Gravity plating with condensed material in micrometer strings held by electron degeneracy pressure from collapsing into black hole.....or something more even technical.
1989. I was in college (undergrad) and joined the Traveller Mailing List. That's a sci-fi pen and paper RPG. The list started a group adventure about visiting a newly discovered ringworld, and I got put on the team to make content for the ringworld (yeah, three of us tasked to make 3 million Earths of content). I'd gotten my hands on some 3D rendering software (we won't mention how), and tried making renders of what it would be like to actually see the ringworld, complete with fractal land, ocean, clouds. Remember, this was 1989. My poor little 80386 PC (with no math coprocessor) took 18-22 hours to render a single 640x480 resolution image. This was all running under DOS - no multitasking. Meaning my computer was completely occupied and unusable while it was rendering. Another guy on the list tried using his work computer (a Sun Sparc I think) and it completed the render in 17 minutes. Those two factors made me give up after rendering just a few images. It's nice to see the same thing rendered with modern hardware. Thanks for the trip down memory lane.
3D app, late 80's, 386, no co-pro so 386-SX, probs 25MHz clock.... maybe 33MHz.... Real early Lightwave? I used POV-Ray and the modeler Moray back in '93 on a DX5-133, and a basic dive to the planet surface animation at 320x240 at 12fps took a couple of weeks to render, when my parents didn't turn the PC off at the power switch while I was in class.... Your pain is well understood. :)
For many people, the cylinder space stations from the Gundam series are iconic and a very important plot point in the series. Thank you for adding Babylon 5!
Yeah quite the oversight to not include Gundam. The designs were ripped direct from Gerard K. O'neill's work which is the seminal documentation on spin gravity space colonies.
You explained everything pretty well. One aspect you kind of overlooked is WHY someone would get nauseous on a smaller spinning hub like the 2001 example. The film shows Dave Bowman jogging inside. If he wanted an easy jog, he would jog anti-spinward. If he wanted a rigorous jog, he would run spinward. His ~10 feet per second added to the hub's angular velocity would increase his 'weight' noticeably. Also, just standing up from laying in bed. The inner ear would experience a noticeable centripetal acceleration change. And as mentioned about Bowman, moving spinward OR anti spinward would also wildly change the inner ear's acceleration.
@@Akio-fy7ep Moving spinward, antispinward, radially in and out. . .all would effect the inner ear noticeably inside a small diameter hub. It would be like being aboard a smaller ship in rough seas. *One big difference in a hub* YOUR movement controls the acceleration fluctuations in a hub by moving in ANY direction as opposed to the sea controlling the acceleration change on a ship. NOT controlling random accelerations is MUCH more nauseating. So yes, I agree. I imagine it would be moderatly easier to get over the "seasickness" on a hub with a smaller radius. As is said in the video, once the radius gets to around 80 meters and the spin speed provides around 0.5g, the changes in accelerations by your movement become too small to notice unless your on a vehicle riding the hub's inner surface.
Ceres would 100% definitely disintegrate if it was spun up like that. Even solid rock behaves almost like a liquid on planetary scales, thanks to the square-cube law.
In the books I believe they covered the dwarf planet in some structure. I might be confusing that with the space dock that was located at the pole though.
You can 'easily' submerge a train track some miles under the surface, and suspend an endless train right under the surface. The train runs on a maglev suspension on its uhm "ceiling" ? This easily creates gravity. I am pretty certain the solar system can be colonized with "embedded" cylinders, little spinning like centrifuges. Angle them a little, so their conical shape compensates for the gravity of the asteroid or moon. In fact you can 'easily' replicate Earth's surface on the moon by constructing endless such embedded cylinders below the surface. Make em as big as a typical O'Neil cylinder (I built one together with Simon Deering in 2010 for Transvision conference) and you can have about 50% of Earth's surface - but with garden/eden level of comforts - so easily a hundred billion people.
Literally applying the same metric for Ceres, a dwarf planet like Ceres could have a population of, assuming one "layer" of habitats "only" (....) literally One Earth - about 8 billion people, living with a population level and relative spacing of The Netherlands. Now if we were to start stacking the rotational habitats, plus a solidly reinforced structural envelope or "casing" on top of one another, say four layers deep, (some 20 kilometers on the moon) we can have hundreds of billions of people living on the moon. But at that scale the heat emitted by each habitat with all the BBQ's and swedish sauna's and such would become a problem. If we build habitats all over the moon, 4 levels deep, and we assume several times USA levels of heat consumption, the waste heat could make the surface glow on the dark side in infrared at over 100 degrees Celsius.
My head canon is that it's not the whole dwarf planet that is spun up but underground centrifuges that is used to add to the natural gravity rather than trying to completely cancel it and reverse it as spinning the whole planet would need to do.
I get so excited when someone mentions B5. It’s been 30 years, but the show still gets so little love. Thank you for doing this! The Agamemnon from B5 is a pretty cool example, BTW. It’s Captain Sheridan’s old ship, about a mile long, with a large revolving section to simulate gravity, but rather than be a wheel like we commonly see, it’s basically two pie slices connected at the center, similar to the Leonov from 2010. Oh, yeah, and the Leonov is kinda cool, too, I guess (Forgot about it until the Agamemnon reminded me). Not saying you should do another video on the subject, I just thought I’d mention it. Again: Thank you for doing this!
@ i always rewatch it a little different if I can. One year I rewatched it with the movies in their proper places (Which is rough because Thirdspace takes place *inside* a regular episode) Another time I watched it, I stopped at “Objects at Rest,” then watched River of Souls, Rangers, call to Arms, Crusade, lost Tales, and THEN Sleeping in Light. This last time through I just skipped Season 5 entirely, and just jumped from “Rising Star” to “Sleeping in Light.” Each time it’s caused SiL to have a different emotional impact on me.
7:21 So glad to see The Culture getting some love. Some people daydream about living in Middle Earth or the Old Republic or what have you. I daydream about living on Masaq Orbital.
For anyone who hasn't read it, Project Hail Mary is excellent. I was a bit skeptical of it going in, but it ended up being my favorite of Andy Weir's novels.
They are making a movie out of it starring Ryan Gosling. I really want to see how they portray rocky. I hope a combination of excellent puppets and CGI
Oh thank you so much! I left Bobiverse on the second book. If only I had known this would be coming later. I loved this size comparison. The graphics here are _chef’s kiss_. Great job altogether.
Oh hey, the exact comment I was about to make! But yes, those are interesting because they actually have distinct rotational periods from eachother, and all their stats are listed on the wiki. Also Orbis class starports can have two different sizes of habitat rings spinning at the same rate, meaning they'd have different internal gravity. (I say "can" because they're modular and not every Orbis has both or even any types of habitat rings.) Elite: Dangerous does also commit the physics sin of spun-up asteroid bases, but natural asteroids in the game already spin unrealistically quickly, so I might give it a pass. :P
The reason for the "spiral tunnels" on Ceres, is that the centrifugal force is being used *additively* to the gravitational force, not subtractively the way you depicted it. This creates increased perceived gravity along a cone shaped surface into the interior of the mass with the poles of rotation at the center of the cone and the point towards the center of the mass. Those tunnels are built along that conical surface. You could also live on the cone at the other pole with the same perceived gravity. The part that's unrealistic, is that the cone should be much more shallow, since it's only a mild increase in gravity. Also, Ceres is definitely not a "rubble pile" asteroid. It's surface is well studied and photographed up close at this point. It is quite solid.
@@CODENAMEDERPY No, the whole thing is spun up, but when you calculate the combined effect of the spin with Ceres' own gravity, the ideal place to build tunnels to utilize the gravity is along the surfaces of those cones, which are mathematical illustrations and not physical structures.
"is that the centrifugal force is being used additively to the gravitational force" Nope. There is no surface where the gravitational and inertial (centrifugal) forces would add up positively. Way worse once you notice that the proposed force due to rotation is the same as surface gravity: It means that the regions furthest from the rotational axis of the planet are no longer bound by gravity and the whole thing would rip it self apart. Gravity always is an inward-vector, centrifugal inertia is always outward. The best you can do to "increase" gravity is to STOP all rotation - for earth that would make a person on the equator about 0.3% heavier - negligible.
Kudos for making a super interesting video on a subject close to my heart. You touch on the angular velocity limitation of five or six RPM, but also the small size of Discovery means the crew feels significantly lighter at the head than the feet, not a comfortable feeling at all. The Coriolis effect would be wicked, too. Imagine playing centrifugal ping pong!
I was disappointed to see no Bishop Ring, defined as the biggest compatible with hard SF. The limiting factor is tensile strength of the the floor material, which is thus the most important detail of any design, limited by the strength of a covalent bond. Interestingly, the limiting diameter is proportional to the length a cable of the material can hold itself up, supported at the top, under the acceleration you want. For 1G, which is the only one we know is compatible with human biology, it comes out to about 1000 miles, and turns in something close to an hour. It is big enough that, with walls, you don't need a lid over. Inner surface area is New Zealand to Italy. You would build it as a thin ribbon, spinning it, and then widen that. Widening it from the center line would let you keep the walls up that hold the air in. At any time there would be long triangular holes along the center line with domes over them: cut some at the point, weld in a plate at the back, repeat. Any sufficiently advanced culture will not be reliant on a star's radiation for energy. Its biggest problem will be radiating away the waste heat from its high-energy operations, making cold the most precious commodity. It will locate its operations no closer to a star than its Kuiper belt, and that close only for ready access to material resources absent in interstellar space. Bishop Ring, given that it is actually possible in principle, deserves its own detailed episode. Certain practical problems remain to be solved.
