One night I was lying down staring at the stars and it dawned upon me that I was not alone. I had only a few of the many alien eyes. Just like them I was figuring out if my god existed. I felt part of this cosmic family more than anything before. Something bigger than our soccer team, our continental heritage, or our world wide scientific efforts. All these eyes… The universe becoming aware of itself.
Where are the aliens?
But where are they? A question asked many times before (see the Fermi paradox). I would like to explore two options here. The first is actually pretty obvious, and the one I like most. So, the thesis is that the earth is not rare, and that there exists other civilizations in our own galaxy. The Milky Way is around 100,000 light years in diameter. Physically populating our galaxy would take, if we consider moving 1000 times slower than the speed of light, only 100 million years. Considering that there are many planets billions of years older than earth, that must have happened already many times over. So, why don’t we see aliens or million year old alien artifacts on earth? There might be a very simple answer: there is a cosmic communication platform. There is a way to communicate between intelligent species in which cosmic matters such as expansion to other galaxies are discussed. Species negotiate between each other, how much resources are required, and where they are allowed to go. They are careful with inter-world interactions because of viruses and other undesirable side-effects. Inevitably, a civilization discovers this communication structure before they are intellectually capable of physical expansion to other galaxies.
So, it’s up to us to find out how they are communicating! If there would be a faster than the speed of light communication method, how would it be implemented?! Has there been a physical coverage of quantum coupled atoms all over the galaxy and we have to phone in by finding these atoms? How would they have labelled these atoms, so we can find them easily?
There is another explanation, which is less exciting, but stems from my experience with evolutionary algorithms.
Where are the dragons?
Evolutionary algorithms seem to have glass ceilings, just as in the job market. Even if you check highly dynamic variants such as artificial gene regulatory networks (Bongard), or neuroevolution of augmented topologies (Stanley), and I even went further (as in evo-devo, to eco-devo, to epigenetics) in incorporating body changes to perceptual phenomena (pdf) as required in the evolution of circadian rhythms. Although interesting light dependent metamorphosis was developed in a simulator, it became quite obvious to me, that it is very hard to scale these things. It is very well known in machine learning that local optima can be very troubling to an algorithm, and evolutionary algorithms, although versatile, are no exception.
Why this long prelude? We have to search over all possible evolutionary trajectories not so much for paths that would lead to our type of intelligence, but for paths that lead to local optima from which it is hard to escape. With our human dexterity, we become quite proficient tool users (as did crows) and very important, we got fire under our control. But, what if evolution “got there first”!? Our stomachs have been evolved to withstand its acidic content. Perhaps, it wouldn’t have been such a stretch to have evolved a small biological oven as an organ, burning all kind of material that is normally hard to chew (for us mere mortals). Cooling systems are required of course, but that has been evolved multiple times over anyway. A newborn would need to get fire from his mother, but that seems a pretty easy procedure compared to feeding milk through specially developed organs for many weeks or months.
It might be that this is actual the normal way of evolution to proceed. And then? We have fire breathing creatures on this alien planet. Would it mean that tool use would get stalled? Or would dragons build space ships as well in the end? Who knows? Perhaps all aliens are dragons…