Dutch town installs bat-friendly red LED street lights (2018)
electronics360.globalspec.com
electronics360.globalspec.com
Another interesting regulation here is related to insulation. Small bats tend to get inside walls and under roof tops. As people are improving insulation en masse, this act may kill or displace these bats. So you have to check for them and make amends if they're there. A common and easy way is to attach a bat home to your house. Some of them are really cool:
https://media.s-bol.com/gJJMmEXxPyRr/781x1200.jpg
I love my little bat friends. During summer months I can time their forage session to the minute. Then I just watch them circle around the garden picking up the mosquitos.
Never knew these were a thing but it's exactly what I expected. Deserves a bat signal.
(and added appropriately bat-wing shaped bargeboards)
This is Edwardian, built around 1902.
That's because they aren't always needed. Only very specific spots pose a real danger.
This location has them since 2015 (even 2014 I thought): https://www.autoblog.nl/nieuws/automobilisten-in-de-war-door... (in Dutch), location on OSM: https://www.openstreetmap.org/?mlat=51.34859&mlon=3.54388#ma...
Everybody complained at first, now it's just a curiosity. The bats thrive though and don't get killed near the roundabout. The lights don't need to be everywhere and only on the spots where the bats fly over regularly and get hurt by traffic and/or the environment (by which I mean the stuff related to the road, called Straatmeubulair in Dutch).
Does remind me of the old low-pressure sodium street lighting that was popular in the UK when I was growing up. They’d glow pink for a while when they first turned on, before turning a deep orange.
I love them. That's the best night-time lightning out there. Blueish LED lightning is unsettling in comparison. These orange street lights are comfortable to eyes and make the streets look pretty.
Except they do break (they dim into a faint glow, and the brown out completely) and they have to replace the whole fixture.
Isn't that just because it is very hot so they die?
> Except they do break (they dim into a faint glow, and the brown out completely) and they have to replace the whole fixture.
That's the big lie of LED industry; we can make ones lasting 50-100k hours... except we won't cos that would put price up by a bit and get out-competed.
For insects and mammals and birds, it's the spectrum, the colour, which is the problem.
Where I live, the city decided in the downtown core to wrap non-diffused non-rectified LEDs around the poles in spirals. What this means is that if you're walking or driving, you are looking directly at the light as opposed to a traditional fixture that is pointed downward and may also have a cover.
I really think we're going to have to ban certain forms of exterior lighting or nobody is going to be sleeping well.
These new LEDs are just trash. Some houses, you see them stuffed in a foot apart all around the soffits on multiple levels and when you walk at night they just make the place look cheap and tacky compared to how it used to be before when people would place an incandescent flood at ground level shining upward.
Would have been amusing if you mounted an adjustable mirror on the wall near your window to aim the high-power beam straight back at their own window if talking to them first didn't work. Seems fair. It doesn't need to be pointed directly at you after all.. when it could be pointed at the driveway instead..
the light they produced was the best and I wish we still used them, or at least an LED that mimics the orange color.
I definitely prefer the warm yellow sodium glow to the harsh 'operating table white' LEDs a lot of councils replaced them with but I think they're finally getting the message now because by the time they got round to my street they used much better warm white LEDs to replace the sodium lights.
earlier posted article https://medicalxpress.com/news/2016-04-debunking-digital-eye...
One of the biggest arguments against blue light (specifically) being disruptive is that the sky spectrum in the evening is also blue (so naturally you'd be exposed to it). Modern airliners use blue lights for overnight flights with red lights at "dawn". I suspect screen brightness is more of an issue than any particular colour.
The amount of blue light you're exposed to from the night sky is trivial. Outdoors on a moonless night is 0.002 lux (of which, my understanding, about half is airglow and fairly blueish).
Compare to a not-too-bright single blue LED in your bedroom, emitting 0.5 lumens. You could spread that over 2000 square feet of surfaces and still have more blue light around than comes from the night sky.
Yes... that is why I divided by area.
It's kind of sad how many of us end up so impatient over common mistakes that we screw up just as badly in our eagerness to snap at people.
Obviously it's fudged a bit. The LED is not an isotropic emitter, and it's not at the center of a spherical room with perfectly reflective walls.
In practice, I suspect the amount of blue illumination from one dim blue LED in a large bedroom and the night sky are pretty much equal.
I have no stance on this. I don't even care. I can sleep well at night.
* Okay they do exist but they are extremely rare. I know of exactly 1 within 10km of my home.
The only advantage red light offers is not disrupting your circadian rhythm.
Airplane instrument panels are lit with white. Saab, Volvo, and plenty of others use white or nearly white light for their dashboards.
Blue is used in theater only because it is less noticeable to the audience when it spills or reflects somewhere it shouldn't.
The real question is: especially with even 10 year old car headlights being so much better than the utter trash car headlights were 30 or more years ago, why are we still wasting so much energy, and impacting wildlife, and hurting millions of people's circadian rhythms, blasting streets with light all night?
There isn't even any argument in terms of public safety; there's never been any proof that lighting reduces crime. Lack of lighting forces people up to no good doing things where they shouldn't be, to use lights themselves - which stands out much, much more than someone doing something they shouldn't be under outdoor floodlights.
For pedestrians?
(I agree with your reasoning as it applies to highways, but most of the world's light pollution from overhead street lighting comes from lighting done either 1. within dense cities, or 2. within industrial complexes — in both cases to aid people walking around outside at night.)
I've found for example that it's extremely dangerous to go beyond 180kmh (110 mph) at night whenever there are street lights, while it's sort of ok if you just have side mirrors on the highway reflecting your own lights (not that I recommend to anyone to drive at such high speeds, especially in low visibility conditions).
