Upward Bound: The Environments of Space Habitats

We like the idea of living on a rotating space habitat, but what if we create alien ecosystems by doing just that? One of our favorite topics on this channel
is space habitats and megastructures, particularly rotating habitats. Without having access to an unknown technology
or planet-sized masses of material, the only way we can currently realistically create
artificial gravity in a space habitat is by spinning a cylindrical or ring-shaped structure
so that centrifugal force and inertia mimic gravity, which we call spin gravity. On Earth, ecosystems arise in all places,
from the sub-zero temperatures of Antarctica to muggy rainforests to sweltering deserts. In order to understand an ecology, we need
to understand the context of its environment as this plays a large role in defining what
that ecology will look like. So, a fish that has adapted to have antifreeze
in its bloodstream, like some of those in Antarctica, would not do too well if suddenly
transported to the brine of the Dead Sea as its adaptations are to the cold, not the high
salinity and higher temperatures of the Dead Sea. So with that in mind, what would the environment
of a rotating space habitat be like? These spinning habitats are often shown by
themselves in space, even on this channel, but in practice you would almost never be
able to see one from the outside. They’re more likely to be inside of a sheath
that’s imbedded inside a protective asteroid, separated from the sheath by vacuum so they
can rotate without friction. There will also likely be superstructure and
auxiliary facilities nearby. These structures are a likely future homes
of humanity, more so than the various planets that we might terraform. But we’ve never talked here before about
what it might be like inside them in terms of the environment, ecology, and weather. In fact, most people are surprised to learn
that an enclosed manmade structure would develop weather systems–but they do, particularly
when the whole thing is spinning and Coriolis forces become a factor. Even if you designed a habitat to replicate
Earth’s environment as closely as possible, there will still be some major differences;
and factors such as size, shape, rate of rotation, and lighting can radically alter the dynamics
of an ecosystem. To avoid confusion we will refer to the spinning
section of a habitat as the ‘drum’. Another term, before we jump into today’s
topic, is the ‘axis’, the imaginary line down the middle of the drum, around which
it rotates. The axis will come up a lot in this episode
because it will be a fairly important and weirdly behaving place in our habitats. We often envision some sort of artificial
sun that runs along that central axis like a cable, but the axis might also be an open
space where you can enjoy zero-g recreation without a space suit, riding powerful winds
or drifting along slowly among the clouds. This is a key first environmental difference
with Earth as a drum is just a pressurized can. On Earth, air pressure is caused by kilometers
of air sitting on top of more air, weighing it down. Gravity holds the air there and keeps it from
leaking off the planet, even though there’s a vacuum all around us. Inside a soda can, where the pressure is a
great deal higher than the rest of Earth, it’s the walls of the can keeping the material
inside and the sheer quantity of gas packed in there that causes the normal pressure. Another difference in environment comes into
play too. Stick a needle in Earth and the air doesn’t
go anywhere, stick a needle in the drum of a space habitat, and it flows out like water
down a bath plughole. Needless to say, making sure punctures don’t
happen or can be patched quickly is an important part of habitat design. However, this also means that the air inside
is not structured like on Earth. In a small drum the air pressure is about
the same at the axis or perimeter, even though the gravity is zero on the axis proportional
to the distance from the axis. Halfway to the axis, get half the gravity. So in a small drum like that, plants and animals
adapted to alpine climates with freezing temperatures and low atmospheric pressures wouldn’t do
too well unless the climate of the drum was specifically designed to be alpine. In the smaller habitats, the weather for the
entire drum is likely to be the same, so very stable and niched ecosystems are likely to
arise. I imagine that there would be all manner of
habitats and somewhere, someplace in the billions we construct, there will be any environment
you could imagine, from the tropical, to the alpine, to the downright weird, like recreating
ones with a high oxygen content that favored massive organisms, such as from the carboniferous
period. In the much bigger drums, the pressure will
vary with distance from the axis, and on the really big ones like McKendree Cylinders,
Bishop Rings, Banks Orbitals, or Ringworlds, pressure will vary with altitude like on Earth. The air gets thinner as you rise until you
get to near-vacuum, but gravity remains essentially the same. Needless to say this results in very different
weather than where the gravity rapidly drops off but the air pressure does not, and the
mid-sized drums would be a bit of both, a big drop in gravity and pressure as you approach
the axis. That also means on the bigger ones you don’t
actually need a closed habitat drum, or ring, because the air sticks there from spin gravity,
but it can still spill off the sides and fly into space, so you need walls along the sides
that rise quite high to prevent that, called rimwalls, as opposed to caps that the normal
cylinders have. One option is to stylize these as mountain
ranges, and very tall ones at that, since while it’s hard to breathe atop Earth’s
tallest mountains, there’s still atmosphere there and far above, whereas to contain the
atmosphere of our ring habitat, the mountain walls will have to rise all the way up into
the vacuum. These are very alien environments as we have
nothing like them on Earth. One can imagine over time that critters could
evolve to survive or even thrive on the tops of the mountains in a near vacuum. We already know that some organisms can exist
in a vacuum too, such as tardigrades. I, for one, am excited to see what life in
this alien environment will evolve. Who knows, we may even be able to borrow their
exotic genetics for our own use in our crops, animals or maybe ourselves. Even on the smaller habitats, like Bryan Versteeg’s
Kaplana One Design, a cylinder won’t have flat end caps. Sharp corners aren’t structurally ideal,
whereas a pill shape, or a cylinder capped by a hemisphere on either end, offers advantages. Those are still spinning but have lower gravity
as you go up, and you’d likely still stylize them as terraced slopes akin to hill or mountains. This results in an interesting difference
from Earth too. On Earth, mountains have a timberline, a height
at which trees can’t grow anymore because of inhospitable conditions. You would likely still have these on the largest
rotating habitats due to changes in evapo-transporative forces. However, on the more modest ones, you might
actually get the reverse. Gravity is lower near the axis, which helps
trees to grow taller, but the air pressure isn’t dropping off, and for a lot of drum
sizes you will have a tendency to get higher humidity as you rise. Depending on drum size, while on Earth it
can rain during the day or night, these would be more prone to raining at night when the
light goes off and all the water vapor condenses and falls down, as rain or snow. Interestingly, I’ve never seen a depiction
of a space habitat with snow, but I imagine it would be quite spectacular, an entire artificial
world clothed in a sparkly white winter wonderland. Redwoods, the tallest of trees, rely on fog
for their water farther up, as it’s hard to transport water that high. If you’re on a cap mountain, with higher
humidity and lower gravity, trees could potentially grow far taller than on Earth, with their
canopies spread far wider. Imagine that sight, vast, interconnected canopies
supporting their own layered ecosystems like we have in rainforests on Earth, but supersized,
