How We Defeated the Dark — and What it Did to Us
By: Historical Insights
Tags: Environment, Science, Society, History, Technology

How We Defeated the Dark — and What it Did to Us

Lighting up the night made life safer, but had unintended consequences

Photo by Artem Kovalev on Unsplash

Before the 1700s, pretty much every human being on Earth spent a fair amount of their time in the dark. In the winter, that meant that the time when people could get meaningful work done — either for profit or personal purposes — was very short. When sources of light became so available and cheap that illumination went from a luxury to an afterthought, people’s everyday lives were revolutionized. Lighting up the night has significantly changed the way we live our lives — and not entirely for the better.

Life in the dark

Photo by Jyoti Singh on Unsplash

Though archaic humans figured out how to control fire before Homo sapiens even existed, an open fire is an incredibly inefficient way to light an indoor space, and it’s fairly useless for lighting up the outdoors. A fire creates enough illumination to allow people to navigate their way around, but it’s very hard to read anything by the light of a fire or do much of anything else.

People developed better ways to illuminate the night in the Neolithic period, using animal-fat-burning lamps, but the fuel was never abundant. By the ancient era, clever people in both Europe and China had developed the candle, which allowed a long-burning and controlled flame. After the candle was developed, lighting technology essentially stalled. Other than a few changes in the materials candle-makers used, candles remained the state of the art for almost 2,000 years.

A nineteenth-century candle advertisement (PD)

What was life like in the age of oil lamps and candles? First, lighting was expensive! The best candles (like beeswax candles, which could last a long time and did not smell terrible), were too expensive through the early modern period for everyday use outside of religious ceremonies and the homes of nobles. Plus, they weren’t very good at, well, lighting. Candles convert only .01% of their chemical energy into light. An average candle packs about 1/60th of the lighting power of one of the three 60-watt-equivalent bulbs I’m sitting under to write this.

These factors combined to make light thousands of times (perhaps hundreds of thousands) more expensive than it is today, as economist William Nordhaus has found. Even in the 1700s, after the more efficient and long-lasting spermaceti candle had been developed (using the goo from a sperm whale’s head as the primary material for the candle), George Washington complained that burning just one candle every night for a year would cost him about $1000 in today’s money.

Lighting has gone from a luxury to essentially free (Our World in Data)

The dark cities of the past were both scary and exhilarating. They were far darker than anything most of us experience in our light-saturated present. On the one hand, the darkness was terrifying. People carried a number of superstitions about what awaited them in the dark, from witches to werewolves. There were real dangers, too — the murder rate was far higher than it is today. Killers, thieves, and arsonists prowled cities, and they were almost impossible for authorities to see, catch, or identify. Authorities were essentially unable to ensure people’s safety at night.

Darker nights were deadly (Our World in Data)

The dark night of the pre-modern past wasn’t all bad — it gave people some freedom. In hierarchical and restrictive societies, the night was the only opportunity for people to move freely, express themselves, and enjoy each other’s company. People honed skills that we have since lost in order to navigate the world by starlight, navigating by sound and touch.

Historian Roger Ekirch has found substantial evidence that human sleep patterns were quite different — and perhaps healthier — before artificial lighting. For most of human history, people went to bed early in the evening, then rose for an hour or two at night, then went back to bed until morning. During the period of wakefulness, Ekirch says, people “did practically everything imaginable,” from having sex to telling stories. It may be that our modern method of trying to sleep for eight straight hours is neither natural nor healthy.

Defeating the Dark

Thomas Edison on the cover of Scientific American (PD)

Around the turn of the nineteenth century, inventors in Europe began to make the first significant strides against darkness in centuries. In 1807, Friedrich Winzer, a German inventor, installed the world’s first public gas street lamps in London. Using coal-gas (a byproduct of the cooking process), most major cities in the world were able to light their streets in the early 1800s. The light produced by these lamps was 75% cheaper and 12 times brighter than a candle. By 1850, the Canadian geologist Abraham Gesner figured out how to distill kerosene from coal, creating a portable, bright-burning liquid that could be used to push back the darkness.

By the late 1800s, it was possible to navigate lit city streets at night and read a book affordably after dark, thanks to gas and kerosene. In 1882, Thomas Edison demonstrated the final big leap in lighting technology, the electric light bulb, which made indoor lighting safer and more reliable. Unlike the kerosene lamp, the Edison bulb required a massive infrastructure, with power plants, grids, and lines, to make it work. The economic infrastructure of the Gilded Age made this possible, with bankers like J.P. Morgan bankrolling the early power plants. Electrification was the “greatest engineering achievement of the 20th Century,” according to the National Academy of Engineering, and 70% of America was electrified by 1930, with much of the world following suit in the next few decades. By the middle of the twentieth century, much of the world’s population could banish darkness with the flip of a switch.

What have brighter nights done to us?

Paris lights up the night, 1878 (PD)

How did defeating the dark change the human experience?

In wealthier countries, going out into the night went from being an opportunity for private and disreputable behavior to a safer, more public experience. Street lamps both protected potential victims of crime and allowed the authorities to surveil people who were out at night. The mystery and terror of the night-time faded.

People had access to many more productive hours of the day. This, of course, was a double-edged sword. Working or reading at night went from a luxury for the rich, who could afford indoor lighting, to a more universal experience, but it was also the beginning of the process by which work has crept into every corner of our lives. It was the first step on the road to you sitting in bed at night answering work emails at 10 pm.

Many of our modern problems with sleep may be attributable to advances in artificial light. References in historical sources to the segmented sleep pattern that Ekirch describes started to disappear among upper-class people in the 1700s. They disappeared entirely in industrialized societies by the early twentieth century. Sleep disorders are incredibly common in industrialized societies; as many as 70 million Americans may suffer from one, and at least a third of us don’t get enough sleep. Some of these problems may be due to the fact that our modern sleep patterns don’t conform to the cues the natural world is giving us.

We’ve lost the experience of the night. Any city-dweller who has ever been out a night in a truly remote place has been stunned by how much there is to see in the sky when you’re away from the city lights. After the 1994 earthquake, a number of Los Angeles residents called 911 to report a strange sight in the sky. It turned out to be the Milky Way, they had never seen it. The combination of awe and unease that the night instills in us is gone.

It’s not just us

Photo by Alfonso Navarro on Unsplash

We shouldn’t forget that artificial lighting has also affected the natural world. Cheap lighting has allowed governments to illuminate city streets, but it has also allowed innumerable people to leave the porch light on all night and string 24–7 lights on their deck. All of this light has an effect on the species around us. Sea turtles are the most famous case — they need to hatch at night and use moonlight to find their way to the water, but almost every animal in our bright landscapes is affected.

Artificial lighting misleads migratory birds and is likely responsible for the death of millions of birds every year. Other migratory species, like Atlantic salmon and monarch butterflies, are similarly confused by our bright cities. Male fireflies can no longer attract mates because their lights aren’t brighter than the artificial ones around them. Tree frogs that find themselves in areas with a lot of artificial light simply stop performing their mating calls. Many species’ reproductive cycles are timed to the cycles of lengthening or shortening days. These have been altered by nighttime light, which means that offspring are born at times of year that make it harder for them to survive.

In recent years, there’s been a small movement to slow our millennia-long effort to push back the darkness. Some cities have started to adjust their lighting during bird migrations, and some nations have passed laws limiting the amount of light that new construction can emit. Arizona even makes the darkness of its skies a feature of its tourism advertising. Let’s hope there’s a way to enjoy safe and productive nights while keeping ourselves and the natural world healthy.