A cut-away diagram of an idealized Dyson shell, a variant on Dyson's original concept, with a radius of 1 AU. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the

A Dyson sphere (or shell as it appeared in the original paper) is a hypothetical megastructure originally described by Freeman Dyson. A megastructure is a built structure typically at least 1000 kilometers in length -- in other words at least 1 Megameter, hence the name Freeman John Dyson FRS (born December 15, 1923) is an English-born American theoretical Physicist and Mathematician, famous for his Such a "sphere" would be a system of orbiting solar power satellites meant to completely encompass a star and capture most or all of its energy output. A solar power satellite, or SPS or Powersat, as originally proposed would be a Satellite built in High Earth orbit that uses Microwave A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth Dyson speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization, and proposed that searching for evidence of the existence of such structures might lead to the detection of advanced intelligent extraterrestrial life. Extraterrestrial life is Life originating outside of the Earth.

Since then, other variant designs involving building an artificial structure — or a series of structures — to encompass a star have been proposed in exploratory engineering or described in science fiction under the name "Dyson sphere". 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 These later proposals have not been limited to solar power stations — many involve habitation or industrial elements. A space habitat, also called space colony, orbital colony, space city, or space settlement is a Space station intended as a Most fictional depictions describe a solid shell of matter enclosing a star (see diagram at right), which is considered the least plausible variant of the idea (see below).

Origin of concept

See also: Future energy development

The concept of the Dyson sphere was the result of a thought experiment by physicist and mathematician Freeman Dyson, where he noted that every human technological civilization has constantly increased its demand for energy. Energy development is the ongoing effort to provide sufficient Primary energy sources and secondary Energy forms to meet civilization's needs A thought experiment (from the German Gedankenexperiment) is a proposal for an Experiment that would test a Hypothesis or Theory Freeman John Dyson FRS (born December 15, 1923) is an English-born American theoretical Physicist and Mathematician, famous for his He reasoned that if human civilization were to survive long enough, there would come a time when it required the total energy output of the sun. Thus, he proposed a system of orbiting structures designed to intercept and collect all energy produced by the sun. Dyson's proposal did not detail how such a system would be constructed, but focused only on issues of energy collection.

Dyson is credited with being the first to formalize the concept of the Dyson sphere in his 1959 paper "Search for Artificial Stellar Sources of Infra-Red Radiation", published in the journal Science. Science is the Academic journal of the American Association for the Advancement of Science and is considered one of the world's most prestigious Scientific ^[1] However, Dyson was inspired by the mention of the concept in the 1937 science fiction novel Star Maker, by Olaf Stapledon, and possibly by the works of J. D. Bernal and Raymond Z. Gallun who seem to have explored similar concepts in their work. A novel (from Italian novella, Spanish novela, French nouvelle for "new" "news" or "short story William Olaf Stapledon ( May 10, 1886 &ndash September 6, 1950) was a British philosopher and author of several influential works John Desmond Bernal FRS (born 10 May 1901 died 15 September 1971 was an Irish-born scientist known for pioneering X-ray crystallography. Raymond Zinke Gallun ( March 22, 1911 - April 2, 1994) was an early Science fiction Writer. ^[2]

Feasibility

While it is believed that some of the design variants commonly described — specifically those based on the Dyson shell — are impractical, if not physically impossible, design variants of the sphere based on orbiting satellites or solar sails do not require any major theoretical breakthroughs in our basic scientific understanding for their construction. Deployment of spacecraft and satellites using photovoltaics might be seen as a first small steps towards building a Dyson swarm (see below for differences between these sub-types). A spacecraft is a Vehicle or machine designed for Spaceflight. This article is about artificial satellites For natural satellites also known as moons see Natural satellite. Photovoltaics ( PV) is the field of technology and research related to the application of Solar cells for Energy by converting Sunlight directly ^[3] However, creating and deploying energy gathering spacecraft and satellites in the numbers needed to create a solar system sized integrated energy gathering system are well beyond our present-day industrial needs or capabilities. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. It is also likely that there are unforeseen industrial scaling difficulties in such a construction project, and that our current understanding of industrial automation is insufficient to build the self-maintaining systems needed for the sphere's upkeep. Automation ( Ancient Greek: = self dictated) roboticization or industrial automation or Numerical control is the use of Control systems

