At some point, we’re going to run out of
living room. So how can we use celestial circular innovation to put humanity’s lack
of real estate in the rear view mirror? Today we’ll be looking at the Banks Orbital,
an immense megastructure in the form of ring shaped habitat more than a million miles in
diameter, and depending on the ring’s width, containing hundreds if not thousands of Earth's
worth of living area, all enjoying more naturally Earth-like conditions than any other rotating
habitat design. We're talking about assembling a structure that makes all of humanity’s
combined constructions to date look like a toddler’s sandcastle. We’ll be deep-diving this
structure, its engineering, why it’s desirable, and what life on it might be like. So, let's jump
into the cosmic deep end and find out just what it takes to live in space's answer to luxury living,
spiced with a touch of celestial extravagance! Rotating habitat megastructures have a lot
going for them, they let you pick your gravity and pressure and use way less material than
a planet does for creating a given amount of living space. And since they are spin-gravity
environments, not mass-generated gravity, it’s very easy for spaceships to come to and from.
Unfortunately the problem we have with our three classic rotating habitats, the Bernal Sphere,
O’Neill Cylinder, and Stanford Torus, is that they are generally in the size range of large town
or county, not a planet, and for the Bernal Sphere and O’Neill Cylinder, when you look up at the
sky, you see the other side of that interior, more landscape. Imagine living in a place where
the sky isn't filled with stars, but more real estate. It's the ultimate in not being able to
escape the neighbors! The stanford torus is a lot skinnier so you just see a big ring in that
sky, but also a big glass dome above. They often have to use either big mirrors or glass panes to
let in natural sunlight or create it artificially. These are hardly fatal flaws, especially compared
to the conditions on most other planets even when heavily terraformed, but they’re not ideal either.
Larry Niven’s Ringworld seeks to get around this by building an enormous ring around a star as
wide as Earth’s orbit, but besides requiring materials stronger than anything we could
plausibly imagine, you still have to put big sunshades orbiting between the ring and your
star to block light to give day and night. And while it contains a million planets’ worth of
living area, it is a pretty big lift to build. Iain M. Banks Orbitals, from his culture series,
also sometimes called God’s Bracelet for their shape and magnitude, seek to split the difference
in size while also allowing very natural lighting, and we have a trick that works to let us build
them out of known materials without requiring super-strong tensile materials. Though
at the cost of a lot more mass. Graphene, our go-to for continent class habitats, has
such a strong tensile strength that it lets us build habitats like the Bishop Ring or
McKendree Cylinder that are orders of magnitude larger than an O’Neill Cylinder or Stanford
Torus, but still are smaller than a planet. So better but still not there.
The Bishop Ring lets in natural sunlight but also needs hugely tall rim walls to
keep the air in compared to its size, since the altitude of your atmosphere is the same on them
as on Ringworlds millions of times bigger in area. They also spin around a lot faster than once a
day to keep gravity at earth-normal of 1-gee, so you can’t really use the natural sunlight and
have to go for a rotating hub mirror or fake sun. The Banks Orbital however can rotate once a day.
For any given planet and day length there is a unique diameter for a rotating habitat that allows
you to mimic its gravity while rotating at its own day length. For Earth gravity and a 24-hour day,
that is a radius of 1.84 million kilometers, or 1.15 million miles. Size really does matter when
it comes to playing Earth. That’s a big number, so let me put that in perspective. That’s over
two and a half times the radius of the Sun, which is the largest body in the solar system
by far. So, while a Banks Orbital still needs a rim wall, even a rim wall a thousand miles high
that leaks less air than Earth itself does would be miniscule in comparison to the ring’s size.
