Dyson sphere
A Dyson sphere is a hypothetical
The first modern imagining of such a structure was by
Since Dyson's paper, many variant designs involving an artificial structure or series of structures to encompass a star have been proposed in exploratory engineering or described in science fiction, often under the name "Dyson sphere". Fictional depictions often describe a solid shell of matter enclosing a star – an arrangement considered by Dyson himself to be impossible.
Origins
Inspired by the 1937 science fiction novel Star Maker by Olaf Stapledon,[4] the physicist and mathematician Freeman Dyson was the first to formalize the concept of what became known as the "Dyson sphere" in his 1960 Science paper "Search for Artificial Stellar Sources of Infra-Red Radiation". Dyson theorized that as the energy requirements of an advanced technological civilization increased, there would come a time when it would need to systematically harvest the energy from its local star on a large scale. He speculated that this could be done via a system of structures orbiting the star, designed to intercept and collect its energy. He argued that as the structure would result in the large-scale conversion of starlight into far-infrared radiation, an earth-based search for sources of infrared radiation could identify stars supporting intelligent life.[5]
Dyson did not detail how such a system could be constructed, simply referring to it in the paper as a 'shell' or 'biosphere'. He later clarified that he did not have in mind a solid structure, saying "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".[6] Such a concept has often been referred to as a Dyson swarm;[7] however, in 2013, Dyson said that he had come to regret that the concept had been named after him.[8]
Search for megastructures
Dyson-style energy collectors around a distant star would absorb and re-radiate energy from the star. The wavelengths of such re-radiated energy may be atypical for the star's
On 14 October 2015,
Feasibility and science-based speculation
Although Dyson sphere systems are theoretically possible, building a stable megastructure around the Sun is currently far beyond humanity's engineering capacity. The number of craft required to obtain, transmit, and maintain a complete Dyson sphere exceeds present-day industrial capabilities.
Stellar engines are hypothetical megastructures whose purpose is to extract useful energy from a star, sometimes for specific purposes. For example, Matrioshka brains have been proposed to extract energy for computation, while Shkadov thrusters would extract energy for propulsion. Some proposed stellar engine designs are based on the Dyson sphere.[22][23]
Fictional accounts
A precursor to the concept of Dyson spheres was featured in the 1937 novel Star Maker by Olaf Stapledon,[1] in which he described "every solar system... surrounded by a gauze of light-traps, which focused the escaping solar energy for intelligent use".[24]
Fictional Dyson spheres are typically solid structures forming a continuous shell around the star in question, although Dyson himself considered that prospect to be mechanically implausible.[2][3] They are sometimes used as the type of plot device known as a Big Dumb Object.[25]
Dyson spheres appear as a background element in many works of fiction, including the 1964 novel The Wanderer by Fritz Leiber where aliens enclose multiple stars in this way.[1][25][26] Dyson spheres are depicted in the 1975–1983 book series Saga of Cuckoo by Frederik Pohl and Jack Williamson, and one functions as the setting of Bob Shaw's 1975 novel Orbitsville and its sequels.[2][3]
Variations on the concept include a single circular band in Larry Niven's 1970 novel Ringworld,[3][27][28] a half sphere in the 2012 novel Bowl of Heaven by Gregory Benford and Niven,[2][3] and nested spheres—also known as a Matrioshka brain—in Colin Kapp's 1980s Cageworld series and Brian Stableford's 1979–1990 Asgard trilogy.[1][3]
See also
- Alderson disk – Hypothetical artificial astronomical megastructure
- Kardashev scale – Measure of a civilization's evolution
- Matrioshka brain – Huge computer powered by a star's energy
- Stellar engineering – Hypothetical artificial modification of stars
- List of hypothetical technologies – Technology that could exist in the future
References
- ^ ISBN 978-0-415-97460-8.
- ^ ISBN 978-1-4408-6617-3.
Some science fiction writers have wrongly given me the credit of inventing the artificial biosphere. In fact, I took the idea from Olaf Stapledon, one of their own colleagues
Fifty [galaxies] were red enough to be hosting aliens gobbling up half or more of their starlight.
External links
- Dyson sphere FAQ
- FermiLab: IRAS-based whole sky upper limit on Dyson spheres, with an appendix on Dyson sphere engineering