Looking at the present article, while these bio-lights are diffuse, they are probably the wrong spectrum. Due to the nature of the light-sensitive proteins in our eyes, humans do best with orange light at night. Our peripheral vision is most sensitive to blue light, and there's a reflex where we look at blue light in our periphery. Blue light is exhausting for us. Intense blue light is blinding.
Back when the lighting companies had all the money in the world to research their lights, scientists figured out how to use artificial light safely. Now that those scientists have mostly retired, and people alive today have no idea what it was like for artificial light to be precious, we're forgotten everything our predecessors figured out. Just last night I was at my current city's newest hotel, and while the lights are mostly pretty good, they also have a bunch of 5000K LED fixtures mounted at exactly eye level. Light is mostly useful to us humans when is bounces off of things.
In the 1970's the outdoor lighting industry standardized on High Pressure Sodium bulbs, because they're incredibly energy efficient AND because they're an almost blue-free light source. Low pressure sodium [LPS] bulbs are even more efficient and a perfect single-wavelength of orange (~590nm), but only a few cities (Flagstaff Arizona) really standardized on LPS.
I was whining to someone about how Phoenix, Arizona switched out its safe HPS streetlamps for 5000K LEDs in 2016 (I think they switched these to ~3000K after people complained about 5000K's effects on wildlife). The guy knew exactly what I was talking about, and said "I wrote the 1982 report that resulted in Phoenix's 1984 lighting ordinances." He'd recommended LPS, but the police didn't like how people have no color perception when things are lit with the single wavelength of LPS. HPS has a bit of a spread of spectrum from red -> yellow, with a peak at the pleasant orange color.
Arizona DOT is gradually switching out the safe HPS lights for defective LEDs. At first these were 5000K, but I watched them switch out one intersection's functional 5000K light for what I think is 3000K. LED streetlights' light is not nearly diffuse enough. I've come to referring to the bright spot under the lights as a 'cone of destruction', and have taken to lowering my car's street lamp visors to protect my eyes from the glare of passing under these streetlights.
Flagstaff Arizona uses pure-orange LED streetlamps, now that LPS bulbs are no longer being manufactured. These are wonderful... Not as nice as LPS, but 1000x better than "white" LED streetlamps.
If you're interested in the guy's 1982 report about street lights, give this comment an upvote, and I'll maybe work on that blog post.
They've been retiring the incandescent street lights around here and the new white LED bulbs they've been replacing them with are obnoxiously bright. I feel bad with the people on the 2nd stories because they're basically shining right into the windows. The orange LEDs sound great.
Back when the lighting companies had all the money in the world to research their lights, scientists figured out how to use artificial light safely. Now that those scientists have mostly retired, and people alive today have no idea what it was like for artificial light to be precious, we're forgotten everything our predecessors figured out. Just last night I was at my current city's newest hotel, and while the lights are mostly pretty good, they also have a bunch of 5000K LED fixtures mounted at exactly eye level. Light is mostly useful to us humans when is bounces off of things.
In the 1970's the outdoor lighting industry standardized on High Pressure Sodium bulbs, because they're incredibly energy efficient AND because they're an almost blue-free light source. Low pressure sodium [LPS] bulbs are even more efficient and a perfect single-wavelength of orange (~590nm), but only a few cities (Flagstaff Arizona) really standardized on LPS.
I was whining to someone about how Phoenix, Arizona switched out its safe HPS streetlamps for 5000K LEDs in 2016 (I think they switched these to ~3000K after people complained about 5000K's effects on wildlife). The guy knew exactly what I was talking about, and said "I wrote the 1982 report that resulted in Phoenix's 1984 lighting ordinances." He'd recommended LPS, but the police didn't like how people have no color perception when things are lit with the single wavelength of LPS. HPS has a bit of a spread of spectrum from red -> yellow, with a peak at the pleasant orange color.
Arizona DOT is gradually switching out the safe HPS lights for defective LEDs. At first these were 5000K, but I watched them switch out one intersection's functional 5000K light for what I think is 3000K. LED streetlights' light is not nearly diffuse enough. I've come to referring to the bright spot under the lights as a 'cone of destruction', and have taken to lowering my car's street lamp visors to protect my eyes from the glare of passing under these streetlights.
Flagstaff Arizona uses pure-orange LED streetlamps, now that LPS bulbs are no longer being manufactured. These are wonderful... Not as nice as LPS, but 1000x better than "white" LED streetlamps.
If you're interested in the guy's 1982 report about street lights, give this comment an upvote, and I'll maybe work on that blog post.