these strategies of getting to the stars in more detail.

# Crossing the Interstellar Expanse

“A continued look at Generation Ships and Interstellar Colonization. Check out Cheddar's video on the Sun: https://chdr.tv/youtue6886 In order to colonize the galaxy, we are going to have to spend huge times on board equally huge spaceships. To move thousands of people, and our ecosystem, to distant planets, will require not only giant ark-like starships, but entire fleets of them.” This video was produced by the SFIA Production Team.

One of the things we'll focus on in the article are the details of how a K2 civilization would attempt to become a K3 civilization by sending entire fleets and armadas of arc ships—each containing up to several million people—to other star systems. An arc ship, or generation ship, is by itself a gargantuan object which would require a vast amount of materials to build. For a K2 civilization to even to attempt to colonize the Milky Way, they would need to send millions of self-replicating Von Neuman probes and millions of these arc ships. The amount of materials and energy which would be required to accomplish such a feat would not be even remotely feasible for a K1 civilization, let alone a civilization such as we who haven't even reached K1 status yet. Only a civilization which could extract material directly from its parent star via the use of star lifting would be able to acquire the amount of materials necessary to build millions of arc ships.

Why, one might ask, would it be necessary to send a fleet of ships? The first reason is because it would better the odds of us actually getting to another star system. This is because, for any given arc ship, there could possibly be unforeseen complications such as that ship having some kind of structural flaws or that ship getting somehow damaged during its interstellar journey. Such unforeseen complications might jeapordize the mission for those onboard of one arc ship, but the other arc ships could be untouched. Thus, by having back up arc ships a castrophere which happens to some arc ships wouldn't jeapordize the entire interstellar mission.

The details of what an interstellar mission would look like very much depends on how advanced the civilization undertaking the interstellar journey is. Indeed, this fact is something which we covered previously. Here's two examples. A very primitive Type 0.72 civilization like us—would likely embark on its first interstellar journey by sending myriad solar-sail space craft—capable of self-replication—to only the nearest stars. A slightly more advanced civilization would attempt their interstellar journey by sending much larger spacecraft—powered by some combination of solar sail and nuclear fusion—to the stars. These two separate examples underscore what I meant by how interstellar missions would differ based on how advanced the civilization embarking on the journey is.

Imagine every advanced K2 civilization—one that is many centuries if not several millennia ahead of we—which has already colonized nearby star systems and have already built various different kinds of megastructures around those stars and planets and which have built laser stations on myriad asteroids and comets within each systems Oort Cloud. What exactly would subsequent interstellar missions of such an advanced civilization look like? The answer to that 1uestion will be the focus of this lesson.

As I previously mentioned, such a K2 civilization would be interested in large-scale operations and sendining millions of arc ships to millions of different star systems. The reasons why they would be interested in "doing things big" is because they would want to colonize the entire Milky Way Galaxy and convert our galaxy into a Birch Planet as soon as possible. (The reason why they would want to do this is discussed in the lesson, Why Colonize the Universe? and is also addressed a little bit in our video on Shkadov thrusters and our article on orbital rings.) It is important to mention that such an endeavor would only be made possible because of the megastructures and othe rinfrastructure built by their ancestors centuries or perhaps even millenia ago. Those megastructures and other infrastrucuture include the star lifters and stella lasers build around stars in colonized star systems and the laser stations located in the comets of Oort cluds surrounding those same colonized star systems.

We discussed in the article, Why Colonize the Universe?, why any advanced technological space fairing civilization would spread more and more outward as a strategy of staying a live. The threat of nearby supernova explosions, in particular, is the most compelling argument that I can think of as to why a K2 civilization—or indeed any technological civilization—would want to spread out to as many star systems as possible. If our descendants become a K2 civilization and are spread across myriad star systems and, due to their experience in interstellar travel, could easily colonize oany other close by star systems which they hadn't colonized yet, then they could effectively thwart any threat of nearby supernovae or supernovae within the Terragen Sphere (to borrow a term from Orion's Arm) by using either Shkadov thrusters to move the super or hyper giant star far away from them or by using star lifting to strip matter from the star which would extend that star's lifetime. Star lifting could also be used to make a star too small to undergo a supernova. At any rate, no matter what method we use to prevent a supernova from effecting us, it is clear that we will want to spead our human and machine presence (aka the Terragen sphere) to other star systems in order to actually be successful at preventing supernova form effecting us.

## Nicoll-Dyson Beam

But how would a K2 civilization actually do that? How would they actually go about settling all of the star system in their home galaxy? The simplest solution: by using self-replicating Von Neuman probes, interstellar arc ships, nuclear fusion as a power source, and likely solar energy in the form of concentrated star light and laser light as a source of power too. That's in a nutshell, basically how they'd get the job done. A stellalaser, also known as a Nicoll-Dyson beam, is a particular type of Dyson swarm that would surround a star; the numerous satellites comprising such a Dyson swarm would primarily be mirrors which could be used to concentrate the Sun's light into an ultra-energy dense, extremely narrow collimated beam of light which could stay focused on inflatable solar sails. Such inflatable solar sails would, of course, be attached to the interstellar ships. If those solar sails are several kilometers wide, then such a beam could stay focus on those solar sails all the way out to the Kuiper belt. This method would work great for accelerating our ships up to relativistic speed and it would allow us to save our fuel for nuclear fusion for later. Such a ship would have to accelerate at 1-gee since that's what would be most comfortable for the humans and biospheres being transported in the ships.