For Martian gravity, which has about the same day length as Earth, that radius drops to about
the radius of the Sun. It would be even lower for the Moon, but because its day is a month long,
that radius jumps up to 267 million kilometers, or something bigger than the orbit of Mars around the
Sun. The longer the day, the wider your ring needs to be, the higher the gravity, the faster it needs
to spin. And the wider and faster both add to the strength requirements a ring needs to avoid being
ripped apart by its own spin and angular momentum. Tensile strength is the bedrock of rotating
habitats - literally - and nothing we know of has the material strength for an Earth-like Banks
Orbital. We're in the realm of needing something so strong, it makes graphene look like overcooked
spaghetti, and that's saying something. However, as we discussed in our episodes on Ringworlds and
continent class habitats, we can cheat around this by building a second and more massive outer
ring, that our inner ring can spin inside and like a maglev train, move over it very quickly by
pushing off it without touching. That outer ring needs to be strong as well and the more massive
you make it, the less strong it needs to be. One of the neat things about rotating habitats is
that you can get some free launch speed or slow down by landing on the spinning hull, which is a
little trickier if you have a non-rotating outer sheath like this. As channel regulars know, I am
of the opinion that rotating habitats will usually be a drum nested inside a larger superstructure
that either doesn’t rotate or counter-rotates with the same angular momentum but more mass and
less speed. So for me this outer ring is already a normal feature of any rotating habitat.
Incidentally, unless stated otherwise, for the rest of the video when I say a Banks
Orbital, I mean one that emulates Earth's day length and gravity, it is our default condition,
though of course if you’re hunting for alien megastructures you would want to widen that
range as their planet probably doesn’t match our gravity and day length. So too, since it is
easier to build a lower-gravity habitat or one with a shorter day, we shouldn’t rule out people
building them with lower gravity, though while I could see folks going for a longer day I can’t
see them opting for a shorter one very often. As a reminder, our Banks Orbital is 1.85 million
kilometers or 1.15 million miles in radius. If you resurrected the fastest commercial plane ever,
the Concorde, with its 1350 mph greater than twice the speed of sound cruising speed,
and circumnavigated the ring with in-air refueling and no stops, it would take you over 7
months to get back where you started. In short, don't expect to get anywhere fast with our current
modes of transportation! For every 43.8 kilometers or 27.2 miles that orbital is wide, you gain an
Earth’s worth of surface area. So, in contrast to the Concorde example, for an orbital with the
same surface area as Earth, you could just about fit the Large Hadron Collider in CERN, Switzerland
that discovered the Higgs-Boson particle into that 27 miles of width. Or for you fitness bunnies,
if we had a Banks Orbital with the same surface area as Earth, you could just squeeze in a
marathon race across its width. Needless to say I think you’d build them a lot wider.
This structure would orbit about as far away as Earth does from our Sun, depending on the
brightness of its star and how warm you want your orbital. None of that needs to be tundra or desert
as it is a flat ring, not a curved planet with an axial tilt. You can actually tilt the rings to
give them seasonal variation but the whole of the ring will be in the same season at a time, which
would play havoc with seasonally migrating species rehoused from an Earth-like world with seasons. It
also doesn’t technically have seasonal variation in day length, but the rim walls cast longer
shadows in the Winter, making it less bright. This will confuse the daylights out of plants
and wildlife that rely on a seasonal day/night length variation. Incidentally, there will be two
Summer/Winter cycles per rotation around the star, adding further consternation. Though if you
are as good at genetic engineering as you are mega-engineering, this is probably easily fixed.
If the orbital lies mostly flat on its orbital plane, also called the ecliptic, the portion
of the orbital currently closer to the star, if it is wide enough, in its night-phase will
block light to the other side, usually getting daytime. This plunges the whole orbital’s inner
surface into eternal night. The opposite extreme also causes complete night. This happens when
the orbital is oriented perpendicular to the ecliptic and its axis is facing the star. In this
case, the rim walls temporarily block the light from reaching the inner surface. Conservation of
momentum in conjunction with the rim walls gives the orbital its seasons. Unlike our Moon, which
is tidally locked to always present the same face to the Earth, the orbital won’t be tidally locked
to the star and actually faces the same direction, irrespective of its motion around the star.
We have an analog of this behavior in our very own solar system. The planets rotate about
their axes roughly perpendicular to the ecliptic plane. Though, like most families, there’s
one individual that doesn’t follow the norm, and with the planets, Uranus is our black sheep.
