Street lights account for only 20% of light pollution?

[clayton]

https://www.universetoday.com/148736/mo ... reetlights

[clayton]

Different Year (2012), Different City ( Berlin) slightly higher 31.6%. Methodology is not quite the same.

..lighting associated with streets has been found to be the dominant source of zenith directed light pollution (31.6%), although other land use classes have much higher average brightness. These results are compared with other urban light pollution quantification studies.

https://doi.pangaea.de/10.1594/PANGAEA.785492


Also Tucson, Arizona in the above study has adjustable smart street lights. Would that be cool if all streets lights city wide could be turned down? Even 5 days a month around new moon and only on clear nights would be cool.

White Bear supposedly has these lights in some areas: https://www.businesswire.com/news/home/ ... oor-Lights https://www.echelon.com/assets/blt339a5 ... Report.pdf

[setnes]

Tuscon already has a much better outdoor lighting code than other cities. It would be interesting to know how much that skews the results on such a test.

For example, they outright prohibit bottom mounted sign lighting, searchlights, and Mercury vapor lamps. I assume the Mercury vapor part was to force the use of the warmer color temperature sodium lights before LED. They also have different lighting codes in some areas to try to protect dark sky.

And... rated color temperatures cannot exceed 3500K!

https://www.tucsonaz.gov/files/pdsd/cod ... _code_.pdf

Imagine if cities and business had to follow similar rules here.

[clayton]

Yeah Tuscon is probably an outlier. I wish Commercial Lighting would be more strongly controlled. I doubt we will ever impact the security and safety segment, however these smart systems may help.

https://statetechmagazine.com/article/2 ... es-perfcon

[SEmert]

White Bear supposedly has these lights in some areas: https://www.businesswire.com/news/home/ ... oor-Lights https://www.echelon.com/assets/blt339a5 ... Report.pdf

Never knew that. Too bad it is only in Railroad Park, a small park in downtown WBL. Lights in the rest of the town seem as out of control as anywhere else.

[pkarri]

Not sure if this has any bearing on the street lighting code in Tucson, but Tucson is also home to the University of Arizona that has one of the world's best, if not the best, optical engineering and physics departments. The level of optics knowledge per capita in Tucson is higher than elsewhere, I'm sure. It was one of my target schools, and I went to another equally well reputed school that offered me more money

[Deane Clark]

Not sure if this has any bearing on the street lighting code in Tucson, but Tucson is also home to the University of Arizona that has one of the world's best, if not the best, optical engineering and physics departments. The level of optics knowledge per capita in Tucson is higher than elsewhere, I'm sure. It was one of my target schools, and I went to another equally well reputed school that offered me more money

It’s mainly because of the nearby observatories. Presence of UA and its strong astronomy program couldn’t hurt