A megastructure, in science fiction and speculative (or exploratory) engineering, is an enormous self-supporting artificial construct.^{[citation needed]} The definition is often informal and varies from source to source, but generally requires at least one dimension to be in the hundreds of kilometers.^{[citation needed]} Other criteria such as rigidity or contiguousness are sometimes also applied, so large clusters of associated smaller structures may or may not qualify.^{[citation needed]} The products of megascale engineering or astroengineering are megastructures. Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Exploratory engineering is a term coined by K. Eric Drexler to describe the process of designing and analyzing detailed hypothetical models of systems that are not feasible with current technologies or methods, but do seem to be clearly within the bounds of what science considers to be possible within the... Megascale engineering is defined as engineering structures on an enormous scale. ... Astroengineering is the construction of megastructures in space by technologically advanced beings. ...

Megastructures are also an architectural concept popularized in the 1960s where a city could be encased in a single building, or a relatively small number of buildings interconnected together. Megastructures are an architectural concept popularized in the 1960s where a city could be encased in a single building, or a relatively small number of buildings interconnected together. ... This article is about the built environment. ...

Megastructures often play a part in the plot or setting of science fiction movies and books.

Existing megastructures

The Great Wall of China is an example of a megastructure. This picture was taken near Beijing in winter.

There are structures on Earth that may be considered megastructures, such as Download high resolution version (2048x1299, 2189 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2048x1299, 2189 KB) Wikipedia does not have an article with this exact name. ... The Great Wall of China (Simplified Chinese: ; Traditional Chinese: ; Pinyin: ; literally Long wall) or (Simplified Chinese: ; Traditional Chinese: ; Pinyin: ; literally The long wall of 10,000 Li (里)[1]) is a series of stone and earthen fortifications in China, built, rebuilt, and maintained between the 5th century BC and the 16th... Beijing (Chinese: 北京; pinyin: BÄ›ijÄ«ng; IPA: ;  ), a metropolis in northern China, is the capital of the Peoples Republic of China (PRC). ...

• The Great Wall of China is a human-built megastructure, a few meters wide and 6,352 km in length, about 4,160,000 m²

• The Rice Terraces of the Philippine Cordilleras, a 10,360 square kilometer (4,000 square mile) sprawling agricultural landscape carved in the mountains by free tribesmen of Ifugao some 6,000 to 2,000 years ago.

Networks of roads or railways, and collections of buildings (cities and associated suburbs), are usually not considered megastructures, despite frequently qualifying based on size. However, an ecumenopolis might qualify. The Great Wall of China (Simplified Chinese: ; Traditional Chinese: ; Pinyin: ; literally Long wall) or (Simplified Chinese: ; Traditional Chinese: ; Pinyin: ; literally The long wall of 10,000 Li (里)[1]) is a series of stone and earthen fortifications in China, built, rebuilt, and maintained between the 5th century BC and the 16th... To aid in the comparison of sizes of different geographic regions, areas between 1 km² (100 hectares) and 10 km² (1000 hectares) are listed below. ... A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ... The Banaue Rice Terraces The Banaue Rice Terraces are 2000-year-old terraces that were carved into the mountains of Ifugao in the Philippines by ancestors of the Batad people. ... The surface of the fictional world of Coruscant, the capital world of the Star Wars galaxy, and a popular example of an ecumenopolis. ...

Proposed megastructures

• Atlantropa, a hydroelectric dam to be built across the Strait of Gibraltar, and the lowering of the surface of the Mediterranean Sea by as much as 200 metres.

Atlantropa was a gigantic engineering and colonization project devised by the German architect Herman Sörgel in the 1920s and propagated by him until his death in 1952. ... Hydroelectric dam diagram The waters of Llyn Stwlan, the upper reservoir of the Ffestiniog Pumped-Storage Scheme in north Wales, can just be glimpsed on the right. ... The Strait of Gibraltar as seen from space. ... Composite satellite image of the Mediterranean Sea. ...

Theoretical megastructures

Stellar scale

A cut-away diagram of an idealized Dyson shell—a variant on Dyson's original concept—1 AU in radius.

Most stellar scale Megastructure proposals are designs that make use of the energy from a sun-like star while possibly still providing gravity or other attributes that would make it attractive for an advanced civilization. Image File history File links Dyson_Sphere_Diagram. ... Image File history File links Dyson_Sphere_Diagram. ... A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ... The astronomical unit (AU or au or a. ...