Nicoll-Dyson Beam

“Unleashing The Nicoll-Dyson Beam from Gigastructural Engineering & More. Inward Perfection has never been so easy when you can delete your enemies Capital systems with the press of a button.

Edit: It also has multiple settings. Ranging from reducing all infrastructure to rubble to Solar System Deleter.”

I'd like to mention that fuel shortages for such an interstellar mission would not be an issue. Allow me to explain. By time we become a K2 civilization, we will, by then, be using gas giant refineries (attached to shell worlds surrounding the Jovian planets) to extract deuterium and helium-3 from those Jovian planets. We could use a combination of electromagnetic launch loops, gravity assists, and laser power directed against inflatable sails  to launch tiny pods containing this fuel (and other resources) up to relativistic speeds with an acceleration far greater than 1-gee (and perhaps up to 100 gees for certain kinds of materials. This means that such cargo pods could eventually catch up to the arc ships and make a randevouz with them. Thus far, we have addressed how we could accelerate our ships up to relativistic speeds using a stellaser and how we could continuously refuel our spacecraft. But how would we maneuver them and slow them down? To maneuver them we could detonate explosives on the side of the ships which would send shock waves to shock absorbers that could steer the ship off of its original path slightly. But slowing down the ship would be much more difficult.

## Von Nueman Ships

Concept art by Mark Molnar

We could send self-replicating Von Nueman probes and autonomous machines to a new star system outside of the Terragan sphere; those machines could be used to manufacture a Dyson swarm of great big mirrors which could be used as a stellaser to slow down incoming fleets of interstellar vessels. Those machines could also be used to 3d print laser arrays on celestial bodies within that star system's Oort cloud.. They would also rely on a technology known as a magnetic sail, or magsail for short. Something called a Bussard Ramjet was originally intended to be used as a spaceship which accelerated by scooping up vast quantities of hydrogen ions in the interstellar medium—the "stuff" in between the stars—and fusing those ions together in order to produce thrust. But later, it was calculated that such a device would be useless for accelerating an interstellar spacecraft; the reason being that the ions slamming against the scoop would actually cause the ships to decelerate and slow down. The use of a Bussard ramjet to slow down a spacecraft is what we refer to as a magsail.

# Star Lifting: Prelude to Life Colonizing the Galaxies

Figure 1: A star lifter would consist of a ring of solar power stations and ion accelerators distributed around a star in the shape of a ring.

In the previous article Orbital Rings and Planet Building: Prelude to Colonizing the Solar System, we did talk a lot about both planet lifting and star lifting. The former, which is to say planet building, is a method of extracting materials from a Jovian planet's atmosphere which could be accomplished by building an orbital ring or shell world around that planet and then attaching gas giant refineries to such structures and using those refineries to suck up useful materials from a gas giant's atmosphere. The latter, which is to say star lifting, would involve building an enormous megastructure and Dyson swarm around a star which would extract and remove materials from a star's atmosphere and outer layers. I had mentioned star lifting quite a lot in that previous lesson without ever explaining to you all, how such a process would actually work? How could a megastructure remove "chunks" of stuff from a star? The most simple way wouldn't even involve using a megastructure; you'd just have a ship descend into a stars gaseous atmosphere and remove its matter by scooping it up. There is a celebrated scene in the TV show series, Stargate Universe, of intrepid human explorers sailing an interstellar ship through the atmosphere of a star and scooping up its matter. But there are also a couple more efficient ways of sequestering atoms from a stellar atmosphere. Think back to that previous article where we discussed building a shell world around the Jovian planets and how those gas giant refineries could be made to dangle from the ceilings of those shell worlds; those gas giant refineries, which are essentially just mega-skyscrapers, would suck up the materials from those gas giant's atmosphere. Now, it might be possible to do something similar with the Sun. Imagine that we build orbital rings around the Sun and use those orbital rings to support a spherical surface that englobes the Sun. That great big sphere would be what is known as a Dyson sphere.

"Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100 is a 2011 book by theoretical physicist Michio Kaku, author of Hyperspace and Physics of the Impossible. In it Kaku speculates about possible future technological development over the next 100 years. He interviews notable scientists about their fields of research and lays out his vision of coming developments in medicine, computing, artificial intelligence, nanotechnology, and energy production. The book was on the New York Times Bestseller List for five weeks."

The physicist Michio Kaku described in his book, Physics of the Future, that ranking how advanced and sophisticated a civilization is based only upon the Kardeshev scale (which only classifies civilizations based on there total power consumption) would be insufficient. There should also be other metrics which determine how advanced and sophisticated that civilization is such as their total data consumption, how well they minimize entropy in industrial processes, and how much they maximize waste. If metrics such as these partly constitute the post-scarcity economics of an advanced civilization, then I'd imagine that they'd hate the idea of having photons being ejected from the Sun and traveling for billions of lightyears across space and never being put to any good use. This is why it would make sense for them to build something like a Dyson sphere around the Sun or at least something which blocks a considerable portion of the Sun's light from beaming away from the solar system. Analogous to what we described in the previous article in this series about planet lifting, perhaps we could attaching very long tethers and refineries to the ceiling of the shell world which could be used to extract materials from the Sun's atmosphere. Whether or not this method or the one which would involve directly scooping matter from a star is uncertain.