Variants

In many fictional accounts, the Dyson sphere concept is most often interpreted as an artificial hollow sphere of matter around a star (see diagram at top of page). "Globose" redirects here See also Globose nucleus. A sphere (from Greek σφαίρα - sphaira, "globe Matter is commonly defined as being anything that has mass and that takes up space. This perception is a misinterpretation of Dyson's original concept. In response to letters prompted by his original paper, Dyson replied, "A solid shell or ring surrounding a star is mechanically impossible. The form of 'biosphere' which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star. "^[4]

Dyson swarm

A Dyson Ring — the simplest form of the Dyson Swarm — to scale. Orbit is 1 AU in radius, collectors are 1. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the 0×10⁷ km in diameter (~25× the Earth–Moon distance), spaced 3 degrees from center to center around the orbital circle.

A relatively simple arrangement of multiple Dyson Rings of the type pictured above, to form a more complex Dyson Swarm. Rings' orbital radii are spaced 1. 5×10⁷ km with regards to one another, but average orbital radius is still 1 AU. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the Rings are rotated 15 degrees relative to one another, around a common axis of rotation.

The variant closest to Dyson's original conception is the "Dyson swarm". It consists of a large number of independent constructs (usually solar power satellites and space habitats) orbiting in a dense formation around the star. A solar power satellite, or SPS or Powersat, as originally proposed would be a Satellite built in High Earth orbit that uses Microwave Space colonization (also called space settlement, space humanization, Space habitation, etc This approach to the construction of a Dyson sphere has several advantages: the components making it up could range widely in individual size and design, and such a sphere could be constructed incrementally over a long period of time. ^[3] Various forms of wireless energy transfer could be used in order to transfer energy between constructs. Wireless energy transfer or wireless power transmission is the process that takes place in any system where Electrical energy is transmitted from a power

Such a swarm is not without drawbacks. The nature of orbital mechanics would make the arrangement of the orbits of the swarm extremely complex. Orbital mechanics or astrodynamics is the application of Celestial mechanics to the practical problems concerning the motion of Rockets and other Spacecraft The simplest such arrangement is the Dyson ring in which all such structures share the same orbit. More complex patterns with more rings would intercept more of the star's output, but would result in some constructs eclipsing others periodically when their orbits overlap. ^[5] Another potential problem is the increasing loss of orbital stability as adding more orbiting constructs increases the probability of orbital perturbations of other constructs.

As noted below, such a cloud of collectors would alter the light emitted by the star system, but as can be seen here, it is unlikely that such an alteration would be complete, and that some of the star's natural light would still be present in the system's emitted spectrum. A Dyson sphere (or shell as it appeared in the original paper is a hypothetical Megastructure originally described by Freeman Dyson. ^[1]

Dyson shell

The variant of the Dyson sphere most often depicted in fiction is the "Dyson shell": a uniform solid shell of matter around the star (see diagram at top of page). This is a listing of the use of the Dyson sphere concept in popular fiction. ^[6] Unlike the Dyson swarm, such a structure would completely alter the emissions of the central star, and would intercept 100% of the star's energy output. Such a structure would also provide an immense surface which many envision being used for habitation, if the surface could be made habitable.