"Any sufficiently advanced culture will not be reliant on a star's radiation for energy" what? Stars have more energy than the rest of the system combined. No sane culture would throw away these growth opportunities
There are the Iconian Dyson Spheres from Star Trek The Next Generation, we even get to see the Inside of 3 In Star Trek Online, The original Jenolan, the Solanae and the Herald Spheres. Star Trek also has Yorktown Station which also has a ton of handwavium involved but it is an interesting design with how it uses all of space with the artificial gravity letting people live on the different sides of those tunnels in it.
Yorktown Station was just absurd for something that was made before the time of the Original Series. I don't care if it's the alternate timeline, that thing was too advanced even for the ST: Picard setting.
Yorktown Station was far too advanced for human technology in Star Trek and is a good example of how the creators of the movie completely failed at world building
@@RocketToTheMoose The Dyson sphere’s creators never came up in the show. The online game tends to make the fictional world smaller, more trivia-mongering and less imaginative, so the idea of the entirely separate Iconians making the sphere might come from there.
Ringworld is mind-numbingly big. A 95 mile segment of it has the same area as all of the land on earth, and there would be ~6.3 million of those segments. Driving 24/7 on a highway straight across the width at 70 mph would take 370 days. An unbroken airliner flight would be in the neighborhood of 50 days.
The cylindrical gundam colonies from the UC timeline, or the hourglass shaped colonies from the Gundam SEED timeline would be nice contenders. They all seem pretty realistic.
When you mentioned the potential to get dizzy, I was surprised you didn't go into some of the weirder aspects of gravity via rotating cylinder: from the perspective of someone on the "ground" -- part of the rotating inertial frame, as opposed to an observer watching the ring rotate from outside -- ballistic trajectories aren't the same as in a mass-induced gravity field. The smaller the ring diameter, the more noticeable the deviance from "normal" gravity.
The Gaea trilogy by John Varley deserves a mention. Titan,WIzard, Demon are the book's names. Humanity finds a fairly stealthy artificial satellite in orbit around Saturn. A crewed mission is sent to Saturn, and detects an artificial but LIVING Stanford torus, 1200 kilometers in diameter. It has an artificially dark surface ( vanta black before that was a thing ), and they can't really get any information from it, they theorise ( correctly ) that it is deliberately covert. As they approach they detect that it has extremely low mass, so is obviously hollow. It is under spin, and as they pass by to measure its mass distribution, it exudes tentacles like a cuttlefish, and gathers in the earth-ship. Hy-jinks ensue. Turns out to be an extremely old genetically engineered INTELLIGENT artifact, part of some civilisations' attempt to colonise the Galaxy. And they are successful, the Gaea the ship encounters is one of thousands in our solar system, and it is in contact with a countless community of others spread out across the galaxy. The Gaea's arrive in a solar system as a seed, if they land on resources, they slowly grow up to size by much the same methods as a tree. In the process they eat up the planetoid they have landed on. When they are fully loaded with the amount of resources they will need to thrive, they put themselves into orbit somewhere that they have a energy source, they do not need much. They ensure that their reaction mass ( the parts of their landing body that they don't need ) is launched at a tangent from their circumference, to give themself spin. During this phase, they are compact. When they have made their orbit, they begin to inflate, melting the frozen gases they have gathered. They also grow and launch countless seeds, aimed extra-solar, again from their circumference to spin themselves up. Inside they have complete and detailed control of the ecosystem that lives in the shell of the living world. And they have near miraculous genetic libraries and genetic engineering ability, and listening to Her "Sisters" among the stars, the Gaea can grow a vast library of creatures, from virus size up to whales.
Gaea Trilogy mentioned! I was at university when those books were new, and they were some of my favourites. One of my friends even went so far as to make a homebrew RPG with a Gaean setting.
There's some way crazier stuff outside Science Fiction, in the realm of speculation, hypotheticals, and pure world-building. Isaac Arthur on UA-cam has some fantastic videos on the subject, and you can find all kinds of blogs and wikis that go over some crazier ideas with viability ranging from fantastical to clever and actually reasonable.
There is also Outer Wilds with the Echoes of the Eye DLC. There the stranger is a spinning Space station. It's about 500m in diameter. As well as Stellaris, where you could find and build a Ring around a planet or even around a whole star.
@@victor6250well they entered close to the only active of 9 gates in the outer shell. In that sense, they were still lucky, but not „with the Jackpot 23 thousand times over“ lucky. They simply saw the sentry drones preferred that gate and assumed Bender was carried through the same way. From There the resistance stole bender and saw now reason to move him further than the next regional headquarters in halebs ending(?).
This video is AMAZING and sets the standard for all the "to scale" type videos out there. Great narration, entertaining and informative, good visuals, all-around banger.
OMG! Not only was I just reading about megastructures and compiling a table to compare them, but when I saw *Heaven's River* , my jaw dropped. Bobiverse is the best! 🤗
I thought I remembered Niven claiming that he used to attend parties that local scientists also attended, and he got ideas for his stories, as well as help getting a hard sci-fi reputation, from them. And of course he did invent a fictional material to hold his Ringworld and its shadow squares together and in place, and described its properties.
@@idjtoal I forget if they ever got a close look, but do remember that they made that assumption. They also knocked a piece of connecting string loose in the first book, which proceeded to fall on and cut to pieces a civilization on the ring floor. In that case I think they confirmed more strongly that it was scrith.
The movie Stowaway also uses a cable spin method of increasing the diameter without making it unreasonably expensive in terms of materials. The crew board whats called a cycler that has an orbit that periodically moves between earth and mars that ships can rendezvous with. Basically once the cycler is created no extra fuel is needed to increase or decrease the velocity. There's also a scene in the movie that shows how a tether based system spins up
8:20 I do not get the day/night cycle bit. In my mind, a ring inherently cannot cast a shadow on itself while the light source is a sphere within the ring. If you ever wanted to do a follow-up vid with a graphic for that, you'd be da boss EDIT: Ah, nevermind. The next graphic cleared it up! I thought the middle of the first ring example was the sun. I got you now. Great work!
Yeah except this principle is garbage. It’s a fairly tale. It absolutely does not work. Weightless is weightless. Spinning a room around you doesn’t “simulate gravity”
This video was awesome! Like a size comparison (one of my favorite visuals in a video) combined with a scientific analysis of fiction. Really lovely stuff, would love to see more of it in the future. Thank you!
Been a fan of Taylor and Weir for years, I am glad to see them getting some proper nerdom recognition! I did some calculations of a Dyson sphere, I think I came up with 21 billion times the surface of the earth, But I solved the gravity issue with mass by making it have a 12k km thick shell. I abandoned it though because that amount of mass could actually alter the internal gravitational forces of the star it surrounded. Fun thought experiment though.
Just binged all of your videos, you are awesome! keep up the amazing content man. Also you pronouncing ecumenopolis and shouting out isaac arthur was hilarious.
@@oatlord Still, the maintenance was a huge problem. You're right to wonder about it. Please pass me some of that Tree-of-Life root and I'll help with the maintenance myself.
The maintenance and repair of the ringworld become major plot points in the sequels. One of the reasons it works is that the people managing it are superintelligent immortals genetically compelled to keep alive anyone genetically similar to them.
If, instead of having the crew capsule on the long end of the tether, you would have a counterweight on the long end, the weight could be quite small and enable decent spin gravity with current technology. I would love to see a math breakdown of this.
6:48 I've used an online calculator, the Halo would have to spin at 0.00942rpm or 106.17 minutes per rotation (assuming scientific accuracy and assuming it uses centrifugal force, which it doesn't).
I would suggest adding at the Orbis, Ocellus, and Coriolis space stations from Elite Dangerous to this list. While they all look quite different externally (the Coriolis design is a cuboctahedron, the Ocellus design resembles a Bernal Sphere, and the Orbis design resembles an ovoid that usually has a Stanford Torus around it). All three use spin-gravity, and all feature a standard-sized interior cylindrical docking area with numerous landing pads for visiting spacecraft. They are quite large, with the entrance "mail slot" being large enough to comfortably pass the entire modern International Space Station through it and then some (the Type-9, the biggest player-flyable ship, is as wide and tall as the ISS, and these jumbos regularly dock to transfer several hundred tonnes of cargo at once). It'd be interesting to see how those stations compare in size to other famous sci-fi stations with spin gravity.
The one thing I wish you did included was the Buthandi (sp?) from Schlock Mercenary. Probably not appropriate for this video because they generate gravity through fictional science. But it is a stellar enclosure which according to the author, the name translated into English is, "this was expensive to build"
In an article in Analog Niven suggested a structure similiar to the one in the Bobiverse. With multitudes of loops. Name of the article was Bigger than Worlds iirc. Probably around 1979. No, 1974.
Arthur C Clarke's books are highly recommendable. You just get sucked into these books, and his ability to describe something extremely complicated in very easily understood language, is amazing. The Rama series is a good place to start. Remember to eat, drink and sleep now and then as you just can't put his books down ! 🙂
Where are the O'Neill cylinders, like from Gundam? I figured those would be pretty big? If it's too realistic, it's also used in many of the Gundam Series, so it's also sci-fi enough, I think.
so haven's river (last thing mentioned) is actually consisting of millions (trillions?) of O'Neil cylinders all linked together to create the massive larger structure basically think of the O'Neil cylinders as beads on a string i very much recommend reading (or listening ) to the bobbiverse series
Rama is an O'Neill Cylinder and what brought that variation of the Oberth cylinder from the 1930s to the west's attention at least. (Similar were shown in sci-fi and futurism books from the Warsaw Pact nations years before Clarke and O'Neill published anything on them). So's Cooper Station, for that matter.
i figured the ringworld books would get one of the last mentions since you were going by size. loved the whole "ringworld is unstable" story. one of my favorite Niven anecdotes.
