Chapter 9
THE EXPONENTIAL
Human technological growth is accelerating in ways that demand explanation.
9.1 The Numbers
Let’s be precise about what we’re claiming.
Homo sapiens—anatomically modern humans—appeared roughly 300,000 years ago in Africa. For most of that time, our ancestors lived as hunter-gatherers, using stone tools that changed little over tens of thousands of years. The Acheulean hand axe, a teardrop-shaped stone tool, was the dominant technology for over a million years. A million years of the same tool.
Then, in the last fraction of our existence, everything changed.
| Period | Years ago | Development |
|---|---|---|
| Cognitive revolution | ~70,000 | Art, symbolic thought, rapid migration |
| Agricultural revolution | ~12,000 | Farming, villages, population growth |
| First cities | ~5,500 | Uruk, writing, administration |
| Bronze Age | ~5,000 | Metallurgy, states, trade networks |
| Iron Age | ~3,000 | Cheaper metal, wider tool use |
| Classical antiquity | ~2,500 | Philosophy, democracy, empire |
| Medieval period | ~1,500–500 | Gradual technological progress |
| Scientific revolution | ~400 | Systematic inquiry, rapid discovery |
| Industrial revolution | ~250 | Machine power, urbanization |
| Electrical age | ~150 | Light, communication, motors |
| Nuclear age | ~80 | Atomic energy, existential weapons |
| Digital age | ~50 | Computers, internet, information |
| AI emergence | ~10 | Machine learning, language models |
The pattern is obvious. The intervals shrink. The changes accelerate. What took millions of years now takes decades.
Another way to see it: measure the time between transformative technologies.
| From → To | Time elapsed |
|---|---|
| Fire → agriculture | ~990,000 years |
| Agriculture → writing | ~7,000 years |
| Writing → printing press | ~4,500 years |
| Printing press → steam engine | ~300 years |
| Steam engine → electricity | ~100 years |
| Electricity → nuclear power | ~60 years |
| Nuclear power → internet | ~50 years |
| Internet → AI assistants | ~30 years |
Each step takes less time than the one before. The curve is not linear. It’s not even simply exponential. It may be hyperexponential—accelerating acceleration.
9.2 The Cosmic Context
Now zoom out.
The universe is 13.8 billion years old. Earth formed 4.5 billion years ago. Life appeared around 3.8 billion years ago. For three billion years, life was single-celled—bacteria and archaea, evolving slowly, filling niches, but not building anything we’d recognize as complex.
Complex multicellular life—animals—appeared only about 600 million years ago, in the Cambrian explosion. Dinosaurs dominated for 165 million years. Mammals were small and marginal. Then an asteroid hit, the dinosaurs died, and mammals had their chance.
Primates appeared around 60 million years ago. The hominin lineage—our ancestors—split from other apes around 7 million years ago. Homo erectus, with fire and better tools, emerged 2 million years ago. Homo sapiens, 300,000 years ago.
Put it in perspective:
| Event | Time ago | Percentage of Earth’s history |
|---|---|---|
| Earth forms | 4.5 billion years | 100% |
| Life appears | 3.8 billion years | 84% |
| Complex animals | 600 million years | 13% |
| Dinosaur extinction | 66 million years | 1.5% |
| Homo sapiens | 300,000 years | 0.007% |
| Agriculture | 12,000 years | 0.0003% |
| Industrial revolution | 250 years | 0.000006% |
Human technological civilization occupies an almost invisible sliver of cosmic time. If Earth’s history were a 24-hour clock, civilization would appear in the last fraction of a second before midnight.
And in that fraction of a second, we’ve developed the capacity to destroy ourselves—and potentially to spread beyond Earth.
The curve isn’t just steep. It’s nearly vertical on any meaningful timescale.
9.3 The Strangeness
This should strike you as strange.
Not just impressive—strange. The pattern demands explanation.
Why only us? In 3.8 billion years of life on Earth, exactly one species developed technological civilization. Intelligence has evolved multiple times—in cephalopods, in birds, in mammals—but only once did it lead to writing, cities, science, rockets.
Why so late? If the cognitive capacity for civilization evolved 300,000 years ago (or even 70,000 years ago, with the “cognitive revolution”), why did civilization itself wait until 12,000 years ago? Why 250,000 years of anatomically modern humans doing essentially nothing that left a permanent mark?
Why so fast? Once civilization started, why did it accelerate so dramatically? The rate of change in the last 500 years exceeds the rate of change in the previous 5,000. The rate of change in the last 50 years exceeds the rate of change in the previous 500. Why?
These questions have standard answers. The answers are probably correct. But “correct” and “satisfying” are different things.
Consider an analogy. Imagine you’re watching a pot of water on a stove. For an hour, nothing happens. The water sits, placid and still. Then, in the last second, it explodes into a boiling frenzy.
You can explain this physically: the water was heating all along; it just needed to reach a critical temperature. The explanation is correct. But if you didn’t know about boiling points, the sudden change would seem inexplicable—miraculous even.
Human history looks like that pot of water. Long stasis, then sudden explosion. The explanation must involve some threshold being crossed, some critical point being reached. But what threshold? What critical point?
And why did it happen exactly once?
9.4 The Question
Here’s the question this part of the book will try to answer:
What made humans capable of exponential technological growth, and why did this capacity emerge in exactly one species?
The question has layers.
At the biological level: What features of human anatomy and cognition enabled civilization? Big brains, vocal tracts, hands—but also something subtler, something that allowed cumulative culture to emerge.
At the cultural level: What social and cognitive mechanisms allow knowledge to accumulate across generations? Why do humans build on the past while other intelligent species don’t?
At the historical level: What triggered the agricultural revolution, the scientific revolution, the industrial revolution? Why those times and places?
At the cosmic level: Is this pattern expected or anomalous? If intelligence naturally leads to technological civilization, why don’t we see evidence of others? If it doesn’t, why did it happen here?
We’ll take these in order. The answers won’t fully resolve the mystery—they’ll clarify it, sharpen it, make clear what we know and what we don’t.
The exponential is real. The question is why.