Dyson Spheres
A Dyson sphere is a hypothetical megastructure that completely encompasses a star and captures a large percentage of its solar power output. The concept is a thought experiment that attempts to explain how a spacefaring civilization 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 orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy. The first contemporary description of the structure was by Olaf Stapledon in his science fiction novel Star Maker, in which he described "every solar system... surrounded by a gauze of light-traps, which focused the escaping solar energy for intelligent use". The concept was later popularized by Freeman Dyson in his 1960 paper "Search for Artificial Stellar Sources of Infrared Radiation".