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 ...

In 1960, British theoretical physicist Freeman Dyson published a one-page paper in the journal Science that offered perhaps the most hopeful vision ever conceived of humanity’s technological future.

We’d need an astronomical amount of resources to construct a Dyson sphere, a giant theoretical shell that would harvest all of a given star’s energy, around the Sun. In fact, as science journalist ...