Physics:Artificial gravity in fiction
Artificial gravity is a common theme in fiction, particularly science fiction.
Rotational gravity
In the film 2001: A Space Odyssey, and the same-named novel, a rotating centrifuge in the Discovery spacecraft provides artificial gravity. The people could walk, run, sit, or sleep along a curving "floor" that continually rotates inside the exterior shell of the spacecraft; the entry from the non-rotating part of the ship is through the centrifuge's central hub. To film the effect, a rotating circular set was used with the actors at the bottom; the set turned as the actors walked or jogged along the curved floor. One scene required one actor to be strapped in place while the set (and actor) rotated and the other actor walked towards him. The movie also features a large rotating space station; its full-scale interior set was a section of curved floor that did not rotate.
In 2010: Odyssey Two, the 1982 novel and second in a series of four by Arthur C. Clarke, the Leonov spacecraft does not have the "luxury" of gravity, yet in 2010: The Year We Make Contact, Peter Hyams' 1984 sci-fi film adaptation and sequel to 2001: A Space Odyssey, Syd Mead's Leonov spacecraft design in the movie features centrifugal force artificial gravity very similar to the Europa One mission in Europa Report, a 2013 science fiction film. In the 2010 movie, a Russian unmanned probe mysteriously disappears near the surface of Europa omitting the novel's premise of a space race to Jupiter with the joint Soviet-American mission following a faster Chinese ship, the Tsien that must land on Europa to refuel with water from the icy moon. The Tsien is ambushed and destroyed by an indigenous Europan life-form attracted to lights stranding the only survivor—also strikingly similar to events in Europa Report.
Larry Niven's novel Ringworld featured a gigantic habitat encircling a star, which created artificial gravity through rotation. Niven also makes a reference to the Coriolis effect when the protagonists see what looks like a giant eye above the horizon. When they get closer, they realise that it is in fact a hurricane, but rotating about an axis parallel to the ground rather than perpendicular to it. Large hurricanes on Earth rotate the way they do due to the Coriolis effect. A number of early Known Space and Man-Kzin Wars stories also make use of rotational gravity, prior to the adoption of "gravity polarizer" technology which generates artificial gravity fields.
In the Gundam universe, gigantic space habitats similar to O'Neill cylinders, called Colonies, are an important aspect to the plot. They spin to generate artificial gravity. Some ships, such as the Argama or Archangel, have rotating sections inside in living areas.
In the anime Cowboy Bebop, the Bebop possesses a ringed area that generates artificial gravity and is often seen being used (with the rest of the ship not rotating).
The book Rendezvous with Rama and the sequels featured an alien construct similar to an O'Neill habitat which was able to generate approximately 0.6 g on the intentionally habitable ground section. The plot employed significant use of the difference in strength of artificial gravity as an object approaches the center of the rotating cylinder.
In the television series Babylon 5, the Earth Alliance made extensive use of rotational gravity in its space stations and some larger military vessels, as well as civilian cruise ships. It has been suggested that the cruise ships would alter their rate of spin gradually en route to match the destination, helping to acclimate the passengers to the new gravity they would find upon arrival. Earlier Earth Force ships are shown using straps and harnesses to hold crew in place, and the Minbari later share the secret of artificial gravity as part of the Interstellar Alliance.
In the stories based on Sid Meier's Alpha Centauri, the Unity provided artificial gravity by spinning, though the game made allusions to less conventional technologies developed later on.
In John Varley's Gaea trilogy (Titan, Wizard, and Demon), the title world Gaea (one of a race of interstellar beings called "Titans"), being a living torus with a diameter of 1300 kilometers, spins at a rate of one revolution per sixty-one minutes, producing an apparent internal gravity of one-quarter g on the floor of the torus. While the 3 values of diameter (1300 km), rotational period (61 minutes; the basis of all time measurements in the wheel, called simply a "Rev"), and apparent gravity (1/4 g), are quoted consistently many times throughout all 3 novels, those 3 values are actually not mutually consistent. According to the standard formula for artificial gravity inside a spinning object (a=((2π)/T)2)R), an object with a rotational period (T) of 3660 seconds (61 minutes) and a radius (R) of 650,000 meters would create an acceleration (a) of 1.9156 m/sec2, which compared to standard earth gravity of 9.8 m/sec2, is 0.1955 g, or slightly less than 1/5 g not the 1/4 g stated often in the novels.
In Iain M. Banks's Culture series, Orbitals are made ten million kilometres in circumference so that they spin with a rate that gives a natural day/night cycle while the center is in orbit around a star.[1]
In the game Halo, the main location of the story is an artificial ringworld that creates artificial gravity by computer-controlled rotational spin (inspired by the aforementioned Larry Niven's novel Ringworld but also uses some form of field or other artificially generated gravity as it is stated in Halo: The Flood, the ring world does not spin nearly fast enough to create the amount of gravity it possesses. "Halo" (or "Installation 04") is approximately 10,000 km in diameter and is eventually destroyed by the same forces keeping it in operation. A fusion explosion weakens part of the ringworld, and centrifugal forces tear the ring apart.
