Making War On Light Pollution 437
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."
San Jose (Score:3, Informative)
Unfortunately, a lot of citizens of San Jose want white lights for some reason (especially car dealerships), so I don't know how much longer that'll last.
A 20 year old fight. (Score:4, Informative)
For what it's worth, some estimate that there are about 700,000 amateur astronomers in the US. It's not a huge number. But it's much bigger than the just a few geeks that some would make you think.
It's a good fight and it starts at home, you can do your part by turning off the exterior lights of your house when you don't need them. With 2009 the international year of astronomy [astronomy2009.org], if you help now, maybe we all will get a better view of the night sky to celebrate the 400 years of telescope observing of the night sky.
Read article, open mouth. (Score:5, Informative)
Re:I live in Belgium (Score:2, Informative)
Re:Women want light (Score:5, Informative)
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.
Re:Women want light (Score:5, Informative)
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
Re:It's true (Score:5, Informative)
Re:"Pollution"? (Score:3, Informative)
Re:It's true (Score:5, Informative)
Re:Use brain, open mouth. (Score:4, Informative)
"Nobody's suggesting we get rid of streetlights, by the way: just make them illuminate straight downwards."
Streetlights already employ reflectors to direct their light downward, they just let it arc over many degrees so that fewer lights will need to be installed, and so that some lights can be turned off to cool while not leaving the street dark. I think they're talking about installing a larger number of smaller lights. I don't know that that would be a worthwhile investment (and it wouldn't reduce the wattage installed in lit parking-lots).
crime (Score:5, Informative)
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.
FalconRe:It's true (Score:2, Informative)
Re:Women want light (Score:3, Informative)
Re:Use brain, open mouth. (Score:5, Informative)
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.
Re:Best skies I've ever seen. (Score:3, Informative)
You can still see that, or at least something close, in a planetarium. The next best thing, if you have a computer, you can download some software for free at:
www.stellarium.org
Besides viewing the computer screen, this software will also allow you you to set up a planetarium if you have a projector and can rig up a dome shaped screen. It will also control certain telescope mounts.
It's not likely that the skies over any large city will ever be the way Galileo saw them, long before the invention of electric power generators and electric lights.
We live in southern Oregon, near the coast and do get to see a full starry sky. The Milky Way and all the stars stand out against a black sky. The glow from Medford, about 45 miles away is mostly blocked by the Mountains.
The eclipse of the moon on August 28 was also a special treat for which we got up at 2AM. Living in the city has its benefits and drawbacks and so does living in the countryside. Most people are not able to earn a living in the country and must live in brightly lit cities.
Re:Simple answer to this (Score:3, Informative)
Speaking as someone who grew up in the 60's in the rural outskirts of Melbourne Australia (40-50Km east of the city center) there were few street lights and the sky at night was nothing less than brilliant, patches of stars so numerous and intesnse they looked like small thin clouds. In the early 70's a faint glow appeared in the west (like twilight was refusing to end), now the city has grown upwards and outwards, "twilight" is permenent, the market gardens where I grew up have been replaced with houses, factories and shopping malls.
I now live on the beach (much cleaner than it was in the 70's), it's ~20Km south-east of the city center. The shit farm still operates but long ago stopped pumping turds directly into the ocean and now pumps out clean water that has restored the wetlands into a haven for water birds. Sitting between the ocean on one side and a large strip of wetlands on the other I can still easily make out the planets and the main contellations, on an clear night after a storm the milky way and the seven sisters are visable away from street/house lights. But to get the same sort of view I had from my back yard when I was a kid requires a two hour drive in order to put a mountains range between me and the permenent twilight. In other words, the "primeval sky" (best viewed with a young naked eye) is still there, but these days I really have to go out of my way to find it.
Re:How Do I Find A Dark Place (Score:1, Informative)
Re:Ascension Island (Score:4, Informative)
OMG! Unsourced claim at Wikipedia is wrong! (Score:3, Informative)
Here are a couple papers which each include several references:
THE EFFECT OF BETTER STREET LIGHTING ON CRIME AND FEAR: A REVIEW [homeoffice.gov.uk]
EVIDENCE-BASED CRIME PREVENTION: SCIENTIFIC BASIS, TRENDS, RESULTS AND IMPLICATIONS FOR CANADA [ps-sp.gc.ca]
I'm all in favor of a darker sky, but we are not going to win many converts if we keep lying about something that can be so trivially debunked.
Re:San Jose (Score:4, Informative)
Re:It's true (Score:1, Informative)
Arlington, MA, near where I live, just replaced every 1950's-era drop-lens mercury vapor light fixture in town with high-pressure sodium fixtures, as most towns have in the last 25 years for energy efficiency and lower maintenance costs. But they opted to go entirely with full cutoffs and strictly regulated wattage guidelines depending on whether it's a residential side street or thoroughfare. The ones on side streets are 50-watters, down from 250-watters that were there previously, and give the exact same amount of light on the roadway and sidewalks while being virtually invisible sideways. I believe the arterial roads went from 400-watters to 250-watters and smaller thru streets from 250 to 100-150 watts. Since Arlington's only 2+ miles from Boston and densely populated the fixtures were already situated overkill on every pole, so there was no need to even add new fixtures. That's an assload of electricity saved, no more glare pouring through 2nd-floor windows ruining people's sleep, easier driving because you can actually see objects on the roadways, and no more illumination of trees screwing with birds or getting insects going crazy at night. The only upward reflection you get is off the actual roadway, which being asphalt isn't very reflective...so it makes a huge difference. Flying into Logan Airport your flight path will take you over severall towns that went full-cutoff, and you can see the difference it makes from above with only soft illumination off the actual roadway seen from the sky as opposed to towns that still use drop-diffusers where you can see the sharp points of light coming off the actual fixtures (the City of Boston, which still uses awful oversize 1960's-era power-sucking fixtures everywhere, looks like its roads are lined with thousands of birthday candles from above).
This isn't an expensive fix. Since most places already have HPS fixtures, you just swap out those ugly drop diffusers on the existing fixtures with the flat lenses, replace the bulbs with appropriately lower wattage, and get each state highway department and city public works department to adopt consistent wattage/placement/spacing guidelines for type of road, traffic load, intersections, etc. instead of slapping the fixtures around willy-nilly like they did previously. All cobrahead fixtures are standard size, the lenses are probably $5 each bought in bulk + labor, and in cities with enough fixtures they usually change all bulbs on a regular schedule of 5 years or so to offset the labor costs of letting all bulbs run out their natural lifespans and having to do too many one-off runs with the truck to change individual fixtures. Problem is as long as utilities charge municipalities per fixture instead of per electricity usa
Re:Women want light (Score:3, Informative)
On the Autobahns, there are almost no lights at all. In whole west Germany I only know about one or two pieces of a few kilometers where there are lights. And when I first came here I was surprised that driving on an Autobahn with no lights is actually more comfortable than driving on the completely illuminated Dutch roads. You can look much further ahead (an eye trained to the dark can distinguish a single photon, you can probably catch the light of a car that is a mile in front of you) . Also by the shape of the lights you can distinguish trucks from cars, which helps when you're speeding. In general, you can just concentrate better.
What I don't like BTW are the LED back lights on cars. For some reason they create a memory effect in my retina, and the eyes seem to automatically follow these lights, which is very distracting. This is probably because they have the overall same intensity as normal back lights, but much more focused. I wonder if this isn't dangerous on the long term.