This Episode is brought to you by Brilliant. To all good and great things there comes an end, but it can be a spectacular end, when it at last comes, and that end can be a long time off. Tomorrow, Sep 17 2021, we will celebrate the 7th Anniversary of SFIA's first episode, “Megastructures in Science and Science Fiction”. So this seems
like a great time to return to what has become one of our favorite topics. For those new to the channel, welcome. And while I realize the episode title sounds like the name of a heavy metal band, the megastructures we discuss on this show are, often as not, entire artificial worlds with as much or far more habitable space than the surface of a planet. The end of Earth is a popular topic of discussion in science and philosophy, and the topic of a recent episode on this show. But in science fiction it’s also common to contemplate the end of alien worlds far from Earth. So given that it’s likely most of future humanity will
live their lives on entirely artificial worlds -- immense megastructure habitats -- it is also quite likely the deaths of these worlds will be of far greater interest to future civilizations than will dying planets. But I suppose contemplating either of their endings would also be an appropriate theme for a heavy metal album. So our focus today is going to be examining the ways these might die, and their stages in life, which will vary a lot depending on the megastructure type. Their end might also come about deliberately, in the way we might demolish a building, or accidentally, in the way a design flaw or unexpected natural event might contribute to their end. We have two classic science fiction examples we will look at for those, with lots of Spoilers to follow, the O’Neill Cylinder in the 90’s classic sci-fi series Babylon 5, and the titular Ringworld of Larry’s Niven Ringworld novels. Now the saying goes that all good things come to an end, but considering the sheer scope of even the smallest megastructures, paralleling or exceeding the largest modern cities, it obviously is beneficial to build with durability in mind. However we have two caveats worth noting upfront.
First, the smallest megastructures are city sized and even those in the Continent-Class which we deemed more medium in scope might be thought of as more nation-sized. Cities and nations can certainly die but in general their centers of population and activity migrate. Many a long-lived river-city has moved around as the river shifted, at the same time sprawling up or down its banks, with areas changing from farmland to affluent neighborhoods to squalid slums and back again, as the city slowly creeps along the river or the coast. With that in mind, a megastructure might be in a constant state of repair with whole regions undergoing massive refit at any given time. Like Thesseus’s Ship, they may still be called the same place or thing even after every bit of the hull has been replaced a hundred times over.
Same, one might think of a city as being composed of many structures akin to living cells in our bodies, and those can repair and replace themselves rather automatically. One tech any megastructure-making civilization would want badly is regenerative buildings and structures, those able to heal or grow themselves, or automated repair bots perhaps. Such structures might be able to last indefinitely, constantly recycling their material powered by nuclear fusion, where a single kilogram of fuel might run them for a year while they had billions of tons of it on hand to last them for eons. Indeed those powered by matter to energy conversion or black holes might outlive the stars themselves, and die by slowly cannibalizing themselves, contracting in size by tiny amounts, the snake eating its own tail but taking a hundred trillions year to do so. Indeed we often tend to assume that a civilization
that builds giant things in space has already mastered such technologies as automated repair and construction and cheap energy, given the scope of the projects, so that such structures might be thought of as grown more than built. However it is worth noting that a self-repairing system can still die, indeed every known self-repairing system has a lifespan, with the possible exceptions of some stranger critters like Jellyfish, Lobster, or Hydras. It is not too big a leap to imagine a megastructure might get the equivalent of cancer, or that some structure in it with auto-repair systems might go off-kilter, though there’s no guarantee an artificially designed repair system would be prone to such faults. There is also no guarantee we would get such technology working or that if we did, we would employ it for this purpose. Self-repairing is also not the same as reproducing, and the check on uncontrolled replication of cells is telomere-triggered apoptosis. A state of constant unchecked growth is rarely a good thing for an organism either,
or arguably the meta-organism that a city, nation, or megastructure habitat might qualify as. Now demolition at the end of life is easy enough to understand. In Babylon 5 – spoilers – we are shown the destruction of the Babylon 5 space station repeatedly as vision of the future by this or that telepath or seer or time traveler, but in the end it occurs 25 years after its built because its purpose has been served and nobody wants to spend the funds to keep repairing it so it gets a controlled and planned detonation to prevent it becoming a navigational hazard, along with a big ceremony. This happens to be one of the most beautiful series finales in science fiction history, titled “Sleeping in Light”. It is my own personal favorite series finale, and a rarity, as most shows’ last episode are mediocre when not anticlimactic.
