Stadyshell

Statite Dynamic Shell, aka, Stapleton Dyson Shell


1. The Standard Story

The continued increase of the human population, expanding into the solar system and later to other star systems, is a common assumption in 20th century science fiction. People move into orbiting space habitats at the L4 and L5, terraform Mars, etc. When planetary systems are exhausted, the expansion continues into more space habitats orbiting the sun, perhaps manufactured from the asteroids, Mercury, and Venus. Some propose dismantling the Earth to build more habitats, eventually capturing most of the energy from the Sun.

Nikolai Kardashev characterized future supercivilizations by the energy they capture and use.

So, a supercivilization capturing all the power emitted by the Sun with a shell of habitats would be a Type II supercivilization.

Olaf Stapleton wrote about type II and type III supercivilizations in his 1937 space fantasy novel Starmaker. Freeman Dyson wrote about how such supercivilizations might appear as highly luminous, compact infrared sources in 1960, Search for Artificial Stellar Sources of Infrared Radiation. He described them as shells, an assembly surrounding a star - he did not claim they would be solid or round.

Because of this paper in Science, a journalist misleadingly named these sources Dyson Spheres, a source of confusion ever since. Dr. Dyson wishes they were named something else, as I will do below.

The "Dyson" "Sphere"

The scare quotes are intentional - the name is wrong, as is the description. I will describe the idea the label has come to describe, before disposing of it.

For many science fiction readers, this is a large solid sphere, inhabited on the inner surface with the sun overhead. Details intentionally vague ... because that doesn't work. The

A Miscellany of Physical Pathologies

The area of a sphere is 4πR² - the area facing in one direction (like the sun) is πR², so the average surface illumination is ¼ of the total. Add in atmospheric reflection, and the average illumination (visible light and near IR < 2 μm wavelength) reaching the Earth's surface is about 250 W. If this was somehow duplicated across the inner surface of a huge sphere, and radiated into deep space on the outer surface,

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