ADyson sphereis a hypotheticalmegastructurethat encompasses astarand captures a large percentage of itspower output.[1][2][3]The concept is athought experimentthat attempts to imagine how aspacefaringcivilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbitingplanet,building structures encircling a star would enable acivilizationto harvest far more energy.
The first modern imagining of such a structure was byOlaf Stapledonin his science fiction novelStar Maker(1937). The concept was later explored by the physicistFreeman Dysonin his 1960 paper "Search for Artificial Stellar Sources ofInfrared Radiation".Dyson speculated that such structures would be the logical consequence of the escalating energy needs of a technological civilization and would be a necessity for its long-term survival. A signature of such spheres detected in astronomical searches would be an indicator ofextraterrestrial intelligence.
Since Dyson's paper, many variant designs involving an artificial structure or series of structures to encompass a star have been proposed inexploratory engineeringor described inscience fiction,often under the name "Dyson sphere". Fictional depictions often describe a solid shell ofmatterenclosing a star – an arrangement considered by Dyson himself to be impossible.
Origins
editInspired by the 1937science fictionnovelStar MakerbyOlaf Stapledon,[4]the physicist and mathematicianFreeman Dysonwas the first to formalize the concept of what became known as the "Dyson sphere" in his 1960Sciencepaper "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 intofar-infraredradiation, 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 aDyson swarm;[7]however, in 2013, Dyson said he had come to regret that the concept had been named after him.[8]
Search for megastructures
editDyson-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'sspectral type,due to the presence of heavy elements not naturally occurring within the star. If the percentage of such atypical wavelengths were to be significant, an alien megastructure could be detected at interstellar distances.[5]This could indicate the presence of what has been called a TypeIIKardashev civilization.[9]
SETIhas looked for such infrared-heavy spectra fromsolar analogs,as hasFermilab.[10][11]Fermilab discovered 17 potential "ambiguous" candidates, of which four were in 2006 called "amusing but still questionable".[10]Later searches also resulted in several candidates, all of which remain unconfirmed.[12][13][14]
On 14 October 2015,Planet Hunters' citizen scientists discovered unusual light fluctuations of the starKIC 8462852raising press speculation that a Dyson sphere may have been discovered.[15][16]However, subsequent analysis showed that the results were consistent with the presence of dust.[17][18]A further campaign in 2024 identified seven possible candidates for Dyson-spheres, but further investigation was said to be required.[19][20]
Feasibility and science-based speculation
editAlthough 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.George Dvorskyhas advocated the use ofself-replicating robotsto overcome this limitation in the relatively near term.[21]Some have suggested that Dyson sphere habitats could be built aroundwhite dwarfs[22]and evenpulsars.[23]
Stellar enginesare hypothetical megastructures whose purpose is to extract useful energy from a star, sometimes for specific purposes. For example,Matrioshka brainshave been proposed to extract energy for computation, whileShkadov thrusterswould extract energy for propulsion. Some proposed stellar engine designs are based on the Dyson sphere.[24][25]
From May until June 2024, speculation grew that potential signs of interstellar Dyson spheres had been discovered. The seven objects of interest – all located within a thousand light-years of Earth – areM-dwarfs,a class of stars that are smaller and less luminous than the Sun. However, the authors of the findings were careful not to make any overblown claims.[26]Despite this, many media outlets picked up on the story. Less fantastical alternative explanations have been made, including a proposal that the infrared from the discoveries was caused by distant dust-obscured galaxies.[27][28][29]
Fictional examples
editA precursor to the concept of Dyson spheres was featured in the 1937 novelStar MakerbyOlaf 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";[30]Dyson got his inspiration from this book and suggested that "Stapledon sphere" would be a more apt name for the concept.[31]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 aBig Dumb Object.[32]
