Modern LED street lighting is more directional than traditional sodium lamps, and results in less overall light pollution.
1. Much blue-er and so WAY worse for people's circadian rhythms 2. Much "sharper" in it's shadows, so you go from blindingly bright to pitch black without your eyes having a chance to adapt, making it unsafer, and making the shadows "darker" 3. Much harder to filter out for astronomers
It's only advantage is really that it's a lot more energy efficient, but it seems like white LEDs are a net decrease to human welfare as opposed to yellow sodium lamps.
Anecdotally, I used to live in front of a park that had yellow lamps and it was never an issue at night, but when they switched to white LEDs my entire house was illuminated with very blue, daylike-like light, really messing up my sleep.
There is always garbage out there, regardless of product category. For streetlights you can get good products. Acuity's Autobahn Series ATB0:
> White Light: Correlated color temperature - 4000K, or optional 2700K, 3000K or 5000K, all 70 CRI
* https://img.acuitybrands.com/public-assets/catalog/122046/at...
* https://americanelectriclighting.acuitybrands.com/products/d...
* Via: https://www.darksky.org/our-work/lighting/lighting-for-indus...
> 2. Much "sharper" in it's shadows, so you go from blindingly bright to pitch black without your eyes having a chance to adapt, making it unsafer, and making the shadows "darker"
Lighting and crime (prevention) is debatable:
* https://www.darksky.org/light-pollution/lighting-crime-and-s...
Further, glare can blind people so as to not being able to see in darker areas:
* https://cescos.fau.edu/observatory/lightpol-security.html#Gl...
> 3. Much harder to filter out for astronomers
IMHO we can start worrying about this after we actually reduce light pollution. If we're at the point that astronomers can actually do useful work around large urban centres then let's start worrying about spectrum. As it stands they probably can't do much of anything now.
Is there a solid research behind this? I know it was intensely shared, but it that real or is it just some idea with none to very limited backing like learning styles.