Red Mars (Mars Trilogy, #1)

by Kim Stanley Robinson

“If you burn our bodies in a microbomb calorimeter you’ll find we contain about six or seven kilocalories per gram of weight, and of course we take in a lot of calories to sustain that through our lives. Our output is harder to measure, because it’s not a matter of predators feeding on us, as in the classic efficiency equations—it’s more a matter of how many calories we create by our efforts, or send on to future generations, something like that. And most of that is very indirect, naturally, and it involves a lot of speculation and subjective judgment. If you don’t go ahead and assign values to a number of non-physical things, then electricians and plumbers and reactor builders and other infrastructural workers would always rate as the most productive members of society, while artists and the like would be seen as contributing nothing at all.”