A spherical shell Dyson sphere in our solar system with a radius of one astronomical unit, so that the interior surface would receive the same amount of sunlight as Earth does per solid angle, would have a surface area of at least 2. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the The solid angle, Ω, is the angle in three-dimensional space that an object Subtends at a point 72x10¹⁷ km², or around 600 million times the surface area of the Earth. Square Kilometre ( US spelling square kilometer) symbol km2, is a decimal multiple of the SI unit of This would intercept the full 4x10²⁶ watts of the Sun's output; other variant designs would intercept less, but the shell variant represents the maximum possible energy captured for our solar system at this point of the Sun's evolution. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. Stellar evolution is the process by which a Star undergoes a sequence of radical changes during its lifetime ^[6] To put this figure in perspective, it is approximately 3. 3x10¹³ times the total energy consumption of humanity in 1998 which was 1. 2x10¹³ W. ^[7]

There are several serious theoretical difficulties with the solid shell variant of the Dyson sphere:

Such a shell would have no net gravitational interaction with its englobed sun (see Shell theorem), and could drift in relation to the central star. In Classical mechanics, the shell theorem gives gravitational simplifications which can be applied to objects inside or outside a spherically symmetrical body If such movements went uncorrected, they could eventually result in a collision between the sphere and the star — most likely with disastrous results. Such structures would need either some form of propulsion to counteract any drift, or some way to repel the surface of the sphere away from the star. ^[8]

For the same reason, such a shell would have no net gravitational interaction with anything else inside it. The contents of any biosphere placed on the inner surface of a Dyson shell would not be attracted to the sphere's surface and would simply fall into the star. It has been proposed that a biosphere could be contained between two concentric spheres, placed on the interior of a rotating sphere (in which case, the force of artificial "gravity" is perpendicular to the axis of rotation, causing all matter placed on the interior of the sphere to pool around the equator, effectively rendering the sphere a Niven ring for purposes of habitation, but still fully effective as a radiant energy collector) or placed on the outside of the sphere where it would be held in place by the star's gravity. Ringworld is a Hugo and Nebula award-winning 1970 Science fiction novel by Larry Niven, set in his Known Space ^[9][10] In such cases, some form of illumination would have to be devised, or the sphere made at least partly transparent, as the star's light would otherwise be completely hidden. ^[11]

If assuming a radius of one AU, then the compressive strength of the material forming the sphere would have to be immense. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the Any arbitrarily selected point on the surface of the sphere can be viewed as being under the pressure of the base of a dome 1 AU in height under the Sun's gravity at that distance. Indeed it can be viewed as being at the base of an infinite number of arbitrarily selected domes, but as much of the force from any one arbitrary dome is counteracted by those of another, the net force on that point is immense, but finite. No known or theorized material is strong enough to withstand this pressure, and form a rigid, static sphere around a star. ^[12] It has been proposed by Paul Birch (in relation to smaller "Supra-Jupiter" constructions around a large planet rather than a star) that it may be possible to support a Dyson shell by dynamic means similar to those used in a space fountain. Paul Birch (born 25 May 1956) is a British author engineer and scientist who has worked in Radioastronomy and Satellite communications, and A space fountain 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 ^[13] Masses traveling in circular tracks on the inside of the sphere, at velocities significantly greater than orbital velocity, would press outwards due to centrifugal force. For a Dyson shell of 1 AU radius around a star with the same mass as the Sun, mass traveling ten times orbital velocity (300 km/s) would support 99 (a=v²/r) times its own mass in additional shell structure. The arrangement of such tracks suffers from the same difficulties as arranging the orbits of a Dyson swarm, and it is unclear how much energy would be consumed ensuring the velocity of the masses was maintained.

Also if assuming a radius of one AU, then there may not be sufficient building material in the Solar system to construct a Dyson shell. Dyson's original estimate was that there was enough material in the Solar system for a 1 AU shell 3 meters thick, but this included hydrogen and helium which are unlikely to be much use as building material, although additional building material might be manufactured if elements such as hydrogen and helium could be transmuted into heavier elements through nuclear fusion. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus Anders Sandberg estimates that there is 1. Anders Sandberg (born July 11 1972) is a science debater futurist, transhumanist, and author 82×10²⁶ kg of easily usable building material in the Solar system, enough for a 1 AU shell with a mass of 600 kg/m²—about 8–20 cm thick depending on the density of the material. This includes the cores of the gas giants, which may be hard to access; the inner planets alone provide only 11. 79×10²⁴ kg, enough for a 1 AU shell with a mass of just 42 kg/m². ^[14]

