Civilization is a strange thing. While one may take it for granted in this day and age, the idea of a modern society only sprang up in the last few thousand years. However, the Earth has been around for billions of years, with every event culminating in humanity’s dominance of the planet. Yet the question remains – are we the norm, or the exception? One only needs to look up to the stars to begin pondering the base of the Fermi Paradox – where is everyone?

The Fermi Paradox states the purported ease of civilizations to establish themselves throughout our galaxy. Billions of stars number the Milky Way, and many are older than the Earth itself. Throughout these solar systems lie countless “Goldilocks planets,” with conditions seemingly perfect for life to begin on them. If even one planet had life evolve, it would soon be able to rapidly colonize the rest of the galaxy, too. At the current rate of human technological advancement, Fermi predicted that the galaxy could be colonized within a few millions years of the evolution of advanced intelligent life like humans. All this, however, simply makes the paradox that much stranger. It’s obvious that life should be somewhere out there – we just haven’t found it yet.

So where is it? Well, scientists and theorists have come up with a few theories as to why space is so devoid of life. The first, and one of the most common theories, is the idea of the Great Filter. The Great Filter is a specific event that occurs in a species’ timeline that is extremely difficult to surpass, often leading to extinction. For humanity, the filter is divided into two sections: behind us, or ahead of us. Both are simple, if terrifying, to comprehend. If the filter is behind us, it means that we have already passed it. Perhaps it’s something as simple as life itself evolving. This means that we are likely to be alone in the galaxy. The other option is it being ahead of us – which means we’re very likely to go extinct sometime in the future.

Another theory common in scientific circles is that we are the first species to reach our level of technological advancement. Perhaps alien species simply haven’t evolved to reach the stars yet. They might still be prokaryotes, for all we know. This is another likely solution to the problem, as even now astronomers have debated the existence of microbial life within our own solar system.

The last, and perhaps most terrifying theory, is the idea of a superpredator. Ultimately, there will be a point where raw resources become scarce and unobtainable. To prevent this, some civilizations may have adopted an aggressive, xenophobic stance against other prosperous and advanced civilizations. Either through constant probing or scanning for signals, they could snuff out any potential spacefaring rivals before they grow too strong, keeping the galaxy’s resources to themselves. If this is the case, the fact that humanity has been broadcasting our location for decades does not bode well.

In the end, nobody will know for sure where everyone else is, and the only way Fermi’s paradox will be solved is through our own technological advancement and colonization of the stars. But even then, for the time being, it might be better to hunker down. The universe is big, and we might just be drifting alone in the shark-infested waters.