Dyson spheres appear as a background element in many works of fiction, including the 1964 novelThe WandererbyFritz Leiberwherealiensenclose multiple stars in this way.[1][32][33]Dyson spheres are depicted in the 1975–1983 book seriesSaga of CuckoobyFrederik PohlandJack Williamson,and one functions as thesettingofBob Shaw's 1975 novelOrbitsvilleand its sequels.[2][3]In the 1992 episode "Relics"of the TV showStar Trek: The Next Generation,[34]theUSSEnterprisefinds itself trapped in an abandoned Dyson Sphere;[35][36]in a 2011 interview, Dyson said that he enjoyed the episode, although he considered the sphere depicted to be "nonsense".[37] Michael Jan Friedmanwho wrote the novelization observed that in the TV episode itself the Dyson sphere was effectively aMacGuffin,with "just nothing about it" in the story, and decided to flesh out the plot element in his novelization.[38]: ix
Other science-fiction story examples includeTony Rothman'sThe World Is Round,Somtow Sucharitkul's Inquisitor series,Timothy Zahn'sSpinneret,James White'sFederation World,Stephen Baxter'sThe Time Ships,andPeter F. Hamilton'sPandora's Star.[1]: 133 Variations on the Dyson Sphere concept include a single circular band inLarry Niven's 1970 novelRingworld,[3][39][40]a half sphere in the 2012 novelBowl of HeavenbyGregory Benfordand Niven,[2][3]and nested spheres – also known as aMatrioshka brain– inColin Kapp's 1980sCageworldseriesandBrian Stableford's 1979–1990Asgardtrilogy.[1][3]
Stableford himself observed that Dyson spheres are usually MacGuffins or largely deep in the backgrounds of stories, giving as examplesFritz Leiber'sThe WandererandLinda Nagata'sDeception Well,whereas stories involving space exploration tend to employ the variants like Niven's Ringworld.[1]: 133 He gives two reasons for this: firstly that Dyson spheres are simply too big to address, which Friedman also alluded to when pointing out that the reason his novelization of "Relics" did not go further into the sphere was that it was only four hundred pages and he had just shy of four weeks to write it; and secondly that, especially for hard science-fiction, Dyson spheres have certain engineering problems that complicate stories.[1]: 133 [38]: ix In particular, since gravitational attraction is in equilibrium inside such a sphere (per theshell theorem), other means such as rotating the sphere have to be employed in order to keep things attached to the interior surface, which then leads to the problem of a gravity gradient that goes to zero at the rotational poles.[1]: 133 Authors address this with various modifications of the idea such as the aforementioned Cageworld nesting,Dan Alderson's double sphere idea, and Niven's reduced Ringworld (discussed in "Bigger Than Worlds").[1]: 133
See also
edit- Alderson disk– Hypothetical artificial solar megastructure
- List of hypothetical technologies– Technology that could exist in the future
- Stellar engineering– Hypothetical artificial modification of stars
- Tabby's Star– Star noted for unusual dimming events
References
edit- ^abcdefghiStableford, Brian M.(2006)."Dyson, Freeman (John) (1923–)".Science Fact and Science Fiction: An Encyclopedia.Taylor & Francis. pp. 132–133.ISBN978-0-415-97460-8.
- ^abcd
- Westfahl, Gary(2021-07-19)."Artificial Worlds".Science Fiction Literature through History: An Encyclopedia.ABC-CLIO. pp. 135–136.ISBN978-1-4408-6617-3.
- Westfahl, Gary(2021-07-19)."Stars".Science Fiction Literature through History: An Encyclopedia.ABC-CLIO. p. 603.ISBN978-1-4408-6617-3.
- ^abcdefClute, John;Langford, David;Sleight, Graham(eds.)."Dyson Sphere".The Encyclopedia of Science Fiction(4th ed.).Archivedfrom the original on 2011-10-28.Retrieved2021-11-18.
- ^Dyson, Freeman (1979).Disturbing the Universe.Basic Books. p. 211.ISBN978-0-465-01677-8.
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
- ^abFreeman J. Dyson(1960)."Search for Artificial Stellar Sources of Infrared Radiation".Science.131(3414): 1667–1668.Bibcode:1960Sci...131.1667D.doi:10.1126/science.131.3414.1667.PMID17780673.S2CID3195432.
- ^Dyson, F. J.; Maddox, J.; Anderson, P; Sloane, E. A. (1960). "Letters and Response, Search for Artificial Stellar Sources of Infrared Radiation".Science.132(3421): 250–253.doi:10.1126/science.132.3421.252-a.PMID17748945.
