I was watching an oldish YouTube video by kurzgesagt about what it would mean if we were to find alien life forms out there. It was an interesting watch. You can find it below. Go, check it out. It’s not that long, and I’m not going anywhere.
Okay, so you are back. Great! Now that we are all on the same page let me go over some of the things that are mentioned in it… and also let me warn you that I am going to be approaching this as a science fiction writer because, well, because that is basically what I am. That means that my perspective might be a little different from a scientist’s, but it takes all kinds to make the world, so here we go.
To begin with there is the fact that I agree that chances are that the damage we have done to the biosphere is already irreversible, and that we are effectively doomed, the question is: was that truly inevitable, as the video would seem to suggest, or are there some things the video is missing.
Well, let’s start with the fact that off the top of my head I can think of a number of filters we have already overcome… or maybe these are places were we just lucked out. Let’s begin with the earth itself.
One thing we have that makes our world stand out is the presence of the moon. This may not seem particularly relevant, after all we are talking of a very pretty chunk of utterly dead rock, but one theory suggests that the Theia impact which gave rise to the blasted thing left our planet with a rather unique characteristic: a much larger iron core than it should have had by rights. That iron core gave rise to the magnetosphere, which in turn protects us from solar radiation. This one may be the iffiest of the lot, but if this theory is correct, then we owe our existence to the moon. The thing is that our moon itself seems to be something of an anomaly, and if that is actually the case, then it would be an important filter we have already overcome.
Next in line is what we know not only of the origin of life, but also of what brought us to this point. The one thing pretty much everyone seems to agree upon is on the fact that life began both in water, and in an anoxic environment (that is, in a world that was devoid of free oxygen). Simply put, oxygen is incredibly reactive, and there is no way the earliest organic molecules would have survived in its presence. It was roughly a billion years after life began that the Great Oxygenation Event… nearly wiped life off this world. Against all odds life made it past that particular filter too, and then found itself in an utterly transformed planet.
In time we evolved into multicellular organisms, and left the oceans behind. Neither one of these developments was likely foreordained, in fact there is nothing to require that habitable worlds have both oceans and dry land, but there is one thing the science fiction writer in me would like to point out –one of those that is unlikely to jump at a scientist in a similar fashion– and that is that without the Great Oxygenation Event, and our migrating to dry land, our cultural evolution would have run into an almost insurmountable bottleneck. Yes, it is true that underwater civilizations are a trope of science fiction, but there is one problem with that particular scenario: it is almost impossible to conceive of an advanced civilization without metallurgy, and metallurgy itself is utterly dependent on the existence of fire, meaning it is inconceivable both under water, and in the absence of free oxygen. So, even if intelligence were to evolve in an anoxic or underwater environment, there would be a serious obstacle to its technological development, one I am not sure it would be possible for it to overcome.
Now let’s turn our attention to some seemingly insignificant traits of our planet that we usually take for granted, like the fact that we can actually look up, and see the stars. That seems like such a minor thing, and yet it is anything but. What would have happened if our atmosphere had been just a little bit denser, dense enough to conceal them, especially if there had been no such a thing as the moon, if the only celestial body whose presence had been obvious to us had been the sun, and there had been no tides to hint at anything else. Would we ever have been able to even begin to conceive of the existence of the universe as we know it? It is hard to imagine how we could possibly have made that conceptual leap, and if we hadn’t the notion of putting a satellite into orbit, or of trying to find if there were other forms of life out there, would have been out of the question. So let’s add those to the list of filters we have already overcome.
And finally let’s turn our attention to the other side of the equation. The video keeps talking of filters that may keep us from moving forward, and lead to our doom, but the flip side of that is that in addition to those filters there may also be some blindfolds we are yet to remove. Yes, it is true that so far we have found no signs of a galactic civilization, and that doesn’t seem to bode particularly well for our species, but think of how we think of what we think we know, and you will realize that what we know is based, either directly or indirectly, on what our senses can perceive, expanded with the aid of technology. The thing is that our senses have evolved to keep us alive here on earth –they are more concerned with helping us avoid being eaten by a lion than with helping us make sense out of black holes– so we don’t know what we might be missing because it falls outside our sensory range, because here on earth it made no sense for us to be able to perceive it at all (think dark energy or dark matter). Now, if there is one thing scientists seem absolutely certain of is the fact that nothing can travel faster than the speed of light. The thing is that for a galactic civilization to be even remotely viable the first thing it would need is to do away with that particular restriction. Light is just too slow for interstellar travel or interstellar communications, but at our current level of technology anything that is traveling faster than the speed of light would be, out of necessity, absolutely invisible, so what if what lies ahead of us is not so much a filter we have to overcome, but rather a curtain that we merely have to pull aside?