This essay is not strictly about science, but most people lump science and technology together so breezily that this seems the place for the idea. But this near-identification between science and technology is only a century old; throughout most of human history, technology progressed through a number of other routes.
Everybody loves to talk about the role of serendipidy in technological progress, but in practice true serendipity has been rare. Most technological advance comes by other means. To get things started, however, I will offer one example of something that was undoubtedly serendipitous: the discovery of pottery. It’s pretty obvious that somebody noticed that a lump of clay in a fire hardened into a solid rock-like object. That was serendipity.
From that point forward, however, the development of pottery was entirely a matter of refinement. People kept coming up with minor refinements. There is no evidence of any quantum leap in pottery technology at any point in human history. It just got better and better over the centuries. At some point, it got so good that it became what we now call ‘porcelain’. There was no sudden leap from clay pots to porcelain; instead, there was a slow, natural progression of increasingly finer pottery growing thinner and lighter as potters experimented with higher temperatures.
This pursuit of higher temperatures was important for two reasons: first, it transformed “fired clay” into glass, and glass is harder and stronger than fired clay. That permitted thinner, lighter products. Even better, the extremely high temperatures necessary for making porcelain also permitted the application of various glazes that yielded stunningly beautiful products.
Thus, potters were always in pursuit of higher temperatures. Wood is not adequate for this task; it doesn’t get hot enough. The pursuit of higher temperatures was most intense in China, which had the largest market for porcelain and therefore the most intense competition. In Europe, coal was used to get higher temperatures, but in China, coal wasn’t as easy to get and it also introduces problems of its own. So the Chinese potters relied instead on charcoal.
There are two ways to get higher temperatures. The first way is to use a fuel with an naturally higher combustion temperature, such as the combination of oxygen and acetylene. The Chinese didn’t have supplies of either, so they had to rely on the second basic strategy: increase the rate of combustion. Burn more fuel faster, and you’ll get higher temperatures. It didn’t take long for Chinese potters to realize the using charcoal powder produced a faster-burning fire than regular charcoal. But a pile of charcoal powder tends to slow down as the ashes on top of the pile deprive the burning layer underneath of oxygen. So there was a lot of experimentation with ways to get the charcoal powder to burn faster.
Chinese technology had already isolated both sulfur and saltpeter; they were used in some medicinal concoctions. I believe that, at some point, a potter tried mixing sulfur powder with charcoal powder and got better results; when saltpeter was added to the mix, the reaction rate jumped up. The resulting concoction, called gunpowder, explodes only when confined; when burned as a powder it merely burns faster and hotter — which is what the potters were looking for.
The third avenue for technological progress is recruitment: the use of a technology from one field in a completely different field. This happened with gunpowder. It wouldn’t have taken long for a few mistakes to produce gunpowder explosions, and from there it took no special genius to explore the military potential of this new stuff. Of course, the technologies had to undergo considerable refinement in order to become powerful weapons, but humanity is good at refinement.
The fourth and most recent avenue of technological progress is the application of scientific principles to the problem. This happened with gunpowder; when chemists examined the chemistry of gunpowder, they realized that the combustion rate could be improved by replacing potassium nitrate (saltpeter) with a substance containing more oxygen: nitroglycerin. This dramatically increased the explosive power of the formulation.
Thus, we see all four avenues of technological innovation in the sequence pottery (serendipity) — porcelain (refinement) — gunpowder (recruitment) — high explosives (scientific development).
Because China had the largest population and the largest market for products of all sorts, it produced higher rates of the first three avenues and thereby led the world in technological innovation until the advent of scientific development. But China never developed science that could be of any use for scientific development of technology.