Centrifugal Gravity

Gravity created within a spaceship, Space Station, or habitat by spinning it.

Currently this is the only way humans have to generate gravity where there ordinarily would be none, or a negligible amount note . While it is most often found in connection with Ringworld Planets, it is not limited to them, and the shape of the ship or habitat is irrelevant to whether this trope is in use or not.

Note that in Real Life, this isn't yet practical, as being in a centrifuge can be Nausea Fuel for many people, as many who have ridden in the Gravitron could tell you. Though a larger cylinder wouldn't need to spin as quickly and thus would be easier on the body, making the main obstacle construction.

The biggest obstacle to this trope in Real Life is our sense of motion. Your ears are very good at sensing motion and gravity (it's how you balance) and while you're being centrifuged, you're subject to the Coriolis Effect, and so if you happen to turn your head to look left or right, you'd be so overcome with motion sickness you'd throw up. The benefits of gravity simply didn't justify the extravagant cost that designing a spinning space station would require. Especially considering they'd have to design it to handle emergency situations that would necessitate the station to stop moving; in other words, everything would have to be designed to operate in two modes. This would have made the project several hundreds to several thousands of times more expensive than it already would be. NASA and other space programs simply weren't willing to design what would essentially be a multi-billion dollar failure-prone space puke bucket. This being said, a modest reduction in the cost of building a station would make this worthwhile for very large stations that could turn more slowly (which would also thus not run into the puke issue as much); however, there is nothing today to make such large stations possible or desirable.

Usually appears in works high on the Mohs Scale of Sci-Fi Hardness.


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    Anime and Manga 
  • The Gundam franchise helped popularize the O'Neill Cylinder space colony (see below in "Literature"), as well as other designs. The franchise also consistently shows characters on spaceships and spacestations as being in zero-g, unless the ship/station happens to have a rotating section to provide that gravity.
  • In Cowboy Bebop most space stations are the ring type. The Bebop and many other ships have rotating sections and no gravity anywhere else on board.
  • The Amaterasu of Starship Operators has a rotating crew section, the showers have signs warning about Coriolis forces.

    Comic Books 

  • Possibly the most famous example is the space station from 2001: A Space Odyssey. In addition, both the Discovery and the Alexei Leonov from 2010 have rotating sections.
  • Elysium rotates to provide this.
  • Moonraker. Hugo Drax's secret space station spins on its axis, providing gravity to those inside. When James Bond stops the rotation, the station interior goes to zero gravity and everyone starts floating around.
    • However, Drax's space station was not cylindrical, rather it had a roughly spherical central portion with long appendages sticking out. When it "spins up", gravity is uniform everywhere, and directed towards the "floor" of the main area, when in reality it would vary enormously depending on where in the station you were, and would be directed away from the axis of rotation.
  • In Mission to Mars, the main space ship seems to have this.
  • Red Planet has two rotating sections on the main ship. The sections rotate in opposite directions in order to counteract each other's force. Otherwise, the ship itself would rotate.
  • Possibly one of the oldest examples: "The Wheel" in George Pal's 1955 movie Conquest Of Space, which is basically a space station built in the shape of a wheel to allow the crew artificial gravity. Outside "The Wheel" and on the spaceship, the characters are weightless and have to rely on magnetic boots.
  • The Endurance of Interstellar includes a spinning ring of modules where the astronauts spend most of their time.
  • The Venture Star in Avatar has a centrifuge section; the only scene aboard it, though, takes place in a free fall zone.
  • Like the novel, the Hermes in The Martian sports Centrifugal Gravity for the long journey between Earth and Mars. Unlike other depictions, the astronauts are shown floating freely about the center of the ship, only experiencing the increasing pull of shipboard gravity as they descend via ladder into the spinning section.
  • The ship in Disney's RocketMan also has this type of gravity, with several sections spinning around a central node, connected by cables (see the Real Life proposal below). Strangely enough, gravity goes from zero to normal in a split second, causing the protagonist to drop instantly. In fact, it would take a long time to "spin up" to anything even remotely like normal Earth gravity. Near the end, the protagonist and his Love Interest are dancing. The Commander disengages the gravity, and they're shown dancing on a wall and on the ceiling, which isn't how weightlessness works.
  • The Avalon in Passengers consists largely of three curved arms in an outwards spiral formation that spin to provide gravity. The elevators that go between sections go without gravity at points. When the power fails temporarily the ship stops spinning and things all over start floating, totally ignoring the laws of inertia.

