The year was 1532. The conquistador Francisco Pizarro had arranged a meeting with Atahualpa, emperor of the Inca, whose dominion then included over 690,000 square miles. The Spaniards were strangers in the Americas and vastly outnumbered; their ranks comprised only 106 infantrymen and 62 horsemen compared to the Incan army, which numbered in the thousands. Nevertheless, the Spanish ambushed Atahualpa and his men, and by the end of the battle, the conquistadors were the clear victors, slaughtering thousands and losing only a few soldiers themselves. While the Spaniards’ use of cavalry and early firearms, both of which the Incas had never encountered, certainly gave them an edge, steel swords and armor allowed the Spaniards to easily demolish the Incan force equipped only with primitive stone weaponry and cloth armor. Such tools were made available to the Spaniards through the practice of metallurgy.

The word ‘metallurgy’ comes from the Ancient Greek word meaning metalworker. It refers to the branch of science dealing with metals, and like its etymology suggests, it is an age-old discipline. The earliest discovered instances of metallurgy, namely the smelting of copper ore, date from the 6th millennium B.C. in southeastern Europe. The ancients noticed that when certain rocks were heated in kilns to temperatures exceeding 1,000° C, the copper contained therein would liquefy and separate from the ore. This blob of pure copper could then be cast and worked into a variety of shapes more easily than the chipping required of stonework. Copper, however, proved to be far too soft and malleable to be used effectively in tools. Hence, it was used primarily to cast trinkets and other such objects of minimal consequence. It was not until the production copper alloys, the most notable of which being bronze, that early metalworkers could begin to produce useful tools and weapons that would ultimately alter the course of history, leading historians to call this era the Bronze Age.

The next major step in the history of metallurgy was the discovery of iron extraction in the 13th century B.C. Iron tools tended to be stronger, albeit more brittle, than their bronze counterparts and therefore quickly replaced them in areas where ironworking developed. The smelting of iron ore requires a higher temperature, however, and was thus more technically difficult, giving a significant advantage to peoples who were able to do so. The Hittites were the first civilization to make extensive use of ironworking, although they remained rather tight-lipped about the process. It wasn’t until the collapse of their empire that the secret leaked out and the Iron Age was ushered in.
Eventually, improvements were made in the smelting of iron, and iron alloys began to be employed. The most noteworthy of these alloys was steel; although it tends to be more brittle than pure iron, it is both stronger and easier to work with. The use of steel tools and weaponry shaped the ancient world, helping to forge both the Han and Roman empires. Furthermore, it paved the way for European colonialism, offering a clear advantage over the stone weaponry often used by indigenous peoples.

Contemporary metallurgy is interdisciplinary, relying on chemistry, physics, and material science. Although metals are often more expensive than plastics or ceramics, their robustness makes them invaluable for industrial infrastructure. Improved forms of steel thus remain ubiquitous in modernity. One such form is commonly referred to as stainless steel. While this alloy of iron and chromium is not actually stain-proof, it is resistant to both rust and corrosion. Another metal that has come into use in the modern era is aluminum. Prized for its light weight, low density, and resistance to corrosion, aluminum alloys have become especially useful in aerospace and robotic engineering. Modern metallurgists also make use of a range of laboratory techniques to produce synthetic metals. Although these materials are often expensive to produce and not particularly useful, they demonstrate the departure of metallurgy from a discipline of guess-work to an exact science.

While metallurgy was integral to the development of the modern world, some civilizations remained in the Stone Age, and others used metals only for decoration, including the Inca empire. One explanation of this disparity is based on geological diversity; some regions of the world simply don’t have the requisite ore to encourage metallurgy. This theory fails to account for areas with rich metallic resources that were never harnessed. For example, Australia is currently one of the largest exporters of iron ore, yet the indigenous Aborigines failed to progress past primitive stone tools. Another explanation, which has become increasingly popular in recent years, is based on cultural diversity; some civilizations fail to encourage the scientific inquiry required to discover new technologies such as metallurgy. This theory fails to account, however, for peoples like the Inca that extracted and worked metals, but solely for purpose of adornment. Personally, I’m inclined to take the middle-ground here. I’ll certainly concede that geography impacts culture and its institutions, which in turn can either encourage or stifle innovation. I am loath, however, to think that the objective success or failure of a civilization can be calculated by predetermined geographical factors. Rather, I think that there is an element of randomness to it; if a 2nd millennium B.C. bushman in Australia had offhandedly tossed some ore in a fire and then noticed the separation of pure metal, perhaps history would’ve turned out much differently.