• The Alderson disk is a theoretical structure in the shape of a disk, where the outer radius is equivalent to the orbit of Mars or Jupiter and the thickness is several thousand miles. A civilization could live on either side, held by the gravity of the disk and still receive sunlight from a star bobbing up and down in the middle of the disk.
• A Dyson sphere (also known as a Dyson Shell) refers to a structure or mass of orbiting objects that completely surrounds a star to make full use of its solar energy.
• The Niven ring is an artificial ring with a diameter roughly equal to the radius of the Earth's orbit. A star is present in the center and the ring spins to provide artificial gravity.
• An Orbital is a space habitat similar to but much smaller than a Niven Ring. Instead of being centered around a star, it's orbiting a star, thus it's diameter is typically in the Order of magnitude of a star. By giving a tilt to it's orbit, there's a convenient day and night experience on it's surface.
• A Matrioshka brain is a collection of multiple Concentric Dyson Spheres which make use of different wavelengths of light.
• A Stellar engine either uses the temperature difference between a star and interstellar space to extract energy or serves as a Shkadov thruster.
  • A Shkadov thruster accelerates an entire star through space by selectively reflecting or absorbing light on one side of it.
• Topopolis (also known as Cosmic Spaghetti) is a large tube that rotates to provide artificial gravity.

An Alderson disk (named after Dan Alderson, its originator) is an artificial astronomical megastructure, like Nivens Ringworld or a Dyson sphere. ... A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ... A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ... Larry Nivens Ringworld, seen from space. ... Illustration of an orbital created by Giuseppe Gerbino. ... An order of magnitude is the class of scale or magnitude of any amount, where each class contains values of a fixed ratio to the class preceding it. ... A Matrioshka Brain is a hypothetical megastructure, based on the Dyson sphere, of immense computational capacity. ... Concentric objects share the same center, axis or origin with one inside the other. ... // A stellar engine is a class of hypothetical megastructures which use a stars radiation to create usable energy. ... A Shkadov thruster is a hypothetical megascale reaction engine that can be used to control the motion of a star. ... // A stellar engine is a class of hypothetical megastructures which use a stars radiation to create usable energy. ... Interior view of a topopolis with windows A topopolis is a tube-like space habitat, rotating to produce gravity on the inner surface, which is extended into a loop around local star. ...

Planetary scale

• Globus Cassus is a hypothetical proposed project for the transformation of Planet Earth into a much bigger, hollow, artificial world with the ecosphere on its inner surface. This model serves as a tool to understand the World's real functioning processes.

A top and side view of the Globus Cassus Globus Cassus is a utopian project for the transformation of Planet Earth into a much bigger, hollow, artificial world with an ecosphere on its inner surface. ...

Orbital structures

• The Bernal sphere is a proposal for a space colony with a maximum diameter of 16 kilometers.
• The Stanford torus is a different design with a diameter just under 1.7 kilometers.
• The O'Neill cylinder is yet another space colony proposal.

A Bernal sphere is a type of space habitat intended as a long-term home for permanent residents, first proposed in 1929 by Dr. John Desmond Bernal. ... Exterior view of a Stanford torus. ... A pair of ONeill cylinders The ONeill cylinder is a space habitat design proposed by physicist Gerard K. ONeill in his book, The High Frontier. ...

Trans-orbital structures

One concept for the space elevator has it tethered to a mobile seagoing platform.

• A Skyhook is a tall structure that is held standing by something other than the materials connecting it to the ground.
  • A Space fountain is held up by the momentum of a working fluid which is shot up to the top at high speeds.
  • A Space elevator is held up by the angular acceleration of the top part of the structure which lies above a Geosynchronous orbit.
• Rotovator proposals call for a large tether to transfer momentum between spacecraft in transit.

Download high resolution version (2048x1536, 71 KB)A conceptual drawing of a space elevator lifting off. ... Download high resolution version (2048x1536, 71 KB)A conceptual drawing of a space elevator lifting off. ... A space elevator would consist of a cable anchored to the Earths surface, reaching into space. ... For other uses, see Skyhook (disambiguation). ... The space fountain concept is a proposed form of space elevator that does not require the structure to be in geosynchronous orbit, and does not rely on tensile strength for support. ... A space elevator would consist of a cable anchored to the Earths surface, reaching into space. ... It has been suggested that this article or section be merged with geostationary orbit. ... Artists conception of satellite with a tether Tether propulsion uses long, strong strings (known as tethers) to change the orbits of spacecraft. ...

