Dyson Sphere, the Realities
I wish we could stop talking about the fantasy of the Dyson Sphere and get real. Let us examine what is wrong with the postulate of a Dyson Sphere, the ultimate source of energy of unrealistic dreamers.
- There must be a stand-off distance between the surface of the pertinent star and the Dyson Sphere. That would be fairly large depending on the stability of the star and the technology available for construction in its vicinity.
- For a variety of reasons; temperature, flares, available materials of construction, etc., it is reasonable to expect the stand-off distance to be as large as the radius of the star, or more.
- Once you decide on this distance and the star you chose, you can calculate the surface area of the proposed Dyson Sphere.
- The thickness of the Sphere would depend on the available technology. Let us suppose it is not much more than currently available solar cells, five centimeters or so.
- A Sphere that large and that thin would be highly unstable structurally. The Sphere will in fact require much more structure in order to assure stability.
- The volume of construction material required for this kind of device would probably exceed the total volume of any home planet. This would obviously depend on the radius of the Sphere, its construction, the size of the star and the resources of the home planet.
- The materials required to construct the Sphere would consist of a specific set of elements; copper, silicon, zink and silver, used in solar panels. While silicon is abundant, silver is not. These and other elements such as iron required in the supporting structure of the Sphere’s construction would constitute just a fraction of these elements present on any home planet but even all of it would be just a fraction of the needs of the Sphere.
- The builders of the Sphere would have to mine many other planets containing suitable resources, to construct the Sphere.
- To do this they would have to journey to nearby planets or even other star systems and bring back vast quantities of refined materials. The materials would have to be refined in order to reduce the mass of material to be transported by factors as large as a thousand or more.
- In order to refine the materials on distant planets there would have to be well equipped colonies and suitable industrial equipment at each source of the desired materials.
- A mighty fleet of vessels would have to operate over a protracted period of time using locally available “traditional” energy resources of the home planet. Where else would they get the energy?
- What would be the effect of such a device on the orbital dynamics of the system?
- The Dyson Sphere would generate energy available only locally, or a relatively short distance from the source, not energy for use in distant space colonies or in interstellar transport.
- If the Dyson Sphere is to satisfy only the needs of the home planet, what kind of energy demand can one imagine on the surface of the home planet. The vast energy resources that will be required are those to carry out exploration far from the home planet, not locally. Using all the Dyson-captured energy of the local star on the home planet would probably melt it! It would certainly make it uninhabitable. Talk about global warming!
Let us stop the Dyson Sphere nonsense and try to imagine a universal energy source available everywhere in space and the universe. That is what we will need. An energy source which would satisfy local and transport needs wherever we might go. We will also need engines to use it. Without that, the chemicals for the action/reaction kind of propulsion we presently use will pose an insoluble fuel-mass requirement on long trips. If we want to travel, or send probes, limiting travel and communication time to a couple of human generations or so, we need a completely new and essentially unlimited source of universally accessible energy and a means of using it.
This is where our attention, our imagination, our hopes, our science, should be concentrated if we plan to explore space. There is a precedent for such an energy source. On a different scale, and with less demand, we had such a source when we explored our own home planet; wind.
By the way, an array for collecting solar energy is present on many satellites and a much larger array is in the planning stages for collecting solar energy and beaming it to earth. Such a device will be very small compared to the Dyson Sphere, be built far from the sun, and will require some propulsion to maintain position. A suitable Lagrange point can be found to reduce propulsive needs but this is not a “partial Dyson Sphere.”