It’s actually cocked to have its axis lie almost on the ecliptic plane and it isn’t tidally locked
to the Sun.[a] If we track the orbit of Uranus and imagine a ring spinning there instead of a
planet, you can imagine how the seasons would play out by how the star’s light hits the ring’s inner
surface and how the rim walls would block some of that light, casting shadows when the ring’s axis
gets closer to pointing directly at the star. If you were standing on the inner surface of
the orbital, the star would rise on the one side of the orbital half the year and rise on
the opposite side for the other half of the year. Much like in the extreme Northern or Southern
latitudes on Earth during the coldest months, the star at midday wouldn’t be directly
overhead and would hug the rim walls, the walls casting longer shadows over the
inner surface landscape and not permitting them to heat up as much compared to when the
star reaches its zenith in Summer. How much the ring is titled controls how severe this is.
So, while the orbital uses natural light, has the same day/night cycle, gravity,
atmosphere, and can be given seasons, it shouldn’t be thought of as perfectly matching
the conditions on Earth. We can fix the doubling up of the seasons per year if we use a different
star system, and I’ll get to that in a bit, but the lack of a consistent direction for
sunrise and sunset, the constant daytime irrespective of the season and the lack of tides
isn’t going to play nice with animals and plants that rely on those things. Setting up working
ecosystems will be a challenge without genetic engineering or careful selection of species.
Things also get wildly different from Earth when we think about orbital velocities.
The orbital rotates every 24 hours, and does so at a tangential speed of 301 thousand
miles per hour, or 0.045% of light speed, a very respectable interplanetary velocity. This would
be sufficient for interstellar travel, albeit it would take just under 10,000 years to get to
Alpha Centauri this way. So it provides a nice boost to or down from interplanetary velocities
and also ironically means that if you’re patient and mining other solar systems for materials, you
could sling them by mass driver to the system you want to broaden an existing orbital in and not
need to slow them down, just tweaking the final trajectory and speed so it meets the orbital’s
inner surface at exactly the same relative speed. We’ll get to how much material we need to build
one in a bit but let’s talk about width. As mentioned, this thing is a couple of million
miles wide in diameter and every 27 miles of width in that band adds another Earth’s worth of
surface area. So, you can get two eclipses a year, but only if the orbital is wide enough. Imagine
having your day interrupted by a scheduled mini-eclipse, courtesy of your local orbital
configuration. It's the new daylight saving time! You’d need an orbital in the order of 800
Earth’s worth of surface area to actually get a full eclipse. That’s a band 35,000 kilometers
or 22,000 miles wide for the specific case of our sun and our orbital distance. So one this
wide does have to be tilted to get sunlight too, and you might use minimal tilting and wide bands
to moderate light if you really wanted a 365 day year but that would be a bit closer to the local
star than comfortable, in terms of lighting. There’s lots of options. Incidentally, I’m
borrowing heavily from the Encyclopedia Galactica entry on Banks Orbitals over at Orion’s Arm,
written principally by Stephen Inniss, and since our calculations keep matching I’m going to trust
his going forward and save some time. And one thing that gets mentioned in there that I don’t
recall noticing before is that when you tilt the ring, you create two warm seasons per year.
