Live data from Hacker News

LEDs’ potential to save our night skies

spectrum.ieee.org

1–10 of 200 posts

Re: LEDs’ potential to save our night skies

#2
> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see.

That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”

Re: LEDs’ potential to save our night skies

#3
I once lived in a city that had replaced street lights that cast light in a circle with modernised ones that cast a sharply delimited rectangle of light on the road, and didn't waste light in other directions.

The thing was, the roads of this city were arranged as a footpath, then a grassed area with trees, then the lights, then the roadway. Only after the city had rolled out thousands of these lights did someone notice the footpaths were now much darker. And also the footpaths were quite uneven, due to the trees' roots - a problem the lights had previously been keeping under control.

It's now common, in winter, to see groups jogging on the road.

Re: LEDs’ potential to save our night skies

#4
post #2

> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see. That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”

Their prime audience for change are governments...

Re: LEDs’ potential to save our night skies

#5
Where I live, we have a small park, 500m away. You need to walk through it if you want to get to the city center from the small neighborhood we live in. To protect the wildlife, the lighting system has presence sensors, so as you walk or bicycle through the park, the way/street lighting turns on, you can walk, and just after you, it turns dark again. Really cool, especially the first time I went through it in the middle of the night.

Re: LEDs’ potential to save our night skies

#6
post #2

> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see. That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”

> That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”

One of the biggest excuses for ultra-bright streetlights is crime prevention (usually shortly followed by CCTV). I'm not really sure why we continue to indulge that point of view, but if one is indulging it...

Re: LEDs’ potential to save our night skies

#7
We need much better engineering standards if we are going to fix night lighting. A simplistic lux-on-the-ground measure combined with cost minimization produces a few lights, with bare bulbs, up hight, with brutal intensity. These are all things that produce glare directly on the eyeball.

You need much less light on the ground if the eyeball itself has no direct line to the hottest part of the lights. Instead, the night-blindness caused by excessive bare lighting is "fixed" by adding more fill lights for the shadows caused by the first lights. Classic addictive behaviour.

Re: LEDs’ potential to save our night skies

#9
I hate outdoor LED lights so much, I won't be surprised if a couple decades or centuries from now we discover that these things have been doing permanent damage to people's eyes. It's getting harder and more unpleasant to walk at night, I can't see and my eyes legitimately hurt every couple of minutes.

Re: LEDs’ potential to save our night skies

#10
post #2

> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see. That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”

> That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system” One of the biggest excuses for ultra-bright streetlights is crime prevention (usually shortly followed by CCTV). I'm not really sure why we continue to indulge that point of view, but if one is indulging it...

It's even funnier that, at least around here, one of the biggest crime problems is people stealing copper wiring... from streetlights...
Post reply on HN