  • Larry Niven:
    • Ringworld is set on a world shaped like a vast ring with a sun at its centre. It's made of Unobtanium called scrith and is so massive that its geographical features include 1:1-scale maps of several planets (including Earth). These maps are significantly less than 1% of the ring's surface area.
    • Footfall by Niven and Jerry Pournelle has the Fithp alien invaders use a ship which sometimes spins for gravity and sometimes not, depending on its current mission role. It is designed so rooms can adjust for whether gravity is present or not.
  • The Culture of Iain M. Banks's novels builds Ringworld-style Orbitals (but smaller) as housing for many of its citizens. They have a few full size, fits-round-a-star Ringworlds, too, but they're much rarer, since you can get more usable area by using the same mass to build orbitals so most of the Culture regards them as tacky.
    • Notably, this is a setting in which anti-gravity devices are common and reliable, but because the centrifugal force is not the same fundamental force as gravity (even if the net effect ends up the same) those anti-gravity devices will not function on a ring orbital as they would on a planet.
  • Arthur C. Clarke's Rama, from the series started by Rendezvous with Rama, is a massive cylindrical spacecraft.
  • The protagonists of Gregory Benford's Beyond Infinity spend a brief time trapped in a Tunnelworld after an encounter with some 4-dimensional aliens. It was a closed loop, so traveling in any direction for a long enough time would return you to your point of origin.
  • Gerard O'Neill proposed a real world cylindrical space colony: Island Three. The page illustration is a representation of the "Stanford Torus", another design inspired by both O'Neill's work and the classic "wheel-and-hub" space stations.
  • Thistledown, from Greg Bear's The Way Series, is a hollowed-out asteroid containing seven cylindrical chambers separated by bulkheads. The seventh chamber connects to a cylindrical pocket universe with several million miles of terraformed interior.
  • The Anne McCaffrey and S.M. Stirling novel The City Who Fought takes place entirely on a cylindrical space station.
  • In the Gor series, the alien Kur race live on "steel worlds" hidden in the Asteroid Belt. The book Kur of Gor takes place on one, and we learn that it is like this. You can look up and see the opposite "land" side. Day and night are controlled artificially, as is weather. At one point they travel to one of the ends, where the gravity is pracitally non-existent.
  • The Battle School of the Ender's Game series is built as a ring. Bean deduces from emergency exit maps that it's larger than they're told, and there were plans to build more rings connected around it. Subverted as, during the events of that book, they realized the gravity was constant throughout the station but suddenly cut off at the entrance to the Battle Room, implying that it was actually using Artificial Gravity (a technology supposedly reverse-engineered from Bugger technology following the First Invasion).
    • In the prequel Earth Unaware asteroid mining ships have a "fuge" aboard where the crew exercise and small children are raised. The rest of the ship is in microgravity. Interestingly, the same prequel novel also reveals that humanity had already made some progress in Artificial Gravity being used for certain military aircraft (specifically, the HERC developed by Juke Ltd. for New Zealand) as a replacement for rotors. This retcons the origin of Artificial Gravity as a purely human invention rather than technology learned from the Buggers.
  • In Destruction of Phaena by Alexander Kazantsev, the eponymous planet's first (and last) space station was a ring that used centrifugal forces to emulate gravity. There was also a compartment in the middle of the ring, where they grew edible plants, which profited from the lack of "gravity".
  • The Whorl in Gene Wolfe's Book of the Long Sun is a rotating cylindrical spaceship. "Whorl" obviously refers to its rotation, but has become confused in the minds of its inhabitants with "world" to the extent that they also call planets whorls.
