âEngineering is the art of the possible, constrained by the physics of the necessary.â â Vaclav Smil
Technological progress is real and measurable. The question is how to measure it meaningfully. Smilâs approach is characteristic: find the right metric, track it over time, and let the numbers speak.
The most important insight from studying technological progress numerically is that improvement is typically gradual â measured in decades, not years â and that the dramatic leaps described in popular narratives are usually the culmination of many years of incremental improvement that nobody noticed at the time. The iPhone didnât appear from nowhere; it was the product of fifty years of semiconductor development, twenty years of portable computing, and a decade of mobile internet infrastructure.
The internal combustion engine that powers most of the worldâs vehicles has improved dramatically since its invention. Key improvements:
This represents roughly a doubling of efficiency over a century of engineering. But here is Smilâs characteristic counterpoint: despite this efficiency improvement, cars today are not dramatically more fuel-efficient than cars in 1980 â because cars have gotten heavier and more powerful. The efficiency gains were consumed by increased performance and weight, not passed to consumers as fuel savings.
The history of commercial aviation is a story of relentless, measurable engineering progress. Jet engines have improved in efficiency by approximately 40% since the first commercial jets flew in the late 1950s. Combined with improvements in aerodynamics, materials science, and operations, fuel use per passenger-kilometer has fallen by roughly 70-80% since 1950.
A modern Boeing 787 Dreamliner uses approximately 2.5 liters of fuel per 100 passenger-kilometers â comparable, per person, to a fuel-efficient car. The early jets of the 1960s used four or five times as much fuel per seat-mile. This improvement is extraordinary by any engineering standard.
Yet aviationâs total fuel consumption and CO2 emissions have grown because the number of flights has increased so dramatically â from roughly 100 million passengers in 1960 to over 4 billion in 2019. Efficiency gains were overwhelmed by volume growth. This is the Jevons Paradox in action: making something more efficient often increases its total consumption by making it more accessible and affordable.
The exponential growth of computing power is so extreme that human intuition cannot grasp it. Mooreâs Law â the observation that transistor density in integrated circuits doubles approximately every two years â has held for over 50 years, producing an approximately 1-trillion-fold increase in computing power per dollar since the 1970s.
A modern smartphone has:
The Apollo missions that landed humans on the Moon used on-board computers with 4 KB of memory and 32 KB of storage. Your phone has roughly 1 million times more memory and 30 billion times more storage.
One of the most impactful and least celebrated technological improvements of the past two decades is LED lighting. The numbers are striking:
LEDs use 75-90% less electricity than incandescent bulbs and last 25 times longer. If all the worldâs incandescent bulbs were replaced with LEDs today, it would reduce global electricity consumption by approximately 5-8% â the equivalent of eliminating hundreds of power plants.
Which technological improvements happening right now are being underappreciated because they are incremental rather than dramatic? What is todayâs equivalent of the LED â an improvement so obvious in hindsight that weâll wonder why it took so long?