Dyson spheres, the hypothetical mega-structures that advanced alien civilizations might use to enclose a star and harness its energy, suffer from a fatal flaw: They are catastrophically unstable. But ...

Sirius, also called the Dog Star, is the brightest star in Earth's night sky. Shining more brilliantly than any other star visible from Earth (excluding our sun, of course), Sirius is outshone only by ...