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Everything You Need to Know About the Dyson Sphere

Tanmay Tikekar
A Dyson sphere is a hypothetical megastructure proposed to harness as much power of a star as possible. Know more about the scientific flights of fancy as well as the practicalities of such a structure.
A Dyson sphere was depicted in the 'Relics' episode of the TV series Star Trek: The Next Generation. It showed the most difficult and improbable kind of Dyson sphere: A Dyson shell.
Ring a Bell, Trekkies?
Proposed by eminent physicist Freeman Dyson, the Dyson sphere is one of the most exciting proposals to emanate from the halls of science.
Formulated on the crossroads between the theory and the social obligation of science, this superstructure is theorized to capture much of the Sun's energy and divert it back to Earth, thus eliminating the reliance of our technologically advancing civilization on the limited stores of fossil fuels.
As civilizations advance, their need for energy increases. Since the Industrial Revolution, mankind has been on a constant upward trajectory in terms of technological advancement, but even today, the majority of the world's power comes from relatively minuscule deposits of decomposed organic matter buried underneath the earth.
This exhaustible supply of energy is surely not adequate as we hurtle along the route we have chosen for ourselves. Solar power, though not completely inexhaustible―for it, too, will run out in a few billion years―is a much better option for such a power-hungry civilization as ours. The problem with the Sun is harnessing enough of its power to run our world.
Such a tiny percentage of the Sun's total energy output reaches the Earth, that it is a testament to the Sun's huge size that we manage to accomplish so much with but a little drop of it. This is where the Dyson sphere comes in.

The Origin of the Idea

The idea of the Dyson sphere was conceived by Freeman Dyson, in a 1960 paper, titled 'Search for Artificial Stellar Sources of Infra-Red Radiation', in Science journal. He wasn't the first to think of the concept, but he was arguably the first to give it a scientific platform; the idea had only been discussed in science fiction prior to that.
In fact, Freeman Dyson is said to have been inspired by the occurrence of the idea in science fiction, more particularly in the 1937 novel Star Maker.
Dyson didn't go into the practical details of actually constructing his brainchild, but rather concentrated on the maximization of the structure's output and efficiency.

Types of Dyson Spheres

There are many possible ways of constructing a Dyson sphere. The most popular constructs are a Dyson Ring, a Dyson Swarm, a Dyson Bubble, and a Dyson Shell.

Dyson Ring

This is the most basic kind of Dyson sphere. It is formed by a large number of co-planar solar sails installed around a star. These units would occupy the same plane as the Earth, so the distance between them and the Sun would be 1 AU (Astronomical Unit).
The solar sails would capture the Sun's radiation. This captured energy could be transferred to Earth via more advanced versions of the various methods of wireless energy transfer known and used even now.

Dyson Swarm

This is simply a structure consisting of multiple Dyson rings on multiple diametrical planes around the Sun. This structure would cause a slight problem, due to the complicated orbital mechanics. Since every unit (as well as the Earth) has to revolve around the Sun, the overlap of the orbits (at the 'poles') will need to be handled carefully.

Dyson Bubble

The problem with the Dyson swarm, the orbital overlap, is solved in the Dyson Bubble. It consists of several Dyson rings occupying separate and parallel planes. The units in this system would be statites, rather than satellites.
Unlike satellites, which orbit their planet in a diametrical plane, statites actively and constantly use solar sails to hold their position with respect to their planet. Such 'intelligent' satellites have not yet been invented, since solar sail technology still needs a huge amount of research before that can be achieved.
However, the recent invention and burgeoning research into carbon nanotubes might just make this possible one day. The ring and the bubble are the relatively more readily realizable forms of the Dyson sphere, though they will require―most probably―centuries of further research into maximizing the efficiency of the resources available to mankind.

Dyson Shell

The most popularly depicted type of Dyson sphere, and the most implausible and difficult to construct, is the Dyson shell. This consists of a complete sphere enveloping the star, thus capturing all of its energy.
This presents various difficulties, the least of which is the lack of gravitational interaction between the star and the sphere (which would, by requirement, have to be much, much less massive than the star), which would eventually result in a collision between the two, unless the sphere had a means of propulsion.


The prime difficulty in this whole matter is the nonexistence, at present, of substances that can be used to construct solar sails of such huge dimensions, and yet, such high efficiency. The least dense option currently available to mankind, a carbon fiber solar sail, is three times denser than the required 0.78 g/sq m of the sail.
The only substance that is less dense than that, a single sheet of graphene, is almost completely transparent, and thus, absolutely useless as a solar sail.
Moreover, even if such substance were to be found (and carbon nanotubes have shown promising signs), it probably won't be available in the amount necessary for such huge constructions. Mining other planets, something very difficult―if not impossible―with the current development in space technology, seems to be the only option.
This has given rise to the idea of breaking apart the planet Mercury to use it for this construction. Needless to say, we can't possibly achieve such a goal with our current technology.
Humans, though, unwilling to conform to the forces of Mother Nature, have always sought to control and maximize her benefits to us, and continue to try to do so with solar power. More efficient solar panels, more energy-absorbent artificial materials are just the start of a trajectory that could, one day, peak at some form of the Dyson sphere.