potentially with two mostly segregated ecosystems, one on the ground, one in the canopy above. They’d be fun mountain forests to visit
too, as the lower gravity would make hiking around much more comfortable and safe. I think your goal in building most such habitats
is to mimic Earth as much as you can, but some variation might be welcome, and probably
unavoidable too given the increasingly alien environment the closer we get to the axis. It’s also fairly easy to make floating landmasses
or structures inside the habitat drum. You just hang things from the tethers down
from the axis. You’d probably have a lot to tethers hanging
down as spokes anyway to ease transport around the place and put platforms for observation
or maintenance on these. Birds would adapt easy enough to low gravity
flight and other animals might be transported up there or learn to climb or hitch a ride
on the elevators. We have plenty of organisms living in the
air too and if the gravity is low, flight or buoyancy can become easier, you might get
weird seaweed equivalents floating around the sky, patches of skyweed blown by the air
currents in the microgravity. End caps are the best place to locate your
mountains, since they would place less stress on the hull. However, your cylinder need not be smooth
any more than it need be flat-capped, and you can distort the habitat’s hull to create
hills and lakes, you can also use some light but sturdy material like aerogel to fill those
fake hills. Though, for your typical drum, you’d have
a problem keeping the drum structurally sound if you modified it too much, and even aerogel
isn’t so light you could disregard that mass if you were piling it into mountains. So you’d probably limit yourself to hills
and valleys and save the mountains and canyons for the sloping caps. This also means that you are getting that
normal feature of rivers running down out of the mountains into lakes below, and same
as the caps don’t have to be flat, the drum itself need not be a cylinder, it could bulge
near the middle for instance, and there gravity would be a bit higher and you’d get a belt
of water. You could also have one cap smaller than the
other, a truncated cone, and on the skinnier end things would be a bit lower gravity and
maybe a bit more arid, while the thicker end would be where your lake was that all the
rivers ran down to. This inevitably brings up the topic of erosion,
rivers cause it, rain causes it, and so does wind. Weather in a drum is normally going to be
fairly mild, enough that you might need to take steps to get some decent wind and storms
in them to support an ecosystem’s seasonal cycle. However, this means that you’ll need to
take steps to maintain the interior. As even gentle rain or wind wear away at the
landscape over time. Now the weather on such habitats will for
the most part be similar enough to Earth without much monkeying around, but more mild. We’ve focussed on rotating habitats, but
the reverse is true on bigger artificial worlds we sometimes discuss like Supramundane planets
or Mega-earths. The two biggest factors for weather are sunlight
and spin. A Saturn-sized planet turning once every 24
hours to mimic Earth, just a hundreds time larger in surface area, is going to have some
vicious winds. As would donut shaped planets like the Hoopworld. Actually, wind speeds on gas giants are almost
always in excess of the most violent hurricanes of Earth. On those, you can break it up by including
mountain ranges for them to slam against and slow, and you can use this trick inside smaller
rotating habitats to help funnel the air around to create more variation and focus areas of
high wind for ecosystems that need it. They can also be used to help vary temperature
and precipitation, if you don’t want a single climate across the habitat. For that matter, you will also want to vary
your lighting levels, spectrum, and duration to simulate seasons. Seasons are pretty critical to ecosystems,
impacting everything from pest control to reproductive cycles, though one handy thing
about such habitats is you can arrange those to be different in severity or duration than
on Earth. The weirdest thing about the sky on rotating
habitats though is that it doesn’t exist, look up on one and you see your neighbors
backyard hanging overhead. There’s many ways to deal with that, if
you feel a need to, but the most blunt force trick is to stick another small cylinder painted
blue inside your drum, maybe with lights in it to fake stars at night. You could stick a lot fins and baffles on
such a thing, that could be folded up or extended to push the air around, not really an elegant
solution but it does work, and it would be pretty natural looking, even without getting
sophisticated and using LED screens, it’s not like painting a sky mural on your ceiling. Though if your sky cylinder is covered in
a ton of pixels faking the normal sky, day or night, I could easily imagine companies
buying billboard time on those. However, you shouldn’t need to go that route
on larger ones at all, air distorts and absorbs light and water vapor does too, and as mentioned
in many of these it will tend to accumulate toward the axis in the day time. You should get normal enough cloud formations
and haze breaking up your view of the other side of the drum, and it might get a lot more
since your artificial sun might need cooling. There’s many ways to light a drum, you can
let light in through side panels in the drum or through the caps using mirrors, you can
have a big lightbulb down the middle like a fluorescent tube, but if you’ve got a
fusion economy you probably have a big Sun on a trolley that moves along the axis. Such a thing likely needs coolant and may
use water as the working fluid for turning its turbines for power generation, and so
would be quite the cloud factory. Indeed that’s what we call the nuclear plant
in the town over from me, since it’s always visible by the clouds the cooling towers put
out. Picturing a big white or yellow sphere on
a trolley, trailing clouds, is probably not quite right though. In some you might have a noon-spectrum lamp
in the middle and red on the edges, pointing their light at an angle, to simulate twilight. This would have the downside of having different
times of day throughout the station and that might not be desirable. I don’t really want time zones in my O’Neill
Cylinder the size of modest island. In this regard the big light bar stretching
down the middle might be preferable, everybody gets the same light at the same time, and
you can dim it and change colors to do your day cycle. Doing that, though has interesting effects
on the ecosystem of that habitat as the angling of the sun that many mosses, plants, and animals
rely on would not happen. This could cause rapid divergence in those
habitats from the original ecosystems that they were installed from. The trolley sun works better on a rotating
donut habitat, not one we see much. We’ve got hoopworlds, where you live on
the outside of a very large donut, and we’ve got smaller toroid space station designs that
spin like a Hula Hoop for gravity, but this is a bit different. On this type it’s the same as a normal rotating
habitat only it’s quite long and has no cap, those ends meet and it forms a hoop. To avoid confusion with hoop worlds or ring
worlds, we will call this a Circle Habitat. It can spin like this, and not just around
like a normal hoop, for the same reason everything is a rope if it’s long enough compared to
its width. Even the sturdiest iron bar can be easily
tied into knots and bows if long enough compared to width. The big brother of this is the Topopolis,
the largest rotating habitat you can build with conventional materials and the only one
that can rival a mega-Earth for living area, we’ll discuss those more in the future. For now, the neat thing about these, is that
if you have a trolley sun moving down the internal axis of one, it will rise and set
just like normal, as it comes around the curve of that torus’ interior. Though you might use multiple such trolley
suns spaced around to get the right day night spacings. You’d also get a steady breeze moving along
with the trolley suns as they moved. So while these would seem at first to be more
