Many readers have openly questioned why the behavior of the light from the star KIC 8462852 is so unusual, and they centered on the sci-fi theory of a Dyson Sphere of alien superstructures encircling the star in order to harness its energy. But if anything, a Dyson Swarm—a loose collection of a structures rather than a solid sphere—is far more likely, given the immense amount of material needed to encapsulate a star from an immense distance. But gravity is an even bigger challenge. Popular Mechanics spoke with Stuart Armstrong, a research fellow at Oxford University’s Future of Humanity Institute who has studied megastructure concepts:
The Sphere would not gravitationally bind to its star in a stable fashion. This is perhaps counterintuitive; you might think that a perfect sphere around a star would be stable. But if any part of the sphere were nudged closer to the star—say, by a meteor strike—then that part would be pulled preferentially toward the star, creating instability.
That’s too bad. If it could be stabilized, a Dyson Sphere built at 93 million miles from the sun, the same distance as the Earth, would contain about 600 million times the surface area of our planet in its interior. However, comparatively little of the surface would be habitable on account of a lack of gravity. By spinning the whole sphere, you create gravity in the form of centrifugal force along an equatorial band. But this rotation would wrack the megastructure with yet more destructive stress.
So any sphere would look much closer to this illustration by Rick Sternbach, published in Future magazine in 1979:
Could a Dyson Swarm be built around our own sun? George Dvorsky explores the tantalizing question: