Is space full of alien megastructures we just haven’t seen yet?
Alien megastructures are a fun idea, but they seem to collapse under the weight of their ambitions. Huge machines that envelop stars, envelop entire planets, or even have the ability to push an entire solar system through space like a rocket ship so big we can’t even fathom it. It all seems to be strictly confined to the realm of science fiction, but a study published in Monthly Notices of the Royal Astronomical Society January of this year suggests that these ideas may not be as fantastic as they sound.
Research led by Colin McInnes at the University of Glasgow investigated whether structures such as Dyson bubbles and stellar engines could remain stable over long periods of time. These are colossal, unimaginably huge construction projects that usually involve societies harnessing the full might and power of their host stars and their own highly advanced scientific and technical know-how.
A Dyson bubble is a dense swarm of reflectors surrounding a star that traps an enormous amount of energy, far more energy than a single world could probably create on its own, and enough potential energy to fuel the civilizations of several planets. A star engine could theoretically use radiation pressure to move an entire star system to steer multiple planets and a star or two away from a major cosmic threat or toward a new region of space for whatever reason. Sounds like stuff that would be impossible to keep from collapsing or sliding apart. McGinnis claims it can work.
Theoretically, of course. At least for now.
Have we already missed alien megastructures in space?
For example, he and his team argue that stability will depend on the design of the structure. A star engine shaped like a ring, and the outermost edge of that ring supported most of its mass, it can theoretically be stable enough not to tear itself apart. A Dyson bubble made of an incalculable number of tiny, lightweight reflectors could theoretically self-organize into a stable cloud that doesn’t have enough of its own gravity to tear itself apart.
McInnes suggests that all this means that megastructures do not need constant maintenance to survive for thousands or even millions of years. If true, it raises the eerily interesting idea that these giant engineering feats are theoretically already out there, some of them perhaps even outliving the civilizations that created them, like the titular halo from Hello video game series.
I’ve already used the word several times, but it’s worth repeating that it’s all purely theoretical. That said, it is grounded in real physics, which is usually how science fiction eventually turns into science fact.
