Pittsburgh Goes Dark: Could This New Dark-Sky Ordinance Begin a Trend?

Can you see the Milky Way from your own home? Diane Turnshek can, and he or she desires to Pittsburgh to see it, too.

Pittsburgh photographed from above
Astronaut Chris Hadfield took this photograph of Pittsburgh from the International Space Station in 2013. The “Three Rivers” are clearly seen among the many lights.

“I would like to shrink the ring people have to drive outside of the city to see the Milky Way dependably,” she says. “It’s about a 40-minute drive at this point.”

Turnshek (Carnegie Mellon University) is a dark-sky skilled who helped draft Pittsburgh City Council’s new Dark Sky Ordinance, which covers town’s parks, amenities, and all streetlights. With the brand new ordinance, the “ring” may very well be about to shorten dramatically. The new ordinance, which applies solely to city-owned property for now, would exchange 35,000 previous high-pressure sodium streetlights over the following 18 months to 2 years. All will likely be dark-sky-friendly, with cut-off fixtures that direct mild the place it must go.

Crucially, the ordinance additionally replaces newer LED streetlights, the type that had been rapidly put in in cities the world over within the 2010s. “About a decade ago, 4,297 streetlights were replaced with 5,000-kelvin LEDs,” says Turnshek. These brilliant, blue-white lights flip evening into day, and are a main reason behind the world’s rising mild air pollution, so Pittsburgh will exchange them with lower-temperature, amber-colored LEDs.

Pittsburgh City Council claims the brand new streetlights will “provide long-term savings and reduce energy usage and light pollution.” The new plans additionally embrace between 3,000 and 15,000 new LED streetlights discovered to be vital in the course of the evaluation. Crucially, these may also all be darkish sky-friendly: motion-sensored, shielded, and with each a decrease wattage and cooler temperature.

Phipps Conservatory photographed from above
The Phipps Conservatory and Botanical Garden, photographed from above through drone, is without doubt one of the organizations that has signed on to Pittsburgh’s dark-sky ordinance.
Michael London & Diane Turnshek

Exactly what will likely be used stays to be seen; Turnshek continues to be in dialog with Pittsburgh City Council about controlling the  2,200-kelvin streetlights. “Dimming is essential, she says. “The lights shouldn’t run at full brightness … They understand that the total lumens output should be reduced.” She says many cities have made the error of choosing low colour temperature lights, however then placing them in way too brilliant. 

Part of Turnshek and others’ preparatory work included the monumental job of constructing a nighttime map of Pittsburgh’s 58 sq. miles. That was achieved utilizing photographs from drones taken solely on clear, snowless, dry, and moonless winter nights — a painstaking job. The staff additionally used a Sony DSLR digicam underneath a Cessna plane in addition to photographs taken by astronauts on the International Space Station.

Is this the start of the top for affordable blue LED lights utilized in public lighting? “It’s too soon to tell,” says John Barentine (now at Dark Sky Consulting), who was peripherally concerned within the effort whereas employed on the International Dark-sky Association. “I think that has been in motion for a while now, and it has been driven by a combination of public rejection of those bluer LEDs in favor of warmer lights, and generally better affordability of those warmer LEDs.”

Amateurs will likely be heartened to listen to that dark-sky-friendly lighting has grow to be extra aggressive with methods with greater colour temperatures. Darker skies now not come at a premium.

Of course, Pittsburgh’s ordinance isn’t particularly associated to the wants of novice astronomers. Its acknowledged goals are to enhance security and safety, cut back mild air pollution, save vitality, and advance fairness in all Pittsburgh neighborhoods.

However, it might even be a signal of an growing curiosity in, and appreciation of the worth of, darkish skies. “There is a groundswell, built of people who feel deprived of a natural right to starlight,” says Turnshek. “Some young, who feel they were not given a choice, and some old, who remember the comforting beauty of the dark night sky as if it were yesterday.”

Turnshek started her mission to deliver darkish skies again to Pittsburgh with a 2015 TEDxPittsburgh discuss referred to as “De-Light The Night.” But Pittsburgh shouldn’t be alone in its adoption of a dark-sky ordinance — neither is it the standard-bearer.

“The new Pittsburgh ordinance is not quite as restrictive as Flagstaff or even Tucson,” says Barentine. “But for major U.S. cities, especially those on the East Coast, it is quite a bit better than others that are out there — I think this is the future of outdoor lighting policy in the U.S.”

There is as but no designation as a “Dark Sky City,” however Pittsburgh may quickly be in a place to use to the International Dark-sky Association to grow to be an “International Dark Sky Community.” Either way, the brand new ordinance in Pittsburgh places it forward of just about each different U.S. metropolis on the subject of darkish skies.


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