September 12 is the second-ever International Night of Skyglow Observation, an official event of UNESCO's "International Year of Light". Around the world, citizen scientists will observe how much light pollution is in their community by looking at the stars. The link above is a very short tip on how to do it.
In Berlin we'll be holding a special event that night, a Flashmob for Science, in which many people will show up to make observations simultaneously at a single location. The flashmob will take place in Park am Gleisdreieck at 21:30 on September 12. More details will be on the Facebook Event page. If you plan to come, please sign up there so that we can communicate with you (e.g. in case of cancellation due to rain).
Here's a map, we will do the observation right on the spot marked by the pine tree.
Hope to see you there!
Monday, August 31, 2015
Wednesday, August 19, 2015
Guest post by Allen Versfeld
Allen Versfeld recently took a trip to capture images of good and bad lighting near where he lives in South Africa, and sent the best images he captured to me. I always welcome images of both good and bad lighting for the "view from your app" series.
So I went on a trip especially to collect some images for a light pollution talk I'll be giving soon. I started at a new shopping mall that was recently built on the edge of town, and then drove out to my home in the country, stopping to photograph whatever notable lights I saw. In practice it didn't quite work out - I saw some pretty shocking examples that I could not photograph because there was no safe place to stop the car (often, the lights themselves were part of the safety problem).
So the two good examples are from a recently built shopping mall. Although their signage out front is very brightly lit so that it can be seen from far away by fast moving traffic on a nearby freeway (not pictured), they put a lot of thought into their parking lots. Good full cut-off fittings that illuminate the ground beneath very well, and they're well placed so that there are no shadows in doorways, stairwells, behind walls, etc.
Only a kilometer away, I found street lights with bad glare - The photo shows how evenly the road is lit, but the glare is so bad from the lights that potholes and other defects on the road surface become hard to see when moving. Further down the same road is a small shop serving a rural community. In the name of security they have put up a number of floodlights in their parking lot. Unfortunately, every one of these lights shines towards the road and into the eyes of oncoming traffic. Very dangerous. (Bonus point: see if you can find the Stop sign in that image, hidden by the glare!)
Finally, even further out from the city, in a bend on a particularly dangerous and badly maintained road, is somebody's home. There is a crime problem in the area, so the owners have obviously gone for the Easy option here: A single enormous floodlight to illuminate the yard. As with the shopping centre above, this means that every passing motorist gets blinded at the worst possible time. And of course, every feature in the garden now casts deep shadows where the bad guys can hide.
So I went on a trip especially to collect some images for a light pollution talk I'll be giving soon. I started at a new shopping mall that was recently built on the edge of town, and then drove out to my home in the country, stopping to photograph whatever notable lights I saw. In practice it didn't quite work out - I saw some pretty shocking examples that I could not photograph because there was no safe place to stop the car (often, the lights themselves were part of the safety problem).
So the two good examples are from a recently built shopping mall. Although their signage out front is very brightly lit so that it can be seen from far away by fast moving traffic on a nearby freeway (not pictured), they put a lot of thought into their parking lots. Good full cut-off fittings that illuminate the ground beneath very well, and they're well placed so that there are no shadows in doorways, stairwells, behind walls, etc.
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| Example of good lighting (closeup) by Allen Versfeld is licensed under a Creative Commons Attribution 4.0 International License. |
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| Example of good lighting by Allen Versfeld is licensed under a Creative Commons Attribution 4.0 International License. |
Only a kilometer away, I found street lights with bad glare - The photo shows how evenly the road is lit, but the glare is so bad from the lights that potholes and other defects on the road surface become hard to see when moving. Further down the same road is a small shop serving a rural community. In the name of security they have put up a number of floodlights in their parking lot. Unfortunately, every one of these lights shines towards the road and into the eyes of oncoming traffic. Very dangerous. (Bonus point: see if you can find the Stop sign in that image, hidden by the glare!)
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| Glaring street lights by Allen Versfeld is licensed under a Creative Commons Attribution 4.0 International License. |
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| Glaring security floodlights by Allen Versfeld is licensed under a Creative Commons Attribution 4.0 International License. |
Finally, even further out from the city, in a bend on a particularly dangerous and badly maintained road, is somebody's home. There is a crime problem in the area, so the owners have obviously gone for the Easy option here: A single enormous floodlight to illuminate the yard. As with the shopping centre above, this means that every passing motorist gets blinded at the worst possible time. And of course, every feature in the garden now casts deep shadows where the bad guys can hide.