Would’ve loved to see real life material limit rings/cylinders and proposals like the Stanford Torus (proposed habitat by NASA, around 1.6km), O‘Neill cylinder (limited by steel strength, around 8km) and the McKendree cylinder (limited by carbon nanotubes strength, around 450km)
My ringworld has many interconnected tanks of mercury. Each tank is roofed with solar panels which power compressors on the tank. As that tank approaches the star, the solar panel generates more electricity which increases pressure. As a tank moves away, solar power and pressure drop. Mercury moves to lower pressure tanks; that increases mass. That draws regions that drifted away closer to the sun. Once they get too close, the mercury mass is again redistributed.
Really enjoy your channel, some of my favorite videos on hard sci-fi. I have a suggest for a video on hard sci-fi of the SevenEves book. The use of the ISS in the story along with the generational space station in the later half of the book are very interesting.
I always wondered why sci-fi creators ignore the fact that mass creates gravity. A planet doesn't have gravity because it is a planet, it has gravity because it has a large enough mass. Looking at the bigger rings, the earth is barely visible. If you build that big, any small section of the ring would create its own gravity; probably even more than the earth. And judging by the size in the video, building them hollow would just make it collapse under its own gravity and create a solid core, lengthwise. So it has to have a lot of mass. On the inside surface there might be some sideways pull because it is a ring and not a sphere, but that doesn't mitigate the sheer amount of mass underfoot. Just imagine the earth and how much gravity it creates. And now imagine a section of that ring, let's say 100x the mass of the earth, and now all of the sudden we need to spin it to create 'artificial' gravity?
@@apennameandthata2017 What is too far away? I am talking about the mass that is more or less right underneath your feet. Just like the earth is, right now.
What would happen if you jumped "up" while onboard a rotating craft? Would you continue upward, hover in place, or would there be some other gravity-like force which would bring you back down?
If you jump up you still have the tangential velocity of the floor. Newton's laws of motion say you will continue to move in a straight line at the same velocity until that line intersects the floor. The end effect would be very similar to jumping on Earth, with a small displacement sideways due to the Coriolis effect. If you run against the direction of rotation you will experience less gravity. If you could run fast enough you would reach a point where there was no more spin gravity effect. At that point you could float away from the floor. It wouldn't be for long though because the air in the craft will be moving at floor speed so wind resistance would accelerate you back up, probably resulting in a pretty spectacular and painful face plant.
Okay.. but can we figure out how to make an actual sphere that mimics what we experience on small moons, astroids, etc.. (BTW there is no room for flat earth bullsh*t, I'm genuinely curious about physics & science. Not kindergarten level conspiracy theories)
Only if we make it as heavy as said moon to use real gravity. There's no way to fake gravity that makes it pull towards the center. And if we have to use that much mass, why bother making an artificial moon in the first place? Just live on a real one.
It's farcical that we have ZERO data on how lower g affects human physiology. We have enormous amounts of data for 1gee. And quite a bit for zero gee. But nothing for the in-between. Two points on a graph. And we could have had some data in the last 4 decades. If we had wanted to. NASA to could have cobbled together an orbital facility that would have allowed gathering some data. Using mostly existing hardware. But getting such a program past the US Congress would have been impossible. Yes here has been a few experiments in LEO using centrifuges and mice etc. Big freaking deal. I'm not saying we should put a ring shaped station in orbit for this purpose. But we could have done it using either tethers (1) or spent stages and a small hab module. My favorite would've been two Shuttle External Tanks docked nose to nose. Attach a Hab Module to the bottom of one ET. After crew transfer spinup the assembly for .17 gee. Later spin it up for .34 gee. When plotted on a graph are the effects from 0 gee to 1 gee a straight line. Or some sort of curve. If a curve does the data show a slow rise then steepen radily as we apptoach 1 gee. Or does the data rapidly rise and then flatten out. And yes l know about the spin gravity experiments that took place on Earth. Both the US and the Soviets did this. But the experiments were more to see if humans could adapt to spin gravity. Not what the effects would be at lower gee. 1) One of the earliest tether methods l remember was in a Harry Harrison novel.
There was a joint NASA/JAXA plan to create a small centrifuge for the ISS. However, it was killed due to budget cuts. It’s too bad because, as you point out, we have zero data on the long term effects of low gravity.
There's a few mega structures in peter f Hamiltons' body of work. The living habitats from the nights dawn trilogy, or the gas halo in around a star in the commonwealth universe. Loving the videos. Keep em commin! Lol
Hard sci-fi is hard 😂. I worked on a torus design for a year, and the economics of manufacture is workable if you build it in space from space-based resources. Build the refinery first, then the manufacturing plants, then the object; resources are easy (relatively) to gather. My final design was about 1.7 km diameter and 2 RPM (thereabouts) with a computer-controlled water-based balance system to account for the movement of equipment and personnel inside. Magnetic slip-rings, micro-gravity operations in the central hub, low gravity for the inner ring, 1g for the outer. The problem with the rotation rate is the effect it has on radius; higher rotation rates mean lower radii, and as one's head is closer to the centre than one's feet, a smaller radius causes a noticeable difference with the pseudo-gravity felt over the length of one's body. This effect causes nausea.
So you either worked on the NASA-Ames space settlement design study which came out in '77, or you're BSing and claiming the work that others _actually_ did as your own. And the water-balancing trick goes back to Velikovsky, so no points for originality there, either.
@AlbertaGeek You are aware that individuals can spend time working on projects, yeah? And that NASA isn't the only space engineering organisation? Space habitat concepts have been developed and modified for decades. You need to stop trying to gatekeep.
@@PeterLGଈ Okay, sure, you _just happened_ to absolutely coincidentally match the almost half-century old aforementioned study's Stanford Torus specs and feasibility path with your "info and comms tech" background. But I _totally_ believe you. Whatever being "info and comms tech" means. That's very vague. I mean, that covers even a phone or cable repair guy, so whatever. Not saying you're not smart, just saying what you're doing is a long way from being an aerospace engineer.
@AlbertaGeek Engineering is engineering, and working out a useful space habitat will generally come up with the same ballpark figures for a torus. No, I didn't crib off a half-century old study; some of us are actually capable of doing our own math. I really don't give a tinker's damn about your opinion of me, just go gatekeep someone else. (And it's not 𝘫𝘶𝘴𝘵 info and comms tech; that was my entry into a world of learning, which has never stopped)
Forgetting about mega structures for a moment, I gave some thought to a "transit" vehicle designed to carry humans from Earth orbit to Mars orbit and vice versa. And it would use spin gravity. It turns out that present day engineering is quite sufficient. Imagine a vehicle built around a truss structure. Launched into Earth orbit in sections and assembled in orbit (some human intervention is required for assembly, but it's not that complicated). At one end of this truss you have your engines and main oxygen tank. Then a relatively modest crew capsule (about 6 meters in diameter and 12 meters in length). On the far end of this truss structure is the secondary oxygen tank (and other tankage). Spin the whole thing end-over-end and you have spin gravity. For the crew, "down" will be towards the engines. Now here's the deal. You have tankage for about 300 tonnes of propellant. Most of that mass is oxygen. To get to a high Earth orbit, you first use a "tanker" vehicle. Or a pusher vehicle if you like. Basically 600 tonnes of propellant, plus engines (this thing returns to Earth orbit and is reused). Once you separate from that vehicle, you burn most of your fuel in one burn, leaving Earth orbit and going into a Mars transfer orbit. Now, you have some of your propellant left on board. This is the propellant you need to execute a Mars orbit insertion and also lowering to low Mars orbit. This propellant that travels with you is mostly oxygen by mass. And after leaving Earth space, you transfer that oxygen to the secondary oxygen tank at the far end of the vehicle (far end relative to the crew capsule). The mass of oxygen in that tank acts as a counter-mass and that allows you to spin the entire vehicle. It's basically a barbell. The remaining liquid methane sits in an annulus shaped tank around the crew compartment. That contributes to radiation protection. Some fuel is pumped back and forth to trim the motion and keep the thing stable. Given a truss of around 100-120 meters, you get a rotation speed of around 3 to 4 rpm and a gravity of 0.6 to 0.8 gs. Just ballpark figures. At 100 meters its not a mega structure. One thing you can also do is use internal pressure to stiffen the major (tube) elements of the truss. And you can adjust internal pressures to compensate for various perturbations and keep the whole thing straight. You can also vary the spin and gravity during the flight, for example gradually bringing the gravity down to Mars level in the weeks prior to arrival at Mars. I've also suggested that if you're wearing radiation absorbing materials in the form of a vest then the mass of that vest will contribute to skeletal loading. Meaning you have 1g equivalent loading on your major muscles, whist in a (roughly) 0.8g environment. My view is that you need some gravity. Probably at least 0.4g but to be safe I've worked around a target of 0.8g. The point I'm making is that its within our present engineering capabilities to build a vehicle that will deliver this on a flight to Mars and back. Using (relatively) modest resources.
