Aside from the occasional power outage when we drag out the candles, oil lamps and flashlights, we take the light between dusk and dawn for granted.
On “All Things Considered” Friday, the Planet Money team interviewed Jane Brox, the author of “Brilliant: The Evolution of Artificial Light.” Brox cites research done by Yale economist Bill Nordhaus who researched the cost of artificial light through the centuries.
I had a driveway moment listening to the story. Do check out the full interview (and I plan to find the book). Here’s a tantalizing takeaway: back about 4,000 years ago in Babylonia, a day’s labor could buy maybe 10 minutes of artificial light. Through the millenniums, making light remained expensive and labor-intensive, and the light produced was not very effective.
Until about 1800, not a whole lot of substantive progress. For example, whale oil was one of the best sources of lamp fuel. Not a particularly attractive solution: smoky, fuzzy and there’d be no whales left today if we kept that up.
In the mid-1800s, a big breakthrough: kerosene produced from coal or oil providing reasonably high-quality light for humans to keep busy long after dark. A day’s labor now buys about five hours of post-dusk light.
Once the power generation and distribution challenges were worked out, the use of electricity, of course, revolutionized everything. But think about it: it took thousands of years to come up with a source of artificial light that really works. Ten minutes of light for a day’s labor back in the old days–not even enough light to read the directions on your microwavable frozen dinner.
So, how much light can you buy with an average day’s labor now? Well, in the developed world, 20,000 hours.
Of course, none of this deals with the environmental impact of all that electricity. That’s for another article. But this photo can serve as a place-holder on the issue.
Meanwhile, back on my farm, where the power goes out fairly regularly, including a brief outage about an hour after I heard the ATC story, my hens decide when to lay eggs based on the amount of sunlight. It’s magic. If you leave the ladies to their own thing, some time in March when we’re all noticing that it’s starting to get light a little earlier and stay light a little later, egg production gears up. Right now, it’s peak production time. As the days lengthen in the approach to the solstice, every hen lays an egg a day. After the solstice, as we move into high summer, production drops off as the daylight hours start to decrease. If you have a light on in the chicken coop for a few hours at the end or beginning of the day–artificially extending the hours of light experienced by the hens–egg production will remain robust through the winter. There’s economic impact for you.
Again, check out the Planet Money story.