exotic than a rotating cylinder, they would actually mimic Earth’s environment more
easily. Incidentally you’re not necessarily using
reflected sunlight or fusion power for these suns either, kugelblitz black holes of the
feedable type are ideal for fakes sun inside rotating habitats or as sun-moons orbiting
artificial planets, provided we filter out the dangerous ionizing wavelengths or convert
them to other wavelengths. The amusing thing about using black holes
and their Hawking radiation for lighting is that the bigger your space station is, the
smaller the black hole you need to light it, since they grow more luminous as they get
smaller, but even at the size of an O’Neill cylinder, the mass needed for such a black
hole sun is less than that of the station. Of course you cannot throttle such things,
they give out their power continually, though you might be able to reflect it back in when
you don’t want it, but you might have the same problem with fusion plants too, which
might not be able to ramp power production up and down over a period as short as a day,
and regardless, there’s no night in space, for all that we talk of it being the Ocean
of Night. So if you’re getting your power to light
the inside from solar or reflected mirrors, at night that is going to waste. You could have two drums, one lit and one
not, at any given time that shared it, or just let it go to waste, but you could also
store surplus power in the drum itself. You might want a pair of drums anyway, as
without it the habitat could suffer from precession, which is the rapid flipping of the habitat
end-over-end. That would be a nightmare for the structural
integrity of the station and the ecosystems on the habitat too. Alternatively, since a cylindrical habitat
is basically a giant flywheel in a vacuum, you could slow it down a little, lowering
gravity, during the day to augment your sunlight power supply, and then dump that power into
spinning it up at night. It might be interesting to live some place
where the gravity was normal at dusk and dawn, but maybe 10% lower and higher at noon and
midnight. Get a little spring in your step midday and
be a bit more lethargic at night. Needless to say that would do peculiar things
to not only the weather, but also to the ecosystem, and peculiar isn’t necessarily bad. As we saw in Exporting Earth, you’d often
have to augment the food supplies for the local critters if you wanted to ensure they
were numerous enough for both decent gene pools of any given species and a decent diversity
of species. One interesting thing about these habitats
would be their ability to maintain distinct species, like you see on isolated islands
on Earth. While they aren’t as genetically diverse,
you do see unique species not found anywhere else because of that isolation. This can be an advantage, especially if you’re
trying to conserve some rare species of salamander, squirrel, or deer, and all things being equal
a simpler ecology is easier to maintain. The downside is that in order to keep the
ecology healthy you may need to intervene more to keep it on track, because the less
complex the ecology, the less redundancy there is, and the easier for a single failure to
destabilize the whole thing. Now you can have some complete ecologies in
fairly small places, even a single petri dish, and even ones including more than microorganisms
can be fairly small and complete, or close to it, but by and large we have to accept
that any artificial habitat significantly smaller than a continent is going to have
some gaps we’ll have to plug with artificial means. We do have some habitat designs that big or
bigger, and for those, we have an easier time creating a stable ecosystem. You might need to maintain a gene bank to
artificially insert diversity through cloning or genetic modification, or bring in stock
from neighboring habitats. You might need to augment nutrients or fill
ecological niches with artificial roles, like tiny robots drones that mimicked bees for
pollination. You might use bees or hummingbirds for pollination
but have to modify them and other organisms that navigate off the Sun or magnetic fields,
so they could navigate off what the habitat has instead. In small habitats you might need to tinker
with their genetics so they used something else, and it might be amusing if a habitats
bees and birds navigated off the wifi signal inside… which it would presumably have,
especially since by default a cylinder habitat is a giant faraday cage so signals from outside
need to be received and repeated inside. Now speaking of bioengineering, all such environments
will need constant maintenance by people, not just ecologically, but also mechanically,
and for their landscape, and since the critters living inside might need some genetic tweaking,
you might as well get them to do some of the work for you. This has some amusing implications. There’s a theme park in France where they
recently trained some crows to pick up trash, and while getting critters to collect trash
and take it to deposit site in exchange for food might be hard to do in the first generation,
over time or with active intervention, it could be done with many critters. One can probably engineer it to be instinctual
if needed, but it’s likely that for many species after you train the first generation
or two, parents would teach their kids what to do and which bits of trash are safe and
what they got for them. I can imagine after some generations squirrels
fighting over cigarette butts or bottle caps as enthusiastically as lions fighting over
a kill. However, one should hope humans in the future
are not such litterbugs that they could support an entire species picking up their trash,
so it’s an amusing example that hopefully wouldn’t be needed but it highlights how
in these environments, doubly artificial by both their nature and them being human habitats,
rather than dedicated eco-preserves, your ecology will either need tons of intervention
or needs to be adapted to include humans and our constructs as part of that ecology. And if you’re not exactly replicating nature,
by fundamentally adapting species to fit this artificial environment, it’s worth considering
using them as part of the maintenance crew. Let’s take an example: Inside such habitats
you need a lot of rock and soil and things like sedimentary rock don’t occur naturally
off Earth, so you have to make it and even things like basalt, which is common on the
Moon, is a bit different than Earth’s, whereas granite is not something you’ll find on
moons and asteroids and will be a pain to make. As it erodes down you’d have to constantly
replenish it and dredge your lakes so they don’t fill in. One might imagine that crabs or coral or other
shell producing critters might be tweaked to maintain the land by creating it, those
are made of calcium carbonate and many rocks are mostly that too. With a bit of tweaking, while they’d still
have their normal food chain, you could set up an ecosystem that self-sustained far more
than on Earth by altering or maintaining the landscape too, much as beavers do in a way,
in exchange for additional food. As we mentioned in Space Farming, while you
can obviously farm the interior of a habitation drum, you’d likely do most of your food
production in simpler, cheaper and more optimized auxiliary space farms near the habitat. So you could produce extra to bribe and pay
the critters who can now live in greater numbers. One might also imagine how that might mutate
down the centuries as they slip into these ecological roles and add new niches, more
scavengers and pirates too, the hawk swoops down on the squirrel not to eat the squirrel,
but to steal its bottle caps, and the squirrels bury their bottlecaps for the winter, so they
can take them in to the recycling center for food in the lean months. Now of course all this could probably be done
with machines instead, and maybe better, but on the higher end of genetic engineering and
machine creation the line gets rather blurry. People often say humans are the apex predator
and the pinnacle of evolution and biology, which may be true, as we say here though,
there is no machine on this planet as artificial as the typical human, nothing more manmade
