Explaining of The Absence of Aliens Around Us

Recently astronomers were able to map about 1 billion stars around us. Sounds impressive, but that’s less than 1% of total stars there are in the Milky Way. It’s statistically impossible that we are the first intelligent species in the galaxy. There were advanced civilizations before us, there are some developing means to communicate with us right now and there will be more. The only question is: where is everybody? One thing you can’t take from humankind is that we are highly optimistic and hopeful. All this time we live under the starry skies, there are a lot of people looking at them and thinking that we are certainly not alone in the Universe. And statistics tell us that it’s most probable that we in all reality aren’t. There are too many worlds out there and life is too adaptable. In 2017 a group of British scientists discovered, that life developed really soon after the planet itself become habitable. Once we thought that the development of life is a highly improbable event, but now this way of thinking is just becoming obsolete.

On the other hand, we’ve been looking for about 70 years for any sign of extraterrestrial life or an attempt of communication from little big-headed humanoids or whatever they are. And we still have absolutely nothing to show for. How is this possible? Exactly that question once asked famous Italian physicist Enrico Fermi, the creator of the first ever nuclear reactor. Since then astronomers and all ET enthusiasts of the world are familiar with Fermi Paradox. In simple words, as it was worded originally: if there absolutely should be developed civilizations in the Universe, then where is everybody? Fermi Paradox has a lot of potential solutions: something along the lines of 75 to be precise, but today I will focus on major ones, that can possibly explain this troubling absence of aliens around us.

The first group is all about two big ideas: The Rare Earth Hypothesis and the idea of the Great Filter. They are closely related to each other and both can be soul crushing for those believers out there that want to meet extraterrestrials in person one day, so please, brace yourself. Can you imagine, how much should fall into place for an advanced civilization to rise to our level – sending radio signals into space, launching huge telescopes and satellites, searching for exoplanets and life out there. Starting with the qualities of the Sun, neighbor planets, the Earth itself and the Moon, and ending with our natural curiosity and aching need to reach out into space. Let’s just say, we hit a jackpot in all categories. These requirements combined are called the Great Filter and the ability of our home planet to come through it and win the biggest lottery in the Universe – is what the Rare Earth Hypothesis is all about. So what filters there are and what conditions are good enough for our possible alien buddies to evolve and develop their civilization?

Their sun must be something like our Sun - not too bright, not blazing into crisps whatever planets may orbit around it, but not too dim, so they won’t be just giant frigid cold spheres. The planet they live on should be in the habitable zone of their star. One thing to notice is that we’ve already found planets around nearest to us stars, that are just like that, so to this point all mentioned requirements of the Great Filter should be quite passable. The true difficulties start here. For example, there must be something like Jupiter around. Jupiter is huge not only in size but also for his benefit to us. Its mass attracts all the space debris, meteors and comets to himself like a giant vacuum cleaner. If not for him, the Earth would be bombarded with giant space rocks all the time. Another big thing that supports us is our moon. Did you know that the Moon is the biggest natural satellite in the Solar system in relation to the size of a planet it’s orbiting? The Moon’s size is a bit under one-third of the Earth’s, and without a body like this in its orbit, the Earth would be unstable and unable to support life at all.

The size of our planet and its speed of rotation, make an optimal day and night cycle. Our planet has lots of chemical elements, crucial for the development of life. Most importantly hydrogen, nitrogen, carbon, oxygen, sulfur, and phosphorus. The last one is actually quite rare in the galaxy overall and originating only from supernova blasts as the recent research from Cardiff University in Wales shows. And you think that makes up for a Rare Earth? That’s not even half of the factors, and we’ll be here all day if we try to go through them all. You definitely got the idea – the Earth is extremely rare planet indeed. More important even, that we’re only a half-way through the Great Filter too. Planets like Earth still must appear in the Milky Way. Let’s imagine these planets developed some kind of life, but they still have to be able to support it long enough for evolution to get to work. From self-replicating organic molecules like DNA and RNA to single-cell organisms to complex life with distinctive organs to all the range of species that can adapt to different environments and inhabit the whole planet, and finally to an intelligent lifeform that can use tools, think and communicate.

That’s a long long road that takes at least 4 billion years. All kind of stuff can happen through that period of time! Gamma-ray bursts flashing through the particular part of the galaxy, extreme ultraviolet radiation, collisions with other celestial bodies – if all of that misses the planet we’re talking about than we have a winner. Eventually, it will have itself some kind of humanoids, that look at the skies from time to time and think that they probably aren’t alone in the Universe. This is just how evolution works - always going for biological complication and the single most effective adaptation tools. And the tool that stands above all others is intelligence. But these intelligent folks still won’t be ultimate winners of this universal lottery. They still have to develop technology to go into space and send signals. Technology development is tough enough by itself, but it’s not as tough as the development of a society that would allow them to live relatively in peace and to aim for the stars. There is no way to calculate how often all of these can happen in the Universe, but let’s be clear: the probability is not looking too good. So the Great Filter idea definitely can be the solution to Fermi Paradox, though a bitter one.

Another solution is far more optimistic. Aliens are out there, but we just can’t properly communicate with them. What we use as a mean of communication is mostly radio signals, but remember all the steps some abstract intelligent lifeform needs to go through to become an advanced technological civilization. What if they went through a significantly different route in technology, that is not even comprehensible for us. What if they did so, because they originally talk to each other not like we do at all? Through the release of pheromones and complex movements like insects on Earth, or through a change of color like octopuses and chameleons, or via smell markers like cats and dogs, for example. How strange to us their high distance communication technology could be? Probably we won’t be able to even recognize it if we look for radio, just as they won’t recognize our signals as something intelligible. In this case, we would be basically invisible to each other no matter how close we are on a galactic scale. Another argument is that they must be already communicating through much more advanced technology for instant messaging between different colonies they might have at this point. But look at this from another point: people still use mail to this date, even when we have the Internet. Nothing stops aliens to receive technologically outdated messages, and nothing stops them to locate where our radio-noisy planet is in the galaxy. But it still doesn’t happen, so the Fermi Paradox stands firm with its question.

The next solution is far more possible. In basic terms, it proposes, that we are not alone, but we are the first to advance our civilization to the needed level of technology. It will take an unimaginable amount of time for us to peak first signals from ETs. This argument is even more believable because of how hard it is for life to find its place in the galaxy. Maybe we are at the start of the Milky Way blooming with life and we are the first to see it for ourselves! There is also a funny argument that aliens are so unlike human in their way of thinking that they simply don’t want to communicate with anyone outside. Reasons for that could be many things. They might be just grumpy like that, too afraid of anything outside of their world or maybe they are able to fulfill all their needs on their home planet in some kind of closed in itself Utopia and simply don’t want to go outside. Let’s leave it to sci-fi writers anyway, but it worth mentioning that such scenarios are possible and they can be quite effective solutions to Fermi Paradox. And finally, the solution all fans of UFOs want to believe in – they really are common in the galaxy, but they can hide from us and maybe they are already around us. They might be something we can’t even recognize as aliens or they are very good at mimicking us. Unfortunately, this argument is as interesting as your imagination allows it to be, because there are no objective restrictions for that. If they are so advanced, that their possibilities are basically magic to us, then these possibilities are endless. You know the joke about the chance of meeting aliens in any given day: it’s exactly 50% - you either meet them or not. This is precisely what this argument means.