We appear to be living in a period of rapid technological progress—one so critical that our current actions might shape humanity’s entire future. With AI and other emerging technologies advancing at breakneck speed, there is growing urgency around alignment and global coordination. Left unmanaged, we risk catastrophic outcomes, from runaway climate change to nuclear war. But in the quest to chart a safe path forward, one question grows increasingly pertinent: how do we know we’re not already living in a sophisticated simulation?

The Logic of Simulation

The idea that we might be inside someone else’s simulation is not new. Think of Nick Bostrom’s Simulation Argument, or Elon Musk’s popularization of the notion that, if we ever build hyper-realistic, fully immersive simulations, it becomes difficult to rule out the possibility that it’s already happened. After all, if an advanced civilization can create simulations indistinguishable from reality, then why wouldn’t it? And if it would, how can we prove that our own reality isn’t just one of its highly elaborate creations?

Beyond Games: Toward Entire World Simulations

We already see early forms of simulation in weather prediction, artificial economies, and video games—domain-specific “sandboxes” that allow us to test ideas, refine strategies, and anticipate outcomes. The natural progression is to scale these models up to include entire societies, then entire worlds. If (or when) we develop such capabilities, we will face questions like:

• How do we create historically accurate contexts to test geopolitical, cultural, or technological experiments?

• Which variations of initial conditions lead to the least destructive pathways—whether to avoid nuclear war, pandemic collapse, or ecological ruin?

This is akin to the Black Mirror episode “Hang the DJ,” where a dating system simulates multiple relationship scenarios. Here, instead, we simulate entire civilizational arcs to evaluate potential futures. And the inevitable philosophical twist: If we are likely to build such simulations, might our own reality be the product of a predecessor civilization’s attempts to do the same?

Final Hours and Nested Simulations

Where it gets even more fascinating—and more unsettling—is the possibility of nested simulations. If a civilization is in its “final hour,” meaning a critical juncture where action or inaction might determine existential survival, it would have a strong incentive to create highly detailed, fast-running simulations to discover optimal strategies. In each simulation, time can be “sped up,” so millions of simulated years might unfold in days or hours from the “base reality’s” perspective.

However, each simulated world may eventually face its own “final hour,” prompting its inhabitants to build yet another set of simulations to search for solutions. This can continue ad infinitum, like fractal layers spiraling inward. One can visualize a timeline from 0 to 1, but each “step” is only half the distance of the previous one, so you never actually cross that final threshold—you simply keep subdividing forever. The end result is a fractal tower of realities, each convinced of its own authenticity, each creating more nested worlds, each living through its own urgent final moments.

Painting the Fractal Picture

Imagine a vast, branching tree of simulations, each blossoming into new nodes:

1. Base Reality (if it exists): Confronting an existential risk, so it launches a “final-hour” simulation cluster.

2. Simulation Layer 1: Millions—or billions—of years of compressed history. Inhabitants face crises and eventually develop the technological means to simulate reality themselves.

3. Simulation Layer 2: Time still flows normally for its inhabitants, who also perceive an inevitable “final hour” and initiate simulations of their own…

4. Simulation Layer 3 … and so on, receding deeper like infinite reflections in a pair of parallel mirrors.

Each “layer” might accelerate time, effectively expanding its “context window”—similar to how a larger context window in large language models lets them process more information. The idea is to pack more insights and outcomes into a shorter duration, thereby optimizing for survival strategies. Yet, from within any given layer, reality feels normal: people have histories, cultures, technologies, and existential questions about their own potential simulations.

Probability and Implications

If (1) advanced civilizations almost inevitably create sophisticated simulations, (2) each of these simulations feels “real” to its inhabitants, and (3) such civilizations can exist in nested layers, then the probability that we occupy the “first,” un-simulated layer seems vanishingly small. Occam’s razor doesn’t outright confirm we’re in a simulation, but it opens the door to the possibility that the existence of so many layers means the likelihood of being in “base reality” might be quite low.

Even if we are in a base reality, the point stands: we will likely create simulations of our own. And once we do, the inhabitants of those simulations—complex AI agents or conscious beings—may themselves question whether they are in the base reality.

Concluding Thoughts

The fractal hypothesis underscores that our existential “final hour” could spawn countless other “final hours,” each launching more simulations, each with the potential to propagate further. Rather than diminish our sense of agency, contemplating the simulation possibility can sharpen our vigilance about AI alignment and existential risk. After all, if simulation-creation is a normal function of intelligent life, ensuring that each new “layer” is benevolent may be one of the most pressing moral and practical concerns in the multiverse—whether we’re in “base reality” or ten levels deep.

By immersively envisioning a universe of recursively nested realities, we glimpse both the fragility of our own predicament and the sheer vastness of possibilities that advanced technology can create. Every civilization in every layer stands at a similar fork in the road, deciding how to shape the next set of realities. If we are indeed in a simulation, it is both a humbling and an invigorating call to learn what we can—and build a future worth simulating.