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A Loss of Night

Southeast Wisconsin Waster of Light This map reveals Southeastern Wisconsin's and specifically, Milwaukee County's waste of light, (and the resulting energy consumption), spilled into the sky at night. Gleaned from military satellites, this map indicates relative brightness of skyward spilled visible light. Comparing the image within the dark outline to the population density map, a similarity to population density can be seen.

Studies of satellite imagery and population density in developed countries has shown a general relationship between population, energy consumption and energy waste.

Notice how industrialized areas such as the Menonomonee River Valley, while sparsely populated, play host to major industries and transportation corridors, which in turn relate to excess lighting. Streetlights, in particular the common "cobra head" type, contribute to light pollution as well. In 1997, the City of Milwaukee had 66,390 streetlight units, many which are this type.

Light spilled skyward makes the sky much brighter at night, and we lose darkness. Inevitably we lose something even more important: the beauty of the stars at night, seeing the changing paths of the planets, and the pale glow of the Milky Way overhead. In losing these we lose our comfort with night and our link to the oral traditions which shape the stories of the sky. Gone is the nighttime text of the seasons, and our understanding of our place within our greatest environment — the universe at large.

What do Do?

While energy efficient night lighting does exist within Milwaukee County, you can make a difference on several levels.

Install energy efficient lighting at your home or encourage its use at your workplace. Light spilled skyward is wasted light — it does not increase safety to dump light skyward. Well shielded, energy efficient lighting puts wattage to good use by lighting the area beneath light fixtures.

Put your outdoor lighting on timers or motion detectors so that you have light when you need it.

Petition your alder-person, county representative and others for shielded lighting fixtures for commercial and industrial sites. Many communities in the western United States and elsewhere have dark sky ordinances which encourage businesses and city lighting to exist as shielded light fixtures and of specific wattage, or to burn for specific times. Remember preserving night means saving energy, and this translates to saving money as well.

For more information about dark-sky lighting, contact:

International Dark-Sky Association
3225 North First Ave
Tucson, AZ 85719

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Look for dark-sky lighting at several sites throughout Milwaukee County. Near the airport along Interstate 94 north, and towards downtown. The University of Wisconsin Milwaukee campus and other locations have some excellent examples of shielded light fixtures.

The Wehr Astronomical Society (WAS) has approached the City of Franklin regarding shielded lighting to preserve the dark-sky conditions of Froemming Park, location of the WAS Observatory.

Wehr Astronomical Society
9701 W College Ave
Franklin, WI 53132
tel. 414/425-8550

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