Is it possible to build a Dyson sphere that isn't catastrophically unstable? New research says yes, but only in one type of star system.
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 now an engineer claims to have figured out a way to stabilize these structures — and all it takes is two stars. In the 1960s, physicist and polymath Freeman Dyson cooked up the idea of these eponymous spheres. He envisioned that a sufficiently advanced society would have an insatiable need for living space and energy. And if they were industrious enough, they could solve both challenges by taking apart a planet and turning it into an enormous spherical shell. This sphere would enclose a star, providing billions of planets' worth of surface area and capturing vast amounts of solar energy. Dyson calculated that a shell made from a planet with the mass of Jupiter could completely enclose the sun at roughly the orbit of Earth. But the gravity inside a hollow shell cancels out, which means there's nothing tethering the shell to the star. They are free to move in independent directions, which means that soon enough a star hosting a Dyson sphere will simply crash into the shell, destroying it. In a paper published Jan. 29 in the journal Monthly Notices of the Royal Astronomical Society, Colin McInnes , an engineer at the University of…