充足的能源可以提供与数百名仆人等价的改变生活的劳动力：如果没有冰箱，我们需要每天寻找新鲜食物，储藏架将保持半空，许多食物都会在我们食用之前变质 — — 这也是1930年胃癌是美国最主要癌症的一个原因。
Abundant energy provides the same life-transforming labor as hundreds of servants: Without a refrigerator, we would need to locate fresh food daily, store shelves would be half-empty, and a lot of food would go bad before we could eat it – one reason why, in 1930, stomach cancer was the leading cancer in the United States.