This does not match very common naval practices, nor my experiences. I believe the underlying mechanism is that the iris responds much more strongly to blue light because that is more prevalent in daylight. Specifically this is about using red light to shine on things to see them. I could imagine that has very different requirements from the color of text on a HUD.
But it takes about 45 minutes for your eyes to fully adapt to darkness.
So if we were to use red lighting at a level of illumination that assumes fully adapted eyes, it means people won't have sufficient brightneses for the first 45 minutes of their drive, which is likely most of it.
Go out on a very dark night and look up at the stars sometime. After half an hour, you'll be able to see stars that you couldn't see fifteen minutes ago.
Cooler light is better at keeping people awake and alert, and people drive safer when they are alert. Given that car accidents are a major cause od death, that is a hard point to compromise on.
The white lights are important for road safety but the Dutch have developed methods of softly discouraging the kind of traffic that makes the road dangerous.
This is especially common in residential areas. Most town centres are pedestrianized but retain brighter lighting as they can still be quite busy public areas in the evening.
Use a red flashlight (or filter) if you need to find stuff in a dark room without waking up the occupants.
(There are quite a few mad people in this world, having said that).
I usually can't ride backward fast enough for that to happen.
It's disconcerting to be walking around Amsterdam, turn a corner, and there's a woman dancing in a rented box seeking customers.
Perhaps outdoor lighting would offer more warning.
Well, to be fair, it's not really widespread all around the city, it's not like you suddenly turn a corner and there is a surprise box right in front of you.
Do you get disconcerted when you go to the beach or when you turn a corner and see a picture of a lady in a bikini in a storefront?
After a €100.000 investment they now have a radar+transponder system that shuts the lights off when there isn't an airplane nearby.
Source [German]: https://www.bundesnetzagentur.de/DE/Beschlusskammern/1_GZ/BK...
The Christelijke Arbeiders Partij was founded in 1956 for the Bunschoten municipal elections. At the time the only people that could be elected were tradespeople, fishermen and farmers. Workers were put in unelectable positions by the elite. The CAP was founded out of dissatisfaction with this.
It doesn't inherently stop crime, but you and potential witnesses will indisputably have an easier time taking a shitty photo/identifying an assailant after the fact given ambient lighting.
The reason LED lights are so terrible for astronomers is because although they require much less light to achieve the same visibility, the spectrum is very spread out across multiple peaks, with different manufacturers having different peaks.
Are we sure it is a good idea to encourage bats to be in close proximity to humans?
You can't be serious. A disease that originated in bats just killed 15-25 million people and shut the entire world down for two years.
> My favourite feature of theirs is that they take care of all the mosquitos
I live in a place where bats abound, and I can assure you that they don't.
Maybe someone should not have eaten them?
Or maybe let’s extend your logic to humans, see how easy it works?
I am not so sure about that. I don’t think bats are either necessary or sufficient for effective malaria control. In parts of the world where there are bats, you still have a problem with mosquito borne illnesses such as malaria.
One of the big upsides of such an outcome would be that we could ditch things like streetlights entirely, cutting back a great deal of light pollution.
Here are some images, unfortunately the article isn't available in English:
https://www.rijkswaterstaat.nl/nieuws/archief/2020/12/vleerm...
They are still able to perceive illumination from red lights. They just can't distinguish its hue from green as well as others.
I say this because someone I know who is colorblind can't use a red headlamp when outdoors. A lot of people use red lights to preserve their night vision, but for this person they can't see clearly with it vs. a white light.
https://www.colourblindawareness.org/colour-blindness/types-...
Small nitpick, I think people use red headlamps to preserve other peoples night vision not their own. Or am I getting that wrong? Wouldn't white light work just as well or even better for for one’s own "vision at night"?
(Blue has the opposite effect, which is why a room lit only by blue light can feel both dim [hard to see] and harsh [unpleasantly bright] at the same time.)
Side note: I recently learned that all of the blue/purple street lights are actually defective LEDs: https://www.businessinsider.com/led-city-streetlights-turnin...
https://www.healthline.com/health/why-not-to-have-red-lights...
https://biology.stackexchange.com/questions/2075/does-red-li...
I found a webcam, but the night shots were black & white so not much use.
Red lights are still there, according to my cousin.
Nieuwkoop is a village and local authority.
*Grackles are small corvids that are fearless, loud, and annoying.
Pretty sure isles in Indonesia recall the heel of the Dutch East Indies Spice empire.
But that's the point!
If we are working on an environment friendly energy alternative, it feel sweird it kills lots of animals.
The article doesn't say anything about white light, but does say "Normal street lighting can affect a bat’s flight" but doesn't go into detail. I would love more detail.
There's no mystery around the reason to use red light either. Nocturnal animals, especially mammals, have far more rods than cones in their eyes. This means they are much more sensitive to brightness than they are to color.
Red light in practice is far less bright than white light for the same input energy (a bit more complicated than this) and for quite a few animals they may not see it at all or very poorly.
None of this is theorizing, the effect can be readily seen in practice.
Even under ideal conditions, the earth receives ≤1 lumen per square meter of light from the moon. A single streetlight can project tens of thousands of lumens (or more) over a relatively small area.
How much is that in torched libraries of Congress?
You say "white" as if there's only one color white, which isn't the case when you're talking about a range of lighting temperatures. The moon also has a unique light profile that it reflects. It's not the definition of white. Either way, if you're advocating for something resembling 6500k daylight white lighting at night, there is nothing at all natural about that. The moon casts a very dim light, even at its brightest.