The Darker Side of Light
After a few months of inactivity I’ve developed an idea that will keep me busy blogging. It’s been cloudy for so much of the summer so I haven’t been able to do much observing. My attention, therefore, has turned to other activities related to astronomy that I can pursue when the weather is not ideal for observing. If you’ve read any of my previous articles on this site you’ve probably read about light pollution. Maybe you’ve heard of it elsewhere or perhaps you’ve never even considered the possibility of light being a pollutant. While electric lighting is a marvel of the industrial age and a wonderful aide to modern life it also, like many good things, has a darker side.
From the beginning of life on Earth approximately 4 billion years ago all of Earth’s creature, including humans, have lived in an unending cycle of light and dark. Bright sun-drenched days give way to the darkness of night and the majesty of a star-strewn sky with its backbone the Milky Way arching across from horizon to horizon. Life has evolved according to that cycle and it has flourished. It wasn’t until just over 100 years ago that we began introducing large quantities of artificial light into the environment. This artificial light disrupts the light-dark cycle (also known as the circadian clock) that life has depended on for billions of years. It has endangered species like insects, turtle, hundreds of species of birds, and all manner of nocturnal creatures. Artificial light is also a known contributor to many human diseases such as obesity, insomnia, diabetes, and hormonal cancers. Besides the biological effects of artificial light, it is also a massive waste of energy. Every year in the United States alone, poorly designed or over-used light that shines up into the sky wastes $2.2 billion!
Last, but certainly not least, artificial light has destroyed the night sky that humans have loved for thousands of years. When the lights from un-shielded fixtures shine up into the sky the light scatters when it hits particles in the air. The result is called skyglow. You can clearly see the effects of skyglow when you look towards a city or town at night from a distance. The yellow, orange, or pink glow in the sky is the sum of all the light from all the street lights, parking lot lights, stadium lights, residential lights, etc…and their light scattered in the air. The dome of light obliterates all but the brightest stars and the Milky Way is a thing of the past. Depending on the size of the city, skyglow is noticeable from as far as 100 miles away as a dome on the horizon.
Light pollution has severe negative consequences on my pursuit of my hobby of astronomy as I have to drive considerably far from my home to view under dark enough skies. I currently drive 33 miles from my home in north Baltimore to reach my observing site in Fawn Grove, PA and even there the effects of light pollution are quite pronounced and the Milky Way is barely visible on clear, moonless nights. To reach a location almost totally unaffected by light pollution I’d have to drive five hours north to Cherry Springs State Park near Coudersport, PA.
What I’ve decided to do over the next couple months (or however long it takes) is to compile a photo essay of sorts that chronicles the effects of light pollution throughout the Maryland and Pennsylvania area. My goal is to photograph constellations, horizons, skylines, and light fixtures everywhere to make known to my readers the harmful effects light pollution has on the night sky and astronomy. I will visit many locations throughout Maryland from the Inner Harbor in Baltimore, to a swamp on Maryland’s Eastern Shore, to rural York County, PA, an international dark sky park, and many places in between. I hope that this project will open some eyes and convince people of the reality of light pollution and the truth that it is something that we CAN fix.
In the United States today, eight out of ten people will never see the Milky Way in their lifetime because of light pollution. It doesn’t have to be that way though. Through public education and teamwork with local governments we can reverse the harmful effects of light pollution and preserve the night sky and its splendor for future generations.