But there is one method which would work, and it wouldn't even involve anything high-tech. Basically, this method would just involve the following steps: first, you'd build either an orbital ring or a Dyson swarm of satellites which surround the star in the shape of a ring; you would use either the orbital ring or the Dyson swarm of separate, individual satellites (depending on which one you built) as an immense particle accelerate which would generate a very large ring of current; according to Maxwell's equations—the laws of electrodynamics—this ring current would generate a magnetic field (see Figure 2) which would exert forces on charged atoms within the Sun's atmosphere. These charged atoms would move along the magnetic field lines illustrated in Figure 2. That matter would flow to magnetic rocket nozzles at both of the Sun's poles. In effect, such a technique could be used to gradually strip and remove matter from the Sun.

Stars naturally lose their material all the time through spontaneous and natural processes such as coronal ejections. Also, there is this thing called the Boltzman distribution which is a concept from thermodynamics. The Sun's atmosphere and outer layers (and, indeed, the outer layers of any star) consist of matter in its gaseous state; it is only at the core of the star do you get matter in its plasma state. The atoms comprising a gas move randomly, in every which way and in every direction; not only are their trajectories random, but so to are their velocities. But if you could somehow determine the speed of every atom, you'd find that they'd follow what's known as the Boltzman distribution. According to this probability distribution, a tiny portion of the atoms comprising the gas will have enough speed to escape the Sun's gravity well and fly off into outer space. Now this isn't light because light is made up of photons; this is actually matter and "stuff" made of atoms. This matter, or "stuff," is what we refer to as stellar wind. A star is constantly losing mass and material from its atmosphere in this way all the time.

But when you're star lifting and producing magnetic fields by a ring current that exerts forces on those atoms in the gaseous atmosphere; those forces cause those atoms to accelerate to even higher speeds meaning that even more of those atoms will achieve a high enough speed to escape the Sun's atmosphere. This would effectively increase the rate at which the star is losing matter. Now, the fact that star lifting increases the speed of the atoms in the star's atmosphere isn't the only reason why that rate at which the star loses material increases. Without that magnetic field generated by the ring current, those gaseous particles will just be moving randomly in all direction like electrons inside of a conductor with no electric field; we'd say that the average net displacement of such particle is zero. But when you have a field present, the motion is no longer entirely random and those particles will acquire what is known as a drift velocity which is in the direction of the field lines. This means that the gaseous particles in a star's atmosphere will tend to move along the magnetic field lines (in a kind of zig-zag trajectory) generated by the ring current, analogous to how electrons in a conductor will move along the electric field lines in "zig-zag" trajectories inside of that conductor after you turn the electric field on.

So, star lifting is essentially just a technique where you set up a ring of current, where the ring of current generates a magnetic field that exerts forces on charged atoms in the star's atmosphere which has the effect of increasing the rate at which that star loses matter. The two jets of matter (which would be the two cones extending away from the star's poles that you see in Figure 2) would be collected using magnetic rocket nozzles and then subsequently stored.

Now, I'd like to spend some time talking about that giant orbital ring or Dyson swarm of ion accelerators, either one of which could be used to star lift. First, I'd like to talk a little bit about how you'd go about building the first star lifter. The first star lifter that we build will likely be a collection of separate, individual ion accelerators that encircle the Sun. A very miniscule percentage (say $$0.01\text{%}$$) of the matter comprising the planet Mercury could be used to build and manufacture those satellites in space near the Sun. What we could do is attach solar panels to each one of those ion accelerators; those solar panels would provide power to those ion accelerators allowing them to generate a magnetic field (not to confuse this magnetic field with the magnetic field that would be used to extract materials from the star) which would be used to accelerate charged particles; those moving charged particles is the current.

These solar power stations could be distributed in the shape of a ring as illustrated in Figure #1. Each station would consist of solar power collectors, on the order of $$100$$ micrometers thick, which would recieve say $$20\text{%}$$ of the Sun's solar flux. $$50\text{%}$$ of that energy could be used to power ion accelerators.

Figure 2

If $$10\text{%}$$ of the solar flux emitted by the Sun was used to uplift plasma from the Sun's surface, then $$6.5 ×10^{18}$$ tons of material could be removed from the Sun per year. At this rate, it would take $$300$$ million years to remove the Sun's outer layers. By removing the Sun's outer layers, its pressure and temperature would have decreased enough for nuclear fusion to stop occurring at its core. Thus, the Sun would have had been converted into a white dwarf. The Sun would therefore no longer have an energy source and it would gradually radiate all of its remaining energy away as it cooled over the course of $$2.3$$ trillion years. The conversion of the Sun from a main sequence star to a white dwarf would be a monumental achievement of human engineering because it would extend the duration of the habitability of the Earth from billions of years to trillions of years. Main sequence stars eventually die after billions of years; but white dwarf stars continue to shine for trillions of years. Eventually, the Sun—even in its white dwarf phase—will cease to shine after a few trillion years or so. Once the Sun started to become too cool to support human civilization, our alien descendants could recompact and squish together a portion of the Sun-lifted materials to create a new white dwarf. This could extend the duration of stellar power sources for their civilization in their home solar system to roughly 30 trillion years since this is how long it would for the white dwarf, manufactured from Sun-lifted materials, to cease to shine.

