General Discussion
In reply to the discussion: We should have been colonizing the solar system by now. [View all]tama
(9,137 posts)in awe and wonder of the gifts of urban technology, such as these computers and Internet we communicate with. The numbers previously given need not be in doubt, but all the other factors left unmentioned, not least of all the human factor which art of engineering with it's rather narrow focus can never fully control.
So no reason to focus on hunting and gathering when the discussion and argument was about gardening or horticulture, of which cultivation of fields, agriculture, is just a special case. Our ecological niche in comparison with other species is that though we are not the only species that does it, we excel in horticulture, our co-evolutionary relation with cultural plants, and that we cook our food with fire, which saves us from lot of chewing and digestive work and gives extra time for other activities. So, starting from basics, cities can have roof and vertical gardens in addition to others for production of food, fiber, medicine etc., but where does the exergy for cooking and heating come from? If we increase the area of self sufficient city, the problem of transport costs comes against. I hope you have good suggestions, and that the calculations are based on the qualitative differences that create exergy, not the concept of energy which is fuzzy and meaningless in this context.