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| Glaring home floodlight by Allen Versfeld is licensed under a Creative Commons Attribution 4.0 International License. |
Citizens push back on LED lighting
If you don't like what you see, why don't you fight it?
If you know there's something wrong why don't you right it?
-Trooper
TLDR: Citizens around the world are raising hell over LED streetlights they don't like. Cities should consult with citizens before undergoing a citywide replacement.
Around the world, people are seeing the LED streetlights that their city is installing, and many don't like it. In this situation, there are two possible responses: living for a few decades with light you don't like, or pushing back against city hall.
In Berlin, citizens challenged the city's intention to switch from gas lighting to LEDs. The city listened, and a compromise was reached: The Technical University of Berlin invented LED lamps that perfectly mimic the color and brightness of gas lamps.
In Davis, California, a citywide replacement was halted when enough citizens complained. The city listened, and set up a test street to let citizens have a choice in which LED lamps should be installed. The citizens chose lamps that were warmer and less bright. In fact, the citizens choice to reduce the brightness below what the city had planned meant that the city ended up saving even more money than it had originally planned!
But cities don't always listen. The mayor of Honolulu is so far ignoring citizen complaints about a plan to install lights similar to the hated ones in Davis. The city also won't consider dimming or turning off lights in low-traffic areas after midnight, despite the fact that a recent study in the UK showed that this has no measurable impact on traffic accidents or crime. (UPDATE 2015.11.04: Honolulu cancelled their original plan, presumably due to citizen action! Hopefully this will lead to better lights for the city.)
Here is an example of a city official from another city trying to "answer citizen concerns" by telling them how it's going to be, rather than coming up with a solution together:
LED street lighting has a lot of potential benefits. If properly installed, LED streetlights are less likely to shine directly into the sky than older lamps. With careful design, it's possible to avoid illuminating people's bedroom windows. A complete re-design with better uniformity could allow cities to use far less light with equal or greater public acceptance.
Unfortunately, it's also possible to make things worse with LEDs, and one of the aspects that really bothers some people is the color of LED street lights. If you've bought LEDs for your home, you've probably noticed that they have a "color temperature": either a number between 2000-6500K, or perhaps "warm white" or "cold white". As a rule of thumb, the higher the color temperature, the higher the luminous efficiency of the LEDs. But as color temperature increases, LEDs are also generally perceived as harsher, more glaring, and colder. To reduce skyglow and glare, the International Dark-Sky Association recommends using lamps with 3000K or lower.
The lesson from Davis, Berlin, and other cities, is that citizens don't have silently accept what city hall decides is best. If you and your neighbors "raise a little hell", you could end up with lighting that's much better and more comfortable than you have today, with a reduced impact on the environment.
Trooper says:
Nobody's going to help youBut that's not true in this case. Plenty of your neighbors will also share your concern, you can find support from local environmental and city beautification groups, and you can get technical information about what's worked for other cities from the International Dark-Sky Association.
You've just gotta stand up alone
Attractive and effective lighting is something everyone from conservatives to greens can support. So if your city is about to do something stupid, don't be afraid to raise a little hell!
Friday, August 7, 2015
First community experiment!
During the coming week (until August 14), we are running the first in a series of Loss of the Night app community experiments. This month we're asking people to make multiple observations as the stars come out during twilight. Since many observers live in places without much light pollution, twilight offers a way to do an apples-to-apples comparison.
The more people that take part, the more likely that we'll have a result that's statistically interesting. So if you have a clear sky sometime in the next week, try making an 8-star observation after the first star is out but before it's gotten all the way dark. Try to do the measurements quickly, so that the sky doesn't darken too much while you are observing.
I will present the results of the experiment at the webinars in September, but there will probably be a sneak preview for everyone on our mailing list.
The more people that take part, the more likely that we'll have a result that's statistically interesting. So if you have a clear sky sometime in the next week, try making an 8-star observation after the first star is out but before it's gotten all the way dark. Try to do the measurements quickly, so that the sky doesn't darken too much while you are observing.
I will present the results of the experiment at the webinars in September, but there will probably be a sneak preview for everyone on our mailing list.