But our alien descendants could probably do even better than that. After 300 million years, marking the end of Sun-lifting when the Sun becomes converted into a white dwarf, the Sun could then be squeezed and compacted into a sphere whose radius is smaller than that of the husbanded Sun's Swartzchild radius. In this way the husbanded Sun could shrink from the size of the Earth to the size of a point tinier than an atom. The husbanded Sun would have had been converted from a white dwarf into a black hole. We could extract energy from this black hole to power our civilization for a sweep of time millions of times greater than the present age of our universe. Over that vast sweep of time, our civilization would not only be supported by power emitted from the Sun but, as we shall discuss in elaborate detail, they would also be supported by the Sun-lifted materials.

After 300 million years of Sun lifting, a total of $$2×10^{27}$$ tons of mass could be extracted. That is the equivalent of over 300,000 Earths of mass. This is an astonishing amount of material and would make many engineering projects feasible which, without Sun-lifting, would be impossible. These engineering projects include the construction of megastructures such as Bishop rings, Bernal spheres, O'Neil cylinders, and ring worlds; the construction of new planets and stars; and the creation of biospheres and the emergence of human populations dwarfing those of present day Earth's by several orders of magnitude.

If we assume that the chemical composition of the Sun is more or less identical to that of the whole Cosmos comprising 63% hydrogen, 36% helium, and 1.4% other elements in the periodic table, then after 300 million years of Sun lifting $$4.8×10^{24}$$ tons of new water could be manufactured using hydrogen atoms scooped from the Sun and oxygen atoms imported from rocky planets, moons, and asteroids residing in the inner-solar system. This amount of water would be sufficient to create active hydrospheres within O'Neil cylinders, or ring worlds, or terraformed worlds within our solar system such as planets, moons, and asteroids.

The Sun-lifted hydrogen and helium could be cryogenically frozen and recondensed into balls of hydrogen and helium. These balls would be tiny gas giant planets which would orbit the Sun at great distances. This is essentially just a clever way of storing Sun-lifted hydrogen and helium. The Sun-lifted hydrogen would be extremely useful.

That 1.4% of "other stuff" are the atomic elements which would be used to manufacture materials such as metals, oxides and plastics. These are the materials which we'd use to build new megastructures besides the pre-existing star lifter. Now 1.4% might not sound like much - but actually it is! The 1.4% of elements comprising the Sun besides hydrogen and helium has a total mass on the order of $$10^{24}$$ kilograms. That is the equivalent of a Earths worth of stuff! Let's assume that for every square meter we used 10 tons of those materials to build stuff like space homes. Then, for each year of Sun lifting, we could build 1 billion square kilometers of new living area. This process could continue for 300 million years until the end of Sun lifting. After 300 million years of Sun lifting, we could have built an astonishing $$5.7×10^{17}$$ square kilometers of new living area. That is the equivalent to the total surface areas of a billion Earths. Perhaps one billion worlds could be inhabited by a mere few million people each. Thus, roughly 300 million years from now, what humanity calls home will have become a much bigger place.

That first star lifter that we build around the Sun is something which we could keep adding to. Over the course of that 300 million years as we extract the Sun's material, we could gradually, over time, build giant orbital rings around the Sun. Eventually, we'd have enough orbital rings to support a large ring-like surface. Now, this would represent an intermediate step in between when we built the first star lifter consisting of myriad separate satellites and when we built a full out Dyson sphere. As Criswell calculated, the process of star lifting would allow us to obtain enough materials to build one of these things and we'd have more than enough water to cover it with oceans, rivers, and ponds. And, using the 1.4% of "other stuff" that we obtained from star lifting, we could use all that material to build cities and transportation systems on that ring. But where do you actually get enough material to build rocky continents on this ring which would be peppered across the oceans. The answer is we could use mass drivers to move all of the asteroids and comets within our solar system to the ring where they could be disassembled and used to make those rocky land formations on the ring.

We discussed a little bit in the previous article how the Earth's lifeforms could life conformably inside of O'Neil cylinders and how those O'Neil cylinder could be used as giant spaceships to transport those living creatures to new worlds besides the Earth. These could be natural planets which have been terraformed like, for example, a terraformed Mars or Venus; but they could also be artificial worlds like a ring world surrounding the Sun. You could have some pretty vast fleets of these O'Neil cylinders arriving at the ring world; once they arrived, it would be very easy to transport the Earth's lifeforms to that ring world. This ring world would have a carrying capacity far larger than that of the Earth. These lifeforms could therefore reproduce much more and get much larger population sizes than we see here on the Earth.

# Use of Orbital Rings as a Launch System

“The Orbital Ring is a type of launch-assist system that goes beyond moving small ships and crews into space and allows cheap movement of bulk cargo up to space, into orbit, and beyond.” This video was produced by Isaac Arthur.