than us. So it’s a blurry line and one that will
get blurrier if you decide to extend this maintenance ecology outside your habitation
drum. I mentioned that organisms that can survive
the radiation blasted ruins of space, and on the outer skin of the drum, they might
do well living just under the surface, same as something can live in ice, just under the
surface too. We’ve already got ecosystems in the permafrosts
and glaciers on Earth, so it’s not a stretch to believe something couldn’t gain a foothold
on our drums too. Also again the drum in unlikely to be exposed
to the void anyway but be surrounded by some protective sheath. Our preferred material for making rotating
habitats is assumed to be graphene, which is made of carbon, we are carbon-based life,
so one might imagine creating organisms which live on the hull and go around eating damaged
and micrometeor scarred sections and replacing them with newly spun bits. They might be more machine than organic, or
based on an entirely different organic chemistry, but not necessarily. Again we’ve got some very bizarre and robust
extremophiles already and often find new ones dwelling and even thriving in environments
we’d call barren or even toxic. Finding things that eat plastics or metals
or silicon or possibly graphene wouldn’t be that weird, and as time passes they become
more likely. Where evolution is involved, if there’s
a niche, a food source, something will eventually exploit it. We’ve now created a new ecosystem outside
of the drum, one that might evolve into a very alien one too. This makes mutation a concern as well, because
if you make a bunch of organisms that eat graphene hull plating and spin new bits, you
will eventually end up with ones that eat undamaged sections and others that adapt to
eat each other. This would tend to happen with self-replicating
machines too, and I should note that we can do things to curb their mutation rates, but
we can also do that to biological organisms. There’s no particular reason you can’t
build a checksum function into a robot’s equivalent to DNA, one of many methods we
use for data integrity when copying it, to cut down on mutation, and you could probably
build that into normal DNA and biological organisms too. Though we have many methods to control such
populations, like building in a requirement for a specific nutrient they can only get
at one place, so they have to stick to that area and it’s easy to spot mutants when
they come by. That’s assuming you’d want to stop such
mutation. Personally I think that’s fascinating and
something we’d want to let progress. If things got too troublesome, you can just
purge the current species or build a new habitat. There’s a habit in science fiction of having
us come across artificial worlds and habitats abandoned by their makers or who went primitive. I think that’s unlikely but it makes folks
focus on how long such places would last without maintenance. To me, that’s a bad way to look at it, the
Earth isn’t static; it’s likely most planets that started off like Earth lost their atmosphere
or oceans, and if they ever had life, lost it with them. Our planet has changed a ton over the eons
and is always changing, mountains rise, oceans sweep them under, forests turn to plains and
back to forests then get swept under by glaciers or torched by volcanoes. Count it luck none of these changes ended
all life, though it certainly ended most of it, we’re mutant leftover survivors of those
species that managed to barely survive many catastrophes that changed the world immensely
and took most of its inhabitants off the table. An artificial world would need maintenance
in general, but if you’re clever you might make one self-sustaining and even more stable
and enduring than Earth. There’re endless options, and while I think
most habitats would try to mimic Earth as close as possible, I’d imagine almost all
of them would choose to have at least one peculiar feature that stood out. Be it gardens in the clouds or a sun that
gave very long sunsets or environmental controls that made sure it was always Sunny on Sundays. Or freakishly tall trees with enormous canopies
spread out across the lower gravity sky, home to whole ecosystem living in those branches. Or ones that incorporate calcium carbonate
into their bark and die as small limestone mountains. Or squirrels that rob tourists of their chewing
gum so they can turn the wrappers and gum in for treats. A little uniqueness never hurts, and who can
say what other interesting things might emerge over time? We’ve a lot of announcements for today and
we’ll get to those and the upcoming schedule in a moment. First, I wanted to mention that while a big
focus for today was designing the ecosystems on these habitats to match up well to human
settlements, Anthropic Ecology if you would, we’ve also mentioned before that you could
use habitats like these as dedicated nature preserves too. Some species don’t do well with humans and
even those who do tend to change a lot, so closed off ecosystems helps preserve them
against extinction and you can’t get more closed off than a space station. However it’s surprising how often critters
we thought went extinct turn out not to have, Lazarus Species, not to mention just how many
species we never even knew about, or at least that biologists didn’t know about, and our
sister channel Cheddar recently released an episode discussing that and how modern technology
is letting us crowdsource our investigations. I’ll link it in the video description and
end titles. They’ve been doing a lot of great videos
recently and sponsoring many others like todays, and I’d suggest checking it out and don’t
forget to subscribe while you’re there. I also wanted to thank Bryan Versteeg of Spacehabs.com
for lending us a lot of the footage of his Kaplana One Space Habitat. He’s one of the best space artists out there
and has brought to life so many of the futuristic concepts we look at here. If you want to see more of those, check out
his website Spacehabs.com, linked below. I recently sat down with John Michael Godier
on his new radio show Event Horizon for an interview, and as you’d expect the two of
us had a lot to talk about, so it ended up needing to broken into two pieces, the first
of those will air tonight at 5 pm Eastern time, 2100 UTC, which gives you plenty of
time to check out Cheddar and some of John’s prior interviews with folks like Robert Zubrin
and Andy Weir, author of the Martian and our November book of the month, Artemis. We also have our second End of the Month Livestream
coming up this weekend, Sunday October 28th at 2 pm Eastern, 1800 UTC, we may start bringing
guests on for those in the future, but while we’re still learning the ropes, I’ll be
there this Sunday afternoon answering all your questions about SFIA and our episodes. Lastly for announcements, while we have all
the episodes available as audio-only for download at Soundcloud, and on iTunes, I recently added
them all to Google Play as well. So we took a look at artificial habitats today
and how their ecologies might change over the generations, and we’ll be looking at
some more of these structures of truly grand scales in coming months. We do often spend a lot of time far ahead
in the future and a common comment made here by viewers is that they wish they could live
to see such things, a sentiment I certainly share. With that in mind next week, we’ll be joining
up with SENS Research Foundation to explore some of the science behind aging and extending
the human lifespan, and we’ll dig down into the biology and other science of it next week. One thing we didn’t discuss much today is
how you turn the barren asteroids you’d be making these habitats out of into good,
healthy soil, and get stuff growing there. In two weeks we’ll be discussing how to
transform our deserts here on Earth into verdant forests and lush jungles or farmland, and
we’ll talk a bit about how you do that aspect of terraforming too. For alerts when those and other episodes come
out, make sure to subscribe to the channel and hit the notification bell. And if you enjoyed this episode, hit the like
button and share it with others. Until next time, thanks for watching, and
have a Great Week!

