German cities emit several times less light per capita than comparably sized American cities, according to a recent publication in the journal Remote Sensing. The size of the gap grew with city size, as light per capita increased with city size in the USA but decreased with city size in Germany. The study also examined regional differences, and surprisingly found that light emission per capita was higher in cities in the former East Germany than from those in the former West.
The lead author, Dr. Christopher Kyba, studies visible light at night as a member of the Remote Sensing section of the German Research Center for Geosciences (GFZ) ( http://www.helmholtz.de/en/ ). "The size of the difference in light emission is surprisingly large. This work will allow us to identify comparable cities in order to uncover the reasons behind the differences." These could include differences in the type of lamps, but also architectural factors like the width of the streets and the amount of trees. The LED lamps currently being installed in many cities are expected to greatly change the nighttime environment, for example by reducing the amount of light that shines upwards.
[Abstract]: http://www.mdpi.com/2072-4292/7/1/1
(Score: 2) by Nerdfest on Tuesday December 30 2014, @03:48PM
I'll assume they're not talking about intelligence. Sorry, I couldn't help myself.
(Score: 2) by VLM on Tuesday December 30 2014, @04:07PM
The LED lamps currently being installed in many cities are expected to greatly change the nighttime environment, for example by reducing the amount of light that shines upwards.
I've noticed this, my suburb has been beta testing LED streetlights for eventual replacement and its creepy how well they focus on the road, people/animals on the sidewalks are just kind of blurry shadows, which makes me nervous not being able to see clearly who's about to step into the road. Other than that overfocus problem, they're pretty cool.
From some pix of Germany I don't think they're into gaudy illuminated signs quite as much as the USA. I'm not convinced the only problem is the street lights.
(Score: 3, Interesting) by bradley13 on Tuesday December 30 2014, @04:24PM
Definitely true, illuminated billboards and garish signs are mostly a feature of the US, presumably a holdover from the days of cheap energy. Larger cities have larger shopping and commercial districts, whereas towns and small cities may have few or none.
LED street lighting will be totally cool; maybe it will spark by other "dark sky" initiatives, so that we can actually see the stars again...
Everyone is somebody else's weirdo.
(Score: 2) by frojack on Tuesday December 30 2014, @09:35PM
illuminated billboards and garish signs are mostly a feature of the US
Seriously? http://goo.gl/8U9ATI [goo.gl]
No, you are mistaken. I've always had this sig.
(Score: 1) by Buck Feta on Tuesday December 30 2014, @05:00PM
> LED streetlights
An improvement over what we have, but better yet would be to get rid of them entirely.
- fractious political commentary goes here -
(Score: 1) by DaTrueDave on Tuesday December 30 2014, @05:47PM
I don't disagree.
I'm always a bit dismayed when friends, family and acquaintances feel the need to use a flashlight to walk on the sidewalk at night when there's a bright starlit or moonlit sky above. Sure, it might help see whatever you shine the flashlight at, but your night vision is destroyed and it makes you unable to see anything else. Ridiculous.
Our dependence on artificial light is not a good thing.
(Score: 0) by Anonymous Coward on Tuesday December 30 2014, @06:02PM
Lights make the shadows darker.
(Score: 4, Informative) by etherscythe on Tuesday December 30 2014, @06:10PM
Like driving, a flashlight at night is not so much for seeing - it is for being seen. It might be nice if we all had Tron-style glowing suits that could easily be made out in any light level. However, in the absence of that, taking a little extra care (especially when wearing dark clothes) might be good for your health. I'd like to think drivers are responsible enough to be able to slow down when they can't see clearly, but I'm afraid I don't have enough faith in the average Homo Sapiens behind the wheel.
"Fake News: anything reported outside of my own personally chosen echo chamber"
(Score: 1) by Bill, Shooter Of Bul on Tuesday December 30 2014, @06:32PM
That would be terribly dorky. Even I wouldn't wear one.
(Score: 2) by tibman on Tuesday December 30 2014, @08:14PM
Except when you saw the suits in the movies you thought they looked awesome : ) Nobody ever gets (accidentally) killed by a troncycle.
SN won't survive on lurkers alone. Write comments.
(Score: 2) by TheRaven on Wednesday December 31 2014, @11:41AM
One of my colleagues has a student who started up a company to make these for cyclists. They're built into a fluorescent yellow jacket and have white lights on the front and red on the back. When you raise an arm above a certain angle, it flashes yellow. The jacket by itself provides enough light that you don't legally require lights mounted on the bike to cycle at night on the road and means that hand signals are visible. I wouldn't buy one for walking, but if they come down in price I'd be very tempted (apparently they're selling pretty well in spite of the cost).