Fictional megastructures

Stellar scale

• The Dyson shell (including its variation, the Ringworld) has appeared in many works of fiction, including the Star Trek universe.
• Larry Niven's series of novels about his Ringworld centered around, and originated the concept of the Ringworld, or Niven ring.
• In the manga Blame! the Megastructure is a vast and chaotic complex of metal, concrete, stone, etc, that covers the whole Earth and assimilates even the Moon. There is even a clue by the end of this manga that suggests the assimilation of Jupiter. The Megastructure continues to expand by itself, being built by robots called builders. The whole history of the manga takes place deep inside of the structure, where there is no sea or sky, and the characters find themselves climbing up thousand of kilometers of labyrinths searching for Net Terminal Genes. It has been suggested by Tsutomu Nihei himself that the Megastructure is actually a growing dyson sphere of gargantuan proportions.(Speculated to be roughly the size of Jupiter's planetary orbit.)
• In White Light by William Barton and Michael Capobianco, a Topopolis is presented as taking over the entire universe.
• In the Heechee books by Frederik Pohl the race of pure energy beings called The Foe have constructed the Kugelblitz, a black hole made of energy and not matter.
• In the Xeelee series of books by Stephen Baxter, the eponymous alien race constructed the Ring, a megastructure made of cosmic string, spanning over 10 million light - years.

Diagram of an idealized Dyson shell of 1 AU radius A Dyson sphere is a hypothetical megastructure first described in 1959 by the physicist Freeman Dyson in a short paper published in the journal Science entitled Search for Artificial Stellar Sources of Infra-Red Radiation. It is an artificial hollow... The current Star Trek franchise logo Star Trek is an American science fiction entertainment series and media franchise. ... This article does not cite any references or sources. ... Ringworld is a Hugo and Nebula award-winning 1970 science fiction novel by Larry Niven, set in his Known Space universe. ... Larry Nivens Ringworld, seen from space. ... This article is about the comics published in East Asian countries. ... Serialized in Afternoon Original run 1998 – 2003 No. ... Net Terminal Genes are a plot device in the manga Blame! by Tsutomu Nihei. ... Tsutomu Nihei (弐瓶 勉 Nihei Tsutomu, born 1971) is a Japanese manga artist. ... A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ... William Renald Barton III is an American science fiction writer born on September 28, 1950. ... Michael Victor Capobianco (born November 12, 1950) is an American science fiction writer. ... Interior view of a topopolis with windows A topopolis is a tube-like space habitat, rotating to produce gravity on the inner surface, which is extended into a loop around local star. ... The Heechee are a fictional alien race from the science fiction works of Frederik Pohl. ... Frederik George Pohl, Jr. ... Stephen Baxter (born in Liverpool, November 13, 1957) is a British hard science fiction author. ... Stephen Baxter (born in Liverpool, 13 November 1957) is a British hard science fiction author. ... Ring is a 1994 science fiction book by author Stephen Baxter. ... A cosmic string is a hypothetical 1-dimensional topological defect in the fabric of spacetime. ...

Planetary scale

Death Star, a fictional megastructure
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• Death Star of Star Wars fame
• Borg Transwarp Hub and Unicomplexes
• Buster Machine III from Gunbuster.
• Culture Orbital
• Trantor, the capital of an interstellar empire in Isaac Asimov's Foundation series, is a planet entirely covered in one huge metal clad building, with only one small green space: the Emperor's palace grounds
• The Ori Supergate seen in a number of episodes of Stargate SG1 could be classed as a megastructure
• In The Hitchhiker's Guide to the Galaxy series, Earth, as well as other planets, were artificial megastructures. Earth was intended to function as a gigantic computer, and was built by a race of beings who made their living by manufacturing other planets.
• The Star Forge from Knights of the Old Republic
• Despite being sentient, the Transformers universes Unicron's 'metal planet' form is comparable to a megastructure.
• The seven Halos from the Halo: Combat Evolved universe are 10,000 km wide rings.
• In the Robotech Sentinels novels, Haydon IV is an artificially constructed cyber-planet with android citizens.
• In the Invader Zim episode "Planet Jackers", two aliens surround the Earth with a fake sky in order to throw it into their sun.
• Nightmare's fortress from Kirby: Right Back at Ya! can be classified as a megastructure because of the fact that it's the size of a small planet.
• In several works, Arthur C. Clarke writes about a colossal hollow tube, first described in "Rendezvous with Rama" (1973), and inhabited by different races.

