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> artificial light is increasing globally by at least 2% every year Um this is scary, isn't it? I want cities across the world to start switching over to low

> artificial light is increasing globally by at least 2% every year Um this is scary, isn't it? I want cities across the world to start switching over to low pressure sodium lamps. Yellow light for the win!

khuey 5y ago
Isn't low pressure sodium vapor a dead technology?
- imoverclocked 5y ago
  It's still used ... so, no?
  - kunai 5y ago
    High pressure sodium is very common and still available. Low pressure sodium is extinct. The last LPS lamp was made in 2018 I believe. It's a shame, because LPS was the gold standard for astronomy as the hyperspecific emission spectrum made it extremely easy to filter out for astrophotographers and telescope users
    - adgjlsfhk1 5y ago
      it's totally possible to make leds with similar properties, but it's generally but done because narrow spectrum lighting messes with color perception
throw0101a 5y ago
Dark Sky approved products: * https://www.darksky.org/our-work/lighting/lighting-for-industry/fsa/fsa-products/ https://www.darksky.org/our-work/lighting/lighting-for-indus...
blue1 5y ago
I also like sodium lighting, especially the LP variety (despite the fact that all the mystic about orange light helping sleep has been basically debunked), but it is still light. We should decrease light pollution, not simply change its color. Anyway, sodium lamps are being replaced by white LEDs.
- inciampati 5y ago
  Blue light doesn't suppress melatonin production? Got a reference for that? This was afaik a reproducible result.
  - openknot 5y ago
    A Time article [0] reports on this paper [1] that reaches the same conclusion as the user's comment. However, it's a mice study, which is an important limitation because rodents are nocturnal, according to the Time reporter. Meanwhile, Harvard Health [2] and WebMD [3] also both continue to report that blue light suppresses melatonin production for humans. From Time: "Animal studies should always be taken with a grain of salt, as they often do not translate directly to human behavior. And there are additional caveats to this particular paper, says Dr. Cathy Goldstein, a sleep specialist at Michigan Medicine. The researchers looked specifically at cones in the animals’ eyes, which detect color, instead of melanopsin, which senses light and is central to the issue of melatonin secretion. "They also kept light levels dim, regardless of color, which may not reflect the bright lights of electronics. "And finally, though mice are frequently used in sleep research, Goldstein notes that since the rodents are nocturnal, they may respond differently to light than humans do. Taken together, Goldstein says these conditions mean the study’s results apply only to a very narrow set of circumstances and metrics. “For this to get extrapolated to saying ‘blue light at night isn’t bad for you’ is a little bit of an extension,” Goldstein says." [0] https://time.com/5752454/blue-light-sleep/ https://time.com/5752454/blue-light-sleep/ [1] https://www.cell.com/current-biology/fulltext/S0960-9822(19)31368-5 https://www.cell.com/current-biology/fulltext/S0960-9822(19)... [2] https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side https://www.health.harvard.edu/staying-healthy/blue-light-ha... [3] https://www.webmd.com/sleep-disorders/sleep-blue-light https://www.webmd.com/sleep-disorders/sleep-blue-light
gtirloni 5y ago
Yellow light is horrible though. It seems to make everything really dark in my neighborhood. Most parts of the city are switching to white LED lights here and they feel much better.
- gsruff 5y ago
  My experience has been exactly the opposite. My neighborhood went from yellow, sodium lighting to stark white LEDs a few years ago. The result, to my eyes, is that the contrast between what is lit by the street lights and surrounding dark areas is much higher. Perhaps what is needed is better diffusion onto the ground.
  - novok 5y ago
    Or 2000K wide spectrum LED lamps vs doing stupid 6000K-5000K LED lamps at night and messing with human sleep cycles even more :/ Or causing nausea with the narrow spectrum yellow sodium lamps.
    - adgjlsfhk1 5y ago
      the problem with 2000k lights is that human night vision is much more sensitive to bluer light. you can use about half as much light while appearing as bright by moving to 3500k
- rmbyrro 5y ago
  That's true. Inside my home I prefer yellow light, but on the streets white light does work a lot better. I know it's psychological, but white light also gives me a better sense of security walking at night on the street.
  - micromacrofoot 5y ago
    There are some weird claims correlated with bluer light... that in public spaces they reduce crime or suicide rates. There's not a lot of actual data, but I've seen a lot of articles about it pop up... maybe it's just everyone's predilection towards easy fixes for complicated problems (like the too-rosy broken windows theory claims) https://urbanlabs.uchicago.edu/projects/crime-lights-study https://urbanlabs.uchicago.edu/projects/crime-lights-study
initplus 5y ago
Modern LED street lighting is more directional than traditional sodium lamps, and results in less overall light pollution.
- deleted 5y ago
  [deleted]
- el_nahual 5y ago
  Unfortunately it's also: 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.
  - throw0101a 5y ago
    > 1. Much blue-er and so WAY worse for people's circadian rhythms 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/atb0_.pdf?abl_version=01%2f19%2f2022+05:11:15&DOC_Type=SPEC_SHEET https://img.acuitybrands.com/public-assets/catalog/122046/at... * https://americanelectriclighting.acuitybrands.com/products/detail/122046/american-electric-lighting/autobahn-atb0/autobahn-led-cobra-head https://americanelectriclighting.acuitybrands.com/products/d... * Via: https://www.darksky.org/our-work/lighting/lighting-for-industry/fsa/fsa-products/#!/Roadway/c/12536252 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-safety/ 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#GlarebombsNoSec 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.
xupybd 5y ago
Maybe something in the temperature you want but more efficient than sodium lamps?

