Status Updates From Energy and Civilization: A ...

Food choices, food preferences and attitudes toward the work necessary to forage preferred vs. non-preferred foods. The taste for fatty animals vs. lean ones, at least partly because fat has more energy (viz polar bears eating the blubber of seals).

Studying foraging behaviors among present-day hunter-gatherers. Tropical rain forests may *look* rich in life, but it turns out that available calories aren't as common as appearances would suggest. Many are out of reach, requiring risky climbs or other techniques that have a high chance of leaving skilled foragers dead or badly injured. Oddly enough, available calories are more abundant in grasslands.

The fundamental problems of comparing the efficiencies of traditional and industrial agriculture. How to treat the inputs of fossil fuels (stored solar energy from ancient life) vs. the food and fodder of people using animal traction for power? The net energy cost of human labor whether using body-powered tools or externally powered tools and the human providing executive function. Natural history of genus Homo.

Key concepts: Energy density, or why lionesses don't chase mice and humans don't subsist entirely on fruit. Power density, or how much can be generated in a given area. Conversion efficiency -- changing from one kind to another is inherently lossy, as generation or consumption involves various kinds of friction or inefficiency. Waste heat, waste volume, whatever.

An introduction on just how fundamental energy is to life -- the energy of nuclear fusion powering a G-class star 93 million miles from Earth, which provides light energy that powers photosynthesis of carbohydrates in plants, which in turn provides energy for the herbivores that eat them, and the carnivores that eat those animals.

29 Jan: Chapter 5