Dyson and the Beginnings of Artifact SETI

In Dyson (1960), the beginnings of a new type of SETI is proposed that has significantly fewer behavioral and technological assumptions about ETI (Wright 2014). If ETI does exist and use a large amount of energy, they will likely be utilizing starlight as an easily accessible energy source and be indirectly converting it into IR radiation. The search for this IR radiation is proposed to complement the existing searches for communication.

Dyson argues that if exponential population and technology growth is sustained for a couple millennia, a civilization could use on the order of a Jupiter mass’s worth of material to construct a spherical shell around the Sun (using only 800 years worth of solar energy!). This is followed by the bold statement that “One should expect that, within a few thousand years of its entering the stage of industrial development, any intelligent species should be found occupying an artificial biosphere which completely surrounds its parent star.” Finally, he notes that the thermal emission of these shells will be in the IR range and that ground telescopes will be able to detect them through the atmosphere.

A popular idea that resulted from this paper was that of a Dyson sphere, a hypothetical megastructure that completely encloses a host star, capturing all of its energy. It is sometimes postulated that the sphere is not only used to capture energy, but to also serve as a space for habitation, where life can live on the inner surface of the sphere. If one was constructed with a radius of 1 AU around out Sun, there would be more livable space than half a billion Earths! There are several problems with this implementation, namely, there is no material we know of that could withstand thepressure imposed by the star’s gravity. Additionally, there would be no effective gravity imparted by the shell on anything in its interior, so there would be nothing holding anything to the interior surface and the shell could drift into the star over time.

The Dyson Sphere has remained a prevalent idea in popular culture to this day, with appearances in many forms of science fiction media (including the television show Star Trek: The Next Generation and the grand strategy videogame Stellaris)

In Stellaris, you can spend an inordinate amount of resources constructing this mega structure. Realistically, it turns all rocky planets and moons in the system into frozen or barren worlds. Unrealistically, the amount of energy provided does not vary between different star types. Tsk tsk developers.