Dyson bubble

A Dyson Bubble: an arrangement of statites around a star, in a non-orbital pattern. A statite (a Portmanteau of static and satellite) is a hypothetical type of artificial Satellite that employs a Solar sail to Note: so long as a statite has an unobstructed line-of-sight to its star, it can hover at any point in space near its star. This relatively simple arrangement is only one of an infinite number of possible statite configurations, and is meant as a contrast for a Dyson Swarm only. Statites are pictured as the same size as the collectors pictured above, and arranged at a uniform 1 AU distance from the star. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the

A third type of Dyson sphere is the "Dyson bubble". It would be similar to a Dyson swarm, composed of many independent constructs (usually solar power satellites and space habitats) and likewise could be constructed incrementally. A solar power satellite, or SPS or Powersat, as originally proposed would be a Satellite built in High Earth orbit that uses Microwave Space colonization (also called space settlement, space humanization, Space habitation, etc

Unlike the Dyson swarm, the constructs making it up are not in orbit around the star, but would be statites—satellites suspended by use of enormous light sails using radiation pressure to counteract the star's pull of gravity. A statite (a Portmanteau of static and satellite) is a hypothetical type of artificial Satellite that employs a Solar sail to Solar sails (also called light sails or photon sails, especially when they use Light sources other than the Sun) are a proposed form of Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation. Such constructs would not be in danger of collision or of eclipsing one another; they would be totally stationary with regard to the star, and independent of one another. As the ratio of radiation pressure and the force of gravity from a star are constant regardless of the distance (provided the statite has an unobstructed line-of-sight to the surface of its star^[15]), such statites could also vary their distance from their central star. Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation.

The practicality of this approach is questionable with modern material science, but cannot yet be ruled out. Materials Science or Materials Engineering is an interdisciplinary field involving the properties of matter and its applications to various areas of Science and A statite deployed around our own sun would have to have an overall density of 0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 78 grams per square meter of sail. ^[8] To illustrate the low mass of the required materials, consider that the total mass of a bubble of such material 1 AU in radius would be about 2. 17×10²⁰ kg, which is about the same mass as the asteroid Pallas. TemplateInfobox Planet. --> 2 Pallas (ˈpæləs, or as Παλλάς) is one of the largest ^[14]

Such a material is currently beyond our ability to produce; the lightest carbon-fiber light sail material currently produced has a density — without payload — of 3 g/m², or about five times heavier than would be needed to construct a solar statite. Solar sails (also called light sails or photon sails, especially when they use Light sources other than the Sun) are a proposed form of ^[16]

However, there has been some speculation about the creation of ultra light carbon nanotube meshes through molecular manufacturing techniques whose density would be below 0. See also Graphene, Buckypaper Carbon nanotubes (CNTs are Allotropes of carbon with a nanostructure that can have a length-to-diameter Molecular nanotechnology (MNT is the concept of engineering functional mechanical systems at the molecular scale 1 g/m². ^[17] If production of such materials on an industrial scale is feasible, and such materials could be used in light sails, the average sail density with rigging might be kept to 0. Rigging (from Anglo-Saxon wrigan or wringing, "to clothe" is on Sailboats and Sailing ships the collection of 3 g/m² (a "spin stabilized" light sail requires minimal additional mass in rigging). Solar sails (also called light sails or photon sails, especially when they use Light sources other than the Sun) are a proposed form of Rigging (from Anglo-Saxon wrigan or wringing, "to clothe" is on Sailboats and Sailing ships the collection of If such a sail could be constructed at this areal density, a space habitat the size of the L5 Society's proposed O'Neill cylinder—500 km², with room for over 1 million inhabitants, massing 3×10⁶ tons—could be supported by a circular light sail 3,000 km in diameter, with a combined sail/habitat mass of 5. For computer memory comparisons see Computer storage density. A space habitat, also called space colony, orbital colony, space city, or space settlement is a Space station intended as a The L5 Society was founded in 1975 by Carolyn and Keith Henson to promote the space colony ideas of Dr The O'Neill cylinder also called Island Three is a Space habitat design proposed by physicist Gerard K Units of mass There are three similar units of Mass called the ton: Long ton (simply ton in countries such as the United 4×10⁹ kg. ^[18] For comparison, this is just slightly smaller than the diameter of Jupiter's moon Europa (although the sail is a flat disc, not a sphere), or the distance between San Francisco and Kansas City. TemplateInfobox Planet.--> Europa (jʊˈroʊpə; or as The City and County of San Francisco is the fourth most populous city Kansas City Missouri only Items for the metro area Kansas City Kansas or North Kansas City MO should go on their respective pages Such a structure would, however, have a mass quite a lot less than many asteroids. While the construction of such a massive inhabitable statite would be a gigantic undertaking, and the required material science behind it is as yet uncertain, its technical challenges are slight compared to other engineering feats and required materials proposed in other Dyson sphere variants.

