For a Technological Civilization, We Must Have Metals
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 development of technology required not only a planet of the right size and possessing the right kind of atmosphere for respiration and the taming of fire, but also a planet where metals would be available and useable. Although some sophisticated cultures have achieved extraordinary ends without the use of metals — the classic example is the Maya — it is very doubtful that any beings anywhere in the universe could develop a technological civilization remotely comparable with our own without the use of metals.
At ambient temperatures on Earth, metals such as copper and iron possess high tensile strength (meaning approximately that they are hard to deform1), but they are also malleable and ductile to a remarkable degree (ductility is the ability to deform under tensile stress — characterized by the ability to stretch metal into a wire2). At temperatures much above the ambient range, metals soften (even steel loses tensile strength above 400° C), while at much below zero, many metals become increasingly brittle.3 So metals can be molded into the “strong hard” steel beams or girders used in construction and can be drawn into fine wire most effectively in the ambient temperature range.
Conductors of Electricity
Not only can metals, because of their tensile strength, be molded into hard implements useful for a myriad of purposes, they are also conductors of electricity. Because of their ductility, they are capable of being drawn into strong, thin wires, a gratuitous combination of properties that made possible the construction of electric generators and electric motors. Without the twin properties of ductility and electrical conductivity there would be no electric age, and it is doubtful that human society could have advanced beyond the steam age of the early nineteenth century. Thus, the Wikipedia article on electricity states:
Electrical phenomena have been studied since antiquity, though progress in theoretical understanding remained slow until the 17th and eighteenth centuries. Even then, practical applications for electricity were few, and it would not be until the late nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion in electrical technology at this time transformed industry and society. Electricity’s extraordinary versatility means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is now the backbone of modern industrial society.4
Indeed, the whole electric age is in a very real sense a gift of the material properties of metals and of one metal in particular: copper.
Tomorrow: “In Praise of Copper, a Gift from Nature.”
- Often defined as: “Tensile strength is a measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. The tensile strength of a material is the maximum amount of tensile stress that it can take before failure, for example breaking.” From “Tensile Strength,” Wikipedia, May 1, 2015, accessed on May 23, 2016, https://simple.wikipedia.org/wiki/Tensile_strength.
- “In materials science, ductility is a solid material’s ability to deform under tensile stress; this is often characterized by the material’s ability to be stretched into a wire.” From “Ductility,” Wikipedia, May 2, 2016, accessed on May 23, 2016, https://en.wikipedia.org/wiki/Ductility.
- Roy Beardmore, “Temperature Effects on Metal Strength,” RoyMech, November 11, 2010, accessed on April 4, 2016, http://www.roymech.co.uk/Useful_Tables/Matter/Temperature_effects.html.
- “Electricity,” Wikipedia, May 16, 2016, accessed May 23, 2016, https://en.wikipedia.org/wiki/Electricity.