Produced by: Tarun Mishra
Dyson spheres are hypothetical megastructures built around a star to harness its entire energy output. Named after physicist Freeman Dyson, these structures would collect all of a star's radiant energy.
Detecting a Dyson sphere could indicate a technologically advanced alien civilization that prefers not to communicate. Such structures could signal a Kardashev Type II civilization, which can utilize all the energy from their star.
Earth receives 1,361 watts per square meter from the sun, a tiny fraction of the sun’s total energy output of 380 billion quadrillion watts per second. A Dyson sphere would capture all this energy that otherwise radiates into space.
A Dyson sphere denotes a Kardashev Type II civilization. Type I civilizations harness all the energy available on their planet, approximately 1,016 watts per second. Type III civilizations utilize energy on a galactic scale, including Dyson spheres around every star, attaining 1,036 watts per second.
Humanity is currently at Kardashev Type 0.7449, not fully utilizing the energy available on Earth. The concept of a Dyson sphere represents a significant leap in technological capability.
While theoretically possible, constructing a Dyson sphere presents immense challenges in terms of resources, engineering, and time. Dismantling an entire planet for materials might be necessary.
Freeman Dyson proposed the idea in 1960, inspired by Olaf Stapledon’s 1937 sci-fi novel "Star Maker." Dyson’s idea was to detect advanced civilizations through their immense artificial structures.
A Dyson sphere would likely be a swarm of solar collectors rather than a solid shell. This "Dyson swarm" would be mechanically stable and resistant to damage.
Dyson swarms could be detected by their waste heat emissions in the infrared spectrum. Astronomers must differentiate these signatures from natural phenomena like dust clouds and distant galaxies.
Various projects, such as Project Hephaistos, have sought Dyson swarms using data from infrared surveys. While several candidates have been identified, most have been ruled out as natural objects. The search continues, considering the vast number of galaxies that might host such advanced civilizations.