There's a mega structure called a Birch world that you may be interested in. It's not quite a spin gravity structure, but uses centripetal force none the less. The underlying concept is that you build a stationary surface above a stellar mass (a dense planet, star, or black hole), at the distance where gravity is 1g. Then you keep it aloft orbiting material in tubes running under the surface faster than orbital velocity needed for distance, and using the outward pressure of that material to maintain it's distance away from the stellar body. While this can be done over planet and stars, a Birch world in particular does this around a galactic core black hole with the surface being a sphere light-month across, perhaps even a light year. On top of that, a birch world can have multiple shells one over the next like that russian doll, as the region of where 1G gravity exists around a galactic core black hole is quite large. Leading to a truly mindboggling usable area. Bonus, this structure uses technology available today, just at a grand scale. The orbiting matter and tube is just a glorified particle accelerator with a lot of material instead of a few atoms near light speed.
I'm assuming Ceres is loose soil and rock, but there is no problem spinning it without disintegration or having uneven gravity. You simply use it as source material to 3d print a ring shaped station. While conventional 3d printing might work i believe melting the rock and soil would be a better approach. You would need a form I think for the first extruded filament of rock, in a spiral patern so that the second spiral uses the first as it's form. You then just continue this process untill the ring is as wide as you want it. After the first layer is laid down then you change direction by 30 degrees and wrap the core layer in a second pass around the circumstance of the ring to get it 3 layers thick. You just keep rotating each additional wrap 30 degrees until after 12 wraps you back to your starting direction. That would make this base layer 23 strands thick. If your extruder was 1 inch in diameter that makes your station 23 inch thick at whatever width and diameter you created. OR, if you used 3 inch extruder it would be 69 inches think. But if you continue this process a second time, but at 15 degrees rotation you add an addition 48 layers for a total 72 layers thick. We built a nation in the Industrial Revolution by extruding metal into beams and other shapes. This is little different other than scale of the end product. You simply continue extruding thecl melted rock, altering the filament orientation until it's strong enough to withstand the stress of rotation. Of course, this just builds your floor. You still have to enclose the ring interior to create your living spaces. It is scalable, the ring could be 10 meters wide and 100 meters in diameter, or it could be 1 mile wide and 1000 miles in diameter.
in one of the Ringworld novels a spacecraft approached a ringworld and waited for an external structure to sho to anchor to. From the outside the ringworld surface would have looked like a horizontal surface streaching way into infinity. Standing in Ringworld the surface would have appeared flat from our perspective.
If you ran the same speed it's rotating but in the opposite direction and jump you can jump directly across to the other side. Or jump more softly to float upward. I would never be bored.
If you spin a planetary object up to a speed where the centrifugal effect becomes stronger than its gravitational force, it should rip itself apart even if its solid rock. Rock is super strong when you try to compress it, but really weak when you try to stretch it. Effectively, your entire spinning structure is hanging from the central axis.
When it is a solid rock, it is not bound by gravity but electromagnetic force. It would not be different from a smal stone rotating in space and i think everyone can imagine a solid smal rock rotating in space that "fast" that its Centrifugal forces overcome its tiny gravitational force.
I would say space stations from Elite: Dangerous? The Orbis stations have 4km and 2km rings and a cylinder for different G-forces; The classiCoriolisis cuboctahedron stations from the original 1984 elite can have very long arms for extra high G-force.
4:00 It's important to note that Rama wasn't designed for Humans, so for that particular craft, 1G isn't the ideal. 7:05 I can't remember if that's a retcon or not. I know that in 343 lore, Halo uses gravity handwavium tech, but it might have been different in Bungie lore. I also seem to remember random math or physics guy calculating that a Halo could theoretically be built using modern steels, and still function via spin gravity. I know that the dyson sphere in Star Trek TNG was 1 AU in radius. Though, dyson spheres are kinda generic nowadays. Warhammer is not the same as Warhammer 40k. Warhammer is a true classical fantasy, Warhammer 40k is a sci-fi.
The Gaia Trilogy by John Varley (books: Titan, Wizard and Demon) takes place in a Sanford torus that's an actual sentient entity. It's an extremely fun and bizarre trilogy that's hard to characterize.
8:24 the Orbitals are angle so as to *not* cast a shadow on themselves. The angle allows the part of the inner surface facing the sun to recieve sunlight without it being blocked by the part of the inner surface facing away, which receives no light
===Recommended Reading=== If you are a fan of Bobiverse check out - The Murderbot Series by Martha Wells - Saturns Children & Neptunes Brood by Charles Stross One of the only books, and the only sci-fi book to make me cry. Truly the most beautiful piece of science fiction ever written. - The book of the Long Sun series by Gene Wolfe And then some of the best, and likely lesser read, Sci-fi ever written: - Accelerando - Terra Ignota series - Ada Palmer - Citizen of the Galaxy - Anything by Adrian Tchaikovsky - Anything by Becky Chambers - The Stone Canal Ken MacLeod
I love the Polaris Space Hotel from For All Mankind, the show doesn’t get the love it deserves. If you can, check out its designs. I’m sure they’re not perfect but they go a long way to show our technology and design philosophy applied in space
For the people talking about the citadel. What are you talking about?? It wasn't even in this video. I don't even recall a mention. Halo didn't even need to be mentioned and could have just been used for scale since it uses artificial gravity.
Handwavium, the miracle material!
Gravity plating with condensed material in micrometer strings held by electron degeneracy pressure from collapsing into black hole.....or something more even technical.
You can do anything with enough handwavium and renderite
Unobtainium
@@Extra.Medium Don't forget "Wantum Mechanics".
@@KnightRanger38 ooh that's a good one
1989. I was in college (undergrad) and joined the Traveller Mailing List. That's a sci-fi pen and paper RPG. The list started a group adventure about visiting a newly discovered ringworld, and I got put on the team to make content for the ringworld (yeah, three of us tasked to make 3 million Earths of content).
I'd gotten my hands on some 3D rendering software (we won't mention how), and tried making renders of what it would be like to actually see the ringworld, complete with fractal land, ocean, clouds. Remember, this was 1989. My poor little 80386 PC (with no math coprocessor) took 18-22 hours to render a single 640x480 resolution image.
This was all running under DOS - no multitasking. Meaning my computer was completely occupied and unusable while it was rendering. Another guy on the list tried using his work computer (a Sun Sparc I think) and it completed the render in 17 minutes. Those two factors made me give up after rendering just a few images.
It's nice to see the same thing rendered with modern hardware. Thanks for the trip down memory lane.
3D app, late 80's, 386, no co-pro so 386-SX, probs 25MHz clock.... maybe 33MHz.... Real early Lightwave?
I used POV-Ray and the modeler Moray back in '93 on a DX5-133, and a basic dive to the planet surface animation at 320x240 at 12fps took a couple of weeks to render, when my parents didn't turn the PC off at the power switch while I was in class.... Your pain is well understood. :)
Ah, Traveller, where, "You haven't lived, until you've died in character creation."
For many people, the cylinder space stations from the Gundam series are iconic and a very important plot point in the series.
Thank you for adding Babylon 5!
Yeah the colonies in Gundam are pretty cool, was almost hoping they'd make an appearance but wasn't expecting it
THE GUNDAMS WILL SAVE US ALL!!!
@@jedisalamander2457 I was thinking the same. Though they're very close to the Ramma (especially the closed-type ones).
Yeah quite the oversight to not include Gundam. The designs were ripped direct from Gerard K. O'neill's work which is the seminal documentation on spin gravity space colonies.
@@jhnoakez They even called them "O'Neil cylinders".
You explained everything pretty well. One aspect you kind of overlooked is WHY someone would get nauseous on a smaller spinning hub like the 2001 example. The film shows Dave Bowman jogging inside. If he wanted an easy jog, he would jog anti-spinward. If he wanted a rigorous jog, he would run spinward. His ~10 feet per second added to the hub's angular velocity would increase his 'weight' noticeably. Also, just standing up from laying in bed. The inner ear would experience a noticeable centripetal acceleration change. And as mentioned about Bowman, moving spinward OR anti spinward would also wildly change the inner ear's acceleration.
Betting people could get used to just about any rotation after a while. None of the experiments ran for any length of time.
@@Akio-fy7ep Moving spinward, antispinward, radially in and out. . .all would effect the inner ear noticeably inside a small diameter hub. It would be like being aboard a smaller ship in rough seas. *One big difference in a hub* YOUR movement controls the acceleration fluctuations in a hub by moving in ANY direction as opposed to the sea controlling the acceleration change on a ship. NOT controlling random accelerations is MUCH more nauseating. So yes, I agree. I imagine it would be moderatly easier to get over the "seasickness" on a hub with a smaller radius. As is said in the video, once the radius gets to around 80 meters and the spin speed provides around 0.5g, the changes in accelerations by your movement become too small to notice unless your on a vehicle riding the hub's inner surface.
the Russians did a bunch of longer term experiments on Coriolis effects and they found that most people just get used to it after a week or two
Ceres would 100% definitely disintegrate if it was spun up like that. Even solid rock behaves almost like a liquid on planetary scales, thanks to the square-cube law.
In the books I believe they covered the dwarf planet in some structure. I might be confusing that with the space dock that was located at the pole though.