- ^Smith, Jack (2020)."Review and viability of a Dyson Swarm as a form of Dyson Sphere".Physica Scripta.97(12): 122001.arXiv:2109.11443.doi:10.1088/1402-4896/ac9e78.S2CID237605010.
- ^"STARSHIP CENTURY SYMPOSIUM, MAY 21–22, 2013".7 July 2013. Archived fromthe originalon 7 July 2013.Retrieved31 August2017.
- ^Kardashev, Nikolai(1985).On the Inevitability and the Possible Structures of Supercivilizations.The search for extraterrestrial life: Recent developments; Proceedings of the Symposium, June 18–21, 1984. Boston, Massachusetts, US: Dordrecht, D. Reidel Publishing Co. pp. 497–504.Bibcode:1985IAUS..112..497K.A86-38126 17–88.
- ^abCarrigan, D. (February 23, 2006)."Fermilab Dyson Sphere search program".Fermi National Accelerator Laboratory. Archived fromthe originalon 2006-03-06.Retrieved2006-03-02.
- ^Shostak, Seth (Spring 2009)."When Will We Find the Extraterrestrials?"(PDF).Engineering & Science.72(1): 12–21.ISSN0013-7812.Archived fromthe original(PDF)on 2015-04-15.
- ^Dick Carrigan (2010-12-16)."Dyson Sphere Searches".Home.fnal.gov.Retrieved2012-06-12.
- ^Billings, Lee."Alien Supercivilizations Absent from 100,000 Nearby Galaxies".Scientific American.Retrieved31 August2017.
- ^"Infra digging: Looking for aliens: The search for extraterrestrials goes intergalactic".The Economist.2015-04-18.Retrieved2015-04-19.
Fifty [galaxies] were red enough to be hosting aliens gobbling up half or more of their starlight.
- ^Andersen, Ross (13 October 2015)."The Most Mysterious Star in Our Galaxy".The Atlantic.Retrieved13 October2015.
- ^Williams, Lee (15 October 2015)."Astronomers may have found giant alien 'megastructures' orbiting star near the Milky Way".The Independent.Retrieved15 October2015.
- ^Boyajian, Tabetha S.; et al. (2018)."The First Post-Kepler Brightness Dips of KIC 8462852".The Astrophysical Journal.853(1). L8.arXiv:1801.00732.Bibcode:2018ApJ...853L...8B.doi:10.3847/2041-8213/aaa405.S2CID215751718.
- ^Drake, Nadia(3 January 2018)."Mystery of 'Alien Megastructure' Star Has Been Cracked".National Geographic.Archived fromthe originalon January 3, 2018.Retrieved4 January2018.
- ^Hrinko, Ivan (2024-05-14)."Scientists start hunting for Dyson Spheres".Universe Space Tech.Retrieved2024-07-15.
- ^Suazo, Matías; et al. (6 May 2024)."Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE".Monthly Notices of the Royal Astronomical Society.531(1): 695–707.arXiv:2405.02927.doi:10.1093/mnras/stae1186.
- ^Dvorsky, George (2012-03-20)."How to build a Dyson sphere in five (relatively) easy steps".Retrieved2016-10-07.
- ^Semiz, İbrahim; Oğur, Salim (2015). "Dyson Spheres around White Dwarfs".arXiv:1503.04376[physics.pop-ph].
- ^Osmanov, Z. (2015). "On the search for artificial Dyson-like structures around pulsars".Int. J. Astrobiol.15(2): 127–132.arXiv:1505.05131.Bibcode:2016IJAsB..15..127O.doi:10.1017/S1473550415000257.S2CID13242388.
- ^"Stellar engine".The Internet Encyclopedia of Science.Retrieved2007-10-08.
- ^Badescu, Viorel; Cathcart, Richard B."Space travel with solar power and a dyson sphere".Astronomy Today.Archived fromthe originalon 2012-02-04.Retrieved2007-10-07.
- ^Goodwin, Simon (2024-05-22)."Dyson spheres: astronomers report potential candidates for alien megastructures – here's what to make of it".The Conversation.Retrieved2024-06-25.
- ^Sutter, Paul (2024-06-10)."7 potential 'alien megastructures' spotted in our galaxy are not what they seem".livescience.com.Retrieved2024-06-25.
