Editor’s note: We are pleased to present a series adapted from biologist Michael Denton’s book, Fire-Maker: How Humans Were Designed to Harness Fire and Transform Our Planet, from Discovery Institute Press. Find the whole series here. Dr. Denton’s forthcoming book, The Miracle of the Cell, will be published in September.
The fitness of metals because of the conjunction of their ductility and electrical properties is certainly an arresting fact. And it is not just their strength and hardness that are maximally useful in the ambient temperature range. Curiously, several metals — especially copper, the conductor par excellence — are far better conductors at ambient temperatures than at higher temperatures. Copper, for example which is still indispensable for dynamos and electric motors, conducts electricity ten times more efficiently (that is, its resistivity is ten times less) at 100° C than 600° C.1 If the conductivity of copper were ten times less, wires would have to be ten times the cross-sectional area to provide the same conductivity, ruling out many applications and make the construction of motors and dynamos far more difficult.
Ideal Fitness for Electrical Devices
Copper does indeed have ideal fitness for its applications in electrical devices:
The inherent strength, hardness, and flexibility of copper building wire make it very easy to work with. Copper wiring can be installed simply and easily with no special tools, washers, pigtails, or joint compounds. Its flexibility makes it easy to join, while its hardness helps keep connections securely in place. It has good strength for pulling wire through tight places (“pull-through”), including conduits. It can be bent or twisted easily without breaking. It can be stripped and terminated during installation or service with far less danger of nicks or breaks. And it can be connected without the use of special lugs and fittings. The combination of all of these factors makes it easy for electricians to install copper wire.2
Copper also resists corrosion more than aluminum or iron. In an article on copper posted on the web the author waxes lyrical about its utility:
Copper’s unique properties make it an invaluable component of our future. Copper is so good at managing heat and electricity, it is practically irreplaceable for use in sustainable energy — from solar panels to wind turbines. Copper can be 100% recycled — making it a perfectly green material. Just shy of 1 trillion pounds of copper have been mined since the dawn of human history — and most of it is still in circulation thanks to copper’s recycling rate (which is higher than that of any other engineering metal)… The entire industry of copper mining and copper alloys is dependent upon the economic recycling of any surplus products. Not only can copper be recycled from post-consumer equipment like old plumbing pipes or discarded electrical cable, but the scrap pieces of copper from factory floors can be recycled into new grade A copper. About half of all copper that is recycled is post-consumer scrap copper and copper alloys have been recycled for thousands of years. In fact, one of the wonders of the old world, the Colossus of Rhodes, a statue spanning the entrance to Rhodes Harbour in ancient Greece, was said to have been made of copper. No trace of it remains since it was recycled to make other items.3
So Helpful of Nature
Nature lent a hand in the initial development of metallurgy. Metals would never have been discovered in the first place nor could their magical properties have been exploited if their ores were not relatively plentiful and accessible in the crustal rocks. The existence of plentiful and common metal ore-bearing strata depends in turn on a variety of tectonic processes being “just right,” including magmatic, hydrothermal, and metamorphic processes.4 If the properties of the various mineral ores, if the abundance of metal atoms in the Earth’s crust and mantle, if the viscosity of crustal rocks, etc., had been somewhat different, then perhaps no ore-bearing mineral strata would have formed, and despite our genius we would be trapped forever in a Stone Age culture.
Over a century ago Alfred Russell Wallace alluded to the same fortuity:
The seven ancient metals are gold, silver, copper, iron, tin, lead, and mercury. All of these are widely distributed in the rocks. They are most of them found occasionally in a pure state, and are also obtained from their ores without much difficulty, which has led to their being utilised from very early times…
Each of the seven metals (and a few others now in common use) has very special qualities which renders it useful for certain purposes, and these have so entered into our daily life that it is difficult to conceive how we should do without them. Without iron and copper an effective steam-engine could not have been constructed, our whole vast system of machinery could never have come into existence.5
Tomorrow, “All the Right Fuel.”
- Glenn Elert, “Electric Resistance,” The Physics Hypertextbook, 1998-2015, accessed on April 4, 2016, http://physics.info/electric-resistance.
- “Copper wire and cable,” Wikipedia, April 24, 2016 accessed on May 23, 2016, https://en.wikipedia.org/wiki/Copper_wire_and_cable.
- “About,” Copper Matters, accessed on April 4, 2016, http://www.coppermatters.org/about.
- Taylor, Stuart Ross, and Scott M. McLennan. Planetary Crusts: Their Composition, Origin and Evolution. Cambridge Planetary Science. Cambridge, UK ; New York: Cambridge University Press, 2009. 7 and 361.
- Wallace, The World of Life, 359-360.