Street lighting in Athens is designed with the reduction of light pollution in mind, but some astronomers say it could go a step further.
The city of Athens has followed the same standards for street lighting for nearly two decades, which was partially the result of trying to find the middle ground between safety and light pollution.
The city lighting standards are designed so that streetlights shine where they are necessary while not casting too much upward lighting in order to lessen the amount of light pollution, a request made to the city by astronomy professors and stargazing hobbyists.
The idea to reduce light pollution first came from Joseph Shields, astronomy professor at Ohio University and vice president for research and creative activity, who advocated for the city to lower the lumen level, or the amount of light produced by lighting fixtures, in order to better see in the sky at night.
But George Eberts, an instructor and outreach specialist for the astronomy program, said city lighting still makes it difficult for astronomers to see at night.
“If you take a low wattage level lumen level, and you direct it properly, your visibility on the ground will be much better than if you have a high lumen level blasting in every direction,” Eberts said. “Good, well-designed lighting means eliminating glare, and glare is harmful to seeing things at night. Any time you’ve put up your hand to block a light, you’re blocking the glare. That’s glare, and you shouldn’t have to do that.”
Eberts teaches three sections of Astronomy 1400, which he tries to teach outside as much as possible.
“I’m not able to see much of what I want to show people with too much light pollution. And we have ways of dealing with that, but it involves hopping in a van and going out into the country,” Eberts said.
Eberts also said beyond a certain point, you can’t see the Milky Way or any faint or even medium stars. Walking around downtown or a suburb or shopping mall parking lot at night makes it challenging to see stars. No matter how clear the night is, only a few larger stars may be visible to those who know where to look for them, Eberts said.
Eberts also said the city could consider using total cutoff lighting, a style of streetlight that directs all of the light toward the ground, illuminating what’s necessary without any glare or light shining upward. This style of lighting has proven its use in Tucson, Arizona, where total cutoff lighting was installed to reduce light pollution near Kitt Peak National Observatory, Eberts said.
All city-owned streetlights and traffic signals are LED lighting, Andy Stone, city service safety director, said. Stone said the city has talked about total cutoff lighting but did not say if the city is planning on using it in the future.
LED lights could be converted to full cutoff lighting, but it would be more difficult than with other kinds of lighting because LEDs cannot be filtered as easily, Eberts said.
“You have to make a real proactive effort to get the wattage down … so LEDs can be fine, but you have to understand how they work and choose them and place them carefully. All of it starts to sound like more trouble than it’s worth.”