The Green Room: Starlight, Streetlight, What Can I See Tonight? Preventing Light Pollution
No matter who we are or where we live, all human being have one thing in common: we all have the night sky above us. But can we actually see it? Studies say nowadays only 20% of the world’s population lives somewhere dark enough to see the heavens untouched by light pollution. Luckily, this is one form of pollution that can be reversed. Join Barbara Lucas as she explores how.
David Fair (DF): Fear of the dark is as old as human history. As civilization progresses, so does the brightness of the night sky. But, is brighter always better? Scientists are telling us there are good, and bad, ways of lighting the night. Municipalities as close as Brighton and Scio Townships are enacting ordinances to limit light pollution. In this month's installment of WEMU’s “The Green Room,” Barbara Lucas sheds some light on the growing concern for protecting the dark.
Telescope-use banter: Have you still got the moon in the scope? …and if it’s out of focus, here is your fine adjustment right there.
Barbara Lucas (BL): I’m at the Headlands International Dark Sky Park, at the top of Michigan’s mitten, west of the Mackinac Bridge. It’s a cool crisp night, and about a dozen folks are taking turns peering through a telescope, near a crackling fire.
Sounds of group moving inside.
BL: Inside there’s a fun, interactive program about the mythology of Venus and Mars. Next month, those two bright planets will be as close together as they can get! Like the ancients, Park Director Mary Stewart Adams finds poetic inspiration in the night sky.
Mary Stewart Adams: …with a degree in literature from the University of Michigan, a story teller. I don’t know how to use a telescope.
BL: But, she values the heavens no less than the scientists, and helped to found the park in 2011. Adams says at that time...
Adams: We were only the 6th in the US and the 9th in the world.
BL: Now, there are 54 certified International Dark Sky Parks in the world. We’ve driven four hours to this one, for a chance to see the night sky in its full glory. Used to be, all you had to do was step outside your door to see the Milky Way. Now, studies show 99% of Americans live with light pollution. Adams says this is one environmental problem we can do something about.
Adams: The best thing to do is to turn on your outdoor lights and step back and look at your house. Where is the light going? Do you need it?
BL: She says if you do need it, make sure there’s no escape of light up or out. It should have a downward-pointing shield, or be recessed. If you can see the bulb, that means light is going where it’s not needed, wasted. For examples of good and bad lighting, she refers me to darksky.org, website of the International Dark Sky Association.
Exchanging greetings with Dr. Oey.
BL: To learn more, I head to the University of Michigan, and meet with astronomer Dr. Sally Oey. It’s after dark, past my bedtime!
BL: Thanks for meeting with me. I’m excited—sleepy, but excited!
BL: Dr. Oey supports more lighting, in places like crosswalks. It’s the quality of the lighting, not the quantity, that’s her concern. To illustrate, first she takes me to the observatory at the top of U of M’s Angell Hall. She opens its huge dome.
Whirring of machinery as the observatory’s dome opens.
Dr. Sally Oey: This is where we have our students do observing sometimes.
BL: Although it’s almost midnight, it’s far from dark outside.
Oey: You can definitely see how the clouds are lit up from the bottom here.
BL: We can see a couple stars, but it’s nothing like the celestial glory that we witnessed at the Headlands Dark Sky Park.
Oey: One of the reasons we have the planetarium is because we can’t see the sky that well.
BL: But, she says Ann Arbor used to be a great place to see the night sky.
Oey: Our telescope that was built in 1857 was basically the third largest refracting telescope in the world at that time. So we have a very long tradition of doing astronomy here. Hopefully if we start thinking about it, we can get back to preserving the sky and allow more people to enjoy it.
BL: She says contributing to light pollution is the idea that the brighter, the safer—which she says isn’t always true. Sound of car driving in parking structure. To show me what she means, she drives me up and up, to the fifth floor of a parking structure overlooking the surface lot next to Ann Arbor’s downtown Transit Center. Car doors close as we get out of the car.
Oey: You can see that the lot is lit up like it's day. Now, you know that that's unnecessary--it doesn't have to be that bright.
BL: It’s a full moon tonight. She points out that the lights we see from up here are far brighter than the moon even.
Oey: Look at the shadows that are cast by the trees for example. If those lights weren't so bright those shadows wouldn't be such a contrast. And so that lot wouldn't be any less safe if you reduce how bright those light were by a significant amount. So in other words somebody couldn't hide in the shade of those trees.
BL: But, on the positive side, she says some of the lights are well-shielded, without escape of light upwards.
Oey: You can’t see the bulb at all, right? You can just see the fixture. And here we are pretty much level with it.
BL: Like most cities, Ann Arbor invests millions of dollars in lighting. Dr. Oey says yes, efficient LED’s are great for their ability to give more light for less money.
Oey: It's true, but are we saving more energy? Because in fact what's happening, it seems, is that people are lighting up more things for the same amount of money.
BL: Dr. Oey would like all new fixtures to direct light down, and illuminate evenly without glare or deep shadows. She refers me to Karin Uhlich, who sits on the Tucson, Arizona city council.
Karin Uhlich: Our ordinance was first enacted in 1972.
BL: Tucson is one of hundreds of municipalities with rules for outdoor lights that welcome lighting for safety, but limit light being wasted.
Uhlich: We're not prohibiting light, we're targeting it. We're preventing light pollution which is misdirected light. It serves no purpose.
BL: And, can even be counter-productive. She says the night blindness we get from glaring light can be a safety issue.
Uhlich: And, so what ends up happening if it's not planned well and diffused appropriately and shielded downward is that you get patches of very bright light and then the pupils can't adjust.
BL: It’s the moving in and out of glaringly-bright light that’s the problem.
Uhlich: And, if it if the street darkens, it can really affect pedestrian and bicycle safety and just traffic safety in general.
BL: She says their 45 year-old ordinance is generally accepted by businesses and residents as a win-win.
Uhlich: In most cases again because they are really typically modest adjustments and the adjustments typically save, ultimately, save anybody who's impacted, save money over time.
BL: Tucson’s ordinance requires lights be in the warmer yellowish or amber range, rather than the glare-producing bluish-white. Uhlich says when you fly over Tucson in an airplane…
Uhlich: It's more of a yellow glow than it is just that stark white bright blinding light that cities often emit. And so to me it's perfectly in keeping with sort of the culture here which is we're very I think appreciative of the environment we're a part of. And so I think it's just a testimony to that.
BL: Dr. Oey says a similar ordinance was proposed about ten years ago in Ann Arbor. But the effort fizzled due to concerns about money and safety. She thinks it’s time to reevaluate, at least when it comes to new lights, moving forward. She says the right lights in the right places can save energy, while preserving both safety and our views of the night sky.
Footsteps on outdoor pathway, chirping crickets.
BL: An example is the walkway back at Headlands Dark Sky Park. It’s lit by fixtures on posts low to the ground. Being red filtered, and only illuminating the path, they preserve night vision. So not only can you see the stars, but you can see your surroundings. That adds a feeling of security.
BL: While the park’s director Mary Stewart Adams acknowledges the challenges of convincing folks to change over to Dark Sky-friendly lighting, she’s motivated by what awaits.
Adams: It’s not like trying to regrow a forest. As soon as you turn the lights down, (snaps her fingers), the stars come right back. It’s really gratifying to have that experience.
BL: In “The Green Room,” I’m Barbara Lucas, 89 One, WEMU News.
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