In the next section in this article (which discusses galactic and intergalactic space travel), we’ll discuss a few different ways that humanity could colonize the Milky Way as well as other galaxies; one of those methods involves using orbital rings as launch systems which launch their payloads across either interstellar or intergalactic space. And so, I thought it would be a good idea to discuss how, exactly, orbital rings could be used as a launch system. To explain this, I’ll remind you that orbital rings do indeed have multiple different uses; one of them, though, would be to build a maglev transportation system within the interior of the orbital rings; maglev vehicles (which would carry the payloads) would ride along the cushion of superconducting materials (and, as we’ll discuss in a subsequent article, Technological Revolutions, we have good reason to believe that we’ll have room-temperature superconductors by the year 2100) within evacuated tunnels that preside within the orbital ring’s interior. Using either space-based solar power (SBSP) collected from solar panels attached to the orbital rings exterior or geothermal energy from tethers that collect energy from a celestial body (i.e. planet’s), we could power those transportation units. The maglev vehicles, each containing their payloads, could be accelerated (at either small or large magnitudes of acceleration depending on the fragility of the payload) along the orbital ring’s circumference until the desirable velocities are achieved; subsequently, those vehicles and their payloads could be ejected from the orbital rings into space. After that, those vehicles and payloads would travel across vast distances across space and eventually rendezvous with either interstellar or intergalactic spaceships.

Let’s briefly discuss the basic underlying physics which describes how the maglev vehicles would be accelerated along the tracks within the orbital rings. If you imagined speeding up a vehicle inside the orbital ring to orbital speed (the speed necessary to orbit the Earth in a circle), that vehicle would essentially just be in free-fall and you’d experience weightlessness. We can use the equation, $$a=v^2/r$$, to confirm this. You might recall from your days in physics class that if you have a particle (in our example, you could approximate the vehicle and its payload as a particle) traveling in a circle around some central point, that particle’s inward centripetal acceleration $$a_c$$, it's tangential speed (also known as orbital speed) $$v$$, and the radius of the circle $$r$$ are all related by the equation $$a_c=v^2/r$$. In our example the vehicle would be traveling in a circular path where the radius of that circle is given by $$(R_E+80)km$$ where $$R_E$$ is the Earth’s radius and $$80km$$ is the assumed height of the orbital ring above the ground. Since $$r~R_E$$, for simplicity we’ll assume that $$r=R_E$$. To speed that object up to orbital speed (which is given by $$~7,900\text{ }m/s$$ for an object traveling in a circle of radius $$R_E$$) along a circular path whose radius is given by $$r=R_E$$, then you’d need to give that object a centripetal acceleration given by

$$a_c=\frac{7,900^2}{6,400,000}=9.8\frac{m}{s^2}.$$

In other words, that object would just be in freefall. The vehicle would travel at a speed of $$7,900\text{ }m/s$$ relative to the conduit floor (which does not have orbital speed and is stationary relative to the Earth’s surface). Passengers inside the vehicle would experience an apparent weightlessness since them and the vehicle would be in free fall. The passengers, of course, wouldn’t technically be weightless since the Earth’s gravity is still present (and, indeed, still fairly strong) at $$80km$$ above the Earth’s surface. The force of gravity (which would remain constant at an unchanging altitude of $$80km$$) is canceled out by the outward centrifugal force acting on the passengers and vehicle. Now if we increased the centripetal acceleration of the passengers and vehicle up to 2 gees (which, is to say, $$19.6m/s^2$$), then the centrifugal force would double while the force of gravity (which must stay constant according to Newton’s law of gravity since $$r$$ does not change) stays the same. Thus, the net force acting on the passengers is equal to the Earth’s gravity, but pointing in the opposite direction of the Earth’s surface. After 2 gees of acceleration is obtained, the passengers would therefore be standing (or sitting) on the “ceiling” of the vehicle.

It is commonly taken that 3 gees of acceleration is the maximum safe acceleration of a manned vehicle. But, as we’ve discussed, if the vehicle is accelerated to 1 gee, due to the effects of the gravitational force (which is also, in this example, the centripetal force) and centrifugal force canceling, the passengers will experience apparent weightlessness (since they are in free fall) and, hence, 0 gees of acceleration; and, at 2 gees of centrifugal acceleration, passengers will only experience a force equal in magnitude to that of Earth’s gravity (this is, again, due to the fact that the centrifugal force negates the effects of Earth’s gravity) and, hence, they will only experience 1 gee of acceleration. This means that we could safely accelerate passengers with a centrifugal acceleration of 4 gees. Using the equation $$a_g=v^2/r$$, we find that accelerating the vehicle and passengers up to 4 gees gives them a final velocity of

$$v=\sqrt{4(9.8)(6,400,00)}~5,800m/s~16km/s.$$

This final speed of the vehicle exceeds the Earth’s escape velocity; thus, by using the orbital ring, you could get your vehicle going fast enough to completely escape the Earth’s gravity well. Using the orbital ring and gravity assists from Jupiter, you could get to anywhere in the solar system.

More generally, you can build any orbital ring around any massive body and, accelerating your crew at 4 gees, the maximum velocity your vehicle could get is given by

$$v=2\sqrt{gr_{ring}},$$

where $$r_{ring}$$ is the radius of the ring. This equation shows that your maximum velocity depends upon only the radius of the ring. This gives us a pretty compelling reason to want to colonize gas giants like the four Jovian planets Jupiter, Saturn, Uranus, and Neptune. Not only can you build these orbital rings around any massive body, but you can build any number of them at any orientation and height relative to that body. The Jovians and indeed any gas giant has gravity far too vast to be hospitable to a biosphere; but at a sufficient distance away from the center of such massive bodies (which we shall call $$d$$), the gravity at that distance is identical to the Earth’s gravity. One way to colonize a gas giant would be to build many orbital rings around that body whose radius is $$d$$ and honeycomb those orbital rings with a spherical surface. This surface could retain an atmosphere, seas, land, and a biosphere and, if built around Jupiter, would resemble a gigantic Earth-like planet (with Earth-like gravity) with a surface area 218 times that of the Earth’s. This is what is known as a supramundane planet or, if the shell is built around the planet Jupiter in particular, then such an artificial planet would be called suprajupiter, according to Paul Birch’s terminology and nomenclature. If one built an orbital ring around suprajupiter, then that orbital ring would have a radius roughly equal to that of Jupiter itself which is $$~70,000,000m$$. If we plug this value of $$~70,000,000m$$ into the equation $$v=2\sqrt{gr_{ring}}$$, we find that the maximum velocity that we could eject a manned crew at is roughly $$52km/s$$.

