Light and Dark
8June 28, 2021 by Jean
This is not a post about race relations or about any metaphorical use of light and dark. It is literally about light and dark. I have been re-reading Paul Bogard’s The End of Night (Back Bay Books, 2014), a book about the loss of natural darkness in a world of ever-increasing artificial light. In a culture where dark is often associated with and experienced as threatening and dangerous, Bogard wants us to celebrate darkness; and he argues that we have flooded the night with artificial light to our detriment.
Bogard is not opposed to artificial light, but he wants us to use just the amount we need in a way that minimizes light pollution. He contrasts the careful, restrained and beautiful use of artificial light in Paris, the City of Light, with the unrestrained and excessive use of light in Las Vegas, the brightest spot on the planet, whose glow pollutes the natural darkness for hundreds of miles.
Why should we care about preserving natural darkness? Here are three reasons:
- Darkness is important to human health. Human beings evolved to live in a world that alternates periods of light and periods of darkness, and not enough evolutionary time has elapsed for humans to adapt to a world of 24/7 light. Artificial light is especially disruptive of human sleep, which is essential to health. As darkness falls and light dims, our bodies begin producing melatonin, which prepares us to sleep. Artificial light (especially the blue light emitted from our various electronic screens and by many LED light fixtures) interferes with the production of melatonin. The disruption of sleep is, in turn, implicated in all kinds of other health problems.
- Darkness is important to environmental health. The artificial light created by humans disrupts the natural cycles of all kinds of wildlife, particularly of insects. Light pollution is probably an important part of the great die-off of insects that has been alarming scientists in recent years. If you are thinking that you’d be quite happy to live in a world with many fewer insects, you should think again; insects are critical to the web of life on which we all depend. As the scientist E.O. Wilson has observed, “If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.” (quoted in Douglas Tallamy, Nature’s Best Hope, chapter 8)
- The star-filled skies of a naturally dark world are breathtakingly beautiful, and this natural beauty is being lost to us. One estimate is that, because of light pollution, 1/3 of earth’s population can no longer see the Milky Way, and that includes 80% of North Americans. And because we have lived with light pollution all our lives, many of us have no idea what we are missing. Bogard asks us to consider the proposition that Vincent Van Gogh’s famous painting Starry Night is not some crazed dream scape, but a representation of what he actually saw when he looked at the night sky.
When I read Bogard’s book several years ago (see Darkness and Light), I focused primarily on the health and sleep issues. I decided to unplug the LED nightlights in my house and to turn off all screens at least thirty minutes before bed. I discovered that I can see just fine by the available light when I need to get up during the night, and with my eyes more dark-adapted, I am more likely to pause and enjoy the night sky outside my big bedroom window.
Living, as I do, on a rural dirt road, in an area with levels of light pollution that are relatively low for the northeast United States, I have long been appreciative of the sights and sounds of darkness. On Summer nights, I sleep with the windows open and listen to the sounds of owls hooting and frogs singing. I am aware of the phases of the moon. And, on winter nights especially, I can look up to see a dazzling, star-filled sky. Nevertheless, in the years since I first read The End of Night, it seems to me that light pollution in my area is increasing. It has been several years since I had one of those experiences of being outside under a breathtaking starry sky on a clear night. Driving home from choir rehearsal one night just before the pandemic, I came around a curve on the two-lane rural road that winds along beside the Little Androscoggin River not far from my home to find myself blinded by the glare from a high and very bright “security” light outside a small used car business. Even if this business needed light to deter crime during hours when they were closed, no attempt had been made to shade the light so that it shone down on their premises rather than out into space or into the eyes of helpless drivers. Bogard’s book provides evidence that this kind of bright lighting does not actually increase security, and the light pollution it creates is substantial.
It was Bogard’s book that first made me aware of light pollution as a serious issue. Fortunately, none of my neighbors have those awful dusk-to-dawn lights on poles outside their houses. Some neighbors do have lights on motion sensors, and when these are triggered by a passing animal in the middle of the night, they can light up my entire front yard and shine into my bedroom. Fortunately, they turn off automatically after 30 minutes or so. I am also much more aware now of light pollution I may be creating, especially the recessed LED ceiling lights over my bed that shine out through windows in three directions if I am up late reading in bed. If I had been more aware when I was planning my new addition, I would not have chosen these recessed lights as the solution for reading in bed, and it is time to get a discrete little bedside light that will shine just on my book and not out into the night.
Rereading of The End of Night made me want to travel to where I can see the glory of the Milky Way while it is still visible. Acadia National Park, a 3 1/2 hour drive from my home, has an annual “Dark Sky Festival,” and I’ve signed up for updates about this year’s event and will consider going. I also went online to look at the website of the Canadian dark sky reserve at Parc Mont Megantic in Quebec, just a three-hour drive for me when the border opens again for leisure travel. In looking at a Dark Sky Map, I’ve discovered that I can find even darker skies at Maine’s new Katahdin Woods and Waters National Monument, which has some of the darkest skies east of the Mississippi and also hosts an annual “Stars Over Katahdin” stargazing event. In other words, there are lots of opportunities relatively close to home for me to immerse myself in the beauties of natural darkness.
For those who would like a better sense of what light pollution prevents us from seeing, check out this short video from National Geographic:
Stepping Into The Future 
I like to sit outside in the dark in the summer. It’s not totally dark but I don’t have neighbors with dusk to dawn lights either or motion lights. I suspect that won’t be the case after I move to the CC Campus. Thanks for reminding me to really enjoy the dark while I can.
Jean, I had the same thought while I was writing this — that there will probably be a lot more outside light when I move to a retirement community. One more thing to check out when I go back to visit the community where I think I’m going to sign up on the waiting list.
I so appreciated this post. I am comforted by the dark and find it to be restorative and comforting. I like sleeping in a dark room and require no night lights. Even in this rural setting, there seems to be enough light to make my way in the darkest of nights.
Like you, I like the dark. I was surprised once when a neighbor told me that she is afraid of the dark.
Jean,
My wife and I were lucky enough to rent a house on a Coast Guard station on the outer part of Nantucket one year. It was right on the water. Minimal light pollution looking out into the Atlantic. The night sky there was the most spectacular we have ever seen. We’ve both have traveled a lot too.
Gary, That sounds wonderful!
We do have a motion sensor light at the front door. Thomas uses it as a doorbell – let me in! It goes off after a few minutes.
Grateful that we didn’t have streetlights when Halley’s Comet flew by – that was a dark sky experience I will never forget. Also Sutherland when we visited the Observatory.
Diana, Perhaps if enough of us seek out those dark sky experiences, we can raise light pollution to a public policy issue.