You can 'easily' submerge a train track some miles under the surface, and suspend an endless train right under the surface. The train runs on a maglev suspension on its uhm "ceiling" ? This easily creates gravity. I am pretty certain the solar system can be colonized with "embedded" cylinders, little spinning like centrifuges. Angle them a little, so their conical shape compensates for the gravity of the asteroid or moon. In fact you can 'easily' replicate Earth's surface on the moon by constructing endless such embedded cylinders below the surface. Make em as big as a typical O'Neil cylinder (I built one together with Simon Deering in 2010 for Transvision conference) and you can have about 50% of Earth's surface - but with garden/eden level of comforts - so easily a hundred billion people.
Literally applying the same metric for Ceres, a dwarf planet like Ceres could have a population of, assuming one "layer" of habitats "only" (....) literally One Earth - about 8 billion people, living with a population level and relative spacing of The Netherlands.
Now if we were to start stacking the rotational habitats, plus a solidly reinforced structural envelope or "casing" on top of one another, say four layers deep, (some 20 kilometers on the moon) we can have hundreds of billions of people living on the moon. But at that scale the heat emitted by each habitat with all the BBQ's and swedish sauna's and such would become a problem.
If we build habitats all over the moon, 4 levels deep, and we assume several times USA levels of heat consumption, the waste heat could make the surface glow on the dark side in infrared at over 100 degrees Celsius.
@@Khannea i see, an isaac arthur enjoyer :)
My head canon is that it's not the whole dwarf planet that is spun up but underground centrifuges that is used to add to the natural gravity rather than trying to completely cancel it and reverse it as spinning the whole planet would need to do.
I get so excited when someone mentions B5. It’s been 30 years, but the show still gets so little love. Thank you for doing this!
The Agamemnon from B5 is a pretty cool example, BTW. It’s Captain Sheridan’s old ship, about a mile long, with a large revolving section to simulate gravity, but rather than be a wheel like we commonly see, it’s basically two pie slices connected at the center, similar to the Leonov from 2010. Oh, yeah, and the Leonov is kinda cool, too, I guess (Forgot about it until the Agamemnon reminded me). Not saying you should do another video on the subject, I just thought I’d mention it.
Again: Thank you for doing this!
it's just excellent - that show is something else...
just started another rewatch of that show
@ i always rewatch it a little different if I can. One year I rewatched it with the movies in their proper places (Which is rough because Thirdspace takes place *inside* a regular episode) Another time I watched it, I stopped at “Objects at Rest,” then watched River of Souls, Rangers, call to Arms, Crusade, lost Tales, and THEN Sleeping in Light. This last time through I just skipped Season 5 entirely, and just jumped from “Rising Star” to “Sleeping in Light.” Each time it’s caused SiL to have a different emotional impact on me.
Agamemnon and the Omega Class ship design is a sci fi classic.
Be sure to catch Star Wreck, then, from the creators of Iron Sky.
Bablyon 5 was really good. The whole Shadow arc was amazing.
Finally! someone made ringworld to "scale" I wish you put a pov camera on every structure for comparison. very cool
I just realised Endurance's 12 modules looks like a clock which ties in nicely with the whole theme of time in the movie.
tick tock tick tock *organ begins playing*
Yeah and it spins clockwise.
7:21 So glad to see The Culture getting some love.
Some people daydream about living in Middle Earth or the Old Republic or what have you. I daydream about living on Masaq Orbital.
I was thinking one of the GSVs, personally.
For anyone who hasn't read it, Project Hail Mary is excellent. I was a bit skeptical of it going in, but it ended up being my favorite of Andy Weir's novels.
The audiobook is fantastic.
Just waiting for the movie now
Nah, it was kinda lame.
I loved it but it had a few glaring logical issues. I'm still checking regularly when the next Andy Weir book is coming, tho 😅
They are making a movie out of it starring Ryan Gosling. I really want to see how they portray rocky. I hope a combination of excellent puppets and CGI
Oh thank you so much! I left Bobiverse on the second book. If only I had known this would be coming later. I loved this size comparison. The graphics here are _chef’s kiss_. Great job altogether.
Honestly the third book is the worst one imo, fourth one is fun so far
First one is the best one but they’re all pretty good.
@@MomirBacic I really enjoyed book 5, book 4 was too slow for my tastes and I didn’t enjoy the starfleet plotline. 1, 2, and 3 were great though, imo.
The Coriolis, Orbis and Ocellus starports from Elite: Dangerous are worth mentioning.
Coriolis would be especially interesting too look atbecause its a cuboctohedra
Oh hey, the exact comment I was about to make!
But yes, those are interesting because they actually have distinct rotational periods from eachother, and all their stats are listed on the wiki.
Also Orbis class starports can have two different sizes of habitat rings spinning at the same rate, meaning they'd have different internal gravity. (I say "can" because they're modular and not every Orbis has both or even any types of habitat rings.)
Elite: Dangerous does also commit the physics sin of spun-up asteroid bases, but natural asteroids in the game already spin unrealistically quickly, so I might give it a pass. :P
So glad to see The Culture series get it's due here.
agreed.
yep
The halo ring is a ring because it’s not REALLY a space station for its purpose. It’s a super weapon to eradicate all life in a radius
Your rendering skills really improved. Good job pal
The reason for the "spiral tunnels" on Ceres, is that the centrifugal force is being used *additively* to the gravitational force, not subtractively the way you depicted it. This creates increased perceived gravity along a cone shaped surface into the interior of the mass with the poles of rotation at the center of the cone and the point towards the center of the mass. Those tunnels are built along that conical surface. You could also live on the cone at the other pole with the same perceived gravity. The part that's unrealistic, is that the cone should be much more shallow, since it's only a mild increase in gravity. Also, Ceres is definitely not a "rubble pile" asteroid. It's surface is well studied and photographed up close at this point. It is quite solid.
Ohh, so Ceres itself isn't being spun up, just the cone section?
@@CODENAMEDERPY No, the whole thing is spun up, but when you calculate the combined effect of the spin with Ceres' own gravity, the ideal place to build tunnels to utilize the gravity is along the surfaces of those cones, which are mathematical illustrations and not physical structures.
@@harbingerdawn Would those tunnels be at the rotational poles?
"is that the centrifugal force is being used additively to the gravitational force"
Nope.
There is no surface where the gravitational and inertial (centrifugal) forces would add up positively. Way worse once you notice that the proposed force due to rotation is the same as surface gravity: It means that the regions furthest from the rotational axis of the planet are no longer bound by gravity and the whole thing would rip it self apart.
Gravity always is an inward-vector, centrifugal inertia is always outward.
The best you can do to "increase" gravity is to STOP all rotation - for earth that would make a person on the equator about 0.3% heavier - negligible.
Kudos for making a super interesting video on a subject close to my heart.
You touch on the angular velocity limitation of five or six RPM, but also the small size of Discovery means the crew feels significantly lighter at the head than the feet, not a comfortable feeling at all. The Coriolis effect would be wicked, too. Imagine playing centrifugal ping pong!
I was disappointed to see no Bishop Ring, defined as the biggest compatible with hard SF. The limiting factor is tensile strength of the the floor material, which is thus the most important detail of any design, limited by the strength of a covalent bond. Interestingly, the limiting diameter is proportional to the length a cable of the material can hold itself up, supported at the top, under the acceleration you want. For 1G, which is the only one we know is compatible with human biology, it comes out to about 1000 miles, and turns in something close to an hour. It is big enough that, with walls, you don't need a lid over. Inner surface area is New Zealand to Italy.
You would build it as a thin ribbon, spinning it, and then widen that. Widening it from the center line would let you keep the walls up that hold the air in. At any time there would be long triangular holes along the center line with domes over them: cut some at the point, weld in a plate at the back, repeat.
Any sufficiently advanced culture will not be reliant on a star's radiation for energy. Its biggest problem will be radiating away the waste heat from its high-energy operations, making cold the most precious commodity. It will locate its operations no closer to a star than its Kuiper belt, and that close only for ready access to material resources absent in interstellar space.
Bishop Ring, given that it is actually possible in principle, deserves its own detailed episode. Certain practical problems remain to be solved.
"Certain practical problems remain to be resolved."
A simple matter of engineering!
"Any sufficiently advanced culture will not be reliant on a star's radiation for energy" what? Stars have more energy than the rest of the system combined. No sane culture would throw away these growth opportunities
There are the Iconian Dyson Spheres from Star Trek The Next Generation, we even get to see the Inside of 3 In Star Trek Online, The original Jenolan, the Solanae and the Herald Spheres. Star Trek also has Yorktown Station which also has a ton of handwavium involved but it is an interesting design with how it uses all of space with the artificial gravity letting people live on the different sides of those tunnels in it.
Yorktown Station was just absurd for something that was made before the time of the Original Series. I don't care if it's the alternate timeline, that thing was too advanced even for the ST: Picard setting.
Yorktown Station was far too advanced for human technology in Star Trek and is a good example of how the creators of the movie completely failed at world building
Was the Dyson sphere really Iconian? The extinct civilization with teleport technology from season 2, I think?
Sorry about the replies who think Star Trek is hard sci-fi. I assume literal children…?
@@RocketToTheMoose The Dyson sphere’s creators never came up in the show. The online game tends to make the fictional world smaller, more trivia-mongering and less imaginative, so the idea of the entirely separate Iconians making the sphere might come from there.
Ringworld is mind-numbingly big. A 95 mile segment of it has the same area as all of the land on earth, and there would be ~6.3 million of those segments.
Driving 24/7 on a highway straight across the width at 70 mph would take 370 days. An unbroken airliner flight would be in the neighborhood of 50 days.