  • Robert A. Heinlein used this a lot:
  • A rotating space station is depicted in the 1959 children's book You Will Go to the Moon by Mae and Ira Freeman
  • In Revelation Space, the Nostalgia for Infinity primarily creates gravity by simply accelerating at a constant 1g using its Conjoiner Drive engines - the decks are arranged like that of a skyscraper. However, when not accelerating, the ship can spin up independent centrifuge sections for the (nonexistent) passengers. Most orbital habitats in the Glitter Belt (and later, the Rust Belt) orbiting Yellowstone resemble carousels or cola cans, and are spun up to generate gravity on the interior.
  • In Sergey Lukyanenko's Star Shadow, the Russian space station Delta is a toroid designed to be able to rotate for this purpose, unlike the other Earth defense stations. It's mentioned to be both a convenience and an inconvenience. It's nice to be able to walk aboard the station, but the rotation must be stopped if lasers are to be used for combat, as it's difficult to aim this way.
  • Star Carrier: The eponymous America has twin counter-rotating habitation rings that are kept at about .5 gravities, due to the mixed crews from bodies all over the Sol system (Earth has 1 G, the Moon has 1/6, etc.). These are also used as an alternative way to launch Space Fighters, by placing them in slots on the rim of the ring and letting inertia fling them clear of the carrier's shield cap.
  • Earthclan's ships in the Uplift series have a rotating ring section, even after obtaining Artificial Gravity from the Galactic Library. Partially because they don't fully trust the Library and partially to remind the Galactics of their status as un-uplifted "Wolflings". Unfortunately this means that most of the drynote  rooms on the Streaker are upside-down or sideways whenever they're grounded.
  • This is one of two types of artificial gravity that Greg Egan plays straight in his Orthogonal trilogy. The protagonists fly their Generation Ship to an Alternate Dimension by accelerating the ship to an infinite velocity at a rate of one-G for about a year. When they turn off the engines and stop accelerating, the lack of gravity unexpectedly causes their crops to fail, so they begin spinning the ship to compensate.
  • All starships and Space Stations in the Alliance/Union and Foreigner universes of C. J. Cherryh use this, as her sci-fi is on the "hard" end of the scale.
  • The Ring from For Your Safety is a massive Earth girdling space colony at geosynchronous orbit.
  • Paradyzja by Janusz Zajdel has centrifugal gravity on the titular space station. Or so they're telling you...
  • The Hermes from The Martian sports this, which keeps the astronauts in shape during the long journey to and from Mars during the Ares missions.
  • In Captain French, or the Quest for Paradise, the titular space trader's ship, the Circe, is equipped with ion thrusters that maintain a rotation of the ship at 0.2g. In order to keep himself from becoming a Sacabon, he forces himself to exercise daily and swim in his Olympic-size pool while traveling.
  • At the end of the David Brin & Gregory Benford novel Heart Of The Comet, the colonists living in the comet have finally figured out the problem of how to raise viable children on a ball of ice and rock with significantly reduced gravity: they refurbish a Ferris wheel-like set of chambers in one of the comet's caverns, where all the children are raised in simulated gravity. Crew members are also mandated to spend a certain amount of time in the gravity rooms to keep their bodies from atrophying.
    "...the centrifugal wheel from the old Edmund had been refurbished and put back to work, rotating slowly, like a Ferris wheel... The wheel's centrifugal force was equivalent only to one twentieth of Earth's pull, but it was enough... As he approached the rolling boundary, Saul heard a treasured sound. Children laughed and flew past him towards the ring, skidding in the soft sand of the landing area as the great cylinder rolled around and around. They looked so much better. Still, the gangling forms seemed barely human. Only a few could speak."