Now, $$52km/s$$ is a pretty good speed for interplanetary travel especially if you also use lasers to speed up and slow down the spacecraft which would make interplanetary travel even faster. By using orbital rings and laser stations spread throughout the solar system, you could travel to anywhere in the solar system within a pretty short period of time. And that’s if you just want to send people to other destinations in the solar system. Other materials like food, water, metals, plastics, ceramics, fuel, and other materials could be accelerated to much higher speeds. Thus provided that your good at extracting materials from massive bodies (which things like star lifters and gas giant refineries are, for example), you could transport those materials to anywhere in the solar system fairly quickly. Less massive bodies, such as asteroids or comets, could be transported using either mass drivers or nuclear reactors, though that would be much slower.

The orbital ring would have tethers attaching to suprajupiter. What’s more is that this shell (which we’re calling suprajupiter) could have enormous gas giant refineries dangling down from it which could be used to extract important materials from Jupiter’s atmosphere which would mainly be helium-3 and deuterium. Those gas giant refineries would suck up this material and bring it up to the surface of suprajupiter; from that point, the helium-3 and deuterium could be encapsulated into a payload, placed into an elevator cab, and ride up a cable attaching the orbital ring to suprajupiter. That payload could then go inside of a vehicle which could be accelerated using the orbital ring. Unlike fragile humans, helium-3 and deuterium could be accelerated at much higher accelerations than a mere 4 gees. We’ll assume that they can be accelerated up to 100 gees. At that acceleration, those payloads could reach a final speed given by

$$v=\sqrt{100(9.8)(70,000,000)}~261km/s.$$

Such a velocity would be more than sufficient for escaping the solar system’s gravity well; thus, an orbital ring erected around suprajupiter could be used to send payloads to interstellar destinations beyond the gravity well of the Sun and most other stars.

# Intergalactic Colonization

“We often discuss the notion of settling the galaxy but do we need to stop there? This episode will examine the additional difficulties with traveling between galaxies and ask just how far we might be able to journey even without faster than light travel.”

As we've just discussed, with star lifting humanity would gradually colonize the Sun in the following phases: first, there would be myriad separate space homes which would surround the Sun; after a long enough time, we'd build several orbital rings around the Sun which would support a large ring-like surface called a ring world; and, in the final phase of humanities colonization of the solar system, we'll build a giant shell world (called a Dyson sphere) around the Sun. Compared to the lifetime of the husbanded Sun which would be trillions of years, a Dyson sphere could be built in less than a thousand years. I'd imagine that if a nomadic species such as we lived on a Dyson sphere and in this solar system for the next several trillion years, we would start to get a little bored and we would want to explore to see what else is out there. That is one reason why we'd want to go to the other star systems in this galaxy, and beyond. But another reason has to do with survival. A nearby supernova would render all species of life on the Dyson sphere extinct. Despite this being profoundly unlikely in the short term, over the course of trillions of years it would become a near inevitable. For this reason, as well as other dangers, our K2 descendants would spread out far beyond the solar system and venture to the star, the galaxies, and, if it is possible, to other universes as we'll discuss in more detail as we go through this article.

If you read the previous article in this series, then I'm sure you'll recall our discussion of how, once we began Sun lifting, we would, as once imagined by Criswell, use those materials to manufacture not thousands or millions, but billions of space homes. And those space homes could be things like O'Neil cylinders or, if we decided to scale up a little, they could even be artificial planets. In the previous article, we talked about how artificial planets like shell worlds could be built using orbital rings to support a spherical surface. Now, there are, however, two other methods which could be used to build planets which, for brevity, I decided to leave out of that article. But, I'd like to mention them, briefly, here.

As we'll see, there are essentially two other ways to build a planet. The first is just to smash together an enormous amount of material until you end up with a planet. Now, this is actually how planets naturally form so it shouldn't be too surprising that using this method would result in planets similar to the ones in our solar system and other solar systems. Now, this would actually be a great way to store materials. For example, our species will eventually become a K1 civilization and, for reasons which we have discussed in this article and in other articles, they'd eventually want to star lift the Sun for its materials. The Sun is comprised of about 98% hydrogen and helium. Therefore, the majority of the materials which we extract from the Sun would just be hydrogen and helium. But, how, you might ask, would we store all of that hydrogen and helium? According to Criswell, we could condense all of that hydrogen and helium into enormous spheres held together by their own gravity which would orbit the Sun at great distances; these spheres would be created by smashing all of that hydrogen and helium together and these spheres would essentially be gas giant planets.

