Dyson sphere
A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its power output.[1][2][3] The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet, or planets resources alone. Variants include Dyson swarms, clouds of orbiting solar collectors, and Dyson shells solid or partial shells surrounding a star. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy.The first modern imagining of such a structure was by Olaf Stapledon in his science fiction novel Star Maker (1937). The concept was later explored by the physicist Freeman Dyson in his 1960 paper "Search for Artificial Stellar Sources of Infrared Radiation".[4] 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 of extraterrestrial intelligence.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.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. George Dvorsky has advocated the use of self-replicating robots to overcome this limitation in the relatively near term.[21] Some have suggested that Dyson sphere habitats could be built around white dwarfs[22] and even pulsars.[23]Another possible way to build a theoretical dyson sphere is to use materials from the planet, and launch spacecraft off the surface of mercury. Such thing could be done much easier on mercury than earthStellar 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.[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 – are M-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