Figure 1 compactly presents the four major interrelated components of human industry (1). Humanity has progressively acquired skill over thousands of years for living on Earth, in its biosphere, and organizing it. The quantity of that skill, historically, has been no more than somewhat positively proportional to the number of humans alive. Limited “learning,” bad organization, and circumstances could and usually have limited rewards for full applications of those skills at any one time. Skill storage, application, and growth are now extending to “intelligent” matter, computers and their kin, invented by man. This “intelligent” or “smart” mass helps us grow on Earth but will help us grow explosively into space. Our slowly won skills have gradually let us use progressively greater quantities of energy (our own foods, foods for our animals, burning of wood, then coal, then oil, then nuclei, then . . .?) taken from Earth. Except for relatively small flows of renewable power (wood, hydroelectric, wind, . . .) our energy use has depleted Earth resources. Depletion is accelerating. This energy has been used to sustain and transport us and to build. Figure 2 presents one very narrow vantage of how explosively our increasing abilities to manipulate matter have grown. Line A approximately indicates the tons of matter manipulated worldwide each year which is extracted from non-r.enewable resources (termed “Demandite”; (2)). Note that the vertical scale (tons per year) is logarithmic. This rapid growth of about 6%/yr began with the increasingly intense use of energy in the industrial revolution 400 years ago. Demandite usage is approximated by: dM/dt (tons/yr) = 4.4 exp (O.OblHyears A.D.)—1600)) (I) Table 1 gives the elemental composition of the various fractions of Demandite and their per capita production rates. In 1968, U.S. citizens consumed about 17 tons per year of Demandite. Coal and oil provided most of the energy to gather and process the Demandite. Substitution of materials will broaden the Demandite composition Fig. 1. Components of human industry.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==