An astronomy paper from September has made massive waves in the news recently, leading to many news organizations publishing splashy articles with titles like "Far-away star's strange lighting patterns could be caused by alien megastructure." Astronomers have found a very unusual light curve from a star and one of the possible explanations for the vast amount of starlight blocked, although extremely unlikely, is alien superstructures used to collect power from the star. Though it is just a hypothesis (and a very unlikely one, at that), it has brought aliens--one of humanity's favorite topics to dissect and debate--back into the spotlight.

Two of the most famous aliens in Star Trek. (Source: CBS)

Putting the label of "aliens" on something unknown is an all-too-common practice. When pulsars were first discovered, they were thought to be alien communications (the belief that pulsars are "alien lighthouses" is still prominent in enthusiast groups). The sight of Venus in the night sky leads to increases in UFO reports. We even have the show "Ancient Aliens" which claims aliens were responsible for everything from the dinosaur extinction to the construction of ancient monuments. While some of these events led to us developing things like standards for responding to alien contact, most of them show that there is essentially always a natural explanation for these phenomena--an explanation that does not involve alien civilizations. Yet we continue to persist, attributing unexplained phenomena to beings from another world.

People are captivated by the idea of intelligent life on other planets. Aliens play prominent roles in movies, books, TV shows, music, art; the narratives surrounding them range from the fear of invasion, to the prospect of collaboration and exploration, and we spend a considerable amount of effort listening for long-distance calls from intelligent life elsewhere in the universe. But why are we so interested? Are we scared of invasion, of encountering something that threatens our beliefs, of the unknown? Are we lonely and worried about being completely alone in the universe? Are we simply curious, and just trying to get the scoop on our neighbors?

Part of the Search For Extra-Terrestrial Intelligence (SETI)'s Allen Telescope Array. (Source: Space.com)

There are almost as many explanations for this as there are alien-related movies (including a very intriguing idea that alien movies, in particular, represent Western society's relationship with colonialism), but regardless of our intent, one thing has become clear: Life on other planets, if it is there at all, is really hard to find. In all our years of listening with SETI's arrays and searching for planets with Kepler, we haven't really found much of anything. Sometimes something promising comes through, like the WOW signal, but oftentimes these anomalies cannot lead to any concrete conclusions, and they are few and far between. If the Drake Equation is correct, and intelligent civilizations (though few and far between) are out there...well, where are they?

The Fermi Paradox offers what may be the starkest explanation: We haven't found anyone else in the universe because there is nobody else--at least, nobody else with technological capability--because if there were aliens, they would have colonized the galaxy already (there's that colonialism again). Other explanations aren't so stark, but far more unnerving. One idea states that sufficiently developed civilizations may leave the universe, focusing on "inner space" instead of outer, and enter black holes to reach computationally optimal domains, so we don't see them. The Planetarium Hypothesis suggests that the universe we observe is an illusion and we instead reside in a virtual reality program that projects an empty universe. A simpler explanation may be that advanced civilizations are sending out signals, but we don't know how to receive or interpret them.

Black holes: a good place to raise the computationally optimal kids? (art by Mark A. Garlick)

Essentially, we have no idea why we haven't found advanced civilization elsewhere in the universe. At this point, we haven't even found civilization that's not advanced (though many suspect Europa will be the best place to find microbes and other life forms). This whole process of trying to find other civilizations is really, really difficult--we're a tiny speck calling out into a universe infinitely vast in size and trying to listen for signals sent from similar tiny specks. Is it worth the work, worth the money and time we're putting into this project that has such a small chance of return?

Well, that's a matter of opinion. Maybe in the end, all we're looking for is another way by which we can understand or define ourselves as a species, our position in this weird existence we occupy, our thoughts and emotions and actions. Simply listening and looking for aliens is teaching us more than we can possibly imagine about ourselves and our world--and, in the end, if that's all we have, I'd say it's worth the effort.