Just take the space train thing that runs along its edges! Even that would probably still take forever to go around the whole thing though.
Good thing the ships are fast, "space pilots tend to forget that Mach 4 in an atmosphere is _fast."_
@@BinkyTheToasterthat’s still not fast enough to visit your friend who lives on the other side though.
@@cjeam9199 easy,.. just jump out of gravity, fart, wait, wait,fart the opposite way, land tadaa
@@cjeam9199 Mach 4 isn't, but this is a spacecraft we're discussing; it'll make like Mach 20000 before you have to engage the hyperdrive to go faster.
The cylindrical gundam colonies from the UC timeline, or the hourglass shaped colonies from the Gundam SEED timeline would be nice contenders. They all seem pretty realistic.
When you mentioned the potential to get dizzy, I was surprised you didn't go into some of the weirder aspects of gravity via rotating cylinder: from the perspective of someone on the "ground" -- part of the rotating inertial frame, as opposed to an observer watching the ring rotate from outside -- ballistic trajectories aren't the same as in a mass-induced gravity field. The smaller the ring diameter, the more noticeable the deviance from "normal" gravity.
The Gaea trilogy by John Varley deserves a mention. Titan,WIzard, Demon are the book's names.
Humanity finds a fairly stealthy artificial satellite in orbit around Saturn.
A crewed mission is sent to Saturn, and detects an artificial but LIVING Stanford torus, 1200 kilometers in diameter. It has an artificially dark surface ( vanta black before that was a thing ), and they can't really get any information from it, they theorise ( correctly ) that it is deliberately covert.
As they approach they detect that it has extremely low mass, so is obviously hollow. It is under spin, and as they pass by to measure its mass distribution, it exudes tentacles like a cuttlefish, and gathers in the earth-ship. Hy-jinks ensue.
Turns out to be an extremely old genetically engineered INTELLIGENT artifact, part of some civilisations' attempt to colonise the Galaxy. And they are successful, the Gaea the ship encounters is one of thousands in our solar system, and it is in contact with a countless community of others spread out across the galaxy.
The Gaea's arrive in a solar system as a seed, if they land on resources, they slowly grow up to size by much the same methods as a tree. In the process they eat up the planetoid they have landed on.
When they are fully loaded with the amount of resources they will need to thrive, they put themselves into orbit somewhere that they have a energy source, they do not need much. They ensure that their reaction mass ( the parts of their landing body that they don't need ) is launched at a tangent from their circumference, to give themself spin. During this phase, they are compact.
When they have made their orbit, they begin to inflate, melting the frozen gases they have gathered. They also grow and launch countless seeds, aimed extra-solar, again from their circumference to spin themselves up.
Inside they have complete and detailed control of the ecosystem that lives in the shell of the living world. And they have near miraculous genetic libraries and genetic engineering ability, and listening to Her "Sisters" among the stars, the Gaea can grow a vast library of creatures, from virus size up to whales.
Gaea Trilogy mentioned! I was at university when those books were new, and they were some of my favourites. One of my friends even went so far as to make a homebrew RPG with a Gaean setting.
Do not visit Cronus, he is quite insane these days...
There's some way crazier stuff outside Science Fiction, in the realm of speculation, hypotheticals, and pure world-building. Isaac Arthur on UA-cam has some fantastic videos on the subject, and you can find all kinds of blogs and wikis that go over some crazier ideas with viability ranging from fantastical to clever and actually reasonable.
Love Isaac Arthur's content.
There is also Outer Wilds with the Echoes of the Eye DLC. There the stranger is a spinning Space station. It's about 500m in diameter. As well as Stellaris, where you could find and build a Ring around a planet or even around a whole star.
OUTER WILDS MENTIONED LETZ GOOOO
I was about to say this exact thing
DYSON-SPHERE’s NEXT PLZ!!
Onyx or Trevalyan, from Halo, is ridiculously huge. The internal surface radius is approximately 1 AU.
The visualization of heavens river really puts into perspective how lucky the bobs were when they were looking for benders matrix
How was it they located the section he was on? I forget. Did they just scan until they detected him?
Good ol' Anek-23 🤗
@@victor6250well they entered close to the only active of 9 gates in the outer shell.
In that sense, they were still lucky, but not „with the Jackpot 23 thousand times over“ lucky.
They simply saw the sentry drones preferred that gate and assumed Bender was carried through the same way.
From
There the resistance stole bender and saw now reason to move him further than the next regional headquarters in halebs ending(?).
@@harriehausenman8623i‘m still not quite at ease with him. But the fact he hates beer is pretty endearing 😂
@@anticlaassic give him some slack. he had a really tough youth 😄
This video is AMAZING and sets the standard for all the "to scale" type videos out there.
Great narration, entertaining and informative, good visuals, all-around banger.
OMG! Not only was I just reading about megastructures and compiling a table to compare them, but when I saw *Heaven's River* , my jaw dropped.
Bobiverse is the best! 🤗
I thought I remembered Niven claiming that he used to attend parties that local scientists also attended, and he got ideas for his stories, as well as help getting a hard sci-fi reputation, from them. And of course he did invent a fictional material to hold his Ringworld and its shadow squares together and in place, and described its properties.
were the shadow square wires made of scrith also ? not saying they weren't, it's been a while since I read any of those.
@@idjtoal I forget if they ever got a close look, but do remember that they made that assumption. They also knocked a piece of connecting string loose in the first book, which proceeded to fall on and cut to pieces a civilization on the ring floor. In that case I think they confirmed more strongly that it was scrith.
@@idjtoal They were. The Pak used it for pretty much everything.
@@AlbertaGeek It should have been superconducting.
@@Akio-fy7ep Yes, but that would have made it the _ultimate_ unobtanium. Had to leave something for the plot, right?
The movie Stowaway also uses a cable spin method of increasing the diameter without making it unreasonably expensive in terms of materials. The crew board whats called a cycler that has an orbit that periodically moves between earth and mars that ships can rendezvous with. Basically once the cycler is created no extra fuel is needed to increase or decrease the velocity. There's also a scene in the movie that shows how a tether based system spins up
8:20 I do not get the day/night cycle bit. In my mind, a ring inherently cannot cast a shadow on itself while the light source is a sphere within the ring. If you ever wanted to do a follow-up vid with a graphic for that, you'd be da boss
EDIT: Ah, nevermind. The next graphic cleared it up! I thought the middle of the first ring example was the sun. I got you now. Great work!
I thought the same exact thing because Ring World is just engraved in my mind, no instead it's just a kinda small station orbiting a star.
@@man-from-2058 The shadow squares should have had more-clever shapes, to emulate twilight. Perforated at the ends, maybe.
Rama and Hailmary mentioned 😊
"don't say warhammer"
Thank you, truly.
Halo is a ring, because it's based on Larry Niven's Ringworld.
Im Commander Shephard, and this is my favorite gravitational demonstration video on The Citadel!
The artwork in this is really impressive. I have to say you did a really great job on this.
Yeah except this principle is garbage. It’s a fairly tale. It absolutely does not work. Weightless is weightless. Spinning a room around you doesn’t “simulate gravity”
It’s tiny in this context but the citadel in mass effect
This video was awesome! Like a size comparison (one of my favorite visuals in a video) combined with a scientific analysis of fiction. Really lovely stuff, would love to see more of it in the future. Thank you!
Been a fan of Taylor and Weir for years, I am glad to see them getting some proper nerdom recognition! I did some calculations of a Dyson sphere, I think I came up with 21 billion times the surface of the earth, But I solved the gravity issue with mass by making it have a 12k km thick shell. I abandoned it though because that amount of mass could actually alter the internal gravitational forces of the star it surrounded. Fun thought experiment though.
Just binged all of your videos, you are awesome! keep up the amazing content man. Also you pronouncing ecumenopolis and shouting out isaac arthur was hilarious.
Thank you for including the Topopolis. Its great to get a visual after listening to the book series. The bobiverse is fantastic.
🤗
You forgot the Alderson Disk, one example of which is in Missile Gap. Then again, it generates gravity the old fashioned way
Imagine being in the maintenance department on the ring world.
I think you'd have a sector you're assigned to, rather then being sent all over the place
"The Ringworld Engineers" goes into this very thing.
@@fantabuloussnuffaluffagus I guess I'm not as clever as I thought.
@@oatlord Still, the maintenance was a huge problem. You're right to wonder about it.
Please pass me some of that Tree-of-Life root and I'll help with the maintenance myself.
The maintenance and repair of the ringworld become major plot points in the sequels. One of the reasons it works is that the people managing it are superintelligent immortals genetically compelled to keep alive anyone genetically similar to them.
2:03 in the book it was specifically mentioned that the gravity on the ship was above 1g
If, instead of having the crew capsule on the long end of the tether, you would have a counterweight on the long end, the weight could be quite small and enable decent spin gravity with current technology. I would love to see a math breakdown of this.
6:48 I've used an online calculator, the Halo would have to spin at 0.00942rpm or 106.17 minutes per rotation (assuming scientific accuracy and assuming it uses centrifugal force, which it doesn't).
I would suggest adding at the Orbis, Ocellus, and Coriolis space stations from Elite Dangerous to this list. While they all look quite different externally (the Coriolis design is a cuboctahedron, the Ocellus design resembles a Bernal Sphere, and the Orbis design resembles an ovoid that usually has a Stanford Torus around it). All three use spin-gravity, and all feature a standard-sized interior cylindrical docking area with numerous landing pads for visiting spacecraft. They are quite large, with the entrance "mail slot" being large enough to comfortably pass the entire modern International Space Station through it and then some (the Type-9, the biggest player-flyable ship, is as wide and tall as the ISS, and these jumbos regularly dock to transfer several hundred tonnes of cargo at once). It'd be interesting to see how those stations compare in size to other famous sci-fi stations with spin gravity.
