On balance, however, tools, engines and electricity have allowed humans to live better from less land and natural resources per person than ever before
Earth Day should Celebrate “Engines and Electricity”.
Most chapters of human history are defined by the tools and machines that were used.
In the Stone Age, the first tools were “green tools” – digging sticks, spears, boomerangs, bows and arrows made of wood; and axes, clubs, knives and grinders made of stone. These were all powered by human energy.
Then humans learned how to control fire for warmth, cooking, warfare and hunting.