I’ve mentioned Dyson spheres in this column before. In the simplest terms, they are macro-engineering projects that seek to capture and use 100% of a star’s energy by enclosing it in a shell. If the shell was large enough, you could even make the inner surface habitable, providing a surface area millions of time larger than a planet.
The idea was first described by Olaf Stapledon in his 1937 novel Star Maker before being popularised in the 1960s by the theoretical and mathematical physicist Freeman Dyson.
Constructing something large enough to envelop our sun is obviously far beyond our present capabilities, and for the last eight decades, the existence of Dyson spheres has been confined to the pages of science fiction. However, according to a report in New Scientist, astronomers may have detected the first evidence of up to sixty of them around nearby stars.
As a Dyson sphere traps all the energy from its host star, no visible light would escape. The star would essentially become invisible to the eye. However, these spheres would radiate an infrared heat signature, and in two surveys of millions of stars in our galaxy, many were found to be giving out mysterious spikes in infrared heat.
It’s quite possible that a mundane explanation exists for this phenomena. However, mundane explanations aren’t really the point of this column, so I’m going to assume that these results really are evidence that multiple civilisations have indeed built solid shells around their suns, and look at what that might imply.
The first thing that springs to mind is that the builders of these objects will be almost unimaginably more advanced than we are, as they would have to be able to harvest the resources of their entire solar system in order to provide the raw materials for their project. This means they would possess the ability to deconstruct planets the size of Jupiter and repurpose their ingredients.
Secondly, the existence of such spheres may suggest that travel between stars is impractical. You wouldn’t go to the trouble of building such a vast artifact if you could easily spread your population across multiple worlds and solar systems. The construction of a sun-wrapping shell is something you wouldn’t contemplate if you had another choice. That implies that each of these civilisations remains confined to their home system, and having to make the best of the resources to hand, which in turn suggests that our future won’t be any different. If interstellar travel turns out to be impractical, we will also remain trapped here until the swelling Sun makes our planet uninhabitable in around 2 billion years.
As a science fiction author, I hate the idea that we might be forever isolated and unable to bridge the gaps between the stars, so let’s consider a different, slightly more worrying, possibility. Let us say for the sake of argument that interstellar travel is possible. Opening an Einstein-Rosen bridge, or wormhole, between star systems would require huge amounts of energy. A highly advanced nomadic species may be migrating across the galaxy, spending generations consuming each star system’s resources, and then when those are depleted, building a Dyson shell to power their jump to the next system.
If we detect a sudden burst of exotic particles on the edge of our solar system, it may be a signal that these locusts have arrived, and our days are numbered.
Alternatively, and I’m afraid this idea isn’t any cheerier than the last two, someone might be going around the galaxy imprisoning civilisations within these spheres against their will. In his 2004 novel Pandora’s Star, Peter F. Hamilton explored the idea that some alien races may simply be too dangerous to be allowed to spread out into the wider cosmos, and so have to be incarcerated within these vast spheres to prevent them running amok.
As a solid Dyson sphere would have to be strong enough not to fly apart or collapse under its own gravity, we have to assume they would be constructed from some unreasonably strong material, and could therefore make effective jails. But this also means the inverse is true, and they could also make pretty good refuges. Maybe, if these spheres exist, they are fortresses in the night sky, designed not to keep their inhabitants inside, but to keep something else out – something frightening enough to drive them to the expense and effort of walling themselves off from the rest of the universe.
Gareth L. Powell is the award winning author of 20 published books. You can find him online at: www.garethlpowell.com
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