Harnessing a Sun
A Dyson sphere is a hypothetical object engineered by highly
advanced extraterrestrial civilizations to harness a Sun-like star’s total
radiant output. In principle, such a civilization would collect the energy
at particular points on the sphere to fuel their own energy demands.
Rather than looking for signs of advanced civilizations by searching for
radio and optical signals, some physicists think it might be more
productive to look for evidence of such spheres.