Image File history File links Death_Star. ... Image File history File links Death_Star. ... This article needs additional references or sources for verification. ... This article needs additional references or sources for verification. ... Star Wars is an epic science fantasy saga and fictional universe created by George Lucas during the late 1970s. ... The Unicomplex, a huge Borg complex in the Delta Quadrant. ... Buster Machine III (バスターマシン三号）, also known as the Black Hole Bomb（ブラックホール爆弾）, is a superweapon of megastructure scale that appears in the science fiction anime OVA Aim for the Top! Gunbuster. ... Gunbuster, known in Japan as Aim for the Top! ) is a six episode anime OVA series created by Gainax in 1988. ... Illustration of an orbital created by Giuseppe Gerbino. ... The Ori (pronounced OR-eye) are characters on the fictional Stargate SG-1 television program. ... A Supergate near a moon, with the Prometheus in the foreground . A closer view of the Supergate Spoiler warning: This article is about the device in the fictional Stargate universe. ... Stargate SG-1 Cast Stargate SG-1 is a television series based upon the 1994 science fiction movie Stargate. ... The cover of the first novel in the Hitchhikers series, from a late 1990s printing. ... Combatants Galactic Republic Sith Commanders Revan, Admiral Forn Dodonna, Master Vandar Tokare, Carth Onasi Sith Lord Darth Malak â€  and Sith apprentice Bastila Shan Strength Ground: Revan, Jedi, during the end Bastila Shan, Canderous Ordo, Jolee Bindo, Juhani, HK-47, Jedi Knights Space:21+ Old Republic medium cruisers, Aurek Fighters, Republic... Star Wars: Knights of the Old Republic (KotOR) is an RPG video game originally for the Microsoft Xbox and later for PCs running Microsoft Windows. ... Figure 1:Three-phase pole-mounted step-down transformer. ... Unicron is a fictional character from the Transformers universes and toyline. ... Halos are fictional megastructures in the Halo video game series. ... Halo: Combat Evolved, or simply Halo, is a video game in the first-person shooter (FPS) genre, created by the Microsoft-owned Bungie Studios. ... Robotech science fiction and anime universe. ... Invader Zim is an American animated television series created by comic book writer/artist Jhonen Vasquez and aired on Nickelodeon. ... Planet Jackers is an episode of the television series Invader Zim. ... Nightmare Power Orb Nightmares final form Nightmare, also known as the Cloaked Nightmare according to the Star Rod trophy in Super Smash Bros. ... Kirby: Right Back at Ya!, known as Hoshi no Kirby (星のカービィ Hoshi no Kaabi, literally Kirby of the Stars) in Japan, is an anime series based on Nintendos Kirby franchise. ... Rama is a mysterious extraterrestrial vessel that is the subject and setting of the science-fiction novel Rendezvous with Rama by Arthur C. Clarke, and the later sequel trilogy by Clarke and Gentry Lee: Rama II, Garden of Rama, and Rama Revealed. ... Rendezvous with Rama is a novel by Arthur C. Clarke first published in 1972. ...

Megascale structures

Structures that might not be classified as "Megastructures" because they do not meet the requirements, but are indeed "Mega" sized structures/constructions.

Stellar scale

• Dyson Bubble - Collection of separate constructions.
• Dyson Swarm - Collection of separate constructions.

A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ... A cut-away diagram of an idealized Dyson shell—a variant on Dysons original concept—1 AU in radius. ...

See also

• Supertall
• Arcology
• Megaproject

This article does not cite any references or sources. ... The Try2004 Hyperstructure or Megacity as featured on the Discovery Channels Extreme Engineering programs. ... This article does not cite any references or sources. ...

External links

• Megastructures in science fiction index by Ross Smith.