A team of astronomers is now looking for Dyson Spheres, massive star-scale solar power plants that extraterrestrial hunters hope alien civilizations employ.

In 1960, mathematician, physicist, and all-around genius Freeman Dyson predicted that every civilization in the Universe eventually runs out of energy on its home planet, provided it survives long enough to do so. Dyson argued that this event constitutes a major hurdle in a civilization's evolution, and that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Astronomers have taken to calling these theoretical megastructures Dyson Spheres. Dyson's insight may seem like nothing more than a thought experiment, but if his hypothesis is sound, it has a striking implication: if you want to find advanced alien civilizations, you should look for signs of Dyson Spheres.

Last month a trio of astronomers led by Penn State's Jason Wright began a two-year search for Dyson Spheres, a search that will span the Milky Way, along with millions of other galaxies. Their project was just awarded a sizable grant from the Templeton Foundation, a philanthropic organization that funds research on the "big questions" that face humanity, questions relating to "human purpose and ultimate reality." 

So how do Wright and his team aim to find a Dyson Sphere? Though the word "sphere" summons to mind a solid structure, Wright says his team won't be looking for solid shells. "Even though there is enough mass in our solar system to construct a solid sphere, such a structure would not be mechanically feasible," Wright told me. "It would probably have to be more like a swarm of collectors."

Dyson swarms are an interesting idea. But perhaps some highly advanced civilizations do not swarm on planets and in solar systems, but rather disseminate throughout the galaxy. The Kardashev scale discussed in this article doesn't really take into account hitherto unknown and exotic ways of producing energy, along with those advanced civilizations that may be deliberately self limiting in their numerical growth, but yet interstellar in the scope of their physical expansion. What we anthropocentrically assume will be indicative of advanced civilizations, may not be the case. To read more, click here.