Now it is an example of a major and unique enterprise. It was basically the galaxy’s UN headquarters and later its acting capital for quite some time, along with a trade hub as a result, much like the Citadel in Mass Effect. Everyone in the galaxy knew where and what it was. So one can see how economics would be secondary both to keeping its repairs up and to eventually deciding to decommission it too, rather than sell it or let it just fall into scavenger hands. We might do something similar to the International Space Station sometime, but with better cause, we have a lot of traffic in orbit and would expect that to only grow with time, so a controlled deorbit or detonation to blow the debris down to burn up in the atmosphere would seem likely and also cause for commemoration. The Mir Space Station
deorbit and burnup in early 2001 was a fairly big deal in the news at the time, also the spring I graduated from college in for those curious. It’s worth noting that it takes some skill to detonate a large object so it doesn’t leave debris incidentally, in practice you’re going to want to shove it down into the atmosphere enough that even debris moving up at high speed will still fall down then detonate it. Such being the case you would have to worry about that not working as planned and dropping intact bits on the populace below, potential megatons bits of scrap, so I suspect the fate of a megastructure past its prime would be disassembly not detonation. Alternatively if we’re talking about some Space Habitat, population 10,000, a minor rotating space habitat built by SpacehabCorp, one of ten thousand built by them to that specification then it shouldn’t be a very big deal for all that it would be to us. Same as the first skyscraper is a big deal but then 997th is not, even if it's far grander than the first was. Doubtless many people would care about it, same as every town or village has its own historic buildings and celebrations, but it's not likely to be big news to the wider world, and might be as minor a concern as some modest and unremarkable home on the outskirts of town falling into disrepair. It only interests
the community because the Fire Marshall wants to use it for practice or the police want it knocked over to discourage vagrants, criminals, or curious kids from hanging out there. In the other direction, we often cite the US Highway system as a candidate for a modern megastructure, and with good reason as it is enormous. Interstate Route 90 is the longest part of that at just under 5000 kilometers or just over 3000 miles, running from Boston, Massachusetts to Seattle Washington and through many points in-between, including my own backyard. Literally my backyard since Sarah and I moved earlier this year, but having lived in Northeast Ohio nearly all my life it’s always had a big footprint in my existence. It is the road that all others lead to, so to speak, and which millions of folks drive on for daily commutes or cross-country road trips. I would
not care to guess how many billions of dollars of freight move down it every single day. Nonetheless, I would have difficulty seeing much fanfare or weeping if it was decommissioned in favor of something new and better, not in the way closing down a major monument might. Though there are so many businesses for which it is their revenue source, every gas station, restaurant, or outlet or novelty store at an exit would obviously have reason to miss it, and for some that might be sentimental not just practical. That might be a tiny fraction of our population but is still many thousands, enough to populate many an ancient kingdom, so it can’t be disregarded either. So it is difficult to imagine any megastructure going down from mere indifference by all, just given the scale of them. We can imagine that scenario and we looked at that in our Trash Worlds
and Space Derelicts episode, and our Mega-Cities episode for that matter. It could happen of course. A trade port built for trade between two stars might fall victim to new technologies that let them be circumvented or even stellar drift changing the path between those systems. Such structures are not just immense of scale in size, but also in time, and may see the rise and fall of ten thousand centuries before the warranty expires. A civilization might be of such a scale that their big defense outposts and border forts had their own civilian populations and habitats numbering in the millions which no longer had resources coming in to support them after a change in the diplomatic environment.
And remember the scale involved, some giant space gun designed for blasting interstellar armadas between warring K2 Dyson Spheres, might be a cannon so big it’s gravity actually allowed for pressurised environments in the various cracks and valleys of the barrel and magazine. I’m not really sure what you would do with a cannon designed for blowing up planets when the conflict it was built for was over, but it’s not hard to imagine a civilization arising on it and getting attached to it, and that would be a weird civilization. Forget a cultural mythos of your world being on the back of a giant turtle, your world was forged by the gods to kill worlds and you’re the post-apocalyptic tribes who hundred-times great grandparents used to maintain it. However while we can imagine situations where a megastructure might slowly grow more and more neglected, it just seems less plausible than how we see that with neighborhoods or homes in modern times and history. A house can fall into disrepair when it need not have simply because its owners died or had their fortunes turn and no one felt like buying it or their kids did not wish it and their neighbors were few and by chance maybe the dozen folks who adjoined it were indifferent to its slow submission to time. But megastructures are just too big, and even if they were not populated, there’s a good chance they might actually have an onboard AI of human or superhuman capacity, possibly many, that regarded the structure or components of it as their home or even body.
