… when we do so small a thing as turning on a 150 W light bulb, we are manipulating a quantity of energy substantially greater than a human being could produce in sustained effort. The energy consumed by an oven, or hot water heater is an order of magnitude beyond our capacity. The energy consumed by an automobile can easily be three orders of magnitude greater. If all the people in the United States worked continuously like galley slaves, they could barely equal the power output of even a single city power plant. ….read on »