Fire-Maker

1. FIRE

The ancient Greeks, who had an answer to most things, believed that Prometheus brought down fire from heaven—and got himself into much trouble with Zeus for doing so. From bright fire, says Aeschylus in Prometheus Vinctus, they will learn many arts.

A. J. Wilson, The Living Rock (1994)

AS I WRITE, A SMALL MOBILE ROBOT NAMED CURIOSITY is searching the sands of another planet, Mars, for signs of life. As it explores the Martian surface, a tiny automated laboratory analyzes the Martian soils for organic chemicals and water. Powered by a solar battery, the robot will be able to function for several years without any assistance from its creators, who are millions of miles away busily decoding and analyzing the cryptic messages it beams back to Earth.

Curiosity is just one of a universe of current technological marvels. The wonders of twenty-first century technology amaze. A mere 200 generations since the first metal tool was manufactured, technology has reached the stage when its accomplishments increasingly resemble what would have seemed to our ancestors a form of magic.

The dramatic technological advances over the past 100 years have provided extraordinary devices that have enabled human beings to gain enormous knowledge of the natural world—from the structure of the cosmos to the structure of DNA—more than in all previous centuries. Using light and radio telescopes, we have peered at distant galaxies, billions of light years from Earth. We have looked back to the beginning of time, to the fireball in which our universe was born. We have estimated the age of the universe and determined its dimension. We have detected other earths orbiting distant stars and estimated the number in our galaxy alone to be in the order of tens of billions!¹ We have discovered how atoms are synthesized in the stars.

The technological wonders of our current civilization—and the deep scientific insights they have provided into the fundamental nature of reality—were not gained easily. They grew out of a long series of technological discoveries and advances that, over several thousand years, led our species from a primitive Stone Age technology to the magic of twenty-first century nano-technology—from making a stone chisel to making a Boeing 787.

Of all the discoveries made in the course of mankind’s long march to civilization, there was one primal discovery that made the realization of all this possible. It’s a discovery we use every day and take completely for granted. But this discovery changed everything.

Humankind discovered how to make and tame fire.

Darwin rightly saw it as Probably the greatest [discovery], excepting language, ever made by man.²

Fire and Metals

THIS PRIMAL discovery of fire opened a long path toward modern technology. The ability to tame fire led to the invention of the art of cooking and to the discovery that fire hardens lumps of clay into hard stone or pottery, which can be molded into containers for storing food. This initiated the development of mankind’s first industry—ceramics, which was well established in many parts of the world before 10,000 BC.³

The mastery of fire also led to the discovery and manufacture of charcoal, produced by burning or cooking wood in an oxygen-depleted environment (a technique used by cave artists as early as 30,000 BC⁴), and to the discovery that burning charcoal generates far greater heat that an ordinary wood fire.⁵ This in turn led to the use of charcoal to generate high temperature inside kilns for the manufacture of baked and glazed pottery, using bellows to give a forced draft to raise the temperature inside the kiln.⁶

Perhaps it was the chance heating of a metal ore in a particularly hot campfire and the subsequent discovery of globules of metal the next morning upon raking through the ashes⁷ which first led to the discovery of metallurgy. Or perhaps, as other authors have argued, the discovery that metals could be extracted from their ores was discovered in a pottery kiln, where the charcoal-fueled fire would have generated temperatures hot enough to smelt metallic ores.⁸ As Arthur Wilson comments in his Living Rock, Adapting… [the process of glazing pottery in a kiln using charcoal as a fuel], copper ores could thus have been reduced to obtain metal.⁹

Figure 1-2: Pottery was one of the early results of harnessing fire.

Although no one knows exactly what sequence of events led to the beginnings of metallurgy,¹⁰ there is little doubt that it was another momentous discovery, second only to the discovery and mastery of fire itself. As Arthur Wilson comments: In whatever manner the secret of metallurgy was unraveled—and we shall never know precisely—it was a momentous step along the road to civilization… man, though still stumbling, entered the Age of Metals and opened up undreamed of possibilities for his future.¹¹

Copper was one of the first of the metals to be widely used and there is evidence that mankind mastered the smelting of copper as early as 7,000 years ago.¹² The subsequent extraction of copper from copper-bearing ores and its mixture with tin to make bronze was independently discovered by cultures in both the old and new worlds¹³ and ushered in the Bronze Age in the ancient Near East about 3500 BC.¹⁴

Copper smelting requires temperatures between 1,150° and 1,250° C,¹⁵ but the smelting of iron requires even higher temperatures,¹⁶ more reducing conditions,¹⁷ and a greater blast of air.¹⁸ This required more advanced kilns and more sophisticated techniques.¹⁹ Iron smelting was only mastered later, around 1200 BC,²⁰ providing mankind access to the most useful