Recently I had dinner with a friend, a woman in her 70s who has lived her entire life in NJ, the most densely-populated state in the US. As we exited the car in the early winter evening, she looked skyward and asked if I thought there were fewer stars than in the past. She said she had read that it seems that way because of all the artificial light we produce.
Her remark really got me thinking about how humans have turned night into day in many ways, and why it might be desirable but also destructive. Since we discovered fire some 1.6 million years ago, we have had the ability to generate light, and the trend toward controlling darkness has continued ever since.
It's easy to list the benefits of natural light: better visibility for safety and productivity, and elevated hormones for better mood, among other things. But does artificially extending the number of hours of light in a day present a physiological downside? All living creatures have circadian cycles, naturally established bio-rhythms that govern important functions like digestion, growth, reproduction and migration. Only humans seek to manipulate or alter these built-in patterns, and to some extent we are successful at it. Unfortunately, our efforts in this arena do not affect only us; plants and animals similarly exposed to our artificial light suffer from changes to their natural cycles. From hatchling turtles confused about the way to the ocean, to birds migrating off-schedule, we are not alone in experiencing unhealthy changes to life cycles. (See Verlyn Klinkenborg's article "Our Vanishing Night" on Nationalgeographic.com.)
The ability to work (or play) through the night may seem a boon to industry, service and even pleasure pursuits. Studies have shown, however, that people who do shift work or night work are more prone to experience poor sleep quality, health problems, family and emotional stresses related to being out of synch. A persistent state of exhaustion makes driving and other similar activities more hazardous as well.
And is the type, quality or intensity of artificial light healthy? No, in many cases. A study by the AMA last year, entitled "Light Pollution: Adverse Health Effects of Nighttime Lighting," addresses in particular the blue spectrum lights now commonly used in vehicle headlamps and electronics equipment. Not only do people experience discomfort from the glare, there is evidence of a possible link between exposure to such lighting and various health problems, vis-a-vis disruption of our natural cycles. Sky and Telescope e-magazine blogger Camille Carlisle presented an excellent review and summary of the AMA article.
In his farcical 1784 essay, An Economical Project, Benjamin Franklin wrote about forcing Parisians to rise with the sun, presumably to tire them out by dark, in order to save on candle costs. What are the financial advantages and drawbacks to generating artificial light? A manufacturing enterprise that runs all the time is theoretically more productive than one that shuts down for several hours in the same 24-hour period. Deduct from any additional profit the operating costs to keep plants open at night, pay the workers the shift differential, cover related healthcare costs, and maintain equipment than runs nonstop, and what is the real financial gain?
Superstorm Sandy ripped through our area on October 29, 2012. For days, weeks, even months in some cases, we were without power all along the coast, here in New Jersey and beyond. One thing I noticed immediately was the utter darkness we experienced at night, and (setting aside the hardships of the situation for a moment) how soothing it felt without the constant glare of light. Over the holidays, did you take note of the differences in effect and sensation to your eyes between older style decorative lights and the newer, brighter LED bulbs? It is said that candlelight is the most flattering; I am starting to believe it is the closest to natural light and possibly the least harmful, too.
There may not actually be fewer stars in the sky, but my friend is correct in her observation that we can't see the stars nearly so well as we used to. I only hope that by the time I am her age we have not washed the view out completely with the fake sparkle of artificial light.
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