in prehistoric times, the only source of artificial light was a wood fire. To produce as much light as a regular household lightbulb now gives off in an hour would have taken our prehistoric ancestors fifty-eight hours of foraging for timber.1 By Babylonian times, the best lighting technology was a lamp that burned sesame oil. To produce the same amount of light, a Babylonian worker in around 1750 BCE would have had to work for forty-one hours.
An earthenware lamp, which used a cotton wick and oil or ghee.
Then came candles. Initially made from animal fat, they were time-consuming to produce (and smelt awful). Even in the late 1700s, the typical worker would have to devote five hours’ work to producing candles that emitted as much light as a regular household lightbulb gives off in an hour. Through the 1800s came developments in gas lamps, which reduced the time cost of an hour of light to a few hours of work.
With the invention of the electric bulb, light got cheaper still. By the early 1900s, it took just minutes of work to buy an hour of light. Today, less than one second of work will earn you enough money to run a modern household lightbulb for an hour. Measured in terms of artificial light, the earnings from work are 300,000 times higher today than they were in prehistoric times, and 30,000 times higher than they were in 1800. Where our ancient ancestors once toiled to brighten their nights, we rarely even think about the cost as we flick on a light.
The progression of lighting technology: a candle, incandescent bulb, fluorescent bulb and LED bulb.
Two forces have driven this remarkable change. Lighting technologies are better (and still improving by the day). And