This was pretty awesome and easy to understand!!!
Thank you for sharing and your rendering skills!!
The one thing I wish you did included was the Buthandi (sp?) from Schlock Mercenary. Probably not appropriate for this video because they generate gravity through fictional science. But it is a stellar enclosure which according to the author, the name translated into English is, "this was expensive to build"
In Schlock Mercenary there's the spingrav Credomar habitat.
In an article in Analog Niven suggested a structure similiar to the one in the Bobiverse. With multitudes of loops. Name of the article was Bigger than Worlds iirc. Probably around 1979. No, 1974.
I remember that.
Arthur C Clarke's books are highly recommendable. You just get sucked into these books, and his ability to describe something extremely complicated in very easily understood language, is amazing. The Rama series is a good place to start. Remember to eat, drink and sleep now and then as you just can't put his books down ! 🙂
Where are the O'Neill cylinders, like from Gundam? I figured those would be pretty big? If it's too realistic, it's also used in many of the Gundam Series, so it's also sci-fi enough, I think.
so haven's river (last thing mentioned) is actually consisting of millions (trillions?) of O'Neil cylinders all linked together to create the massive larger structure basically think of the O'Neil cylinders as beads on a string
i very much recommend reading (or listening ) to the bobbiverse series
Rama is an O'Neill Cylinder and what brought that variation of the Oberth cylinder from the 1930s to the west's attention at least. (Similar were shown in sci-fi and futurism books from the Warsaw Pact nations years before Clarke and O'Neill published anything on them). So's Cooper Station, for that matter.
Did I miss something? Spin gravity produces outward “force”. So planets actually get reduced gravity on surface because of rotation.
i figured the ringworld books would get one of the last mentions since you were going by size. loved the whole "ringworld is unstable" story. one of my favorite Niven anecdotes.
The final book in the 3 body problem series 'redemption of time' has lots of rotating space stations that would be cool to see in a follow up
I'm saying
Automatic upvote for a B5 reference.
I love this video, and I love your inclusion of Project Hail Mary and Rama, but why didn't you include Hermes from The Martian?
It just didn't make the cut... :-(
im glad i found this video- the level of attitude through this was refreshing lmao
Would’ve loved to see real life material limit rings/cylinders and proposals like the Stanford Torus (proposed habitat by NASA, around 1.6km), O‘Neill cylinder (limited by steel strength, around 8km) and the McKendree cylinder (limited by carbon nanotubes strength, around 450km)
I love a nice hot cup a scrith in the morning.
The UN & The Patriarchy want to know how you managed to liquify that stuff!
kim stanley robinson had a few spin ships and cylinder stations, like in 2312
My ringworld has many interconnected tanks of mercury. Each tank is roofed with solar panels which power compressors on the tank. As that tank approaches the star, the solar panel generates more electricity which increases pressure. As a tank moves away, solar power and pressure drop. Mercury moves to lower pressure tanks; that increases mass. That draws regions that drifted away closer to the sun. Once they get too close, the mercury mass is again redistributed.
Really enjoy your channel, some of my favorite videos on hard sci-fi. I have a suggest for a video on hard sci-fi of the SevenEves book. The use of the ISS in the story along with the generational space station in the later half of the book are very interesting.
I always wondered why sci-fi creators ignore the fact that mass creates gravity. A planet doesn't have gravity because it is a planet, it has gravity because it has a large enough mass. Looking at the bigger rings, the earth is barely visible. If you build that big, any small section of the ring would create its own gravity; probably even more than the earth. And judging by the size in the video, building them hollow would just make it collapse under its own gravity and create a solid core, lengthwise. So it has to have a lot of mass. On the inside surface there might be some sideways pull because it is a ring and not a sphere, but that doesn't mitigate the sheer amount of mass underfoot. Just imagine the earth and how much gravity it creates. And now imagine a section of that ring, let's say 100x the mass of the earth, and now all of the sudden we need to spin it to create 'artificial' gravity?
Yeah, but its too far away
@@apennameandthata2017 What is too far away? I am talking about the mass that is more or less right underneath your feet. Just like the earth is, right now.
Cool to see topopolis visualized, i somehow thought it was much smaller than this, great ro see it compared like that!
I quite love the level of detail “Heaven’s River” goes in to when describing the titular station. It’s by far my favorite book of the series to date.
What would happen if you jumped "up" while onboard a rotating craft? Would you continue upward, hover in place, or would there be some other gravity-like force which would bring you back down?
If you jump up you still have the tangential velocity of the floor. Newton's laws of motion say you will continue to move in a straight line at the same velocity until that line intersects the floor.
The end effect would be very similar to jumping on Earth, with a small displacement sideways due to the Coriolis effect.
If you run against the direction of rotation you will experience less gravity. If you could run fast enough you would reach a point where there was no more spin gravity effect. At that point you could float away from the floor. It wouldn't be for long though because the air in the craft will be moving at floor speed so wind resistance would accelerate you back up, probably resulting in a pretty spectacular and painful face plant.
@@LesNewell Wow, that's fascinating!
“Ringworld” is a fantastic novel- as a sci-fi enthusiast it’s my all time favourite.
Okay.. but can we figure out how to make an actual sphere that mimics what we experience on small moons, astroids, etc.. (BTW there is no room for flat earth bullsh*t, I'm genuinely curious about physics & science. Not kindergarten level conspiracy theories)
Only if we make it as heavy as said moon to use real gravity. There's no way to fake gravity that makes it pull towards the center. And if we have to use that much mass, why bother making an artificial moon in the first place? Just live on a real one.
It's farcical that we have ZERO data on how lower g affects human physiology. We have enormous amounts of data for 1gee. And quite a bit for zero gee. But nothing for the in-between. Two points on a graph. And we could have had some data in the last 4 decades. If we had wanted to. NASA to could have cobbled together an orbital facility that would have allowed gathering some data. Using mostly existing hardware. But getting such a program past the US Congress would have been impossible. Yes here has been a few experiments in LEO using centrifuges and mice etc. Big freaking deal. I'm not saying we should put a ring shaped station in orbit for this purpose. But we could have done it using either tethers (1) or spent stages and a small hab module. My favorite would've been two Shuttle External Tanks docked nose to nose. Attach a Hab Module to the bottom of one ET. After crew transfer spinup the assembly for .17 gee. Later spin it up for .34 gee. When plotted on a graph are the effects from 0 gee to 1 gee a straight line. Or some sort of curve. If a curve does the data show a slow rise then steepen radily as we apptoach 1 gee. Or does the data rapidly rise and then flatten out.
And yes l know about the spin gravity experiments that took place on Earth. Both the US and the Soviets did this. But the experiments were more to see if humans could adapt to spin gravity. Not what the effects would be at lower gee.
1) One of the earliest tether methods l remember was in a Harry Harrison novel.
There was a joint NASA/JAXA plan to create a small centrifuge for the ISS. However, it was killed due to budget cuts. It’s too bad because, as you point out, we have zero data on the long term effects of low gravity.
I had a dream where I was standing inside Heavens River.... it was beyond awesome :)
I had that too. And then I was back in my matrix.
PROJECT HAIL MARY MENTIONED!!!!!
FUCK YEEEAH I LOVE THAT BOOK
Good job mixing the Bobiverse with a reference to Skippy from Expeditionary Force. Two of my favorite series.
I didn't know I needed this, but here I am. Subbed!
Id probably add birch world as the grand pappy of them all
Was looking for someone mentioning Birch world
A sphere around SMBH... it is BIG.
Birch World doesnt spin for gravity, it uses the SMBH at its center for gravity as a shellworld
@@fiiral5870 true, but would not be that out of place here
@fiiral5870 you are correct, I retract my recommendation.
Then a recommendation for a future vid. Habitable megastructure scale maybe?
I love videos like this. I would love to hear similar details about Dyson spheres
*PLEASE* KEEP MAKING THESE VIDEOS!!!
There's a few mega structures in peter f Hamiltons' body of work. The living habitats from the nights dawn trilogy, or the gas halo in around a star in the commonwealth universe. Loving the videos. Keep em commin! Lol
Thanks for the vid. This was super interesting.
Hard sci-fi is hard 😂. I worked on a torus design for a year, and the economics of manufacture is workable if you build it in space from space-based resources. Build the refinery first, then the manufacturing plants, then the object; resources are easy (relatively) to gather. My final design was about 1.7 km diameter and 2 RPM (thereabouts) with a computer-controlled water-based balance system to account for the movement of equipment and personnel inside. Magnetic slip-rings, micro-gravity operations in the central hub, low gravity for the inner ring, 1g for the outer. The problem with the rotation rate is the effect it has on radius; higher rotation rates mean lower radii, and as one's head is closer to the centre than one's feet, a smaller radius causes a noticeable difference with the pseudo-gravity felt over the length of one's body. This effect causes nausea.
So you either worked on the NASA-Ames space settlement design study which came out in '77, or you're BSing and claiming the work that others _actually_ did as your own. And the water-balancing trick goes back to Velikovsky, so no points for originality there, either.