Some things can be constantly repaired, others really are cheaper to break down and replace, and it varies by type and technology and circumstances too, but we would rarely expect a habitat megastructure to simply be shut down and evacuated rather than repaired gradually as a patchwork. Even major hull work that might require you de-spin it so you could repair stressed materials is probably easier done by just wrapping new rotating sheath around the outside. This might amusingly make for many layers of new hull, oldest to youngest as you dug down from inside it, potentially allowing its inhabitants to mine those older and higher layers for materials. That’s an interesting option given how often civilizations are imagined to have decayed to being techno-primitives because they had no metals in the ground on such habitats. Sort of a reverse archeology too, the top layers are the old ones. Repairing hulls with new outer sheath might avoid every needing to shut one down. On the other hand, one that took a ton of
damage at once, especially from something like an attack during a war, might be evacuated or even had everyone in it die, and nobody wants or particularly needs to repair it. A burned-out husk of a megastructure is a dead thing and probably tricky to repair like a burnt house. Neighborhoods can matter too, people rarely are rushing to fix up a house in a bad part of town, or in a demilitarized zone or the border of two hostile nations. Except for fortresses of course and in
that same way, a border fortress is expensive to maintain and serves little point if the borders move. Traditionally you either repurpose it or wait for the local population to do so by slowly stealing the stone and bricks. Of course, automated construction and repair also permits the idea of automated demolition too, instead of blowing stuff up you let the robots carefully cannibalize or demolish it. Though it also might have automated defenses, such as those robots, that attacked anything on site when that damaged. These set the stage for why a Megastructure might perish, and there are many other reasons but some are probably not as plausible as we often assume. For instance in the novel Ringworld, we find an artificial world with a million times the living area of Earth but which for some reason has little to no remaining technology.
Abandoned relics or worlds with once impressive technology from bygone days is a common theme in stories but not really very realistic. For narrative purposes it allows the heroes to explore it, and we discussed some more examples of that in our recent Xenoarcheology episode, but it would not make sense for a civilization to build and people an artificial structure able to support millions of times the population a planet can and not expect some of them to go in for technology. Now as a caveat, artificial worlds often are assumed to be metal-poor, with no large ore deposits, though the reasoning for this is a touch debatable in some cases. If you’ve got thick terrain on one to simulate mountains and ravines, you might have done that by just grinding up various asteroids and dumping them down there, still rich in ore. Alternatively, metal has no place to go, it doesn’t vaporize by magic, so you can presumably recycle existing material. And if you’re constantly spinning new outer layers of protective sheath, you can cannibalize the inner layers. In any event, Ringworld is an example
of a megastructure built by a powerful and advanced civilization that has disappeared and whose technology is failing. While it seems implausible that one that huge wouldn’t have other new civilizations arise able to study or fix the structure, the fact that it was failing from neglect is certainly plausible. In Ringworld’s case, a ring spinning around a star is not actually stable. It's common to describe the Ringworld as a vast ring orbiting a star,
about as wide in radius as Earth’s orbit of our Sun is, lit by that Sun and relying on centrifugal force to provide gravity. Except this is wrong, it doesn’t orbit that star at all. Anything orbiting anything else experiences microgravity from that orbit. That’s how orbiting works, you are in a constant state of free fall in regard to that central body. The orbiting body can have its own gravity or internal spin, like Earth does or like an O’Neill Cylinder in Earth orbit would, but that spin around the main object is not an orbit if you’re not in microgravity from it. Which means you are not actually stable. The star pulls on the ring from each side
but it’s subject to slow perturbation making it drift off so that the ring might get roasted. Now this matters for the Ringworld because on reading it some folks saw that problem and told the author and he added in stabilizing engines in the sequel and getting them turned on to save the Destabilizing Ringworld was a plot point, and one would expect such engines to be very sturdy and big. We often see things orbiting Earth fall out of orbit and it would be a concern for any megastructure that gravity and time aren’t its friends. Planetary orbits are not stable and eternal things either, but they are a fairly natural conglomeration and planetary decays around stars are slow and can only happen when after millions of years of formation, most of the unstable orbits have decayed, merged, ejected and so on. So our