And while all of that hydrogen and helium is just sitting there, we might as well live on those gas giant planets. This brings us to our second technique which would essentially involve surrounding a gas giant planet with a giant inflatable, spherical surface. That spherical surface would be built with a specific radius such that the surface gravity on the surface of the inflatable sphere is equal to Earth's gravity. All of the hydrogen and helium gas contained within the sphere would exert a pressure on that sphere. But by placing just the right amount of dirt, water, cities and atmosphere on that surface we could, more or less, cancel out the outward pressure acting on the interior of the surface. The net effect would be to have the inflatable sphere hover in a position that is stationary with respect to the gas giant. This second technique is very useful for making an artificial Earth-like planet (with Earth-like gravity) out of a gas giant planet. Tethers could be suspended from the interior surface of such a sphere and be used extract materials from the gas giants in relatively small and manageable quantities. So, the second way of making an artificial planet would involve building an inflatable surface around the gas giant and using it as an artificial planet. But, as we discussed in the SFIA episode on mega-Earths, it would actually be much better to build the sphere using orbital rings. One of the cool things about orbital rings is that they are dynamics structure, meaning that they can change their shape, orientation, and size. This would allow you to alter the size of your shell world. As you extract more and more materials from the gas giant using gas giant refineries, you could let the shell contract.

It would be desirable build shell worlds around the four Jovian gas giants in our solar system and to extra materials from them using gas giant refineries and to subsequently use those materials for fuel for interstellar ships. Now, whether you're using that Helium-3 and deuterium as fuel to use the artificial planets as spaceships or if you're using that fuel to power something like an O'Neil cylinder is something which our descendants would have to decide on. You could convert the four Jovian planets into shell worlds and extract material from them, but by taking Sun-lifted hydrogen and helium and smashing them together you'd have dozens of additional gas giant planets in this solar system which we could build shell worlds around and to use to extract useful materials from when we need them.

The importance of the materials extracted from those gas giants for sending arc ships like O'Neil cylinders to other star systems will be discussed in greater detail as we go through this article. To put it briefly, we could take the helium-3 and deuterium extracted from one of those gas giants (say, Jupiter), package it into a payload, and then accelerate that payload to relativistic speeds. After a long enough time, that payload would "catch up to" the arcship where the payload and arc ship could randevous; this would allow you to refuel the arc ship that is on its interstellar mission. But I'd like to pose to you all two questions: first, after manufacturing that arc ship using Sun-lifted material, how would we accelerate that ship up to a relativistic speed? Second, how, exactly, can an orbital ring be used as a propulsion system that would allow you to launch payload into space? We're going to tackle that second question first.

We have previously discussed creating human habitats on the interior surfaces of cylinders; by rotating those cylindrical habitats, we can generate centrifugal forces along the inner surface area of such cylinders. The centrifugal forces act as a kind of artificial gravity.

If the goal of our species and even our remotest descendants is to maximize long term survival, then as we discussed in our video on Shkadov thruster we'd want to spread outward to not just the stars but the galaxies. Almost every single one of those other galaxies are flying away from us and, after another five billion years or so, they will be receeding away from us faster than the speed of light. Due to Einstein's special theory of relativity, no object can move through space faster than the speed of light. This means that such galaxies would become impossible to detect and visit after five billion years. All of their matter and energy would be wasted and forever separated from us by the expanding intergalactic abyss. Spreading to other galaxies and moving them closer together and, eventually, even deconstructing them into Birch planets isn't something that our descendants would do on a whim; rather, they'd do this because it has actual practical benefits, the most notable being the extension of their species (or perhaps multiple species) lifetime. By having access to more matter and energy, they could extend the lifetime of our species. When faced with the option of extinction, or life, the decision to choose life seems like the right one because the universe is inherently more valuable with life such as trees or birds than without such sentient creatures. Not to mention, it is very wasteful to just let useful matter and energy "fly away" without being put to good use; the same argument applies to justifying the construction of a Dyson sphere in order that we don't allow a star's photons to just "fly away" without every being put to good use like power our cities or maybe powering a giant supercomputer like a Matryoshka brain. Assuming that our descendants still have the same goal of their hunter-gatherer ancestors which is to maximize their long term survival, they would have an important reason to spread to other galaxies and use Shkadov thrusters to bring those galaxies very close to one another. They would, of course, begin by doing this with the most nearby galaxies. We would in fact begin our first intergalactic mission to the Milky Way's "nearby" satellite galaxies long before we fully colonize the entirety of our home Milky Way galaxy. We would, for example, want to colonize the Canis Major Dwarf galaxy located a mere 25,000 lightyears from Sol, the Sagittarius Dwarf Spheroidal galaxy which is just 70,000 light years away from Sol, and the Small Magellanic Cloud and the Large Magellanic Cloud.

