There is a thread running through the entire history of technology that rarely gets named directly. It is not a story about speed, or scale, or intelligence. It is a story about fungibility — the gradual dissolution of barriers between things that were once incompatible, the slow process by which the world's resources become composable with each other.
Every major technological era has advanced this story. Each one removed a different kind of friction. Each one revealed a new bottleneck that hadn't been visible before. And each one, in retrospect, looks like an obvious step toward something we couldn't quite see at the time.
We are living through the latest step now. And like all the previous ones, it is easy to underestimate — because the friction it removes is so pervasive that we've stopped seeing it as friction at all.
- Four eras of fungibility — force, energy, information, access — each dissolving a barrier that had seemed permanent
- The repeating pattern: composability creates value, then exposes the next bottleneck hiding behind the old one
- Why the internet solved copying and reach but left systems unable to understand each other — the plumbing problem
- What the current era dissolves, and what that dissolution is likely to reveal next
Fungibility of Force
Gears, Pulleys, and the Transformation of Motion
The first great fungibility revolution was mechanical. Gears, pulleys, levers, cams — the entire apparatus of classical mechanics — solved a specific problem: force and motion existed in particular forms, at particular speeds, in particular directions, and they needed to be transformed.
A waterwheel captures rotational energy from a river. But the thing you want to do with that energy — grind grain, pump water, drive a bellows — may require a different speed, a different axis of rotation, a different kind of motion entirely. Gears make these transformations possible. They are the first universal translators: they take mechanical energy in one form and produce it in another.
This sounds modest. It was revolutionary. For the first time, the source of energy and the application of energy could be designed independently. You could optimize the waterwheel for the river without worrying about the millstone. You could optimize the millstone for the grain without worrying about the river. The gear between them handled the translation.
Fungibility, in this first form, meant that force became composable. You could combine mechanical elements from different contexts into systems that none of them could have achieved alone.
Fungibility of Energy
How Steam Became Light Became Work
The mechanical era had a hard limit: distance. A waterwheel could power a mill, but only if the mill was next to the water. Force could be transformed, but it couldn't travel. The producer and consumer of energy had to be in the same place.
Electricity dissolved this constraint. A steam engine burns coal and turns a generator. The generator produces electrical current. The current travels wire — miles, then hundreds of miles, then thousands — and at the far end it can do work: light a lamp, drive a motor, heat a resistor. The producer and consumer of energy are decoupled for the first time in history.
This is a profound fungibility leap. Energy produced in one place, by one process, for one purpose, can now be consumed in a completely different place, by a completely different process, for a completely different purpose. The grid is the translation layer. It takes energy in any form that can turn a generator and delivers it in a form that anything electrical can consume.
Geography stops being destiny for power. The constraint shifts — from where is the energy to where are the wires.
Fungibility of Information
When Knowledge Left the Person Who Held It
Electricity made energy fungible across space. Electronics — and then computing — did the same for information.
Before digital storage, knowledge was inseparable from the person or physical artifact that held it. A craftsman's skill died with him unless he taught it to an apprentice. A book's contents were unavailable unless you were physically near the book. Information was local, fragile, non-reproducible at scale.
Digital storage changed this completely. Information could be captured, copied perfectly, transmitted instantly, reproduced at zero marginal cost. The separation between knowledge and its holder — between information and its physical substrate — became total.
The fungibility leap here is from information tied to a place or person to information as a freely flowing resource. A formula discovered in one laboratory could be in every laboratory on earth the next day. A piece of music recorded once could be heard by millions simultaneously. Knowledge decoupled from the knower.
Fungibility of Access
Everything Connected — Almost
If digital storage made information copyable, the internet made it universally accessible. Any piece of information, anywhere, could in principle reach any person, anywhere, instantly.
This was another enormous fungibility leap. But it introduced a new problem — one that became visible only because the previous problems had been solved.
The data existed everywhere. But the systems that held and processed it were still islands. A database in one company couldn't talk to a database in another without enormous effort. An API built on one convention couldn't be consumed by a system built on another without translation work. The standards wars of the internet era — competing protocols, incompatible formats, the endless proliferation of data conventions — were all attempts to solve this problem by forcing things into common shapes.
They partially succeeded. REST, SQL, JSON, OAuth — these are genuine achievements of standardization that made large categories of integration possible. But they left enormous gaps. And filling those gaps became the dominant activity of software development.
Something had shifted. The limiting factor was no longer whether information could exist or travel. It was whether systems could understand each other. The plumbing problem had arrived.
This is where we'll pick up in the next post — because the plumbing problem turns out to be more interesting, and more recently dissolved, than it might appear.
What Each Era Reveals
Looking across these four eras, a pattern emerges.
Each revolution in fungibility followed the same structure. A barrier that had always existed — between types of force, between locations of energy, between holders of information, between connected systems — was dissolved by a new technology. The dissolution created enormous value. And it immediately revealed the next barrier, which had been invisible before because the previous one was so dominant.
Mechanical work stayed where the power was; electricity carried energy across distance. Digital storage made information copyable at negligible marginal cost; the internet made it reachable from almost anywhere — and together they exposed a different problem: not whether bits could exist or move, but whether the systems that held them could mean the same thing to each other. Each solved layer exposed the friction underneath.
There is also a second pattern: each era generated anxiety that the previous era's skills would become worthless. The millwright worried that mechanization would eliminate craftsmanship. The telegraph operator worried that telephony would eliminate their expertise. Each time, the worry was partly right and mostly wrong — the specific skills became less valuable, but the demand for human judgment about how to use the new capability increased.
The question worth holding as you read this: what does the current era dissolve? And what does dissolving it reveal?
The answer — which involves software developers, plumbing, and a specific kind of friction that has consumed an enormous fraction of human technical talent for thirty years — is the subject of the next post.