Comments 100

  • After the news coming out of the past few days, I'm ready to move into one of these things right now.

    What are housing prices like?

  • Would a vacuum tube train in the center of a rotating habitat make sense, given the zero g at that location?

  • My grandmother worked at KSC in the 60's and 70's. She told me about it raining in the Vehicle Assembly Building. Indoor weather is a real problem when putting rockets together. They had a team just to predict and control the weather inside the assembly bay.

  • 25:52 Well hello there M'Lady ( ͡° ͜ʖ ͡°)

  • You should start a foundation to make this stuff a reality.

  • A central axis is like an internal orbital ring

  • 25:20 Issac plays fallout

  • Playing Stellaris while learning about artificial space habitats. 😀

  • This video just described the whole 3rd Millennium.

  • I love the idea of self-sustaining ecosystems but I would like to see your thoughts on how we maintain such systems as nothing operates with perfection over long periods of time. For example, destructive organisms might evolve that wipe out crops and take chemicals or another creature to eradicate. Who is producing those chemicals and how do we maintain that chemical factory? My thought is that the core functionality of the ship will have some sort of maintenance and logistics trail such that either it is supplied by other ships/stations OR only a small fraction of it is dedicated to the primary function. For example, on a farming cylinder who is producing the equipment and replacement parts (such as batteries, tillers, harvesters, gears, etc.). Is it a separate cylinder dedicated to producing widgets or is only a portion of the primary cylinder dedicated to farming while the remainder of it is dedicated to maintenance? It's difficult to not go too far down the rabbit hole and hit a chicken vs. the egg on the maintenance cycle (e.g. How do you maintain a machine that's producing your replacement parts, and then make parts for that machine, etc.). How do we or a future society work around this issue? We on Earth have this same issue, but we have resources available to continue production of new things whereas a closed system does not (or must otherwise be VERY efficient at recycling).

    Keep up the great work, I look forward to your content!

  • Rendezvous with rama anyone?

  • I usually think that habitats would be double hulled so that there would have to be a hole threw both layers to get a catastrophic leak, probably also combined with oxygen reactive foam that expands into a hole then hardens, and then some kind of mechanism that can later seal off that section of hull in order to affect permanent repairs.

  • Nice presentation, Isaac. Shades of "Silent Running", eh. Going to check out Cheddar. Thanks.

  • Does a rotating habitat actually need a night though I'm sure many people would like a night but people could just retreat inside darkened buildings in order too sleep, and the fact that its always day means peoples work shifts/routines could be more easily staggered which reduces peak demand on infrastructure eg. in real life a lot of infrastructure inefficiency comes from power generation/roads etc that have to have much higher than their average required capacity simply to allow for peak usage twice a day.

  • So spinning habitats for artifical gravity, could you make artifical gravity through bending
    spacetime like gravity does? would it have the same effect? just an idea.

  • "Sister channel"? What exactly is the connection between this channel and Cheddar?

  • we have a sort of skyweed it's called Spanish moss

  • Excellent as always Isaac ☺️👍🏾

  • Very interesting.

  • I wondered about the crows picking up trash idea.
    Yep, it's already being done! https://www.popularmechanics.com/technology/startups/news/a28543/startup-trains-crows-to-pick-up-trash/

  • I wrote on another video too from years back. But can someone tell me how we can have such structures with all the bodily effects of zero-g? I know blindness and even short trips (say for maintenance or your day job as a space window cleaner) would damage your eyesight for seeing up close. And if you regularly travel from zero-g back to the "gravity" of the giant habitat, wouldnt SAS make that impossible without acclimating between them? Thank you.

  • Trolley Suns 😎 what a concept

  • I wonder if there are meta materials that let you deflect light in a direction not perpendicular to its source, so you can have your "light bar" on the axis and still have the light come in from angles.

  • I can already imagine the octopuses of our oceanic space habitats squeezing their way into maintenance areas to take loose scrap metal to turn in for a more abundant source of food, or at least an easier to get source of food. That, and raccoons are already pretty good at finding their way into buildings, now we're giving them even more incentive.
    Also, I think I'd like to visit a low gravity zoo some day. Maybe see the zero-G giraffes. Humanities future is certainly going to be strange.

  • woa what if we could grow this jungle vine canopy so thick, that it could become the walls of the space habitat itself. So it's like a spinning hollow tree, full of air.

