Lots of scientists think our Galaxy should be full of advanced alien civilizations (see the Drake Equation and Fermi Paradox posts). But when they’ve looked the Galaxy appears to be quiet and lonely. Where are all the alien civilizations they ask?
Many insane people would of course argue with this, pointing out that aliens have visited us; that they created the pyramids, Atlantis and humankind itself. That they regularly abduct and probe drunk Americans, that the government knows and is covering it up, and that the government itself may even by aliens, alien communists, sent here to steal freedom from God-loving Americans. But then they’re insane. None of this is true.
In a previous post I argued that alien life might be common, but that simple life rarely evolves into intelligent life, and that even if it does, intelligent life may not exist for very long. However I may be wrong, I’m wrong about things all the time, especially as some astronomers may have discovered evidence for vast alien structures in space, I shit you not.
The story begins in 1964 in communist Russia, an astronomer called Nikolai Kardashev had been thinking about advanced alien civilizations, as most astronomers do, especially communist astronomers. Kardashev proposed a scale for categorising a civilization’s level of technological advancement based on how much of their star’s energy they use. All energy on Earth ultimately comes from our Sun, one of the most direct ways of harnessing it is through solar energy technology, which humans are totally crap at doing, apart from on calculators and watches in the 1990’s. Anyway, the scale was imaginatively called the Kardashev Scale and there were three categories:
Type 1 civilizations – use all of the energy that their planet receives from their star. Every beam of light (or photon in science speak) that hits the planet would be used. We’ve not achieved this, human civilization is not yet a type 1 civilization, but maybe in a few hundred years we’ll get there. Unless Sarah Palin and the other lunatics get their way. Then we’ll be back in 18th century.
Type 2 civilizations – use all of the energy that their star emits, every single photon of it, not just the energy that hits their planet. One of the ways a civilization might do this is by building a Dyson sphere. These are enormous structures that surround a star and collect all of its energy. Lots of different variations have been proposed, from Dyson rings (a bit like in Halo) to Dyson swarms, vast clouds of orbiting solar-panel satellites. Scientists have even suggested you could live on the inside of a Dyson sphere; there’d be loads of room as its area would be vast, and you could throw all your rubbish into the star. Brill.
Type 3 civilizations – use all of the energy that their galaxy emits. So not just the energy from one star, the energy from hundreds of billions of stars. This kind of energy would probably allow the civilization to do all kinds of cool things like fold space or travel in time. It’s so technologically advanced though that who knows what this would involve, or if it would even be impossible. Those communists sure knew how to dream though.
So I promised you proof of vast alien structures in space. Have you guessed yet? Yep, astronomers just may have found evidence for some kind of Dyson spheres floating around out there.
So what would you look for if you were hunting for Dyson spheres? Well firstly, they’d probably be very big, so they’d have quite a strong gravitational attraction, and secondly they’d emit some heat, but nowhere near as much as their star, as they’d absorb their star’s energy, and would re-emit it back to space, but at a lower temperature as the energy would be emitted from an object with a greater surface area. This energy would likely be re-emitted as infrared energy, so Dyson spheres would not be bright objects, like stars. Any dark object with a lot of mass could be a Dyson sphere.
Astronomers have found such objects, primarily through using the Infrared Astronomical Satellite (IRAS), and have even made a catalogue of potential Dyson spheres from this data. You can see more details on this at Dick Carrigan’s website (he’s a particle physicist with a passion for the search for intelligent alien life).
Lots of these objects can be explained by phenomena we already know about, like stars surrounded by clouds of dust, but some can’t.
Of course, these objects could be something totally different, not at all related to alien life; something we don’t know about yet. And there’s no certainty that alien civilizations would choose to make Dyson spheres, just as there is no certainty that alien civilizations exist at all. But its still exciting to know that these objects are out there, and that one feasible explanation is an alien Dyson sphere. Fingers crossed!