1. Light Pollution: a Primer

2. The basic problem: Sky Glow Light from fixtures reflects off particles in the sky— ”Sky Glow.” Large cities visible from tens of miles. The stars are not brighter here in the country—the sky is darker!

3. The Global Problem

4. Light “Made in the USA”

5. Boone,NC 35 years ago…

6. … today

7. The Horsehead Nebula

8. M13 Globular Cluster

9. Where does the sky glow come from ? Poor fixture design Lack of shielding Over-lighting Poor installation Market pressure

10. Floodlights Almost horizontal No shielding At night …

12. Better: Full Cut Off (FCO) “Shoebox” design Why do you think they are chosen? … Appearance in the daytime! At night …

14. Billboards: the Bad Way Uplighted Most light reflected into the sky Often on all night

15. Better for the sky, but… Glare spot (illustrates the sky problem, though…)

16. Roadway lighting-overhead glare

17. Cobra heads Filament below reflector Glaring to driver Light polluting

18. Better, FCO Fixtures No light above horizon Non-glaring to drivers, too! May require more poles per mile At night …

20. “Security” Lighting “Dusk-to-dawn” Security or lighthouse? Refractor very glaring and light polluting Frequent light trespass and neighbor problem Installed by amateurs and utilities

21. The Glare at Night (From High, Too!)

22. Solution: Sky Cap GE prototype shown Hubbell available Total FCO See results …

23. The Capped Light at Night

24. The Data

25. Car Sales Lots Often grossly overlit This one at 60-110 Fc on lot, 65 on road Use astronomically unfriendly metal halides Can use sodium with 10% while to get color rendition

27. Wall Packs One of the worst fixtures for pollution as well as glare Are available in FCO What is the point of these? 

28. Sports Lighting Usually done poorly with lots of light pollution and light trespass. Can be done well as shown here, using fixtures like ….

29. … Musco fixtures Costs ~$100/fixture

30. Gas Station Canopies

31. Compare to This This station ~ 35fc Large diffusers easy on the eyes Easy on the camera, too…

32. How You Can Help Teach your students about the importance of dark skies by including a light pollution lecture in your astronomy course (we are handing out a PowerPoint presentation suitable for this, ask us for one!) Look at your own lights–are they needed? Could you have it capped? Put it on a switch, timer or a motion sensor. Put in a lower wattage bulb. Where do you eat out? Do the restaurants have glaring lights? If so, complain! …

33. Are there some roadside lights that bother you as you try to drive? Complain! Is there a street light that shines into your window at night? Call up the utility and ask for them to put a sky cap on it. Don’t settle for simple spray painting of the fixture’s lens! Spend some time at www.darksky.org and become (more of) an expert! Join the IDA.www.darksky.org Write letters to your newspaper….

34. Teach your friends about good and bad lighting– point it out when you are out with them at night. Make a difference! Start a project to get owners of “security” lights to have sky caps installed on them. Is there a street light that shines into your window at night? Call up the utility and ask for them to put a sky cap on it. Don’t settle for simple spray painting of the fixture’s lens! Spend some time at www.darksky.org and become (more of) an expert! Join the IDA.www.darksky.org Realize that you are the ones with rights to speak for (“pursuit of Happiness” [Dec.Ind., par.2]). Develop a local ordinance….

35. Lighting Ordinances A simple ordinance can get 90% of the gain: FCO, no floods (or or shielded floods) Down-lighted signs Caps on security lights Limits on gas stations (< 35 fc max) 0.5 to 1 fc trespass at property lines General limit (“in excess of need”) Coming: Model Lighting Ordinance (IDA and Jim Benya, Benya Lighting Design)

36. Concluding… Like the background on this presentation, let’s make the orange glow of sodium vapor go away. Thank you for your time and attention, and... Let’s make some changes!