For this reason, you could get away with a wide orbit too, to make a longer year if you wanted
to avoid a double set of seasons per orbit. Another way to get seasons is to use an elliptical
orbit, which will make it winter when the orbital is further away from the star, and summer when
it is closer to the star. You can also combine the two effects. If you thought deciding where
to install and how to tilt your satellite dish was tricky, try choosing an orbit and tilting
a megastructure for optimal seasonal variation! If the season variation is too quick for your
preferences, a slightly brighter star than our G2 yellow sun might be preferable, such as
a G1 or G0 or even an F8 or 9, as these are only a touch more massive than our sun but a
good deal brighter, so their habitable zone distance has a longer year, and again the
lack of spherical curvature on these rings, like planets have, mean they are going to be
warmer overall than planets at the same distance. You can also still use shades or mirrors to
enhance or decrease or modify the brightness and spectrum of the native star, but while a Banks
orbital is quite massive it still isn’t really going to have proper lagrange points like a planet
does, so your shade or lens or mirror needs to be lagite to keep up good pacing with the ring’s own
orbit around that star. You could use a similar trick to give it a moon if you wanted but that
ring is still rather bright at night time as we’ll get to in a bit, along with mass. See our Statites
and Lagites episode for more discussion of that. As a general point, the habitable zone and year
length of any star is based on its brightness and mass, but brightness rises at a bit over the
cube of mass while orbital period drops with the inverse-square root of mass, so habitable
planets around red dwarfs have periods of weeks or months, while big giant stars can
have habitable zone periods of centuries. That is for main sequence stars, and I should
also note that a subgiant star on its way to a red giant is brighter for the same mass and
thus might also be popular places to stick such rings. The timelines for subgiant phases for stars
like ours tend to be on an order of a billion years so you can easily migrate or increase your
sun shields as it slowly brightens. Those L1 sun altering effects are not altering that star
to look unlike a normal sun, even ignoring that we do not look at the sun directly - which
appears quite white if you do, not yellow - you would not really see a swarm of satellites there
altering the content of the light coming through. And of course if you can build things you
can also migrate them, should you decide your star is nearing its end, nothing stops
you from artificially lighting one of these for a trip and you could build your engine on the
backside to serve as a your fake sun for the trip, flipping it around for the slow down.
Should your star start to show its age, just pack up your several trillion square
kilometers of living space and move. It's just like moving house, but with a slightly bigger van.
Of course they take a lot of energy to move and we should discuss mass. We usually hold that at a
bare minimum you need a meter of thickness under you or at least one ton of material for every
square meter of artificial land under your feet, and many would prefer something closer to a
kilometer of landscape and hull under you at more than a thousand times that mass. For Earth
that ratio is several thousand kilometers and about 12 million tons per square meter.
That means your mass per unit of living area for rotating habitats is normally anywhere
from 10 million times as good as Earth to maybe 10,000 times. We tend to assume these bigger
continent and planet scale habitats go a lot thicker on their landscaping too, even if
they are dimpling their hull for deeper or taller lakes or mountains and filling the
latter with aerogel to cut down on mass. In the absence of something like magmatter
that makes graphene seem like weak warm butter, we have to use that thicker outer ring approach.
That might be a giant torus, flattened on one side for the ring to sit inside, and the rest
covered in solar panels and ancillary facilities. It might just be full of compressed hydrogen and
helium gas too, like a donut shaped brown dwarf, given their abundance and limited usefulness for
construction. If you have a fusion economy that can actually use hydrogen or helium as your fuels,
then it's a good way to store your reserves, and if not, if you can’t do better
than deuterium fusion, then it gives us something useful to do with that material.
If we just for the moment imagined disassembling Jupiter to make a such a ring from, and one of
about a thousand Earth’s worth of living area, you should have no problem getting all
the material from Jupiter’s core to build a mile-deep landscape, and still have tons
left over for that outer ring. Disassembling Jupiter for material might just upset a
few folks, but think of the real estate opportunities. Always look on the bright side of
planetary destruction. Of course, for some of us, planetary destruction is the bright side too.
Indeed you should have enough material for several of these kilo-Earth scale Banks Orbitals,
and you can always import from other star systems with less desirable locations or spectrums,
if you need more material or want to leave Jupiter alone for sentimental reasons.
A solar system like ours should have the raw materials for a couple hundred of them
in this size range, or a thousand of the smaller variety of just 200 Earth’s worth that is
referenced in Banks’ novels discussing Orbitals, and that’s before resource extraction options like
star lifting or importing matter from neighboring systems with less desirable stars. Field trips
in a Banks Orbital would be epic. Today's lesson: orbital mechanics, followed by a practical
demonstration. Tomorrow: How not to get lost on a megastructure. Essential survival skills.
You could in fact set these up like chain links, with each habitat on the same orbit of its
sun having a neighbor spinning through its middle and with its seasonal angle cocked in the
opposite direction. Usually when I refer to chain link worlds I’m talking hoop-worlds, donut shaped
artificial planets that are full of mass for gravity, but this is probably the easier version.
