Seeing Dyson Civilizations

In summary, the circumstellar shells of Dyson civilizations-at temperatures ~300 degrees K and radii ~1 a.u.--can be detected with existing telescopes and state-of-the-art infrared detectors in the 8-13-u window out to distances of several hundred parsecs. But discrimination of Dyson civilizations from naturally occurring low-temperature objects is very difficult, unless Dyson civilizations have some further distinguishing feature, such as monochromatic radio-frequency emission.

 Dyson Spheres

The mathematician Freeman Dyson, of the Institute for Advanced Study, offers a scheme in which the planet Jupiter is broken down piece by piece, transported to the distance of the Earth from the Sun, and reconstructed into a spherical shell – a swarm of individual fragments revolving about the Sun. The advantage of Dyson's proposal is that all of the sunlight now wasted by not falling upon an inhabited planet could then be gainfully employed; and a population greatly in excess of that which...