uploaded to flickr by MichaelPgh
The desire and ability to dispel darkness has been one of the blessings of modernity. It has enabled us to extend our days and pursue our interests for longer. However, such is the disquiet that only now are concerns about the unintended consequences of our lust for light being given an airing in the likes of National Geographic magazine. The ‘peripheral glow of our prosperity’ that is light pollution has been significantly screwing up the habits and dispositions of many of our creaturely neighbours. And we are only beginning to query what it might be doing for us –
Unlike astronomers, most of us may not need an undiminished view of the night sky for our work, but like most other creatures we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself. The regular oscillation of waking and sleep in our lives—one of our circadian rhythms—is nothing less than a biological expression of the regular oscillation of light on Earth. So fundamental are these rhythms to our being that altering them is like altering gravity.
For the past century or so, we’ve been performing an open-ended experiment on ourselves, extending the day, shortening the night, and short-circuiting the human body’s sensitive response to light. The consequences of our bright new world are more readily perceptible in less adaptable creatures living in the peripheral glow of our prosperity. But for humans, too, light pollution may take a biological toll. At least one new study has suggested a direct correlation between higher rates of breast cancer in women and the nighttime brightness of their neighborhoods.
In the end, humans are no less trapped by light pollution than the frogs in a pond near a brightly lit highway. Living in a glare of our own making, we have cut ourselves off from our evolutionary and cultural patrimony—the light of the stars and the rhythms of day and night. In a very real sense, light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way—the edge of our galaxy—arching overhead.
I wrote about the need to cut light pollution, and to develop awareness of the starry sky, before.