In The Martian and the film of the same title, the Hermes spacecraft achieves artificial gravity by design; it employs a ringed structure, at whose periphery forces around 40% of Earth's gravity are experienced. Such artificial gravity is similar in strength to the gravity on Mars. At the center of the ringed structure, lack of gravity makes the astronauts practically weightless.
In the Expanse series by James S. A. Corey, space stations generate artificial gravity by rotating, as do spun-up, hollowed-out asteroids, usually at around 0.3 g. Moving ships under constant thrust also simulate gravity by linear acceleration.
In the video game Elite: Dangerous, the various large space stations seen throughout the galaxy rotate in order to create artificial gravity for the people who live and work on them. One class of these stations is the Coriolis starport, in reference to the eponymous effect it uses to generate gravity.
In the movie Interstellar (film) co-produced by Christopher Nolan, the Endurance space stations and capsules create artificial gravity by rotating at a certain rotational frequency to simulate gravity. At the outer ring of the structure, the gravity experienced is similar to that on Earth.
In the TV show Away (TV series), the spaceship shown in the movie has artificial gravity in the crew quarters, which are orbiting the main part of the ship which does not have artificial gravity.
In the movie Stowaway the spacecraft creates artificial gravity by rotation with the crew module and booster connected by cables, according to the writers this began as a way to design away problems of shooting simulated zero gravity and ultimately lead to an creating an important part of the story where crew have to 'climb' the cables between both modules.
Field generators
In many science fiction stories, there are artificial gravity generators that create a gravitational field based on a mass that does not exist. It helps the story by creating a more Earth-like spaceship, and in the case of a movie or television program, it reduces production costs by eliminating the need for special effects to simulate weightlessness.
In the Star Trek universe, artificial gravity is achieved by the use of "gravity plating" embedded in a starship's deck.
- In the Star Trek: Enterprise episode "In a Mirror, Darkly", the gravity plating of the USS Defiant is used to fend off a Gorn attack by greatly increasing the ship's gravity in one section. The Gorn attacker was forced down to the floor and immobilized, where the "Mirror" Jonathan Archer easily killed him.
- Benjamin Sisko once built a replica of an ancient Bajoran solar-sailer spacecraft. As these craft were not normally equipped with artificial gravity, Sisko added gravity plating to make it easier for him and Jake to pilot the vessel. (DS9 episode "Explorers")
- Star Trek novels more specifically explain the specifics of artificial gravity technology. It is often explained as making use of virtual gravitons.
In Gene Roddenberry's Andromeda, set thousands of years in the future, gravity field generators not only provide gravity for the people inside the ship, but also reduce inertial mass of ships such as the Andromeda Ascendant to just under a kilogram. This greatly increases the efficiency of their Magneto-Plasma Dynamic Drive, allowing them to go from a stop to percentages of light speed very quickly. It can also be easily manipulated to do things like increase gravity and immobilize intruders (though prepared intruders can use an antigravity harness to prepare for this possibility), and reversed to expel things from the ship.
In the anime Dragon Ball Z, gravity simulation plays a key part in various characters' training regime. It is also used to demonstrate the characters' increasing strength. For example, when Goku first arrives on King Kai's planet, he is nearly crushed by the gravity, which is ten times that of Earth's. By the end of his visit, nearly a year later, he is able to move at great speed under such conditions. This method of training gradually appears more and more in the universe, and the gravity gets stronger as well. Ten times Earth's gravity goes from a seemingly indomitable level of opposition to nothing, and several hundred times Earth's gravity becomes the standard. Vegeta even had a Gravity Room built into his house.
In the Doctor Who story The Sontaran Experiment, a Sontaran used similar technology to make a bar above a human very heavy, so that his friends had to lift it up with as much force as they could to prevent him being crushed. The Sontaran gradually increased the bar's weight as part of an experiment to study not only their physical strength but also their loyalty, as their friend had recently attempted to betray them.
In the BioWare series Mass Effect, the eponymous "mass effect" is responsible for the manipulation of gravity or kinetic forces (if the mass effect field is alternating), caused by subjecting a quantity of fictional "element zero" to an electric current. A negative current reduces the mass of anything within the field, a positive current increases mass, and an alternating current will create a barrier force of immense power that can shield or crush anything the force is directed at. Mass effect is used in faster than light travel, artificial gravity on spacecraft, weapon technology, kinetic barriers and shields, and much more. Individuals exposed to element zero are known as "biotics," the nodules of element zero embedded into their nervous systems allow them to use neural impulses to create mass effect fields themselves if the power of the element is amplified with a biotic amp, granting specific types of abilities such as certain types of telekinesis. An individual exposed to this "eezo" would often rather cause cancer.
In the video game Dead Space, artificial gravity plates are used to simulate an Earth-like environment in outer space. In several levels, gravity plating is off and the player has to navigate in weightlessness using 'Zero-Gravity Boots', similar to magnetic boots. Defective gravity plates are also encountered sometimes, which push objects upward rather than downward with great force, killing the player or enemies instantly if they step on them.
In the 2014 film, Guardians of the Galaxy, Peter Quill uses a device called a "Gravity Mine" which creates a powerful short-range artificial gravity field that attracts all nearby objects towards it.
See also
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