In theory, if enough statites were created and deployed around their star, they would compose a non-rigid version of the Dyson shell. Such a shell would not suffer from the drawbacks of massive compressive pressure, nor are the mass requirements of such a shell as high as the rigid form. Such a shell would, however, have the same optical and thermal properties as the rigid form, and would be detected by searchers in a similar fashion (see below).

Other types

Another possibility is the "Dyson net", a web of cables strung about the star which could have power or heat collection units strung between the cables. The Dyson net reduces to a special case of Dyson shell or bubble, however, depending on how the cables are supported against the sun's gravity.

The Ringworld, or Niven ring, could be considered a particular kind of Dyson sphere. Ringworld is a Hugo and Nebula award-winning 1970 Science fiction novel by Larry Niven, set in his Known Space Ringworld is a Hugo and Nebula award-winning 1970 Science fiction novel by Larry Niven, set in his Known Space Larry Niven, who first developed the concept, described it as "an intermediate step between Dyson Spheres and planets". Laurence van Cott Niven (born April 30, 1938 Los Angeles California) is a US Science fiction author. ^[19] The ringworld could perhaps be described as a slice of a Dyson Sphere (taken through its equator), spun for artificial gravity, and used mainly for habitation as opposed to energy collection. Like the Dyson Shell, the Niven ring is inherently unstable without active measures keeping it in position with regards to its central star – a fact recognized by Larry Niven and addressed in the sequels to his novel on the concept, Ringworld. Ringworld is a Hugo and Nebula award-winning 1970 Science fiction novel by Larry Niven, set in his Known Space ^[20]

A bubbleworld is an artificial construct that consists of a shell of living space around a sphere of hydrogen gas. The shell contains air, people, houses, furniture, etc. It was invented to answer the question "what is the largest space colony that can be built". ^[21] However, most of the volume is not inhabited and there is no power source.

Theoretically, any gas giant could be enclosed in a solid shell; at a certain radius the surface gravity would be terrestrial, and energy could be provided by tapping the thermal energy of the planet. A gas giant (sometimes also known as a Jovian planet after the planet Jupiter, or giant planet) is a large Planet that is not primarily ^[21] This concept is explored peripherally in the novel Accelerando (and the short story Curator which is incorporated into the novel as a chapter) by Charles Stross when Saturn is converted into a human habitable world. Accelerando is a 2005 Science fiction novel consisting of a series of interconnected short stories by British author Charles Stross Charles David George "Charlie" Stross (born Leeds, 18 October 1964 is a writer based in Edinburgh, Scotland.

Stellar engines are a class of hypothetical megastructures, whose purpose is to extract useful energy from a star, sometimes for specific purposes. Stellar engines are a class of hypothetical Megastructures which use a star's radiation to create usable energy A megastructure is a built structure typically at least 1000 kilometers in length -- in other words at least 1 Megameter, hence the name For example, Matrioshka brains extract energy for purposes of computation; Shkadov thrusters extract energy for purposes of propulsion. A matrioshka brain is a hypothetical Megastructure, based on the Dyson sphere, of immense computational capacity Stellar engines are a class of hypothetical Megastructures which use a star's radiation to create usable energy Some of the proposed stellar engine designs are based on the Dyson sphere. ^[22]

