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Making War On Light Pollution
Hugh Pickens writes "Almost thirty years ago I worked in the Middle East helping install a nationwide communications system and had the opportunity to be part of a team doing microwave link tests across Saudi Arabia's Empty Quarter. Something I've never forgotten were the astonishing nights I spent in the desert hundreds of miles from the nearest city where the absence of light made looking at the sky on a moonless night feel like you were floating in the middle of the galaxy. In Galileo's time, nighttime skies all over the world would have merited the darkest Bortle ranking, Class 1. Today, the sky above New York City is Class 9 and American suburban skies are typically Class 5, 6, or 7. The very darkest places in the continental United States today are almost never darker than Class 2, and are increasingly threatened. Read a story from the New Yorker on what we have lost to light pollution and how some cities are adopting outdoor lighting standards to save the darkness."
If you would RTFA instead of rushing for first post you'd see that it mentions that, when properly done, reducing the excessive and inappropriately strong lighting that covers most cities would actually aid nighttime vision by eliminating the glare.
Those of us from "out in the country" have a different perspective.
Most nights, it's easier to see in the absence of artificial light, because our eyes adapt to the more complete light coverage provided by the moon and stars. City and suburb folks have problems with darkness because of the incomplete coverage of the artificial lights causes ordinary darkness to appear pitch black, and creates shadows causing even more darkness.
Driving at night, I generally prefer to be out in the middle of nowhere, because I can see better with my headlights being the only light source.
many women demand more lighting during the night, for reasons of safety.
.7 foot-candles, around 20X the brightness when you are right under the streetlight, but how far outside of the immediate scope of the streetlight can you see? The brighter the bright spots get, the higher the contrast and the less overall visibility you have. My point is that if you keep the brightness low, but take care to light up the dark shadowy spots as well, you can actually see better. Well lit shouldn't be confused with "brighter".
They may be saying "more" light but they probably mean "more even" lighting. You could see better down a street or across a parking lot if it had half the brightness but it was evenly spread, vs intermittent very bright spots. So having it bright as the noon day sun in front of the bar actually makes it worse to walk across the parking lot, unless that is just as bright. If you have every been out in the country at night and you could see moderately well with a full moon (enough to play soccer, I've done it) that was what even lighting at about 0.035 foot-candles gives you as far as visibility. Most streetlights give you about
We are all just people.
I have a friend who lives in Park City, UT who got fed up enough with the local light pollution that he decided to do something about it. He founded a company that only sells dark sky friendly lights. Its called Starry Night Lights http://www.starrynightlights.com/. Check it out if you really want to do your part.
... but that would inevitably just lead to an increase in crime for that night, so... darn. Actually, I read an article in Sky & Telescope (I think... might have been Astronomy) a year or so ago that addressed this. They cited studies that suggested that lighting areas has no effect on crime, but rather on the perception of safety. Consequently, (this is purely my conjecture) using fewer lights may just make people be more careful because they feel endangered, thus having a net reduction in crime, as well as making the sky a prettier place.I always thought it would be nice if we had one day a year where people made a conscious effort to turn off all their lights, like "Star's Day" or some other stupid name so people could have one night a year to keep lights off, but that would inevitably just lead to an increase in crime for that night, so... darn.
Not really, criminals need light too. And as TFA says when San Antonio started turning lights off at night at schools vandalism went down not up.
FalconShould there be a Law?
-1, Wrong and Uninformed
/ 054b_exposure_light_and_exposure_values.htm#Light) You can see with a lot less light than you think you can, if you'd just turn out the damn lights.
People walking at night *do* experience glare. First off, lots of folks wear glasses. Secondly, the presence of streetlights, even assuming no stray reflections, *does* affect human vision by preventing the eye from becoming fully dark-adapted. Many lighting schemes actually make things worse by creating very uneven lighting patterns. The eye will wind up adjusting its levels based on those bright areas, and then be completely unable to see in the dark areas.
Naturally, anyone up to no good will be in those shadows where nobody can see, because their eyes are metering for the bright areas.
*Contrast*, not the absolute amount of light, is the real limiting factor here. Two examples:
I was out in the forest today and saw a bird land on a tree branch west of me, backlit by the setting sun. I couldn't tell what it was; it appeared completely black to me because my eyes were adjusted to the huge amount of light coming from the western sky. I can, however, override my camera's automatic exposure setting, and was able to get a picture (at ISO 100, fyi). There was plenty of light to see by, there was just too much light coming from what I didn't want to see. Your eyes don't have an exposure override.
You can also see quite well in a whole hell of a lot less light than you think. I've been in situations where moonlight is actually bright enough to be dazzling (compared to the previous starlight when the moon was obscured); starlight is even enough to see where you're going by.
Starlight is 512 times dimmer than a streetlit street; moonlight is 64 times dimmer. (Reference: http://www.photokaboom.com/photography/learn/tips
Also, studies have been done that show that, when streetlights are removed from neighborhoods, crime actually goes down. Why? Because there are no shadows to hide in, and, if it's really that dark, the boogeyman (who's much less common than you think) won't be able to see you either without a flashlight. My neighborhood is unlit and is in a city with a pretty high crime rate (Tucson, Arizona); I've never felt unsafe because of the lack of streetlights.
Benefits of turning off the lights, since you asked:
1) It saves power. Gobs of power.
2) People can enjoy the natural world, and possibly learn something in the process.
3) Less damn glare, helps drivers and walkers (who can see just fine by moonlight/starlight
4) Astronomy.
5) It has been hinted at that excessive artificial lighting at night screws up people's circadian rhythms and might be responsible for certain sleep disorders, fatigue, depression, etc. This hasn't been shown conclusively yet, of course, and in any case looking at a 14" LCD like I am now is far worse.