- ^Today, Universe (2024-06-01)."Mysterious Dyson Spheres Could Have Another Explanation, Scientists Say".ScienceAlert.Retrieved2024-06-25.
- ^NBC News (2024-06-14).New study finds potential alien mega-structures known as 'dyson spheres'.Retrieved2024-06-25– via YouTube.
- ^Tate, Karl (14 January 2014)."Dyson Spheres: How Advanced Alien Civilizations Would Conquer the Galaxy".Space.com.RetrievedJanuary 14,2014.
- ^Sudbery, Tony;Langford, David(2022)."Dyson, Freeman J".InClute, John;Langford, David;Sleight, Graham(eds.).The Encyclopedia of Science Fiction(4th ed.).Retrieved2024-03-20.
- ^abPringle, David,ed. (1997)."Space Habitats".The Ultimate Encyclopedia of Science Fiction: The Definitive Illustrated Guide.Carlton. p. 50.ISBN978-1-85868-385-0.
- ^Stableford, Brian(1999). "Fritz Leiber". InBleiler, Richard(ed.).Science Fiction Writers: Critical Studies of the Major Authors from the Early Nineteenth Century to the Present Day(2nd ed.). New York:Charles Scribner's Sons.p. 441.ISBN0-684-80593-6.OCLC40460120.
- ^Hadhazy, Adam (October 30, 2020)."Could We Build a Dyson Sphere?".Popular Mechanics.Archived fromthe originalon March 10, 2021.RetrievedMarch 20,2024.
- ^Howell, Elizabeth (March 12, 2020)."'Dyson sphere' legacy: Freeman Dyson's wild alien megastructure idea will live forever ".Space.com.RetrievedMarch 20,2024.
- ^Nemecek, Larry(2003).Star Trek: The Next Generation Companion(3rd ed.).Pocket Books.pp. 218–220.
- ^Wright, Robert(2011)."MeaningofLife.tv".slate.com.Slate.Archived fromthe originalon 20 August 2011.Retrieved20 March2024.
Wright: Did they actually use the phrase 'Dyson sphere' onStar Trek?
Freeman Dyson: Oh yes.
Wright: Did they really?
Freeman Dyson: One of my daughters sent me a tape of that program afterwards and so I watched it. Oh yes, it's very clearly labeled and actually it was sort of fun to watch it, but it's all nonsense. But it's quite a good piece of cinema. [punctuation supplied for unedited transcript] - ^abAyers, Jeff (2006).Voyages of Imagination: The Star Trek Fiction Companion.Simon and Schuster.ISBN9781416525486.
- ^Nicholls, Peter(1983)."Far-future energy".InNicholls, Peter(ed.).The Science in Science Fiction.New York: Knopf. pp. 44–45.ISBN0-394-53010-1.OCLC8689657.
- ^Mann, George(2001)."Dyson Sphere".The Mammoth Encyclopedia of Science Fiction.New York: Carroll & Graf Publishers. p. 477.ISBN978-0-7867-0887-1.
Further reading
edit- Gunn, Alastair (2022-12-29)."Dyson spheres: How humans (and aliens) could capture a star's energy".BBC Science Focus.Archivedfrom the original on 2024-03-11.Retrieved2024-03-20.
- Mann, Adam (2019-08-01)."What is a Dyson sphere?".Space.com.Archivedfrom the original on 2024-03-07.Retrieved2024-03-20.
- Schulze-Makuch, Dirk(2014-01-29)."Dyson Spheres: Still Missing, Maybe Impossible".Smithsonian Magazine.Archivedfrom the original on 2023-09-28.Retrieved2024-03-20.
- Stableford, Brian(2004)."Dyson Sphere".Historical Dictionary of Science Fiction Literature.Scarecrow Press. p. 99.ISBN978-0-8108-4938-9.
- Stanway, Elizabeth (2023-05-21)."Megastructures".Warwick University.Cosmic Stories Blog.Archivedfrom the original on 2023-05-26.Retrieved2024-03-25.
External links
edit
- Dyson sphere FAQ
- FermiLab: IRAS-based whole sky upper limit on Dyson sphereswith an appendix on Dyson sphere engineering