My cycle home from work has a combined pedestrian and bike track for part of it and pedestrians wearing dark clothes are very hard to see (and often walk alongside each other completely blocking the path). It would be really nice to have a mechanism that made them glow tron-style...
sudo mod me up
(Score: 0) by Anonymous Coward on Tuesday December 30 2014, @06:40PM
That's pretty important if you are walking in the road.
(Score: 2) by Adamsjas on Tuesday December 30 2014, @08:21PM
Since most street lights have downward reflecting tops, that also act as light spreaders (to provide wider coverage), I don't see how LEDs change this, other than by producing less light and/or concentrating it directly under the light pole. Neither is desirable, and both of those could be considered defects.
Lighting is not ONLY for the benefit of drivers, but also (or perhaps mostly) for the benefit of (and protection of) pedestrians. A light that doesn't light the sidewalk is probably not doing half its job.
So unless LEDs somehow repeal the laws of light reflection, the observed effect is simply less total light.
(And I'm not arguing that we need the light level commonly used, just that goal post moving isn't a proper evaluation method).
Your nervousness about poor sidewalk visibility is probably a much much larger issue for women and children that want/have to walk at night.
(Score: 1) by Nephandus on Thursday January 01 2015, @10:44AM
Because attackers might mistake them for adult males thus target them accidentally?
"One does not become enlightened by imagining figures of light, but by making the darkness conscious."
(Score: 2) by DrMag on Tuesday December 30 2014, @06:33PM
One night when I was working a late shift, I was chatting with my brother about a class he was teaching about understanding energy issues from a policy perspective. I brought up an experience when I was a teaching assistant for a similar class; the students were assigned to explore parts of the campus and estimate how much energy was being used. Most every group came back with one similar conclusion: every building had way more electric lights than it needed.
That night, as I was driving home, I was pulled over. I had forgotten to turn on my headlights, and not noticed because they made no difference in what I could see because of all the street lamps.
Americans turn on too many lights.
(Score: 0) by Anonymous Coward on Tuesday December 30 2014, @09:36PM
You must have an instrument panel that is extremely readable in the dark.
...or you never look at it.
Not being able to read my old analog instruments was how I would realize I had failed to turn on my headlights.
...and, yeah, there is a tremendous amount of ambient light in cities in the USA.
-- gewg_
(Score: 1) by aardvark on Tuesday December 30 2014, @07:12PM
There's no great mystery here. Back in the 1970s intense lighting was much in vogue in the U.S. as a crime-prevention measure. The idea was that lighting a city to high levels would deprive the bad guys of the darkness they needed for their operations.
That also was the time of wholesale replacement of mercury street lights with much-brighter sodium lamps. When that was done in my neighborhood in 1974, nighttime essentially disappeared; the soft bluish light coming in my bedroom window was transformed into an intense yellow glare. Ugh.
(Score: 0) by Anonymous Coward on Tuesday December 30 2014, @07:32PM
There's no great mystery here. Back in the 1970s intense lighting was much in vogue in the U.S. as a crime-prevention measure.
And since that failed, the next obvious step is MOAR LIGHTS! And more full spectrum lights, completely wrecking the circadian rhythm leading to all sorts of problems - heart disease, cancer, etc.
http://en.wikipedia.org/wiki/Circadian_rhythm#Importance_in_animals [wikipedia.org]
http://en.wikipedia.org/wiki/Melatonin#Circadian_rhythm [wikipedia.org]
(Score: 2) by frojack on Tuesday December 30 2014, @09:28PM
Back in the 1970s intense lighting was much in vogue in the U.S. as a crime-prevention measure.
And since crime has been falling since the 70's [gallup.com] who is to say that isn't true?
Sodium vapor was just the prior cost saving technology. Just as LED lighting is the current cost saving technology.
The issue of lighting public places remains the same. Ask you wife/gf/sister how she feels about it. You will find men see this issue very differently than women.
Because of the instant on capability of LEDs and the advancing in motion sensing, it would seem we could provide street lighting for pedestrians cheaper by having lights turn on as you approach, and go off as you depart the area. Perhaps every stray dog lights them up, but so what. There would still be a large saving.
No, you are mistaken. I've always had this sig.
