who’s afraid of the big, bad alien invaders?
It makes sense for an alien species not to care about wiping out a civilization on another planet. Question is whether it would be worth the hassle.
Another day, another proposed solution to the Fermi Paradox, which asks where are all the aliens if the skies are just filled with extraterrestrial empires. Yesterday, my good frienemies at the arXiv blog shone a light on a paper by a quantum theorist which tackles the possible interactions between alien species from evolutionary points of view, seeing each extraterrestrial civilization as competing for resources, and trying to keep quiet as not to attract too much attention to itself. It’s certainly not a new idea, though it’s a minor twist, and I’m tempted to jokingly call plagiarism on it for reasons long time readers may remember. It sounds pretty solid, right? A certain number of galactic predators with the means to travel between stars certainly need a lot of resources, and they probably won’t feel any warm fuzzies about the inhabitants of other worlds, so they just may colonize whatever lives on their target planet, or exterminate any advanced society and take whatever they want. Well, it sounds solid unless you’ve been paying attention to some of my posts about alien invasions that is…
Here’s how it all breaks down. Habitable worlds that can support intelligent, complex life are likely to be rather rare and far between, true. Having those habitable worlds go through an evolutionary history where traits like intelligence and creativity offer a distinct selective advantage is rarer still, also true. And the odds of a new and growing society of aliens choosing to create entire cities and start to explore the cosmos while asking if there are other beings like them out there are even smaller than that, again true. However, when we shift to whether an alien species will invade another’s home world because it’s lacking certain resources, we run into issues with their motivation for an attack. Our solar system alone has enough resources to sustain whatever human beings will diversify into for tens and tens of millions of years. There are countless tons of metals, several big oceans filled with water, and more ice than we can even imagine. Even a trillion starving aliens would take an extremely long time to consume so much, they have to move on to another solar system to sustain their vast, seemingly insatiable societies. And they’d likely find another billions of years worth of the same stuff with just one quick hop to the next solar system over. So why do they need to attack other habitable planets?
But wait, you might interject, what if they need some very special resource found on a habitable planet? Some organic compound or enzyme they can’t do without? Well, chances are that they won’t find it any place outside their home planet then because such a specific resource implies millions of years of very narrow evolutionary pressures and a very unique result. The odds of finding another planet with even a similar substance present in the biosphere is an incredible long shot, and if these aliens know how to travel to another solar system, I’d be willing to bet that they can build a lab to synthesize it in greater quantities than it’s found in nature. After all, all the raw materials needed to build complex organic compounds are just floating out there in space, simply there for the taking and protected by no one. Considering the sheer glut of usable materials out there, it’s very hard to justify any concept of intense competition for resources and base how aliens will interact based on an extrapolation of what happens here, on Earth, in tight quarters and among high levels of competition for rather scarce resources or resources in high demand. Of course that said, boldly challenging another alien species to a fight or shining a beacon to who knows what may be a very bad idea, but considering how unlikely it is to backfire, it doesn’t seem like every alien other there would decide to go into stealth mode.
Maybe the solution to the Fermi Paradox may lie in the very simple problem of communication between aliens and the vast differences between cultures separated by billions of years of evolution and quadrillions of miles of space. Like we’ve discussed before, what to say to an alien to make sure it understands us is a question we really can’t answer without knowing at least a little about the aliens themselves. It may be that we already hit pay dirt and there are several alien civilizations nearby who have heard us. They just have no idea what we said and didn’t know how to properly separate our signal from the cosmic noise or what we said. And while a mysterious, one-off event like the Wow! Signal still makes us scratch our heads and wonder what if, some bit of our spike in radio signals might have registered on an alien SETI array and there are bizarre little beings in labs pouring over their data, asking what if they might have caught a snippet of a signal coming from another life form from another solar system. And neither of us may ever know for sure. I suppose this is just one more way in which nature shows its utter indifference to our desires, indifference often bordering on contempt.
See: Adrian Kent (2011). Too Damned Quiet? arXiv: 1104.0624v1