  • That monstrous ecosystem where redwoods can grow to their own limits would require enormous amounts of CO2
    I imagine an entire industry around it, where people sell their waste CO2 to some vendor for some cash that pools it and sells it to said orbiting carbon sink
    (Timber manufacturing sector 68A4373 needs more CO2 increase buying prices)

  • i know this series (and channel) usually thinks BIG but all the anthropic tendency seems such a detriment to progress. It's all about building spacious environments that cater to humans, with the supporting ecologies as some type of service industry. It would be far easier to just build environments that cater to microbes, easier to build and maintain, without waiting for that breakthrough in fusion power, and other technologies. Let's face it, all these pie-in-the-sky dream structures not only require tech that is 80+ years away, it requires a level of human cooperation that is not available, and may not ever be. Building an 'ark' that is designed to survive 250,000 years in space and ferry highly adaptable microbes, that can evolve into new terrestrial life, ought to be more of a conversation. We don't need to land an astronaut on a exoplanet. Just a dead frozen astronaut, and its gut bacteria splattered into a puddle can take it from there!

  • Simplicity is not so simple, any ecosystem is amazingly complex. With these future mega-projects, we can expect some catastrophic failures however this is our history and some shall survive.

  • I'm kinda wondering why it would rain in a rotating habitat. Wouldn't the water vapour just rise till it's in the zero gravity axis and just condense there so you'd end up with a floating lake?

  • I'm wondering if rain and snow wouldn't accumulate at the axis where there is no gravity growing to the limit of what the water surface tension could hold. Something created away from the interior edge shouldn't feel the kind of gravity but it might be slammed into the ground by winds. You might have an entire lake fall out of the sky.

  • Prove it !!!!

  • All talk , just like the rest fools that think they know everything …

  • The observations of Lui Woo

  • Why is a cylindrical habitat a Faraday Cage by default (please pardon my ignorance)?

  • Imagine that wheel more unbalanced with mountains here and there, occasional lake and aesthetically placed river…spinning https://www.youtube.com/watch?v=zJ3TABb1MRY

  • Hey Isaac, I’ve been watching your videos for some time and each one is fascinating and inspiring. But there is a question I have regarding animals’ reliance on earth’s magnetosphere for navigation, especially migratory animals. How would we do that when it comes to O’Neal cylinders, ringworlds, etc?

  • So watching this typically excellent SFIA video, it struck me that the habitat within a rotating O'Neill cylinder would be even more bizarre. Isaac talked about the safety of hiking in the giant forest canopy and the rain and snow falling and covering the entire inside "ground" surface of the cylinder, but help me out here. Would it ? in a rotating cylinder the gravity is not real, but simulated by centrifugal force and only where one was supported by that "ground" surface would there be any pseudo gravity. So why would rain, snow or a person "fall" toward the "ground". I guess there would be a minor, genuine gravitational force due to the mass of the wall of the cylinder, but it would not be anywhere near 1g due to the proportionally negligible mass of the wall. Indeed, if a person were to "fall" from the axis of the cylinder they would practically float in place while the habitat rotated around them and the most dangerous threat would be to drift too close to the "ground" and get squashed like a bug on a windshield by a speeding building !

  • When the Burj al Arab Jumeirah was first built, apparently it had to be cooled down gradually, over the course of a few months, in order to avoid clouds forming in the lobby (I know, that sounds like something in "The Hitchhiker's Guide to the Galaxy", but it was on a documentary I watched on its contruction), so it would hardly be surprising if much larger structures developed weather systems.

  • I disagree with you. I am against of having ecosystems in space. If they are for us, then they are going to be for us, and not from something else.

  • In the future, humans will be engineering from the inside out, meaning they will 'ask' their cells and microbiome 'what they want' (and the only way to 'ask' is through experimentation, which is also the only way they will give you answers)…

    What changes here (as compared to current self-identity notions) is our vision (concept) of who we are – we are higher-conscious beings on the emergent level, but we are also colonies of cells and microbes. The two are not always in harmony (indeed, it can be argued that, in the 'modern' world (quotes are used to denote a screwed-up modern world that still needs a LOT of improvement, especially in the enlightenment department, which far lags technology). Given ignorance and unenlightenment, there can be conflict between conscious decisions and the biological platform, where your actions are detrimental to your cells and internal microbes, which in turn can be detrimental to your consciousness, which is self-defeating…

    So there will be three things working together: Engineering, microbiological knowledge, and philosophy. Currently, philosophy is far, far behind, which is potentially fatal (enter me to fix that) (and I've created the tool, the rest is up to you).

  • How the flip your not on our TV and on Netflix with your own shows in a big mystery to me! Your voice is hypnotic. Your writing and voice-over skills are on par with anyone out there on YouTube or on Netflix or Amazon. You need your own show. We need to start a petition to get this man where he belongs

  • Omg why do u twak like dwat 😩😩🙈😂🙊 antwatica swetowin dwesots lage wolll cwowld 😫😫😩

  • Isaac, have you ever addressed "crime and punishment", particularly as related to these small closed societies? I envision mostly the same kinds of crimes, but some truly "unique", shall we say, punishments!! Would the "cruel and unusual" standard still apply on a space habitat. Simply "spacing" criminals or confinement near the reactor immediately come to mind.

  • Hi Isaac! I had an idea for visions of earth: Colonizing the Earth but underground! I always wondered what it would be like to live in an underground city powered by geothermal energy, nuclear fusion, or seismic activity. I'm extremely curious as to how the economies of such underground cities would work….what life would actually be like in them…

    My inspiration was Jules Verne's journey to the center of the earth.

  • 9:30 Someone with a long rope gives an end to  friend who walks somewhat perpendicular to the axis. Eventually the rope Is not resting on the "ground" but angles upwards as the friend goes further away. Now, to go from one end to the other you can climb up the rope as gravity decreases & then slide down it.

  • Congrats on 300,000 subs Issac! Will be over a million by next year.

  • Speaking of canopy ecosystems, we already have them on Earth: https://www.ted.com/talks/richard_preston_on_the_giant_trees

  • Hi. I love your videos! But sometimes I also get very depressed because I know that I have small chance to ever experience what you show.
    But In this video your animations are too fast, and make me feel sick… Do you think it will be an issue in real habitats? I know it will be different, but still it will be quite different than what we are used to.