     Live Action TV 
  • The eponymous Babylon 5 is a small O'Neill Cylinder—a kind of spinning cylindrical space station. Babylons 1-4 were of the same design, but larger. Earth Alliance destroyers and Explorer ships have a pair of spinning "arms" around the center. Meanwhile, more advanced races such as the Centauri and Minbari have Artificial Gravity, and everyone else without either uses seatbelts.
    • Those Earth Alliance spinning "arms" are there for crew spaces (e.g. quarters, mess, sickbay). The Bridge is actually located in a central, less exposed area, and is zero-g, so everyone still straps in. The only Earth warships to feature Artificial Gravity are the new Warlock-class destroyers and, even by the time of Crusade, there are only 50 of those in operation.
    • According to the fluff, the "spinning arms" are a fairly recent introduction, the bugs having been worked out just before the outbreak of the Earth-Minbari War. The two previous EF workhorses (Hyperion-class heavy cruiser and Nova-class dreadnought) only operate in microgravity. The Omega-class destroyers, mass-produced after the end of the war, are, basically, Novae with spinning arms and different weapons. Only four prototypes were built by the time the war began, and all were destroyed in the first battle of the war (which lasted all of 12 seconds).
    • The station's gravity has some interesting consequences. Sections near the core of the station have less gravity than those near the outer hull (so species used to lower gravity tend to be assigned quarters towards the core). The centreline of the station where the transport system runs is effectively zero-gravity and requires people to use hand rails at all times. When a transport is destroyed in the core and its occupant is forced to jump from it, said occupant is also effectively weightless, but drifting towards the outer walls of the station thanks to his momentum (this incident took place in a part of the station with a large open space to provide a sizeable garden). If not rescued before making contact with the hull, the station's angular momentum would hit him as if he jumped from a car travelling at motorway speeds and would almost certainly be fatal.
  • The civilian ship Zephyr (the "Donut Ship") in Battlestar Galactica (2003) consisted of a ring-shaped section rotating around a central axis. Word of God said the ship is a relic from when gravity on starships were created through centrifugal force. Although proper artificial gravity was widespread by the time the series begun, Zephyr and its type were kept in commercial use for novelty value.
  • The 100 uses this to explain the artificial gravity on The Ark.