@AlbertaGeek You are aware that individuals can spend time working on projects, yeah? And that NASA isn't the only space engineering organisation? Space habitat concepts have been developed and modified for decades. You need to stop trying to gatekeep.
@@PeterLGଈ Okay, sure, you _just happened_ to absolutely coincidentally match the almost half-century old aforementioned study's Stanford Torus specs and feasibility path with your "info and comms tech" background.
But I _totally_ believe you. Whatever being "info and comms tech" means. That's very vague. I mean, that covers even a phone or cable repair guy, so whatever. Not saying you're not smart, just saying what you're doing is a long way from being an aerospace engineer.
@AlbertaGeek Engineering is engineering, and working out a useful space habitat will generally come up with the same ballpark figures for a torus. No, I didn't crib off a half-century old study; some of us are actually capable of doing our own math. I really don't give a tinker's damn about your opinion of me, just go gatekeep someone else. (And it's not 𝘫𝘶𝘴𝘵 info and comms tech; that was my entry into a world of learning, which has never stopped)
@@PeterLGଈ _"I didn't crib off a half-century old study"_
Oh, I totally believe you.
Forgetting about mega structures for a moment, I gave some thought to a "transit" vehicle designed to carry humans from Earth orbit to Mars orbit and vice versa. And it would use spin gravity. It turns out that present day engineering is quite sufficient.
Imagine a vehicle built around a truss structure. Launched into Earth orbit in sections and assembled in orbit (some human intervention is required for assembly, but it's not that complicated). At one end of this truss you have your engines and main oxygen tank. Then a relatively modest crew capsule (about 6 meters in diameter and 12 meters in length). On the far end of this truss structure is the secondary oxygen tank (and other tankage).
Spin the whole thing end-over-end and you have spin gravity. For the crew, "down" will be towards the engines. Now here's the deal. You have tankage for about 300 tonnes of propellant. Most of that mass is oxygen. To get to a high Earth orbit, you first use a "tanker" vehicle. Or a pusher vehicle if you like. Basically 600 tonnes of propellant, plus engines (this thing returns to Earth orbit and is reused). Once you separate from that vehicle, you burn most of your fuel in one burn, leaving Earth orbit and going into a Mars transfer orbit.
Now, you have some of your propellant left on board. This is the propellant you need to execute a Mars orbit insertion and also lowering to low Mars orbit. This propellant that travels with you is mostly oxygen by mass. And after leaving Earth space, you transfer that oxygen to the secondary oxygen tank at the far end of the vehicle (far end relative to the crew capsule). The mass of oxygen in that tank acts as a counter-mass and that allows you to spin the entire vehicle. It's basically a barbell. The remaining liquid methane sits in an annulus shaped tank around the crew compartment. That contributes to radiation protection. Some fuel is pumped back and forth to trim the motion and keep the thing stable.
Given a truss of around 100-120 meters, you get a rotation speed of around 3 to 4 rpm and a gravity of 0.6 to 0.8 gs. Just ballpark figures. At 100 meters its not a mega structure. One thing you can also do is use internal pressure to stiffen the major (tube) elements of the truss. And you can adjust internal pressures to compensate for various perturbations and keep the whole thing straight.
You can also vary the spin and gravity during the flight, for example gradually bringing the gravity down to Mars level in the weeks prior to arrival at Mars. I've also suggested that if you're wearing radiation absorbing materials in the form of a vest then the mass of that vest will contribute to skeletal loading. Meaning you have 1g equivalent loading on your major muscles, whist in a (roughly) 0.8g environment.
My view is that you need some gravity. Probably at least 0.4g but to be safe I've worked around a target of 0.8g. The point I'm making is that its within our present engineering capabilities to build a vehicle that will deliver this on a flight to Mars and back. Using (relatively) modest resources.
There's a mega structure called a Birch world that you may be interested in. It's not quite a spin gravity structure, but uses centripetal force none the less. The underlying concept is that you build a stationary surface above a stellar mass (a dense planet, star, or black hole), at the distance where gravity is 1g. Then you keep it aloft orbiting material in tubes running under the surface faster than orbital velocity needed for distance, and using the outward pressure of that material to maintain it's distance away from the stellar body. While this can be done over planet and stars, a Birch world in particular does this around a galactic core black hole with the surface being a sphere light-month across, perhaps even a light year. On top of that, a birch world can have multiple shells one over the next like that russian doll, as the region of where 1G gravity exists around a galactic core black hole is quite large. Leading to a truly mindboggling usable area. Bonus, this structure uses technology available today, just at a grand scale. The orbiting matter and tube is just a glorified particle accelerator with a lot of material instead of a few atoms near light speed.
Nice Culture reference
Very neat renders and great explanations!
This was brilliant, thank you 🙏
I'm assuming Ceres is loose soil and rock, but there is no problem spinning it without disintegration or having uneven gravity. You simply use it as source material to 3d print a ring shaped station.
While conventional 3d printing might work i believe melting the rock and soil would be a better approach. You would need a form I think for the first extruded filament of rock, in a spiral patern so that the second spiral uses the first as it's form. You then just continue this process untill the ring is as wide as you want it.
After the first layer is laid down then you change direction by 30 degrees and wrap the core layer in a second pass around the circumstance of the ring to get it 3 layers thick. You just keep rotating each additional wrap 30 degrees until after 12 wraps you back to your starting direction. That would make this base layer 23 strands thick. If your extruder was 1 inch in diameter that makes your station 23 inch thick at whatever width and diameter you created. OR, if you used 3 inch extruder it would be 69 inches think.
But if you continue this process a second time, but at 15 degrees rotation you add an addition 48 layers for a total 72 layers thick.
We built a nation in the Industrial Revolution by extruding metal into beams and other shapes. This is little different other than scale of the end product. You simply continue extruding thecl melted rock, altering the filament orientation until it's strong enough to withstand the stress of rotation.
Of course, this just builds your floor. You still have to enclose the ring interior to create your living spaces. It is scalable, the ring could be 10 meters wide and 100 meters in diameter, or it could be 1 mile wide and 1000 miles in diameter.
in one of the Ringworld novels a spacecraft approached a ringworld and waited for an external structure to sho to anchor to. From the outside the ringworld surface would have looked like a horizontal surface streaching way into infinity. Standing in Ringworld the surface would have appeared flat from our perspective.
If you ran the same speed it's rotating but in the opposite direction and jump you can jump directly across to the other side. Or jump more softly to float upward. I would never be bored.
If you spin a planetary object up to a speed where the centrifugal effect becomes stronger than its gravitational force, it should rip itself apart even if its solid rock.
Rock is super strong when you try to compress it, but really weak when you try to stretch it.
Effectively, your entire spinning structure is hanging from the central axis.
When it is a solid rock, it is not bound by gravity but electromagnetic force.
It would not be different from a smal stone rotating in space and i think everyone can imagine a solid smal rock rotating in space that "fast" that its Centrifugal forces overcome its tiny gravitational force.
NASA replicated the Discovery One on Skylab and had someone run around it like in the film. 2:48
I would say space stations from Elite: Dangerous? The Orbis stations have 4km and 2km rings and a cylinder for different G-forces; The classiCoriolisis cuboctahedron stations from the original 1984 elite can have very long arms for extra high G-force.
4:00 It's important to note that Rama wasn't designed for Humans, so for that particular craft, 1G isn't the ideal.
7:05 I can't remember if that's a retcon or not. I know that in 343 lore, Halo uses gravity handwavium tech, but it might have been different in Bungie lore. I also seem to remember random math or physics guy calculating that a Halo could theoretically be built using modern steels, and still function via spin gravity.
I know that the dyson sphere in Star Trek TNG was 1 AU in radius. Though, dyson spheres are kinda generic nowadays.
Warhammer is not the same as Warhammer 40k. Warhammer is a true classical fantasy, Warhammer 40k is a sci-fi.
The Gaia Trilogy by John Varley (books: Titan, Wizard and Demon) takes place in a Sanford torus that's an actual sentient entity. It's an extremely fun and bizarre trilogy that's hard to characterize.
8:24 the Orbitals are angle so as to *not* cast a shadow on themselves. The angle allows the part of the inner surface facing the sun to recieve sunlight without it being blocked by the part of the inner surface facing away, which receives no light
===Recommended Reading===
If you are a fan of Bobiverse check out
- The Murderbot Series by Martha Wells
- Saturns Children & Neptunes Brood by Charles Stross
One of the only books, and the only sci-fi book to make me cry. Truly the most beautiful piece of science fiction ever written.
- The book of the Long Sun series by Gene Wolfe
And then some of the best, and likely lesser read, Sci-fi ever written:
- Accelerando
- Terra Ignota series - Ada Palmer
- Citizen of the Galaxy
- Anything by Adrian Tchaikovsky
- Anything by Becky Chambers
- The Stone Canal Ken MacLeod
Bruh, I LOVE the Murderbot series.
@@OverviewEffekt - How about Saturns Children & Neptunes Brood by Charles Stross?
I love the Polaris Space Hotel from For All Mankind, the show doesn’t get the love it deserves. If you can, check out its designs. I’m sure they’re not perfect but they go a long way to show our technology and design philosophy applied in space
Babylon 5 definitely has 1g, not lower. I mean people walk there the same way we do on Earth
The Bobiverse is a truely Fantasitic series. it fits nicely with Revelation Space as my top favorites.
For the people talking about the citadel. What are you talking about?? It wasn't even in this video. I don't even recall a mention. Halo didn't even need to be mentioned and could have just been used for scale since it uses artificial gravity.