  • "the hawk swoops down on the squirrel not to eat the squirrel not to eat the squirrel, but to steal its bottle caps" – you knew how it would sound and you went with it.

  • Speaking of how trees could change based on these factors makes me realize something amusing. If in the far future, one finds trees on worlds and structures beyond the Earth, it is likely the fault of Humans that they are there.
    A lot of science fiction shows trees on alien worlds, but rarely do they stop to think about how odd that is. We have no evidence to show that tree like organisms would be at all common. Trees didn't even exist on Earth till around 400 million years ago.
    Of course, we humans like our trees and other greenery, having evolved to live such environments. So we would of course bring them along with us into space.
    Heh, lazy trees letting us do all the work while they just sit there as usual.

  • My machinist brain is confused on something.
    By the Oneal Wiki page the Cylinder would need to revolve 28 times per hour with a 5 mile diameter. So the circumference would be like 15 miles and the surface speed would be about 420 miles per hour. Also the surface speed would be universal regardless the diameter. What are the odds, that the universal surface speed to keep a person stuck to the surface of a space habitat, would be 420???

    Smoke up homies

  • Isaac your channel is the best. Keep up the good work👍

  • Whoever banned me, fix that.

  • It's interesting you think about day cycles so much… I would imagine we would just live 'inside rooms' and use LEDs where needed.
    – There might be some 'garden'/'forest' areas, but I don't see a reason to build the entire habitat that way. – I'm sure the plants and animals will adapt to whatever necessary: Probably constant light, because we want to make our park accessible to customers 24/7…

  • a thought on "winter cylinder habs", instead of the normal day nigh cycle it could have a longer slower day night cycle kinda like a mix between the months long days and nights of the arctic circle and perhaps the month long days of the moon, with the "day cycle" being like a mild spring of fall and the night stage is a low light winter wonderland

  • Mountains inside drum habs could be made as shells enclosing other ecosystems, or extensions of the system-wide one. Or they can contain human communities. I imagine the "ground" as a covering over a labyrinthine collection of caverns and tunnels, with multiple weather systems throughout, expanding the habitat's interior several times over.
    Where simulated gravity becomes almost nonexistent near the axis, I don't see what's to stop cats from flying through the air to chase birds. If that happens, I think wing spans will decrease over many generations as better maneuverability will enable birds to evade cats that can only fly in straight lines. Okay I'm being a bit silly here. Or maybe not?

  • 9:50 "Birds would adapt easily to low-gravity flight"- are you sure about that? How well would they orient themselves outside Earth's magnetic field, or different lighting (building lights above and below)?
    AND MOST IMPORTANTLY: how to adapt to landing on the inside surface spinning hundreds of miles an hour?

  • Mostly DC Power in Space? Will Inverters be common? What about Variable Frequency Drives? What will Grounding be like on an Artificial Habitat?

  • Question: How much apparent gravity is needed to keep people healthy? As launch costs come down, we're moving from the era of astronauts to that of space workers and off-earth colonizers. We CAN ask astronauts to risk their health to explore and add to human knowledge. We SHOULD NOT ask space workers to sacrifice their health to make corporations wealthy nor should we ask future space colonizers to take their families to places where they and their children will, over time, wither and die. We know that people cannot endure extended periods of time in zero G without suffering permanent damage to their health. The question is, what is the minimum amount of apparent gravity needed to keep people health? The answer to this question will dictate the types of structures we build in space as well as determine whether Mars or the Moon are suitable targets for colonization. Is anyone researching this seriously?

  • "We like the idea of living on a rotating space habitat." Actually no I don't. I like the invention of gravity plating better.

  • 'Get a drink and stack.' Starts talking about pressurized can.

  • So the sky-weed would be…… high.

  • Would we take mosquitoes, human head lice, common cold viruses or other such things currently considered nasties?

  • The birds and insects would experience a weird moment when they are flying against the habitat's rotation and suddenly find themselves weightless while the habitat keeps moving below them… Or struggling to maintain altitude when flying with the habitat rotation…

  • An economy based on bottlecaps … I like where this is going.

  • "the radiation blasted ruins of space…" Wow! I wanna go there.
    I think an airsphere, as found in Iain M. Banks"The Algebraist, would be a fine thing to build.

  • I'm ok with O'Neil cylinders.. as long as we get Gundam's as too.

  • Will we be able to hunt the chewing gum thieving squirrels?

  • SO, we can teach crows and squirrels to pick up after us, but we can't be bothered to pick up after ourselves?…
    Hmm… I think we need some 'advancements' that have nothing to do with technology.

  • If the trees we're to keep growing past the axis gravity would start to pull at the crowns possibly causing them to continue growing downwards. This could result in trees evolving to root themselves into both sides of the habitat.

  • Here's a question, not sure where to put it so here it goes.


  • 8:20 Go watch Gundam 0080

  • We won’t be bringing fucken crows! Leave the bastards on earth…..

  • So the movie, “The Birds” doesn’t actually happen in North Carolina then? It takes place on a space station that looks like NC where the birds were trained to pick up humans garbage? And the birds got sick of it an rebelled?

  • Who are the few weirdos who dislike these videos? Shit doesn't even make sense….

  • After seeing how NASA almost fed the mice on CRS 16 moldy food, I was thinking maybe give them something like frog food. Except if they ate it, they'd probably croak.

  • The system of longterm survival of the Spaceship is not acceptable because of the millions of small rocks flying around the empty space can destroy this man made planet like only for the wealthy and also not everyone ? 😇 🌏 🎭

  • A bit late… but lets say this anyways.
    19:30 I think that you mean normal gravity at noon and midnight, as the habitat would start drawing power at dawn and thus be at maximum stored energy and thus gravity then. And that would mean that you would have the minimum gravity at dusk.
    This would also have the side-effect of getting out of the bed easier the later it is doe to lower gravity.

  • Such a great episode! I guess, hypothetically you could make a totally self sustaining habitat with genetics and and machines. Caretakers that take care of the caretakers…

  • For security reasons, we must cluster the ring, because of asteroids.

    Each group of cluster must be the same as the other, with food…

  • Those clouds are accelerating without touching anything…

  • Imagine one of these the size of the United States and Canada and having the climates from Arizona and Texas all the way to the North Pole, now that is a mega structure!😍

  • What kind of a home is that in the opening CGI scene? An open bedroom, no bathroom and living room seating but outside!

