Dyson Spheres
By Jack Shea
Preface: Dyson Spheres are a purely theoretical concept and almost journey into the realm of science fiction. However, looking at dyson spheres can offer insight into how the human race could push the envelope of energy production as we inevitably journey into the final frontier.
Energy is essential to human existence. Beginning with the inception of our species, we have utilized energy to live and thrive in the environments we choose to settle in. As society has progressed, so has our means of energy acquisition. We began purely with the energy produced by our own muscles, then our ancestors discovered how to use fire, and generations later industrialists learned how to use the fossil fuels under our feet. As human civilization inches towards the space age, our need for energy will exceed that which Earth can provide us. We will have to take as large of a jump in energy acquisition as our ancestors did with fire. To find this energy, we will have to look at the ultimate source of energy: the stars.
A Dyson Sphere is a theoretical megastructure that would surround a designated star and collect a percentage of its thermal output, (ideally all of the energy in an advanced enough civilization). Hypothetically, a dyson sphere would enable any spacefaring civilization to acquire enough energy to colonize and terraform prospective planets. The idea was popularized by Freeman Dyson in his paper “Search for Artificial Stellar Sources of Infrared Radiation”, in which he states that such a structure is essential for the long term survival of the human species. He even suggests that such structures may already exist, “If extraterrestrial intelligent beings exist and have reached a high level of technical development, one by-product of their energy metabolism is likely to be the large-scale conversion of starlight into far-infrared radiation. It is proposed that a search for sources of infrared radiation should accompany the recently initiated search for interstellar radio communications.”
Dyson makes reference to the Kardashev Scale, a metric of a civilization’s technological advancement. The hypothetical scale, posited by astronomer Nikolai Kardashev in 1964, measures energy consumption on a cosmic scale. The original model places civilizations into three categories, Type I, II , and III. Type I civilizations control all of the energy available on their planet, the energy consumption on Earth would have to be about 2 x 1017 watts for human civilization to be categorized as Type I, (we haven’t even reached this level yet as our consumption is about 2 x 1013 watts as of 2020). A Type II civilization is defined as being able to harness all of the energy radiated by their respective star. This can be measured by the completion of a dyson sphere or similar megastructure, which in our solar system would harness about 4 x 1026 watts. Finally, a Type III civilization is defined as one that consumes energy on the galactic level, which in the Milky Way Galaxy would be about 4 x 1037 watts. Based on infrared radiation, scientists do not think there are any local Type III civilizations, but suggest that there may be some Type II civilizations out there. Although Kardashev did not believe that energy consumption could become intergalactic due to the expanding nature of the universe, others have posited higher categories of civilizations such as Types IV and V.
Feasibility is obviously the biggest question when it comes to consuming energy on a systems and galactic level, as we have yet to even access all of the energy available to us here on Earth. This is extremely apparent when talking about dyson spheres, as an optimized concrete design has not been created. Currently, a dyson sphere is not feasible for the human race, as we have yet to create the technology and infrastructure necessary for a dyson sphere. Barriers preventing the creation and implementation of a dyson sphere include the amount of energy we currently have available to us, lack of interplanetary infrastructure, and insufficient materials. We will likely not see any significant progress within our lifetimes, and maybe not even for generations to come. Although the concept remains unrealistic, scientists have proposed a few viable, but theoretical solutions. These include the dyson swarm, basically solar panel satellites that orbit the star; the dyson bubble, which is similar to the swarm, but instead utilizes stationary statutes place around the star; and the dyson shell, which is a uniform shell that would completely envelop a star, (this is the form of dyson sphere most often depicted in works of fiction and is very unrealistic).
Although the implementation of a dyson sphere is not realistic for the human civilization of 2022, the concept emphasizes our constantly growing energy consumption. Although the world is trending towards the implementation of green energy technologies, the acquisition of new sources of energy will always be an uphill battle. As the human race grows, expands, and innovates, we will have to adapt to our new energy needs. With billionaires Jeff Bezos and Elon Musk beginning their own ventures into the stars it might be time for us to start thinking about our energy needs beyond Earth.