existing planets in this solar system tend to make us think these are unchanging, but they are not. A megastructure could be built to be even more resistant to time and perturbation than a natural planet or moon but they need not be, and that presumably takes a great deal of effort. And realistically, when building big things these days, we do not ask the architect if his plans for maintenance included our civilization going extinct or into a dark age. The whole thing might rely on a few dozen ten-cent washers that take about five minutes to replace once a decade. If the factory making them closes down, or is shut down by having a mushroom cloud grow out of it as the civilization falls into nuclear war, those washers might not be getting replaced. Nonetheless I don’t think the typical building inspector or investor would ask
if you’ve checked to ensure your building is able to survive a breakdown in supply chains, unless it was for a survival bunker perhaps. On the other hand, let's not assume artificial means fragile. A shellworld for instance can seem an incredibly fragile place. It’s surface is a thin layer of dirt, water, and rock sitting on a firmament made of countless orbital rings, containing either condensed gas below or a black hole. Folks worry about what would happen if a
hole got poked in it or the power went off. And yet the typical planet is a thin layer of rocky plates floating on a sea of superhot magma surrounding a core of liquid metal, much of which is highly radioactive uranium. Poke a hole in that and you get a volcano, or much worse. What happens when you blow a hole into a Shellworld, or rotating habitats for that matter? Well, we need to keep in mind that these are artificial structures and usually built out of super-strong materials. Now nukes beat matter everytime, you should not expect to have any material that can just shrug off an atomic bomb except maybe those which operate on the strong nuclear force for binding rather than electromagnetic forces as mundane matter does, like magmatter or stabilized neutronium, or the Scrith from Ringworld that its built from.
That Scrith was so tough it deformed when hit by something like a dwarf planet to form an inverted crater that looked like a volcano from the inside, only far taller than any natural mountain, and the air of the Ringworld slowly drained out through it. We could imagine building habitats so big that a collision just ripped a crater that helped keep a lot of air and water inside, but there are big limits on things like that and nothing shrugs off a nuclear blast. However, don’t fall into the trap of Hollywood science where nukes obliterate everything, they aren’t that powerful and their ability to damage stuff is directly related to how powerful an individual bomb is, be it low kilotons or high megatons, which indicates difference of tens of thousands of times the yield. Earth’s get hit by nuclear bomb levels of energy in meteor form all the time, thousands of tons of meteors hit this planet every year, each carrying way more destructive force than their weight in explosives, and Earth getting hit by individual rocks weighing thousands of tons is pretty common too. For raw vaporization of metals, it varies by
the metal but usually you need several TNT-tonnes equivalent to vaporize a cubic meter of metal, which is something to keep in mind when blowing holes in artificial structures with lasers or big bombs or kinetic weapons. Don’t assume some nuke, even a megaton sized one, can just punch a hole into any megastructure that’s kilometers wide. Don’t assume that they instantly vent to space either. Air generally moves from normal to vacuum at roughly the speed of sound, and like that speed it decreases as the pressure drops, which is one reason we like spaceships and spacesuits at partial pressure, all oxygen and no nitrogen, it leaks slower that way. Punch a meter wide hole in some large space station, one much, much bigger than a modern space station, and if the internal environment was Earth like, each square meter of hole in the hull should be spitting out about 343,000 liters or 420 kilograms of air each second. Which is a lot of air loss but means it loses 36,000 tons of air a day, an O’Neill Cylinder – our smallest megastructure habitats – might be 8 kilometers in diameter and 32 kilometers long, which would make for an internal air volume of 1.6 trillion cubic meters or 1.6 quadrillion liters, or 2 billion
tons. Meaning it would take nearly a century to drop to half-pressure and be barely livable even then, all while having a hole big enough to step through and losing all its air out it. Assuming it ever did. Space Stations are likely to have constant leaks everywhere and have
systems constantly pumping new air in, able to increase that production above normal capacity. Aircraft for instance are not pressurized statically, they leak and have compressors running constantly to keep up with that, so do modern space stations. Big space stations would probably leak way less per unit of mass or hull surface, but way more over all, in raw mass terms. With that in mind, a McKendree Cylinder – the big brother of an O’Neill Cylinder – might contain millions of times that much air, meaning even a kilometer-wide hole in one might take centuries to drain it. And even bigger H-bombs, the multi-megaton affairs,