  • Looks straight up and see my neighbour. Look 30 degrees to either side, and see the stars! Why would you want to ruin that with a blue cylinder?

  • Who put Kripke in charge of voice over?

  • Hey can i aske where you find those videos of space habitats from the start of this vid?

  • 25:00 — Hawks stealing the squirrels stash of bottle caps. How did I even get here?

  • So we're gonna have to install Adblocker for the sky now, huh? Hey, Google! I'm not interested in that ad for Viagra! Let me watch the sunset, damn it!

  • 5:50

  • 7:00 O'm not sure that even tardigrade can live in a vacuum. They can survive, bit only by shutting down their life function and waiting for conditions to improve. If they don, I suppose eventually they will die.

  • 8:20 And now we know you have never played Halo.

  • Are seasons critical to ecosystems though? Sure, Earth life is adapted to the seasons, because Earth has seasons. But it seems to be that a more steady climate would be more conducive to life.
    Every species on Earth seems to have a hard time for part of the year. A time when death rates increase because food or water becomes scarce, or because the weather becomes hostile. Different species have different ways of dealing with these hard times. Some move from one area to another, which requires a great deal of energy to migrate. Some animals hibernate, which requires building up a reserve of energy, usually by eating enough to survive the hibernation period and hoping some hungry predictor downs find them, and some don't bother trying to survive at all, fitting their entire life cycle between into the few months that life is possible.
    Even for animals that can survive, this limits reproduction to just a few months a year, because you have to get your babies alive and grown up enough to survive the hard time.
    If the climate were more stable all year, animals could adapt to that climate perfectly.
    You'd still have varied climates, but those climates would be aligned by latitude and would not change throughout the year. This would mean species could adapt to a given climate perfectly.
    Even if the climate changed over time, animals would adapt to that change or they would not and become extinct,

  • 2:18 In fact, you can find photos of the Vehicle Assembly Building at Kennedy Space Center with clouds forming inside.

  • At 21:01, He mentioned "Buy N Large". Does that constitute a sponsorship by Pixar?

  • This channel's episodes that include wildlife or pets are like someone put peanut butter in my chocolate. <3

  • One thing that worries me greatly about creating new ecosystems, is the fact that ecosystems here on Earth are very brutal places. Essentially any species get vastly more than two cubs per pair of parents and evolution works by letting those excess cubs die off by they grow up. This means that life in the wild is usually short and has a gruesome end, such as by starvation, thirst or being eaten up alive.

    Is that really the kind of living conditions that we should spread into space?

    Some people might describe wild animals as flourishing, so long as we don’t make them go extinct, but this seems to put up some double-standards.

    Imagine that you had a life-expectancy of 10% of a natural human lifespan and that you were often had to battle against disease, predators and hunger. You would rightfully reject the claim that this a good human life.

    There is a reason why we are horrified by the thought of people living for under a dollar a day, and it isn’t about the survival of mankind, it’s about the individuals, who lives under those conditions. Somehow, it seems that we forget this reason, when we turn our attention to the wild.

    I get that ecosystems are full of beauty and biodiversity, and there may well be some value to that. If so, then makes sense to try to create such value in the void around us, but it has to be done within some constraints. If you were told, that you would wake up tomorrow as a wild animal, then you must be able to look up upon those space habitats and be glad that they are the way they are.

    This in turn requires these ecosystems to differ from those on Earth.

  • I think in a habitat like that A change in management could be interesting and very amusing.

    In the habitat where they taught the animals to retrieve the trash for recycling so they can get treats and food for it. The new manager decides to take one look at the place and not understand what's going on. So he decides to bring in a bunch of cheap fast manufactured hover drones to retrieve the trash. After a couple of years the squirrels start piling bottle caps up underneath trees. When the Drone comes for the bottle caps the squirrel drops a limb or a coconut or something else heavy on to the Drone damaging it so it can no longer fly. Then all of a sudden from all of the trees around come squirrels to fight for the new junk. And the great war between rodent and machine begins.;)

  • i love your content and the visuals you use. they're always so fitting.

    there is someting funny about one of them though. at 29:47 the dinosaur is biting an invisible tree and ripping off a few invisible leaves or in other words someone got lazy and reused that render. i know… not you who did this, but someone did^^

  • any episodic shows pertaining to space habitat on going? family transfered to one of numerous earth orbital living facility, the life and hazards, friendships, camaderie, space politics, trades, sanctions, some space school bullies, exploration, debate about debrie, micro meteors/ bigger, new research findings, mars colonist complain why space force flying about overtime visual pollution, the debate about water supplies etc, further use of fossil fuel, quadrant triton researcher discovered a new ways to shave off unnecessary hairs, monthly new findings here and there, bandit problem, so called boba fett doing stuff, academia of science, interplanetary news etc. using real physics and stuff. then there's upgrades of our current five senses, space olympics, advert executives came up a new better ways i.e drone giant whales, shars, jellyfish etc gliding about, new holiday itinerary package 5 days and 4 nights to earth surface etc etc etc. netflix?

  • Homeostatisphilia: the love of keeping things the same. I think is a bit a of a problem with people because they make assumptions that because things are like they are now they have been this way and should be this way into the future, and if they aren't we should do something to 'get it back on track'. This is something I think people on both sides of the climate change 'debate' have a issues with. This maybe an odd POV but is climate change, even if we caused it or at least exacerbated it, bad? Yes it could kill people and animals in quite large numbers. But nature and time have been doing that far better and longer than we could. Even if we did nuke the earth life would still survive. Some of the cute and cuddly animals, and not so, would die. But if we are reading the evidence correctly then all the lifeforms currently on the planet only represent 1% of all the variations that have existed in this small pale blue dot in the vast ocean of night. So changes to animals, either through natural changes to their environment or purposely made changes by humanity, happen and life has continued. So the only place we should really try to keep things as we want them, the same, is where we make it that way. If an environment changes maybe we should let it change and see what happens. This isn't to say that I don't think we should neglect our duty to, at least ourselves, to minimize our negative impact on the world. Efficiency and reusability should be done regardless of their environmental positives.

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