(Score: 2, Informative) by ah.clem on Tuesday December 30 2014, @07:29PM
Living in a bloated red zone on the east coast of the US (highest level of light pollution) makes observing from my driveway a sad joke, let alone doing any decent astrophotography - result? Diving 1.5 hours each way to a so-called "dark zone" (actually, dark green - not black). All the cities and towns have to do is put shades that keep the light from heading skyward on all the fixtures (doing nothing to help anyone), which lets them save money and power in the long run, but they are not so inclined. It's pretty damn frustrating. And no, I can't relocate, so save your fingers on that one. What is really sad is that I can read a manual for a new piece of gear in my driveway in the middle of the night without my headlamp on. Just my opinion, but I think that's what killed interest in astronomy as an avocation in america, that and cheap kit that only serves to frustrate. Man, you should see the look on someone's face the first time they see Saturn or Jupiter through a scope (the "gateway drug" views!). Or a stacked and processed photo of the Milky Way taken from the driveway while standing outside at night pointing into the light polluted sky and trying to convince someone that, beyond all that bright light, it looks like the photo. How many elementary schools have a telescope anymore, or a science teacher that knows how to use one, let alone viewing nights from the school's property? At least we're not considered terrorists yet, but I have had the cops roll up on me with bright white lights shining due to a complaint about some guy "doing something funny" on his own property outside at 2:00 AM. Crazy.
(Score: 2) by frojack on Tuesday December 30 2014, @09:46PM
Shielding doesn't help that much.
Reflections from the street will still be a problem.
Next time its foggy or snowing out, go look at street lights. They are already shielded and direct their light downward.
http://dailyphotoblog.net/media/1638/Fog-Central.jpg [dailyphotoblog.net]
Light pollution definitely makes for poor star gazing, but I doubt that is going to change any time soon. The numbers just aren't there.
No, you are mistaken. I've always had this sig.
(Score: 0) by Anonymous Coward on Tuesday December 30 2014, @09:59PM
In Hawaii they have used low-pressure sodium lights for decades specifically because they are the least likely to interfere with telescopes - in particular they emit a very narrow frequency range so it is easy to filter them out without hurting sensitivity for other bands. Over the last couple of years they've been replacing them with specialized LED versions. [bigislandnow.com]
(Score: 2) by frojack on Tuesday December 30 2014, @11:01PM
That is not uncommon where-ever there are large multi-million dollar telescope installations. Usually these are in some way government funded and pressure is brought to bear to create a light pollution control zone.
But that's not going to be a factor in every city and burg just because Joe Telescope want's to gaze at the stars.
No, you are mistaken. I've always had this sig.
(Score: 1) by ah.clem on Wednesday December 31 2014, @05:40AM
I was fortune enough to live and work on Windward Oahu for 7 years, and my recollection was that it wasn't just for Mauna Kea (well worth the visit if ever on the Big Island, BTW) but the Hawaiian aesthetic is not like the mainland; one of the many reasons I have continued to return there most years for two-three weeks since I left. Mauna Kea is fairly far from Oahu, the main source of light pollution in the state, and I suppose it might have been a reason for the lights, but being pretty familiar with the Hawaiian culture and the love for the land and environment, I think it is mostly because Hawaiians (and most locals, whatever cultural background) do not like to have their environment disturbed if at all possible. Obviously, this is just my haole understanding/interpretation of the situation, and there is nothing worse than a "dumb haole", but I'd bet money that it's as much about aesthetics as observatories.
(Score: 2) by frojack on Wednesday December 31 2014, @06:26AM
Yeah, I never bought into that "haole" thing. Racism with a smile is still racism.
No, you are mistaken. I've always had this sig.
(Score: 1) by ah.clem on Wednesday December 31 2014, @09:06PM
I've been called worse out Waianae way but I understand it. For folks not familiar, the short of it is, about 100 years ago, US mainland "christians" forced their superstitions onto the Hawaiians while stealing their land, then arranged a coup so they could control all the islands and divide the wealth up among themselves. The only thing missing was a "Trail of Tears" march off the Pali. More McKinley "Manifest Destiny" bullshit. So yeah, as a Hawaiian, I'd still be pretty pissed off at white mainlanders.
(Score: 2) by kaszz on Tuesday December 30 2014, @11:20PM
The modern method is to have a remote controlled telescope..
(Score: 1) by ah.clem on Wednesday December 31 2014, @05:52AM
To the best of my knowledge, remote controlled scopes are still generally outside your home or in your "roll off roof" observatory, controlled from the warm room. I've considered reinforcing my roof and putting a remote controlled system up there. To my knowledge, it's unusual to have a personal telescope a few hundred miles from your site. I don't know if I'd want 10-20K worth of equipment sitting in a remote, unsecured location. Well, yes I do; I wouldn't do it.
(Score: 0) by Anonymous Coward on Wednesday December 31 2014, @04:17AM
Too bad they can't turn them off until a car approaches from maybe 1/2 block away. It would save a lot of energy and create a lot less light pollution. Having them on for 12 hours every night with very little traffic is a joke, not to mention every property owner has to pay for them in their property taxs.