Real Dyson spheres? How alien megastructures might survive in space

A recent study by Professor Colin McInnes at the University of Glasgow explores the feasibility and stability of hypothetical megastructures known as Dyson spheres, which advanced alien civilizations might build to harvest energy from their stars. Dyson spheres, first proposed by Freeman Dyson in 1960, include various concepts such as stellar engines—large reflective disks that harness a star’s power to generate thrust—and Dyson bubbles, swarms of small energy-harvesting spacecraft surrounding a star. A major challenge for these structures is maintaining gravitational stability, as larger megastructures tend to be inherently unstable. McInnes developed mathematical models treating Dyson spheres as extended objects influenced by realistic gravitational and radiation-pressure forces. His findings suggest that stellar engines could achieve passive stability if their mass is concentrated in an outer supporting ring rather than uniformly distributed. Similarly, Dyson bubbles could remain stable if composed of a sufficiently large number of low-mass reflectors arranged densely enough to avoid gravitational instabilities. This research not only advances theoretical understanding of such