Now I said temperature is the same everywhere but that’s not quite true, and doesn't imply
similar weather either. As an example, my home is at 42 degrees latitude and is in the
northeast corner of Ohio, and is the same latitude as Rome in Italy. My area has only slightly
more mild winters than Buffalo, New York, my home away from home, which is at 43 degrees
and legendary for its snowy winters. Paris, France is way further north, 48 degrees, more
than most of Canada’s population, and London almost 52 degrees. Your landscape controls your
weather and temperature a lot and we can build those as we please on such artificial worlds.
But not every place gets a 12-hour day all year either. Those rim walls are enormous
structures hundreds of miles high, potentially even a thousand. We usually imagine
stylizing them as impossibly tall mountains and on smaller habitats they would even have
significantly lower gravity as you got higher but on a Banks Orbital, even a thousand
mile high wall is tiny compared to the radius under rotation so gravity would barely diminish.
In theory they could be made of a clear material but given the necessary thickness I think even
something translucent would be dubious, indeed you’d likely nest the ring and entire rimwall
into your outer torus for added protection, and that means you have shorter days near the rims.
How much this affects the habitat as a whole depends on the width of your bracelet or axial
length, again every 44 kilometers or 27 miles of this axial length is giving you another Earth
of living area. But half your time your area near a rimwall is under partial shadow and how
much just depends on that rimwall height and your tilt. If your habitat is much wider than
your rim walls are tall, the effect is fairly minimal outside those areas, and the same if your
axial tilt of the ecliptic is fairly minimal. The sharper the tilt, the more seasonal variation
habitat wide and the more shadow by that rimwall, and this will also help drive weather. Especially
as you might decide you don’t want a flat ring but one with a little curvature, either bowing
up in the middle or down in the middle. Up in the middle means water will tend to drain
toward the rim walls, down, toward the middle, and you could get away with shorter rim walls
if you had enough drop toward the center. Any mountain ranges you place throughout the
habitat are going to locally cool things too, and those things can help drive weather and break up
storms, but there is no coriolis effect and major temperature gradients driving the more vicious
cyclonic weather we see on earth, let alone places like Jupiter which is more massive than one of
these rings but considerably smaller. Though the axial tilt can allow some monsoon-like effects.
You can also place them on a more elliptical orbit, rather than something circular, so that
you get your twice-a year season from the tilt overlapping with your high-eccentricity season
caused by getting further and closer from the Sun, with a summer effect when its closest, or
at perihelion. In this way you could get a high-summer effect by timing one of the two
axial summers with the perihelion summer, and your aphelion winter would be at the same time
as your other summer, making it a lot more mild, or even still wintery if you were using
a rather eccentric elliptical orbit. In the absence of a moon of real mass, which
would probably be a pain in the neck, you do not get lunar tides. We're missing out on those
romantic moonlit nights and werewolf stories, but on the bright side, no high tides means no
unexpected swimming sessions. If you want a moon, you could fake one with lagites or orbit
some hollow moon around the Banks Orbital, though I would not trust that moon option unless
you were using the supermassive outer sheath secondary ring to add a lot of mass. You do still
get solar tides though and pretty impressive ones, as you are getting 2 million miles or 3 million
kilometers closer and further from your sun every day as that bracelet spins. That’s a 2% change in
distance for any given spot of that ring relative to its sun every day, or a 4% change in its
gravity on you and that would parallel ocean tides here on Earth, though you may want to use
smaller basins akin to seas or great lakes,which would reduce that. Those near dimmer stars will
have worse tides, and those on eccentric orbits would have tides varying over the year as
they get closer and further from the Sun. Now the one thing you probably don’t have
on these is a moon and that’s because they are wider than our moon’s orbit and unlike
a sphere, a big ring is not exactly ideal for orbiting around stably. Again you could
fake one with a lagite and it would appear exactly like our own moon if you liked.
But that ring is quite bright at nighttime too. Our moon when full has a solid angle of about
65 microsteradians, about the same as our Sun has, and Earth from the Moon is about 14 times
bigger, at 880 microsteradians and would be about 14 times brighter in the sky
on the moon than the moon is here, adjusting for different albedo or reflectivity.
A Banks orbital is further away, so that a given moon or Earth sized object would be reflecting on
a 24th as much moonlight - or ring light - onto it’s nightside when getting sun, but that still
means even a relatively thin ring of only a handful of Earth’s living area is much brighter
than our Full Moon. Like some big bridge across the sky. Who needs constellations when you've got
the ultimate night light? And very visible with its landmasses too. To the naked eye, with two
layers of atmosphere in the way, it probably looks like a blue-green-and white smear but even simple
binoculars would let you identify bigger seas and land masses readily enough, and especially
directly overhead where light passes through the least air both ways, you might be able to make
out seas and continents with the naked eye too. You do not see it curving away either, the
curvature is a hundred times less than on Earth, and turns up rather than down, but should smear
off into a red haze than remerge as a red hazy ring slowly turning blue and green as your look
higher. When looking in the ring direction, which we’ll call east and west. North
and south are toward the rim walls, and by default we assume this is flat, other
than landscaping changes, but I do think you would put a slope into make the middle or equator
slightly lower, which would result in a thin ocean belt around the whole ring, sort of like we
discussed in Topopolis, the Eternal River, in our February Nebula Exclusive. That structure
is the exact opposite of the Banks Orbital too, very skinny radius and incredibly long axial
width, so it looks like a thread not a ring. Don’t think of the ring as being ruinously
bright either, folks tend to forget our eyeballs are logarithmic, the sun at noon is
400,000 times brighter than the Full Moon, so even a wider ring that might be a thousand
times brighter than the full moon is still darker than twilight or very overcast days.
You do have options for handling that too, like having a nested ring inside made of panels
that flipped out of the way for sunlight, turning perpendicular, but then rotated in
to block ring light at night. I personally don’t think you’d bother, given it wouldn’t
be as bright as many suburbs at nighttime, much less cities, but you might.
Speaking of nested rings, in addition the chain-link connection of orbital, which I’ll dub a
Banks Chainlink World, which could be through the middle or even close enough to touch atmospheres,
which might be a neat effect, you could nest some smaller rings inside the orbital cocked at higher
angles to give an appearance of an orrery of three of four of these together, maybe more, and of
course you have countless additional facilities and smaller habitats in and around one too,
adding themselves as constellations in the sky. Those cock-eyed ones, which I will name a Banks
Orrery, could get away with being just, say, 10,000 kilometers smaller in radius
for each one with just half a percent drop in gravity in order to maintain the
same day length of that shorter radius. The rings would shadow each other a bit,
but create far more connected living area, and direct physical connections would be possible
using the same sorts of tricks we discuss in the megastructure compendium for devices like space
towers or sky hooks. You’d rotate under each one once a day, for an extra eclipse, so you
wouldn't have more than a few unless you want to move your Banks Orrery a bit closer to its
star, but it would be pretty minimal. You are spinning 300,000 miles per hour, so crossing
under a higher ring even 20,000 miles wide is only eclipsing things for 4 minutes at a time.
This episode should air about a month after the big annular eclipse a lot of North America is in,
including my house, so for those experiencing it you will recall that it’s not really dark during
an eclipse, just dimmer, more like a very thick cloud passed in front of the sun on a partially
cloudy day. Amusingly you could chain link these Banks Orreries together too, a Banks Chain Orrery
I suppose, and if you are chaining these, you can also do nested rings of them around that sun, just
as we sometimes contemplate doing with Ringworlds or Rungworlds to form a partial Dyson Sphere.
