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Simple streetlight hack could protect astronomy from urban light pollution

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Re: Simple streetlight hack could protect astronomy from urban light pollution

#21

Post by bombela »

wruza wrote: post #9

Ah, the good old "human eye can't see N Hz" that will make night lights insufferable for those who happen to see it. My grandma has a couple of lightbulbs in her apartment that annoy nobody except me. I feel like laser-blinded when they are on, no matter where I look. It's blindingly bright and visually dark. Idk if it's flicker frequency or light spectrum tbh, but it's that same "hey you shouldn't see it, cause nobo…

I experience the same "blinding bright but visually dark" on a battery powered light I own. I wonder if it depends on the length of time the light is off.

Most light that flicker below 400hz really bother me, but I still perceive the surrounding as illuminated. While this particular torch light feels like "blinding darkness".

Re: Simple streetlight hack could protect astronomy from urban light pollution

#22

Post by cm2187 »

wruza wrote: post #9

Ah, the good old "human eye can't see N Hz" that will make night lights insufferable for those who happen to see it. My grandma has a couple of lightbulbs in her apartment that annoy nobody except me. I feel like laser-blinded when they are on, no matter where I look. It's blindingly bright and visually dark. Idk if it's flicker frequency or light spectrum tbh, but it's that same "hey you shouldn't see it, cause nobo…

Dogs apparently see at a higher frequency. For those who want to torture animals...

Re: Simple streetlight hack could protect astronomy from urban light pollution

#23

Post by cassianoleal »

Anotheroneagain wrote: post #16
nightowl_games wrote: post #8

Earlier quoted context omitted.

> Even better: turn the darned things off when they are not needed - why illuminate empty streets? That is a way better idea than the one in the article, for sure. So many benefits. Would need the motion sensing technology to be top notch tho. Need to illuminate for pedestrians as well. Or perhaps illuminated sidewalks, or smaller lights for pedestrians.

No it's a horrible idea, imagine the lights turning on and off as people pass. No!

Indeed that would be terrible, especially in dodgier areas. Not only you're advertising your position to potential attackers, but you're also less likely to see them until they're very close.

I believe relatively dim, warm coloured lights are a much better idea.

Re: Simple streetlight hack could protect astronomy from urban light pollution

#24

Post by jcalvinowens »

da768 wrote: post #12
bradley13 wrote: post #5

Right. They're going to get all the streetlights in an entire city to blink in unison. Sure they are. Anyway, in most cases the LEDs don't run at 100%. In our area a, I happen to know that they are between 29% and 40%. That dimming is accomplished by blinking. Which would conflict with the idea of having them blink synchronously. Much simpler solution: ensure the LEDs ghts are directed exclusively downward, and have…

Why not, just sync them to the AC power grid they're all powered from.

Different types of transformers introduce different phase shifts.

Re: Simple streetlight hack could protect astronomy from urban light pollution

#25

Post by herodotus »

zokier wrote: post #14

> But there is a downside to LEDs: They're much brighter than old-fashioned energy-guzzling light bulbs. Such a weird statement to make. LEDs are not somehow intrisically brighter than other light sources, it is simply a design parameter. If new LED lights are brighter than whatever they replaced, it is because someone purchased lamps with higher light output, not because they are LEDs. You can get plenty bright with…

I think what is more accurate is that the frequency spectrum of typical LED street lights makes them seem brighter (much more blue).

Re: Simple streetlight hack could protect astronomy from urban light pollution

#28

Post by persnickety »

> But there is a downside to LEDs: They're much brighter than old-fashioned energy-guzzling light bulbs.

Are light bulbs actually being used in street lighting? I can't recall ever seeing that. Typically there's some gas-discharge lighting for that, and as far as I know, good old sodium-vapor lamps are pretty energy-efficient, on top of being not-terrible for astronomy.

This makes me wonder: what are LEDs replacing? And why are LEDs being installed rather than sodium-vapor lights? Is it because they are whiter? Cheaper to install? Just more hip?

Re: Simple streetlight hack could protect astronomy from urban light pollution

#29

Post by fragmede »

persnickety wrote: post #28

> But there is a downside to LEDs: They're much brighter than old-fashioned energy-guzzling light bulbs. Are light bulbs actually being used in street lighting? I can't recall ever seeing that. Typically there's some gas-discharge lighting for that, and as far as I know, good old sodium-vapor lamps are pretty energy-efficient, on top of being not-terrible for astronomy. This makes me wonder: what are LEDs replacing?…

Cheaper to operate, which over an entire city's worth of street lamps is very material. Sodium-vapor lights eventually need to be replaced (as do LEDs), so why not replace them with a modern technology that's cheaper to operate?

Re: Simple streetlight hack could protect astronomy from urban light pollution

#30

Post by canoebuilder »

cassianoleal wrote: post #23
Anotheroneagain wrote: post #16

Earlier quoted context omitted.

No it's a horrible idea, imagine the lights turning on and off as people pass. No!

Indeed that would be terrible, especially in dodgier areas. Not only you're advertising your position to potential attackers, but you're also less likely to see them until they're very close. I believe relatively dim, warm coloured lights are a much better idea.

Last sentence is a fine idea, it is also possible to move toward developing a society where “potential attackers” is a thought much more distant in people’s minds.
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