A Dyson sphere is a hypothetical giant structure that surrounds a star and can capture its solar output. Two separate groups of astronomers have claimed that they have detected dozens of possible Dyson spheres within the Milky Way galaxy. NBC’s Gadi Schwartz speaks with Dr. Michio Kaku about what it would take to create a Dyson sphere and how advanced a civilization would need to be to make it happen. A Dyson sphere is a hypothetical giant structure that surrounds a star and can capture its solar output. Two separate groups of astronomers have claimed that they have detected dozens of possible Dyson spheres within the Milky Way galaxy. NBC’s Gadi Schwartz speaks with Dr. Michio Kaku about what it would take to create a Dyson sphere and how advanced a civilization would need to be to make it happen. NBC News Science