By Suzanne Vanderhoef
When you look up at the night sky on a clear night, you expect to see stars. But around most cities and towns, you may not be able to see much of anything but darkness because of something called “light pollution”.
According to Professor of Physics and Astronomy at Truman State University Vayujeet Gokhele, there are two or three ways in which you can define light pollution.
“The strictest definition is the introduction of any artificial light into the natural environment. A more pragmatic definition is the introduction of light into the environment that is not serving any purpose that is useless. And so, if it doesn’t serve purpose, then it’s wasteful.”
Dark Sky Missouri is a chapter of the International Dark Sky organization –or IDA– that advocates for environmentally friendly lighting, including using lights that are “warmer” on the spectrum, like red or amber, as opposed to “cooler” white or blue lights.
“We have five principles actually, of responsible lighting, that’s one of them, the warmer colors,” explains Stephanie Todd, Vice Chair, Dark Sky Missouri . “Use it only when you need it, don’t have lights on all night long. And motion detectors are great if you think you have to have some light at night. Focus it only where you need it. So, you know, and so don’t shine up light in the sky. And then the light should be shielded so that you’re not shining light up into the sky because it’s just wasted light.”
Here in the St. Louis area, amateur astronomers can often be seen looking through their telescopes at Stacy Park, in the heart of Olivette. In fact, Dark Sky International just named Stacy Park as an official “Urban Dark Sky Place”– the first in Missouri and one of just 4 in the world to get such an honor.
“What that means is that even though we are surrounded by a lot of light pollution, we are a little oasis of darkness,” says Beverly Tucker Knight, Director of Parks and Recreation for the City of Olivette . “The way we look at that is, it’s our practices. So, when we use lights here, we follow the IDA guidelines, which are that they’re down facing there on a certain spectrum of the lighting, so that we aren’t being a bad neighbor and putting light pollution into our neighboring homes. But also, we’re not adding artificial light that negatively impact fireflies and birds, and even trees that grow differently when they have lights on them.”
But, you don’t have to be in charge of a city to make a difference. As Prof. Vayujeet explains, there are simple things you can do in your own yard.
“All you have to do is have light shields that point light fixtures that point downwards. Use amber colored lights rather than blue-white lights for the reason I mentioned earlier, amber color, the least disruptive to most life forms. And the amber color really means very little blue light in your light source outdoor lights indoors, you can do whatever you want. But outdoor lights, we can be we can be a little more careful about directionality, and the lack of blueness in those lights.”
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