Behold, one of my favorite tables of all time:
There’s so much to absorb here. Let’s look at just the “Light Price in Terms of Labor” column. At 500,000 BC, our starting point, we have this handsome guy:
The Peking man was a Homo erectus found in a cave with evidence of tool use and basic fire technology. At this point, it would have taken him about 58 hours of work for every 1000 hours of light. Lighting a fire by hand or even with basic tools is hard, as seen here:
Nothing much changes for hundreds of thousands of years, until people begin using basic candles and oil lamps in the 1800s. After that, things slowly begin to accelerate, with gas lighting, incandescent lamps, and eventually fluorescent bulbs and LEDs…
Notice that this is a logarithmic plot! So a straight line corresponds to an exponential decrease in the amount of labor required to produce light. By the end we have less than 1 second to produce 1000 hours of light. And this doesn’t even include LED technologies!
Here’s a more detailed timeline of milestones in lighting technology up to the 1980s:
And finally, a comparison of the efficiency of different lighting technologies over time.