The key to a civilization's survival: resilience.
Some science fiction concepts imagine that technologically advanced civilizations might build Dyson spheres around their stars to harness their energy output. However, new research suggests a civilization's survival depends more on its internal governance and its ability to recover from collapse. Image credit: Kevin Gill / Wikimedia Commons (CC BY 2.0).
Human history is filled with civilizations that have vanished. The process of their collapse has long been a subject of intense study for historians and archaeologists. A general conclusion is that widening inequality and a breakdown of trust among the elite are often precursors to a civilization's downfall. So, a natural question arises: how might our own human civilization come to an end?
This question is even linked to a famous paradox in astronomy: the Milky Way has existed for billions of years, so why haven't we found any evidence of alien civilizations? This is the well-known Fermi paradox. A leading hypothesis to explain it is the existence of a "Great Filter" in the universe. This idea suggests that on the path from simple life to an interstellar civilization, there might be one or more extremely difficult hurdles to overcome. In short, this could be why the cosmos seems so silent today.
What exactly is the Great Filter? Is human civilization currently positioned before or after it? The answer to this question is directly related to the way a civilization collapses. In many sci-fi stories, humanity's crises are brought on by a specific monster, like "Red King arriving on Earth in three hours." But compared to these clichéd tropes, issues like oil crises, global warming, and volatile geopolitical situations appear far more pressing.
A Civilization Game
In a new paper, researchers abstracted an Earth-originating technological civilization into a model system. This system has just two state parameters: technological capability T(t) and available resource stock R(t), both of which change annually. The way they change is determined by seven other parameters. When the civilization is active, its technological capability grows at a fixed rate (r), and resources are consumed at a fixed rate (δ). If resources are exhausted, or a random crisis event occurs (with an annual probability of h), the civilization collapses.
After a collapse, the civilization's technological capability is slashed to a fixed fraction (cf) of its current level, while resources drop to zero. The civilization then enters a dormant recovery period lasting rd years. After this recovery period, resources are restored to a certain fraction (rf) of the initial resource level. This cycle of survival and collapse can occur multiple times in a simulation.
Having set these parameters, the researchers turned to simulations. Starting from an "Earth-originating civilization," they outlined 10 possible future scenarios. For example, "Big Brother is Watching" (S1) is a scenario of high control, high resource pressure, and elevated external risks. The "Golden Age" (S3) features abundant resources and stable governance. "Transhumanism" (S5) is somewhat akin to biological engineering from science fiction, a scenario the research team considered to be highly complex with sufficient resources but lingering minor risks.
The 10 scenarios designed in the study. Image credit: Original paper.
The researchers set different initial states and parameters for each scenario and ran 200 simulations, each spanning 1,000 years, for every scenario. The results showed vastly different outcomes.
The simulation results fell into two broad categories: S3 Golden Age, S5 Transhumanism, and S10 Exodus from Eden remained continuously active throughout most or all of the 1,000-year simulation period. The remaining seven scenarios all experienced collapses, though with varying collapse frequencies and recovery capacities.
For instance, in the S1 Big Brother is Watching scenario, the first collapse event occurs before year 210, and the civilization collapses an average of 10 times during the 1,000-year simulation. Moreover, these collapses are followed by long periods of inactivity.
The S8 Ouroboros scenario represents a civilization that can recover quickly from collapses. In a 1,000-year simulation, this civilization collapses only twice on average. However, it remains active for an average of 870 out of those 1,000 years.
After running the simulations, the paper concluded that a civilization is not necessarily doomed by a single collapse. The more critical question is whether the civilization can recover from a collapse. Upon conducting a sensitivity analysis of various parameters, the researchers found that the rate of resource consumption and the degree of post-collapse recovery were the most influential levers among the hypothesized scenarios. These factors' impact on a civilization's trajectory was even greater than the overall collapse risk the civilization faced.
People often assume that a more technologically advanced civilization is safer. But the model offers a more cautious conclusion: if technological growth is coupled with higher resource consumption, then technology itself doesn't necessarily make a civilization more secure overall. It may simply be driving the civilization toward its resource limits at a faster pace. In other words, the precursor to a civilization's collapse might not be an increasing number of disasters, but a steadily shrinking margin for the future.
Of course, this paper couldn't account for every possibility—an obviously impossible task. The authors also pointed out the simulation's limitations at the end of the paper. For example, in theory, a civilization's technological level T could influence its available resource quantity R, but the paper did not consider this effect. From this perspective, the paper is more like a rigorous set of sci-fi worldbuilding rules, carrying significant subjective biases in its scenario design, rather than a reliably quantitative predictive model like a climate simulation.
Searching for Alien Civilizations
The paper is more deeply concerned with the Fermi paradox itself.
In 1961, the American astronomer Frank Drake formulated an equation intended to estimate "the number of intelligent alien civilizations in the Milky Way with which we could communicate." This equation posits that the number of detectable civilizations is the product of several factors, including the number of stars in the galaxy, the number of planets, the probability of life emerging, intelligence developing, interstellar communication being attempted, and the duration of such a civilization's communicative phase. We can use the Drake Equation to calculate the number of civilizations in the Milky Way and thus judge the validity of the Fermi paradox.
Image credit: Pixabay
The lifespan of a civilization, L, is the final term in Drake's equation. However, this new paper argues that this final term should be changed from a continuous lifespan to an effective detectable timespan. The authors found that even for an Earth-level civilization with decent technology, the future holds a significant probability of collapse under various scenarios. Drake's L parameter implicitly assumes a civilization transmits signals continuously. If a civilization's activity is intermittent, a detectable duty cycle factor should be multiplied into the equation.
And this duty cycle can only reduce the number of civilizations calculated by the Drake Equation. The paper found that civilizations with high energy consumption tend to be short-lived. When this is compounded by a low detectable duty cycle, the probability of detecting such a civilization is doubly suppressed. Perhaps this answers the Fermi Paradox—maybe we haven't found aliens because a large fraction of them are currently in a dormant, post-collapse "sleeping" period.
Reference links:
https://www.universetoday.com/articles/which-types-of-civilizations-collapse-and-which-can-endure
https://arxiv.org/abs/2604.13774