Earlier this summer, I visited the Hayden Planetarium in New York City. It was a joy to see fellow astronomers present a live tour of the night sky in a state-of-the-art facility. The best moment of any planetarium show always comes midway through, once everyone has adjusted to the low light and is starting to get acquainted with the constellations twinkling above. The narrator pauses. The lights fade further still. As the dome transforms to inky black and countless new stars obscure once-familiar constellations, the audience audibly gasps.
When I ask students in my introductory astronomy class if they have seen the Milky Way, very few hands pop up. The night sky as our ancestors saw it is a novelty, a luxury; something foreign to gasp at.
That night in Manhattan, the planetarium show was followed by telescope viewing. As I headed outside and looked up to get my bearings, I felt very disoriented: in spite of mostly-clear skies, I could count the number of visible stars on my hands. And two of those were actually planets. I was struck by Neil deGrasse Tyson’s embarrassing admission that, as a child, seeing a dark night sky while camping reminded him of the Hayden Planetarium.
It is one thing to read about pervasive light pollution. Yes, our cities are growing and getting brighter, and it is increasingly impossible to see very many stars at night. Intellectually, I know this, and I know that it is a huge waste of money and energy; a large-scale, slow-growing problem with no easy fix. But experiencing it is something different altogether. It is deeply distressing. I fear we are literally blinding ourselves from the Universe’s past and our species’ future when we block our only window to the starry heavens above.
Also this summer, I traveled to northern Vancouver Island in Canada. My room faced northeast, toward the water, with expansive windows and no blinds or curtains. Night was dark. Not “it’s difficult to see, can you shine a light over this way?” dark, but truly, utterly, all-encompassingly DARK. There was no telltale glow on the horizon of some distant city or rogue gas station. There was no streetlight casting orange light in an unwanted direction.
One cloudless night as I lay in bed, I could see stars twinkling out the window, and woke my husband to drag him outside. We reveled in proper, glorious darkness. Like the Hayden Planetarium, there were so many stars that familiar constellations were hard to pick out. The sunrise, early though it was, reset my circadian clock. I reconnected with the night and felt whole.
We have a natural tendency to equate light with good, with safety and security, and with happiness. But we have slowly eased into modern life with an overabundance of this good thing. (Not to mention: studies have demonstrated that more light does not equal more safety.) I do what I can in my personal life to get lots of natural light during the day, use fewer lights at night, and take the irritating blue glow out of my backlit screens.
Of course, while it doesn’t make sense to shine excessively bright lights, it doesn’t make sense to turn them all off, either. Smart solutions exist for dark-sky friendly light fixtures. But I fear it will take a health or energy crisis to make us truly examine how we wash out the night. Until then, we must cherish every sliver of darkness we can find.