generally would not leave a crater that big in a thick steel hull and layers of dirt like we would expect from the larger rotating habitats. A Ringworld on the other hand should have an atmospheric mass of around 5 or 6 billion-trillion tons, given that it’s got around a million times the living area of Earth and Earth’s atmosphere masses 5500 trillion tons. One quick note, for pressurized habitats mimicking Earth’s atmospheric conditions, there’s roughly 1.2 kilograms of air per cubic meter, but on Earth and any place where atmospheric pressure is achieved by gravity or spin-gravity, continent-class habitats or bigger, the air gets thinner as you go up and you expect about 10 tons per square meter of surface area. Of course air isn’t the only thing draining through a big hole in your habitat, though it's worth noting that since most liquids can’t exist in a vacuum, water draining out a hull puncture should vaporize or freeze, and so for instance cutting a hole into a space habitat with a laser whose beam diameter was much thinner than the hull thickness, poking a tiny but deep hole, would probably have that hole clog with ice or dirt eventually.
For a big wide gash considerably wider than the thickness of the structure though, I wouldn’t count on clogging unless the structure had some ability at self-repair that way. On the other hand for these real megastructures, stuff in the continent class or bigger like Bishop Rings, Banks Orbitals, or Ringworlds, we often imagine them having hulls measured in a thickness of kilometers not meters or centimeters like we imagine with spaceships, and likely made out of diamond hard materials. It is not actually that hard to bandage over a hole into space. Movies make folks think you could get a finger-sized hole in a ship and
folks would be sucked through it like a sausage grinder. If you want a more realistic example, turn your vacuum on and stick your hand over the intake. From normal atmosphere to total vacuum is a much smaller pressure drop than a hole in a water pipe or garden hose. You obviously cannot duct tape a football field sized hole in a space habitat with actual duct tape but don’t assume any particular hyper-strong materials or near-instant deployment is needed to fix this.
Patches might vary from some spider-like robot spinning a web over it to some rapidly solidifying patch material you could spray on, which isn’t too hard considering liquids don’t do well at lower pressures or exist at all in vacuums. Though if it's leaking, you won’t have zero-pressure at the edge of the leak, it should stay at roughly the internal pressure. Voided stations that leaked everything out already though, derelict and empty to space, would be very easy to reseal and pressurize in most cases. Especially if their rotation had slowed. This does not mean a typical O’Neill Cylinder made of plain old steel, or even something like Kevlar, is surviving a nuclear blast, but it is plausible a lower-yield nuke on a larger end O’Neill Cylinder might survive, and for a bigger blast, it’s worth keeping in mind that a smaller hole followed by a missile that went inside and detonated in the internal landscape would kill everyone too, in the same way one detonating over your town will. It’s all a numbers and scale game, but don’t assume you insta-kill space habitats with nukes or cutting lasers. There’s also defenses too. As I often note on the show, a rotating habitat
is probably going to be nested inside a bigger non-rotating or slow rotating superstructure, and you might actually do several layers of rotating drums nested inside each other, with outer ones rotating slower or faster and just being a thin hull, so that various gaping holes quickly spun shut to choke off leaks. Spaceships might play this same trick with multiple rotating shells of armor so that gashes through several at once would all rotate out. Probably worth remembering that a thick stream of gas jetting out your space station is going to shove the space station around too, though this can be mostly ignored for the big habitats whose atmospheres are significant but pretty small compared to overall station mass. One in orbit of planet might be de-orbited by this happening too, though since the hole is probably spinning around in a circle the jet coming out of it might negate out. I also would be surprised if any attack that didn’t utterly scatter a megastructure as gaseous debris managed to kill everyone on it. You’re bound to have lots of compartments, even on a
space habitat, that can be sealed and pressurized. As a comparison with nukes, we usually say any hardened underground structure will remain intact and pretty undamaged even just half-again the radius of the blast crater away, and potentially even less. It’s also plausible that even normal homes on space habitats would be built with the ability to act as a bunker or lifepod. So for those contemplating military engagements, yes you probably would need to send in the drones or clones or space marines to go clear out every single compartment on a battleship or space station if you were hoping to seize it vaguely intact, same as a city, only fighting through a megastructure is likely to be even more nightmarish than urban warfare. Especially given that if it's self-repairing to any degree, that most likely means automated repair drones and the ability to deploy and manufacture them, which is likely very, very easy to militarize. Kind of brings a different flavor to the term ‘Megastructure Death’ when you contemplate battling through one while it cannibalizes itself to throw ten-trillion murderbots at you.