khuey 5y ago

Isn't low pressure sodium vapor a dead technology?

imoverclocked 5y ago
It's still used ... so, no?
- kunai 5y ago
  High pressure sodium is very common and still available. Low pressure sodium is extinct. The last LPS lamp was made in 2018 I believe. It's a shame, because LPS was the gold standard for astronomy as the hyperspecific emission spectrum made it extremely easy to filter out for astrophotographers and telescope users
  - adgjlsfhk1 5y ago
    it's totally possible to make leds with similar properties, but it's generally but done because narrow spectrum lighting messes with color perception

throw0101a 5y ago

Dark Sky approved products: * https://www.darksky.org/our-work/lighting/lighting-for-industry/fsa/fsa-products/ https://www.darksky.org/our-work/lighting/lighting-for-indus...

blue1 5y ago

I also like sodium lighting, especially the LP variety (despite the fact that all the mystic about orange light helping sleep has been basically debunked), but it is still light. We should decrease light pollution, not simply change its color. Anyway, sodium lamps are being replaced by white LEDs.

inciampati 5y ago
Blue light doesn't suppress melatonin production? Got a reference for that? This was afaik a reproducible result.
- openknot 5y ago
  A Time article [0] reports on this paper [1] that reaches the same conclusion as the user's comment. However, it's a mice study, which is an important limitation because rodents are nocturnal, according to the Time reporter. Meanwhile, Harvard Health [2] and WebMD [3] also both continue to report that blue light suppresses melatonin production for humans. From Time: "Animal studies should always be taken with a grain of salt, as they often do not translate directly to human behavior. And there are additional caveats to this particular paper, says Dr. Cathy Goldstein, a sleep specialist at Michigan Medicine. The researchers looked specifically at cones in the animals’ eyes, which detect color, instead of melanopsin, which senses light and is central to the issue of melatonin secretion. "They also kept light levels dim, regardless of color, which may not reflect the bright lights of electronics. "And finally, though mice are frequently used in sleep research, Goldstein notes that since the rodents are nocturnal, they may respond differently to light than humans do. Taken together, Goldstein says these conditions mean the study’s results apply only to a very narrow set of circumstances and metrics. “For this to get extrapolated to saying ‘blue light at night isn’t bad for you’ is a little bit of an extension,” Goldstein says." [0] https://time.com/5752454/blue-light-sleep/ https://time.com/5752454/blue-light-sleep/ [1] https://www.cell.com/current-biology/fulltext/S0960-9822(19)31368-5 https://www.cell.com/current-biology/fulltext/S0960-9822(19)... [2] https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side https://www.health.harvard.edu/staying-healthy/blue-light-ha... [3] https://www.webmd.com/sleep-disorders/sleep-blue-light https://www.webmd.com/sleep-disorders/sleep-blue-light

gtirloni 5y ago

Yellow light is horrible though. It seems to make everything really dark in my neighborhood. Most parts of the city are switching to white LED lights here and they feel much better.

gsruff 5y ago
My experience has been exactly the opposite. My neighborhood went from yellow, sodium lighting to stark white LEDs a few years ago. The result, to my eyes, is that the contrast between what is lit by the street lights and surrounding dark areas is much higher. Perhaps what is needed is better diffusion onto the ground.
- novok 5y ago
  Or 2000K wide spectrum LED lamps vs doing stupid 6000K-5000K LED lamps at night and messing with human sleep cycles even more :/ Or causing nausea with the narrow spectrum yellow sodium lamps.
  - adgjlsfhk1 5y ago
    the problem with 2000k lights is that human night vision is much more sensitive to bluer light. you can use about half as much light while appearing as bright by moving to 3500k
rmbyrro 5y ago
That's true. Inside my home I prefer yellow light, but on the streets white light does work a lot better. I know it's psychological, but white light also gives me a better sense of security walking at night on the street.
- micromacrofoot 5y ago
  There are some weird claims correlated with bluer light... that in public spaces they reduce crime or suicide rates. There's not a lot of actual data, but I've seen a lot of articles about it pop up... maybe it's just everyone's predilection towards easy fixes for complicated problems (like the too-rosy broken windows theory claims) https://urbanlabs.uchicago.edu/projects/crime-lights-study https://urbanlabs.uchicago.edu/projects/crime-lights-study

initplus 5y ago

Modern LED street lighting is more directional than traditional sodium lamps, and results in less overall light pollution.

deleted 5y ago
[deleted]
el_nahual 5y ago
Unfortunately it's also: 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.
- throw0101a 5y ago
  > 1. Much blue-er and so WAY worse for people's circadian rhythms 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/atb0_.pdf?abl_version=01%2f19%2f2022+05:11:15&DOC_Type=SPEC_SHEET https://img.acuitybrands.com/public-assets/catalog/122046/at... * https://americanelectriclighting.acuitybrands.com/products/detail/122046/american-electric-lighting/autobahn-atb0/autobahn-led-cobra-head https://americanelectriclighting.acuitybrands.com/products/d... * Via: https://www.darksky.org/our-work/lighting/lighting-for-industry/fsa/fsa-products/#!/Roadway/c/12536252 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-safety/ 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#GlarebombsNoSec 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.

xupybd 5y ago

Maybe something in the temperature you want but more efficient than sodium lamps?