

Is it possible to detect a Dyson Sphere from Earth ? Image Credit: CC BY 3.0 John Masterson, CSIRO

Could an alien civilization build a large spherical energy-harvesting structure around a distant star ?

The concept of a Dyson Sphere was originally proposed over 50 years ago by physicist Freeman Dyson who suggested the possibility that a sufficiently advanced extraterrestrial race may be able to surround a star with a huge spherical structure and then live on the inside of the sphere.For a time there were actually efforts by astronomers to pick up the infrared heat signature of such a structure, but after years of failing to find anything the idea has more or less fallen out of favor.Now however two physicists have put forward the notion that the reason we are unable to find these huge structures out in space is because they are likely a lot smaller than scientists had imagined.It certainly makes sense, given the tremendous scope of constructing a sphere encompassing, for instance, the distance from the Earth to the sun. Instead, the physicists' argue, anyone attempting such a feat would be more likely to build it around a much smaller star such as a white dwarf.The smaller the star however the weaker the infrared heat signature, meaning that even if this were true and these smaller Dyson Spheres do exist, we'd be unlikely to pick them up.For now, at least, the existence of these incredible structures will continue to remain a mystery.