The Local Group is a collection of over 54 galaxies (including our home Milky Way galaxy) which spans a distance of ten million lightyears. Between one billion and one trillion years from now, all of these galaxies will merge into a single super galaxy. But is there a way to speed up this process? Yes, there is. By using Shkadov thrusters in the way described in our video on Shkadov thrusters, by building Shkadov thrusters in all of the star systems in every galaxy in the Local Group we could merge together all of these galaxies in a much shorter timeframe. The Local Group is a small bundle of galaxies; but there are many more of these bundles. The Laniakea Supercluser consist of an estimated 300-500 groups and clusters of galaxies and contains approximately 100,000 galaxies spanning a distance of over 520 million light years. All of these galactic groups and clusters orbit around the barycenter (called the Great Attractor) of the Laniakea Supercluster. But, unlike the Local Group, these galaxies will not spontaneously merge together; the Laniakea Supercluster is expected to one day get torn apart by dark energy. But it is in fact theoretically possible (even if we assume that our descendants never develop faster-than-lightspeed spacecraft) to use Shkadov thrusters to bring all of the galaxies in the Laniakea Supercluster very close together. Now, as we discussed in the previous article in this series, it would be desirable for our descendants to deconstruct the Milky Way into a Birch planet - that is, we would dismantle every star and celestial body in the galaxy and use it to construct a single Shell World with a diameter of roughly 1 lightyear. Indeed, we would want to do the analogous for all the other galaxies. This system of Birch Planets could be concentrated into a region of space very compact and those Birch Planets would not begin to recede away from one another due to dark energy for a very long time. So, all in all, there would be many advantages to decomposing galaxies into Birch Planets: you could extend the lifetime of your species, and you could vastly decrease the time period required for communication and transportation. Such an assemblage of Birch Planets would be present for many eons and for a very long time; though, in the long run, even this set up would not be stable. But we shall save the discussion of the finite lifetime of Birch Planets and any civilization for the next section. In this section, we're going to discuss how a species might actually go about colonizing other galaxies.

As we star lift the Sun and other stars, we would manufacture billions of arcships which would make way for the stars. But not all of the arcships would be interstellar. And not all of the Von Neuman proves would be destined to reach merely the stars in the Milky Way. Some of those spacecraft would be intergalactic and set sail towards the nearest other galaxies.

Indeed, we would even reach some of those satellite galaxies long before the Milky Way is fully colonized.

The first actual spacecraft of the kind proposed by Project Genesis and Breakthrough Starshot will likely not be first launched until the 22nd century, despite being concepts that were proposed in our time. Project Genesis would, of course, be the Genesis and not the telos meaning there would certainly be follow up missions. The next phase of "Genesis," so to speak, would "take off" shortly after the begining of star lifting. I'd like to first point out that artificial intelligence and robots only require tiny probes and vehicles to cross the expanse of interstellar and intergalactic space; but in order for a human to cross such an expanse, it would be desirable for them to depart in enormous vessels like the O'Neil cylinders and perhaps something like a suprajupiter. The reason why it would be preferable to "go big" is because there are an enormous number of human needs which must be satisfied for a human society to remain peaceful and harmonious over a long interstellar voyage. Those needs are best satisfied by the Earth, or a kind of replica of the Earth. Large interstellar arc ships like O'Neil cylinders simulate all of the conditions that we experience here on the Earth including the Earth's gravity, day/night cycle, and even the Earth's ecosystems and environments. 99.8% of all the matter comprising our solar system is contained in the Sun and, in order to manufacture billions of these generational arcships, we'd need to acquire access to those materials and the way of getting those materials is by using star lifting. In a previous SFIA episode, we discussed the notion of a "gardener ship" which is essentially an arc ship which arrives at alien planets and colonizes and terraforms them. It is somewhat dubious whether or not AI and robots, alone, could fully colonize and terraform alien planets like those in the TRAPPIST-1 star system and elsewhere in the galaxy and beyond; but if those robotic missions are followed up by manned missions where humans actually arrive at those alien worlds, then colonizing and terraforming those alien planets becomes something that is entirely feasible, despite being an engineering task of epic proportions. The prospect of colonizing and terraforming those alien planets is greatly simplified by the fact that the interstellar spaceship (which could be an O'Neil cylinder) is in of itself a scaled down replica of the Earth's biosphere and environments. Terraforming planets is usually very difficult and requires an enormous amount of time and energy; but once it's done, transferring the Earth's ecology from an arc ship to that terraformed world wouldn't be very difficult.

“The galaxy is an immense place, with billions of solar systems to colonize, and interstellar voyages to even nearby stars can take centuries. In order to explore and settle those new worlds, we may wish to take advantage of a type of generation ship that stops at planet after planet, colonizing each in turn, and entire colonial fleets that grow as they venture outward from Earth, creating new spaceships as often as terraforming new worlds.” This video was created by the SFIA Production Team.

By using Genesis probes and "gardener ships," we have a way of colonizing the entire Milky Way galaxy and beyond with not just human life but all other forms of life too. Because of the Fermi Paradox, it seems very unlikely that there are many other forms of intelligent life even within our own galaxy. This, to me, was initially at first disappointing: that in all this vastness, the nearest other intelligent lifeforms are probably many millions, if not billions, of lightyears away. A common theme in many religious texts is that humans ought not to ascend to be "god like"; but, as Carl Sagan once wrote, when we humans first landed on the Moon and sent spacecraft to the nearby planets and moons, we humans had already ascended into the realm of "myth and legend," and that perhaps it is, after all, our destiny to become god like. All regions and myths throughout human history ascribe abiogenesis to god or multiple gods; today, we are fairly certain that abiogenesis and the emergence of life can arise through entirely natural processes. Indeed, for a K2 or K3 civilization to reach alien worlds with probes like Genesis probes and with gardener ships like O'Neil cylinders and using their scientific and engineering know-how to terraform and colonize those worlds, such beings would have indeed entered the realm of the gods, or as Sagan put it the realm of "myth and legend."