By Sri Dhanya
A Dyson Swarm (Image: Wikimedia Commons / Vedexent)
What is a Dyson Sphere?
Humanity has come so far from the discovery of fire to the industrial revolution and now, the push for sustainable energy. What if instead of being constrained to terrestrial options we advance to an interplanetary species that could harness the Sun’s energy infinitely? Introducing the Dyson Sphere:
First posited by physicist Freeman Dyson as part of his thought experiment, a Dyson Sphere is a megastructure that completely encompasses a star and captures a significant part of its output that can be used by an interplanetary species to meet their ever increasing energy demands. The general structure consists of rings of solar collectors surrounding the star that each absorb and re-radiate energy from the star, making it more so a swarm, but generally referred to as a sphere nonetheless.
Building the Dyson swarm is no easy feat and would require significant amounts of energy beyond terrestrial capabilities. To completely utilize the energy of the Sun, a large number of satellites would be required to completely surround the 6.07 x 1018 m2 surface area. Hence, another planet’s resources need to be used, Mercury being an ideal candidate. Its close proximity and metal-rich surface would make the assembly and launching process efficient. Furthermore, the low surface gravity would ensure lesser energy is required for launches.
Building, launch and harnessing process
The satellites would be powered using solar sails that have mirrors which refocus sunlight to central collecting stations, mirroring the concept of solar power. They are lightweight and made of polished metal foil mounted on the satellite base.
The launch process is completely autonomous to reduce human cost and ensure minimal repairs are required. First, the solar collectors on Mercury provide the solar power required to power the mining equipment that strip-mines and refines Mercury’s metal-rich surface. These metals are essential to building the aforementioned satellites. Lastly, a large electromagnetic track is built to launch the swarm satellites by exploiting the low surface gravity, making this more cost-efficient. During the launch process, they are tightly packed and upon successful launch they unfurl to reveal the mirrors. Future launches will be easier as they can be powered using the existing satellites already in place.
Once in position, these solar sails balance against the pressure of emitted light from the Sun. One should also note that these satellites are not in orbit and are simply hovering about, hence referred to as “statites”. These rings of statites surround and harness the Sun’s energy before beaming it back to Mercury and Earth. However, after absorbing and exploiting the energy, it needs to be re-radiated to prevent excess energy build-up that could melt parts of the statite. One of the preventative measures in place is thus building the statite using a lightweight but dense material.
Dyson spheres or swarms are the next leap that will pave the path for terraforming and interstellar travel. While the scientific principles present this as a feasible solution, the economic and practical costs are hurdles we are yet to cross, forcing us to take a step back.
Sources
Cramer, J. (2021, November 7). Kardashev Civilizations, Dyson Spheres, and Black Holes. Analog Science Fiction & Fact Magazine.
Deborah Byrd. (2021, July 30). What is a Dyson Sphere. EarthSky | Updates on Your Cosmos and World. https://earthsky.org/space/what-is-a-dyson-sphere/
In a Nutshell, K. (2018). How to build a dyson sphere - The ultimate megastructure [Video]. In YouTube. https://www.youtube.com/watch?v=pP44EPBMb8A
Mann, A. (2019, August 1). What is a dyson sphere? Space. https://www.space.com/dyson-sphere.html