This also gives us one more plausible scenario for Megastructure Death. In theory if you’ve got mass and energy and automation you can keep repairing and refitting one indefinitely from pretty much any blow it might take and not be obliterated outright by, be it a natural meteor or manmade bomb, a rapid event or the creeping destruction of time. However, that assumption of robots doing the work leaves us open to needing to abandon one because those repair or growth systems went haywire, or its defense system did – and indeed such things might be so close to alive as to qualify as having an immune system. So they could get diseased or cancerous or hacked and have repair systems running around inside mutating it or killing anything that’s not supposed to be there to make new patches for the hull out of.
I am guessing if this happened there’s a chance the place would be quarantined rather than obliterated and might be left semi-derelict till a cure or purge team or whatever could be sent. Takes a lot of firepower to utterly vaporize something like that and if you don’t, it is possible every thumb-size scrap of it remaining as debris now flying everywhere is infected with grey goo. So you might need to surround a megastructure gone diseased with an armada that’s just pounding it with atomic ordinance and vaporizing every bit of flying debris with point defense systems. Or blow its radiators off and shine a lot of light on it to bake the thing, like sterilizing something in an oven. Which sounds like a good approach except depending on your technology, you might just be feeding it tons of energy to build ten-trillion murderbots out of to attack your fleet.
In such a case I could imagine instead spinning a cocoon or membrane around the whole, or hitting it with EMPs, installing physical or metaphorical quarantine beacons and leaving it. However there would likely be in-between infection states where you’re actually trying to combat it. That really might be horrifying too, with some chunk of a station trying to cannibalize itself to murder its inhabitants while the rest cannibalized it to fight them off, make escape pods, and try to hold the place while fleets arrived to evacuate one or fight the plague.
That’s just space habitats too, imagine megastructures designed for other purposes like a system’s actual defense guns, asteroid disassemblers, or megastructure manufacturing sites. Remember we’ve contemplated structures designed for disassembling whole stars before, or others with black holes in their basements, or for ripping holes in spacetime. I don’t think you want to be in the same galaxy as one of those if it goes rogue, let alone on board it. Odds are the designers of any megastructure invested a lot of time and thought into failure modes and attacks on it, which is an upside, most would probably be more survivable than the typical structure, or even planet in the case of artificial planets vs natural ones. Though it also
probably means whatever killed it was the sort of weapon best used for demolishing worlds. So as mentioned at the beginning, this episode celebrates the 7th Anniversary of our original episode and I want to talk about that before we get to our upcoming schedule, but first I wanted to thank one of this show originals and longest sponsors, Brilliant, for helping make this show possible. We’ve grown a lot over the years, constantly seeking to improve the show, and so have they. Brilliant is an educational site just a couple years older than our show
and dedicated to that same core mission, increasing people’s knowledge and love of math and science, and it’s been a fun time working with them and seeing the constant expansion of topics and improvements to interactivity. That’s fundamentally critical to learning or teaching, the topic has to be interesting and is always best when interactive and hands-on. Brilliant is focused on learning not memorizing, for instance, most folks know that the area of a circle is pi-R-squared, but rarely why it is pi-R-squared, and Brilliant’s Geometry Fundamental Course, explains why and is full of intuitive lessons like this that let you see and interact with Geometric concepts in ways you've never done before. You learn best while doing and solving in real-time, not by long lectures or memorising formulas and facts, and Brilliant understands that and has something for everybody — whether you want to start at the basics of math, science, and computer science, or go straight to advanced material. If you'd like to join me and a community of 8 million learners and educators today, click the link in the episode description down below or visit: brilliant.org/IsaacArthur. So today wraps up our seventh year of the show,
