Sphere of Dyson

A sphere of Dyson is a hypothetical Mégastructure described in 1959 by the Physicien Freeman Dyson in a short article published in the newspaper Science and entitled “Search for Artificial Stellar Sources off Infra-Red Radiation”. It is a artificial Sphère hollow of matter around a star, designed to almost capture all the energy emitted by star for an industrial use.

Although Dyson is recognized to have been the first to formalize and popularize the concept of sphere of Dyson, it had itself the Idée in 1945 of a news of science fiction entitled Star Maker of Olaf Stapledon. The original proposal of Dyson did not go into the details in the way in which a sphere of Dyson could be built, concentrating more on the fundamental problems: how a advanced civilization could increase its energy production to the possible maximum for a Planetary system given. Such a civilization would be named civilization of the Type II following the classification developed by the Astronome Nikolai Kardashev.

Properties

A star contained in a sphere of Dyson would not be directly visible of the external universe, but the sphere of Dyson would emit itself an equivalent quantity of energy in the form of light Infra-rouge because of the heat of star. Moreover, as the spheres of Dyson are made up of solid matter instead of hot gases, the emission spectrum of the sphere of Dyson would resemble more the spectrum of a black Corps than with that of an ordinary star, which has properties of absorption introduced into the Stellar atmosphere. Dyson proposed that the astronomers seek giant “stars” presenting anomalies in order to detect extraterrestrial civilizations advanced, but none was recorded. Attempts at detection of spheres of Dyson using the data of monitoring of the sky of the WILL GO (satellite astronomical infra-red) are in hand.

However, if the creators of a sphere of Dyson wanted to increase the variation in temperature (and to thus increase the effectiveness of the process of recuperation of energy), they could reflect the light of the interior surface of the sphere towards certain zones of the surface of the sphere. The concentration of light would be limited by the maximum temperature tolerated by materials concerned in the process of energy transformation. Consequently radiation in direction of the outside world would not be omnidirectional, therefore the spheres of Dyson could be invisible well.

Varieties

There are several varieties of spheres of Dyson.

Swarm

Most realistic of all, and nearest to the original design of Dyson is l'" swarm of Dyson". It consists of a great number of independent solar collectors in orbit in a dense formation around star. The solar heat collectors can vary in the face and form, and include/understand space dwellings to make there live biological creatures, but groups some they would collectively intercept almost all the luminous energy of star. Several types of orbitation were proposed for the collectors, each one with various advantages and disadvantages. Whatever the type chosen, certain solar heat collectors pass part of their orbit in the shade of other solar heat collectors, thus reducing the effectiveness of the sphere. As the collectors operate independently from/to each other, a swarm of Dyson can be built in an incremental way over one long period of time and provide useful energy during this time.

Cockle

A second type of sphere of Dyson is a solid uniform shell around star, sometimes called a “shell of Dyson”, often with a layer of atmosphere and ground on interior surface in order to provide a space for the life of organic forms of life. This form of sphere of Dyson is much more popular in the Science-fiction, but is not physically realizable for many reasons. One of it is the immense force which would be necessary for such an enormous structure.

Another is the fact that the gravitational force exerted by a sphere digs uniform towards its interior is null; there would be nothing retaining the atmosphere on the surface sphere, and it would fall towards star.

The sphere could be put in rotation to produce a centrifugal pseudo-gravity around its equator, but the conditions of force structural for materials of the shell become even more important in this case. Another possibility would be to put the atmosphere on the side external of the sphere, which although nonenlightened by interior star, would have a gravity. The energy provided by the sphere of Dyson thus created could potentially be used to cure the problem of lighting or heat which this last configuration poses.

Bubble

A third type of sphere of Dyson called “bubble of Dyson” is sometimes considered, composed of Statite S (Mot-valise of statics and satellite) which would float motionless compared to the sun included by using the pressure of the light; this form of sphere of Dyson requires a mass so low that it could be built starting from the matter contained in small a satellite or in large a Astéroïde. However, a bubble of Dyson has few practical applications (to collect energy would be difficult from its low mass and its dependence in a high reflectivity), thus it is seldom question.

Other types

August 1st

Spheres of Dyson in the fiction

  • Omale of Laurent Genefort is a world created on the model of a sphere of Dyson.

  • the series Star Trek, the new generation gives a good description of a sphere of Dyson in an episode entitled Reliques .
  • Even if it is not a sphere, to see the Ring-World of Larry Niven which refers to the Sphere of Dyson.
  • the roleplay Tears of rust of Nicolas Davoust whose decoration is a sphere of Dyson (Rust) placed around a double star.
  • the principle of the sphere of Dyson was then taken again in an original way in plays-vidéos, Such as Freelancer
  • the set of futuristic figurines AT-43 takes up the idea for industrial planets of its extraterrestrial faction. They would be built around dwarf white stars.
  • In the video game Freelancer , the player is confronted with a secret civilization which draws its energy from a sphere of Dyson.
  • In the video game Prey the player is found in the middle of an immense vessel planet which is a sphere of Dyson.

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