The history of light (classic) | Planet Money

The episode argues that the history of artificial light is a clean way to see economic progress: over time, the same amount of work buys vastly more light, which means more productivity and more room for the rest of life. The host traces that change from animal fat candles and other improvised fuels to whale oil, kerosene, and finally electric light. The point is not just that technology improved, but that it got cheaper and easier to use, so ordinary people could stay out of the dark and spend their labor on something other than basic survival.

Bill Nordhaus’s work anchors the story. He compared the cost of light across centuries and found that an ancient Babylonian day’s wages bought only about 10 minutes of light, while kerosene later stretched that to about 5 hours, and modern electric light made it effectively abundant. The episode says the big leap came in the 1800s, when science, patents, corporations, and banks created the financial and institutional machinery needed to build systems like Edison’s power plant.

The conclusion is that growth is usually not one magical invention but a long process of making things faster, cheaper, and more efficient. That process has trade-offs, including pollution, but it explains how societies moved from subsistence living to a world of abundance.