A black hole could be the power source instead of a star in order to increase energy to matter conversion efficiency. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e A black hole would also be smaller than a star. This would decrease communication distances which would be important for computer based societies as those described above. ^[21]

Search for extra-terrestrial intelligence

In Dyson's original paper, he speculated that sufficiently advanced extraterrestrial civilizations would likely follow a similar power consumption pattern as humans, and would eventually build their own sphere of collectors. Constructing such a system would make such a civilization a Type II Kardashev civilization. The Kardashev scale is a method of measuring a civilization's level of technological advancement ^[23]

The existence of such a system of collectors would alter the light emitted from the star system. Collectors would absorb, and re-radiate, energy from the star. ^[1] The wavelength(s) of radiation emitted by the collectors would be determined by the emission spectra of the substances making them up, and the temperature of the collectors. An element's 'emission spectrum' is the relative intensity of Electromagnetic radiation of each Frequency it emits when it is Heated (or more generally when Since it seems most likely that these collectors would be made up of heavy elements not normally found in the emission spectra of their central star — or at least not radiating light at such relatively "low" energies as compared to that which they would be emitting as energetic free nuclei in the stellar atmosphere — there would be atypical wavelengths of light for the star's spectral type in the light spectrum emitted by the star system. The stellar atmosphere is the outer region of the volume of a Star, lying above the Stellar core, Radiation zone and Convection zone. In Astronomy, stellar classification is a classification of Stars based initially on photospheric temperature and its associated Spectral characteristics If the percentage of the star's output thus filtered or transformed by this absorption and re-radiation was significant, it could be detected at interstellar distances. ^[1]

Given the amount of energy available per square meter at a distance of 1 AU from the Sun, it is possible to calculate that most known substances would be re-radiating energy in the infrared part of the electromagnetic spectrum. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the The Sun (Sol is the Star at the center of the Solar System. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies Thus, a Dyson Sphere, constructed by life forms not dissimilar to humans, who dwelled in proximity to a Sun like star, made with materials similar to those available to humans, would most likely cause an increase in the amount of infrared radiation in the star system's emitted spectrum. Solar-Type, Solar Analog, and Solar Twin stars are those stars that are particularly similar to the Sun, with solar twin being more similar than solar analog Hence, Dyson selected the title "Search for Artificial Stellar Sources of Infrared Radiation" for his published paper. ^[1]

SETI has adopted these assumptions in their search, looking for such "infrared heavy" spectra from solar analogs. Search for Extra-Terrestrial Intelligence ( SETI) is the collective name for a number of activities to detect intelligent Extraterrestrial life. Solar-Type, Solar Analog, and Solar Twin stars are those stars that are particularly similar to the Sun, with solar twin being more similar than solar analog As of 2005 Fermilab has an ongoing survey for such spectra by analyzing data from the Infrared Astronomical Satellite (IRAS). Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Fermi National Accelerator Laboratory ( Fermilab) located in Batavia near Chicago, Illinois, is a U The Infrared Astronomical Satellite ( IRAS) was the first-ever space-based Observatory to perform a survey of the entire Sky at Infrared ^[24]

Fiction

Main article: Dyson spheres in fiction

As noted above, the Dyson sphere originated in fiction,^[25][26] and it is a concept that has appeared often in science fiction since then (see Dyson spheres in fiction for listed examples). This is a listing of the use of the Dyson sphere concept in popular fiction. This is a listing of the use of the Dyson sphere concept in popular fiction. In fictional accounts, Dyson spheres are most often depicted as a Dyson shell with the gravitational and engineering difficulties noted above with this variant, largely ignored. ^[6]

See also

References

External links

• Dyson Sphere FAQ
• Dyson Sphere
• Search for Artificial Stellar Sources of Infra-Red Radiation
• Dyson Shell Supercomputers as the Dominant "Life Form" in Galaxies
• Toroidal Dyson Swarms simulations using Java applets
• Outside Dyson shells
• Dyson Sphere article at Memory Alpha, a Star Trek wiki