Alien filter
I figure if aliens are visiting our solar system, I should probably write something about them. Seriously though, if you aren’t following the 3I/ATLAS object, you probably should be. I’m not saying it’s aliens… but it’s aliens. There are a lot of anomalies surrounding it, and while I’m sure many will eventually be explained by science, I’m not convinced they’ll explain everything. Seriously, with a 4 signma significance, why arent more people talking about this?
The Fermi Paradox is the discrepancy between the lack of conclusive evidence for advanced extraterrestrial life and the apparently high likelihood of its existence. There are billions of stars, with billions of planets, across billions of years. So where is everybody?
My theory is related to the Great Filter hypothesis, but it diverges in an important way. The Great Filter suggests there is some barrier to development that makes detectable intelligent life exceedingly rare or outright impossible. The usual explanation is that too many unlikely conditions must align … habitable planets, stable chemistry, complex life, intelligence, technology, …
My idea is simpler although perhaps more pessimistic: any sufficiently advanced life form will consume its accessible resources before it gains the ability to expand meaningfully beyond its origin. This limits civilizations to a small region - perhaps a continent, a planet, a star system, or even a galaxy. But resource constraints prevent them from spreading further.
You can see this pattern in animals like rabbits. Given unchecked growth, they consume available food while reproducing rapidly, often overshooting the carrying capacity of their environment and collapsing into starvation. Nature sometimes regulates this through predator–prey dynamics, but the balance is hardly perfect, especially in isolated or constrained environments.
Look at some remote human tribes. They are limited to their island or territory, with no capability to expand. Even if the motivation exists, they may lack the necessary resources. An island might produce canoes but be fundamentally incapable of producing true seafaring ships because they lack the appropriate resources like iron.
Zoom out to modern humanity. We are consuming oil at an unsustainable rate. What if we exhaust it on cars, shipping, and domestic travel? That same oil is needed for advanced materials, infrastructure, and the research required to reach beyond our planet. I was playing Factorio (again) and mined all my iron. I didn’t have enough left to build railroads to reach new deposits. I exhausted my resources, granted mostly fighting alien hordes, but the result was the same. I couldn’t expand further.
The Kardashev Scale becomes especially interesting when you pair it with the idea of activation energy. In chemistry, activation energy is the minimum energy required to start a reaction. A side point of my theory is that civilizations face something similar. A Type I civilization can harness the energy of its planet, while a Type II civilization can harness the energy of its star. If it takes, say, 25% of a planet’s total energy capacity to begin harvesting stellar energy, but you’ve already consumed 80% of what the planet can provide, then progressing to the next stage may be physically impossible.