The idea of a Dyson sphere has captured my imagination.
An engineering megastructure that hugs an entire star like a paper wrapping a Christmas present, and can harvest its energy. That’s awesome!
What is a Dyson Sphere?
A Dyson Sphere, also known as a Dyson Sphere or Dyson Shell, is a hypothetical mega-engineering concept proposed by physicist and astronomer Freeman Dyson in 1960. He suggested that extreme energy demand would push a technologically advanced civilization towards such a solution.
The essence of the idea is as follows:
A Dyson-sphere can be created around a star using a huge number of solar panels or other devices that collect energy from the star’s radiation.
This sphere creates an artificial shell around the star, which allows capturing almost all of its energy.
The resulting energy can be used for any purpose, including sustaining life, powerful computing, material production, and more.
Two versions of the Dyson sphere are possible:
- The envelope completely covers the star and absorbs all of its energy and the
- The shell does not completely enclose the star, but only partially, allowing for more practical energy and life support on the inner surfaces of the sphere.
How do the energy needs of advanced civilizations evolve?
There are several general phases through which a civilization passes in its energy needs:
Primary economy phase: when agriculture and primitive technology predominates, energy is mainly extracted from the physical labor of humans and animals. The main source of energy is food.
Hydrocarbon era phase: large-scale use of hydrocarbon fuels such as coal, oil and gas. This allows societies to dramatically increase their production capacity and energy efficiency.
Nuclear and atomic energy phase: the 20th century saw the beginning of the use of atomic energy to generate electricity. This phase is also associated with the development of nuclear technology for military and peaceful purposes.
Renewable Energy Phase: With the growing awareness of environmental issues and the limitations of hydrocarbon fuels, the use of renewable energy sources such as solar, wind, hydropower and others begins to develop.
Technological Utopia Phase: As civilizations become capable of harnessing and managing vast amounts of energy, concepts such as the Dyson Sphere and transgalactic structures emerge that involve harnessing the energy of the stars to supply all of civilization’s needs.
We could start by wrapping the entire surface of the Earth in solar panels. In that case, we would still capture less than one ten billionth of all the energy produced by our sun. Most of its energy is uselessly radiated into empty space.
How do we find the Dyson Sphere?
We can now use the Dyson Sphere as a marker for finding extraterrestrial civilizations. Given that the sphere blocks the light of the star, in the visible wavelength range, the star will not be visible or it will be very faint. But in the infrared, such a star will be clearly visible.
Star KIC 8462852, also known as “Tabby’s Star” or “Mysterious Star”, is an F-type star located about 1,480 light-years from Earth in the constellation of Swan. It has become known for its unusual and mysterious light changes that were detected in data from the Kepler Space Telescope.
From time to time, the brightness of the star drops dramatically by a significant number of percent, which is unusual for normal stellar changes. These episodic “darkenings” can be highly variable in duration and depth. What has sparked interest is their nature: such deep and irregular changes in brightness are difficult to explain by standard astronomical processes.
There are several hypotheses attempting to explain this strange phenomenology:
- One hypothesis suggests that these darkenings may be caused by debris from planets or asteroids that are in orbit around the star and periodically block its light.
- Another hypothesis is related to the presence of interstellar dust near the star that periodically masks its light.
A more exotic idea is that these darkenings could be caused by artificial structures such as orbital platforms, clouds of smoke from mega-engineering projects, etc.
In 2018, results were even published that observed small but regular changes in the brightness of Tabby’s Star, which adds to the complexity of finding an explanation.
According to the NASA report , because of its infrared emission, Dyson spheres are considered a kind of technosignature – a sign of activity that distant astronomers could use to infer the existence of intelligent beings in the universe . Several ground-based researchers have scanned infrared maps of the night sky in hopes of detecting Dyson spheres, but so far no one has seen anything unusual.
Maybe the James Webb telescope will be luckier.