    Tabletop Games 
  • Sigil from Dungeons & Dragons Planescape setting is this. It's also a sort of hub that connects to all the other planes of existence.
  • In Eclipse Phase many people following the Fall live in space habitats, many of the bigger ones are toruses or O'Neil cylinders. However there's also a number of habitats that don't bother with spinning since basic biomods counter the degeneration from microgravity.
  • 2300 AD does this with human-built ships. Justified in that it's trying to be a hard science setting.
  • The Mundane Dogmatic BattleTech universe lacks conventional artificial gravity, forcing ships to make do with "grav deck" centrifuges or ship acceleration for pseudo-gravity. JumpShips which just hang around a star's nadir points while recharging make the most use of centrifugal gravity, whereas Drop Ships continuously accelerate in intra-system travel, providing pseudo-gravity. Prohibitive costs and maintenance means that there's generally more crew than room on the centrifuges, so space on the centrifuges are generally relegated to exercise, entertainment, and medical bays, with crew being allotted a certain amount of time per day in centrifuge areas. Centrifuges are most obvious on the descriptively named Wagon Wheel class of WarShips, which has a trio of nested centrifuges mounted on the exterior of the fuselage.

    Video Games 
  • Halo:
    • Halo: Combat Evolved takes place on a ringworld (Alpha Halo aka Installation 04) resembling Banks's Orbitals set at the midpoint between a gas giant and its moon. Most of the other Halos in the series appear to orbit gas giants as well.
    • Halo: The Fall of Reach claimed that the Pillar of Autumn starship had cylindrical rotating sections within it to create gravity, but these are never seen in gameplay and the encountered layout does not seem to fit them. In general, while early UNSC ships and stations used this trope, current models have actual gravity generators.
  • Startopia has you turn one of these into a profitable space station.
    • Several, actually. Apparently, all known races use the same exact design for their space stations, right down to the color scheme.
  • You can make ringworlds in the Space Empires series. A Dyson Sphere is better, though.
  • You can build ringworlds in Star Ruler, admittedly as a lategame option. They are Capital-H Huge, larger than some planetary orbits.
  • Shores of Hazeron has ancient ringworlds which can be colonized. The ringworlds are almost exactly like those from the Ring World novel, with mountains flanking the inner walls, and with shadow squares creating day/night cycles on the surface.
  • In the X-Universe series, both Argon and Teladi trading stations and shipyards have large centrifuge sections to generate gravity for its occupants and workers. In Xtended Terran Conflict, all Teladi space stations have a rotating centrifuge at their core, along with several new ships having small centrifuges. In X Rebirth, Teladi capital ship freighters have a centrifuge section, and their sole space station is a colossal dozen-kilometer wide Ringworld Planet-esque space station; habitats run along the rim of the wheel, while the core of the station has docking and manufacturing centers.
  • In the expansions of Galactic Civilizations 2 the limitations of centrifugal force are discussed in the description for the "Artificial Gravity" tech. Apparently during the stargate era a Drengin troop transport once had an arm motor jam and toss thousands of troops out into space. A number of the default human ship designs have rotating sections, in particular the colony ship.
  • Many Earth ships in Nexus: The Jupiter Incident have large centrifuge sections to generate gravity for the crew. This is because it frequently takes weeks, if not months to travel anywhere in the Solar System. No one else uses these, as they have Artificial Gravity, Interplanetary Drives (that can shorten the same trip to days or even hours), and wormholes for intersystem jumps.
  • In Mass Effect, while artificial gravity is standard on most ships, the Citadel is mentioned as using centrifugal force, giving the Ward Arms a comfortable standard 1.02 G's, while the Presidium Ring is a lighter 0.3 G's. The Presidium itself also takes the form of a Stanford Torus.
  • The Elite series (up to Elite: Dangerous) features this in its Space Stations, as artificial gravity is nonexistent. Their spin makes docking difficult, as pilots must match the spin or crash into the airlock.

    Web Original 
  • The world of Pendor, from The Journal Entries of Kennet Shardik, is Niven's Ringworld with the Serial Numbers Filed Off, because Niven had threatened to sue Elf Sternberg over writing gay BDSM Known Space fanfic of the Kzin.
  • Darwin's Soldiers: Card of Ten takes place primarily on one of these.
  • Practically the only means of simulating gravity in Orion's Arm. There are even Banks Orbitals, though system-encompassing rings are impossible to construct. The archailects might be able to produce Artificial Gravity with spacetime engineering but they generally don't because it would be too inefficient (ex. a small black hole).

    Web Comics 
  • Schlock Mercenary: While Artificial Gravity via manipulating existing internal gravity sources is in regular use among the various space-faring sophont races, there are a few exceptions:
    • The space station Credomar is a cylinder designed to make use of this, but it's considered to be so inefficient that it's a mystery why anyone would build a space station like that. It's eventually revealed that Credomar wasn't really a space station, but a Wave Motion Gun turned into a space station to prevent its use as a weapon.
    • Earth's original stepping stone to the stars, MEL-Onenote  spins to generate its gravity. As a historical landmark, except for the crew quarters it retains centrifugal gravity.
  • The orbital space-cities featured in Episode Three of Space Kid.
  • In Questionable Content, the Space Station where Hannalore grew up is of the "pencil-and-donut" design, as seen best in #2111.

    Western Animation 
  • Archer "Space Race": The ISS Horizon has gravity thanks to its central cylinder spinning on its longitudinal axis. The central cylinder is divided up into separate sections that are spinning in opposite directions.

    Real Life 
  • Conventional centrifuges are a subversion, used not to create "gravity" where there is none, but to increase it.
  • A cancelled (but built) Japanese module for the ISS would have housed a small centrifuge unit for biological research.
  • While it is typical to see a spacecraft mount a separate spinning unit for centrifugal gravity ("pencil through donut"), it is possible to skip the moving parts and spin up the whole craft (a "tumbling pigeon" design), with the tricky bit being pointing an antenna at Earth all the while.
    • An even crazier design (albeit backed by Buzz Aldrin in his Mars proposals) is the "bola", which has two sections of the craft connected by cables to get the longest possible distance from the barycenter with the least required mass.
  • The crew of Skylab were able to simulate this somewhat, not by spinning their space station, but by running along a convenient ring of panels. See it here.
  • Carnival or theme park rides sometime incorporate the effect; a classic ride, called "The Rotor," placed riders inside a cylinder which was spun vertically. After sufficient speed was achieved, the floor would drop away, leaving the riders "stuck" to the wall. Some of the more "adventurous" would be able to actually sit upright against the wall, until the end of the ride.