There are some fascinating variations of these structures over at Orion’s Arm and some
short stories and fiction set there, Orion’s Arm is a shared open source hard sci-fi
setting and it’s Encyclopedia Galactica has always been a favorite resource of mine long before I
started the channel and many articles also cite me or were contributed to by me too so odds are if
you like the show you’ll enjoy that site. The same goes for Iain M. Banks excellent Culture series,
which is generally pretty upbeat and optimistic, and where the Banks Orbital is just one of
several giant megastructures we get to explore, and Banks was a great storyteller. The Orbitals in
there are their alternative to settling planets, as they just build those orbitals to live
on as more mass-efficient and customizable. Now that we’ve explored them in theory and in
fiction, will we ever see them become a reality? Hard to say, I think if no other engineering
barriers pop up, which is probably optimistic, we will at least see some built to prove it can
be done, maybe even as soon as in a few millennia, but I’m a little less optimistic about them
becoming the mainstay of civilization as they are in the Culture novels. In a few millennia, if
we've not found something shinier to distract us, we might just build one. Or we'll get
halfway and decide it'd make a great tourist attraction as the galaxy's largest
unfinished project. Either way, it's a win. Their size makes them a big investment
and an interconnected one, whereas you can build O’Neill Cylinders and smaller
habitats still able to house many thousands, connect them by tethers and shuttles if you like,
and still be able to pack one up and leave, since they are very easily modified to be spaceships.
So I think it's easier for me to see a billion O’Neill Cylinders built and parked
near each other, connected by tethers, than a Banks Orbital, and both having
similar total living area. Besides, we have bigger versions of those in the forms
of Bishop Rings and McKendree Cylinders than can allow a potentially happy medium.
That said, powerful people like to leave behind imposing monuments. You only need to look
at the pyramids to understand how that works. So, if you’re an all-powerful ostentatious ruler or
community wanting to leave your mark on history, you could do worse than creating a Banks Orbital
legacy that a trillion people can live on with tons of elbow room. For more altruistic pursuits,
we could produce continuous ecosystems bigger than a planet to house all those wonderful species
that were snuffed out through natural calamities or human encroachment. So I think there’s a
future for Banks Orbitals, and a beautiful future at that. How could it be otherwise in
a solar system decorated with God’s Bracelets? To build and maintain an enormous
construct like a Banks Orbital, you need patience and determination at a
level almost inconceivable for a human, or even a whole civilization. For ultra long-term
projects like these, we may use machine minds, and in this month’s Nebula Exclusive, Machine
Monitors, we’ll examine what sort of artificial intelligence we might select for such missions and
consider some of those missions, from building and maintaining megastructures to monitoring
deep system defenses, exploring galaxies, or primitive worlds where life is emerging
and may need monitored for millions of years. Machine Monitors is out now exclusively on Nebula,
our streaming service, where you can also see every regular episode of SFIA a few days early
and ad free, as well as our other bonus content, including extended editions of many episodes,
and more Nebula Exclusives like last month’s episode Galactic Beacons, Crystal Aliens from
March, February’s Topopolis: The Eternal River, January’s Giant Space Monsters, December’s episode
The Fermi Paradox: Hermit Shoplifter Hypothesis, Ultra-Relativistic Spaceships, Dark Stars at the
Beginning of Time, Life As An Asteroid Miner, Nomadic Miners on the Moon, Space Freighters,
Retrocausality, Orch Or & Free Will, and more. Nebula has tons of great content
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We were talking about mega-engineering only advanced civilization could manage in today’s
episode, and we’ll continue that look at advanced civilizations on Thursday May 9th as we look at
the Interdiction Hypothesis of the Fermi Paradox, which asks if civilizations out in
the galaxy might leave large buffer zones between their empires, and ask if Earth
might be inside one such empty buffer zone. Then we’ll continue the alien theme with a
look at the reverse case of Interdiction, where civilizations sprawl near each other
and set up alien embassies. After that, it's on to the idea of massive galactic empires and the
enormous cosmic capitals that might oversee them. As a heads up, in the last few weeks we
launched Youtube Memberships, as another option folks can choose to help support our show.
Memberships on youtube come with some perks too, so if you’re interested in learning more, just
click the join button under any of our videos, or the link in the episode description on any
of our platforms, and you’ll see the options and perks. I also wanted to thank everyone who
has joined this last month and everybody else who's been supporting this show for years.
In a sea of clickbait and algorithm-chasing, personal support really is what helps us and
other shows keep producing quality episodes, and… If you’d like to get alerts when those and other
episodes come out, make sure to hit the like, subscribe, and notification buttons.
You can also help support the show by becoming a member here on Youtube or Patreon, or
checkout other ways to help at IsaacArthur.net. As always, thanks for watching,
and have a Great Week!
