“What happened to the night sky?”
My great-grandmother lived to be 102 years old, and I can remember her telling stories of the starry night skies over the mountains of West Virginia. When she was a child, light came from candles, fires and oil lamps. There were no cars, no electricity and no city lights. She had a clear view of the night sky and could easily spot the Milky Way galaxy’s edge as a streak of light across the entire sky. She was born in 1900 and witnessed the advancement of society from no electricity at all, to seeing the first light bulbs, first cars, first computers and first airplanes. Among these amazing technological advances we lost something, the night sky.
I can remember my great-grandmother saying she missed the stars, and wondered why there were so many fewer stars than when she was a child. I used to think it was because she was losing her sight – she did wear big thick glasses and could not see anything without them – but I recently read an article about light pollution. We have all experienced the effects of air, water and land pollution, but have you ever actually noticed light pollution?
Light pollution occurs from the over-use of artificial light and, believe it or not, can have catastrophic environmental consequences for humans, wildlife and our climate. Light pollution is a side-effect of our technological advancements. The first light bulbs were incandescent lights, which basically means they were heated wires that created a glow inside a vacuum sealed bulb. These early incandescent bulbs were limited in their light production to about 14 lumens per watt, and the largest of these bulbs could only produce 1400 lumens. A lumen is a unit of measure that tells how bright a source of light appears to the human eye and is approximately the amount of light emitted from a single wick candle. The invention of the light bulb increased the lumens in a household from a few dozen lumens to a few thousand lumens in just a few short years.
Our modern LED lights produce approximately 100 lumens per watt, which was expected to reduce electricity usage but instead it has caused an increase in the use of artificial light sources. Instead of replacing the 1400 lumen/100 watt incandescent bulb with a single new LED bulb using only 14 watts, most people have installed more lights, consuming nearly the same amount of power, but producing four times more lumens of light. This has led to a 1000 times increase in the amount of artificial light since 1700. The latest studies show that nearly 80 percent of humanity experiences light-polluted night skies and all our major cities can no longer see the Milky Way.
You might ask yourselves exactly how this impacts your life, other than missing the beauty of the night sky. There have been many scientific studies showing the impact of light pollution. The first and most personal impact is that of the sleep cycle; our bodies were designed to rest at night and work during the day. In the early 1900s the work day started at dawn and ended at dusk. During the winter months in most of the U.S. this is about 7.5 hours and peaks at 15 hours during the summer solstice, leaving us with the medically proven 8-9 hours of sleep on the shortest of nights. Artificial light has allowed us to extend our working/waking hours and many of us are sleeping much less than eight hours a night.
The second impact is on the hibernation and reproduction cycle of animals. A great example is that of chickens. Anyone who raises chickens for egg production knows that when left to the natural light source, egg production is greatly reduced in the short winter days, and adding sufficient artificial light in the coop will increase egg production. This is great for chickens in captivity, but not so great for wild birds that may eventually be impacted by the artificial light sources triggering early egg production and resulting in a lack of viable eggs, thus reducing the bird populations. I can openly admit that before moving into rural Missouri, I was missing the stars in the night sky from the growth of my hometown in West Virginia. The night sky is not the same in big cities and it’s not just because the buildings get in the way. I still cannot forget the first time I visited rural Missouri and clearly saw the Milky Way streak across the night sky. I was finally able to understand my great-grandmother’s comment about missing the stars, and I suspect that the night sky was much more spectacular in 1900. We need to work towards methods of reducing light pollution just as much as we focus on air, water and land pollution, because if we continue with the current trends a whole generation may grow up in perpetual twilight, never truly seeing the night sky.
So turn off the lights and enjoy the night sky. Until next week, stay safe and learn something new.
Scott Hamilton is an Expert in Emerging Technologies at ATOS and can be reached with questions and comments via email to email@example.com or through his website at https://www.techshepherd.org.