and the anniversaries are always right around my birthday on September 20th - I’ll be 41 this year - and so it tends to be an extra time of reflection for me. It’s become a bit of tradition to commemorate the occasion personally by going back and watching that first episode, though I tend to cringe a bit at the audio, video, and overall presentation, as I suppose is unavoidable for anyone who's been doing something for years and comes back and sees their original work. Truth be told, I don’t recommend watching any of our first year of videos except for folks who never had a problem with my speech impediment even in its early form. Years of practice and speech
therapy later, and several hundred episodes, livestreams, interviews, and so forth under the bridge, it's hard to reflect on that first effort and remember that originally I’d just wanted to practice a new feature of Microsoft Powerpoint for unrelated work and picked a random topic to do. In this case, I’d been missing talking about science and scifi much as my work at the time wasn’t nearly as geeky as college, grad school, and the military had been, and I mostly used social media to keep up with old friends from the service but had joined a couple of facebook forums, one for scifi writing and worldbuilding because a member had asked me join to answer a couple physics questions for some of the authors there and another on the Fermi Paradox. I always got a bit frustrated how few authors ever wanted to do anything but classic space opera, one or two planets per solar system with homogeneous culture on them, so often mentioned megastructures and space habitats and decided it would be a fun practice topic and did a video on it figuring it would be easier and better to do the topic that way over the text-only or text-and-image website or blog approach. That’s more or less the origin of the videos and why to this day it remains essentially a script that I narrate and put visuals up for. It is sadly why we don’t do more megastructures episodes though because the reasoning in the first place was that these structures are hard to envision and need images or animations for them, and there just aren’t many around. Probably about half the graphics assets for space megastructures in existence were developed for this show with most of the remainder being for Orion’s Arm, and I did want to take a moment to thank all our animators who’ve volunteered their time and art to the show over the years. If you animate for a hobby and want to try
your hand at doing any of the megastructures we discuss, I can honestly say that a handful of animations of one of them is usually the difference between whether or not we do an episode on a given megastructure. And we are always looking for folks to help animate, edit scripts, brianstorm up episode ideas, and moderate our various social media so if you’ve got some free time and want to let me steal it from you, just shoot me an email at Isaac.Arthur.email@example.com, and youtube is spelled U-T-U-B-E in this case and is on our channel’s About page if you lose that. Anyway, the episode’s already on the long side, and while I take partial credit for encouraging other science shows to break the norm and do episodes longer than 5-15 minutes, I do try to keep them shorter than half an hour so we’ll wrap up here and do the upcoming schedule, but I did want to thank everyone for making the last 7 years such a fun and rewarding experience for me personally, and I hope to keep doing it for another 7. I occasionally get asked if I ever worry about running out of topics and the answer is
no, not even a little bit, we’ve tons of Science & Futurism topics waiting to be done and the nice thing about the Future is there’s always so much more of it. Speaking of upcoming episodes, we still have 3 more outings for this month, and we’ll be returning to the Fermi Paradox on September 23rd for a look at the notion of Hidden Alien Civilizations. Then we’ll have our Monthly Livestream Q&A on Sunday, September 26th at 4pm Eastern Time before closing the month out by asking if it’s possible for future civilizations to exist without money, on Sept 30th. Another thing about all these huge megastructures is they are designed to let humanity grow our population comfortably into the countless trillions, and we’ll open October up by asking how someone could stand out in such a vast sea, then on October 14th we’ll ask how we might feed all those folks, as we look at the future of farming in the next few decades and beyond. Now if you want to make sure you get notified
when those episodes come out, make sure subscribe to the channel, and if you enjoyed the episode, don’t forget to hit the like button and share it with others. If you’d like to help support future episodes, you can donate to us on Patreon, or our website, IsaacArthur.net, and I will shamelessly remind everyone it’s my birthday too, and patreon and our website are linked in the episode description below, along with all of our various social media forums where you can get updates and chat with others about the concepts in the episodes and many other futuristic ideas. Until next time, thanks for watching for the last 7 years, and have a great week!