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It’s possible to install warm colored LEDs with very little blue light output though. You get all those benefits without giving up the more-suitable-for-night sodium light spectral benefits.


The funny thing is, in my neck of Seattle (the city this post is complaining about), I've seen some of the harsh white LEDs that went in switched over to a warmer color. I remember being quite shocked when I pulled into a city-owned parking lot one night and realized that all of the lights around were all now a warmer color instead of the harsh white. The lights in my neighborhood also seem to have been switched over at some point. I suppose they're the tunable LEDs, but clearly someone here does care.


In my city they started turning off all streetlights at midnight outside of major driving lanes and active center areas.

It's weird and somewhat unnerving at first but brilliant. I'd argue road-wise it is possibly even safer because headlights work so much better when it's pitch black by virtue of the human eye having so much dynamic range.

Pedestrians can't miss cars as they're blasting light through the dark; cars can't miss bikes because even passive reflectors are blaring in the surrounding darkness; even pedestrians end up being more visible because of the higher contrast, cast shadows, and movement that conspire to make them plainly pop out like cardboard props or Doom 3 flashlight jumpscares.

And when you go out of the dark zone into a major axis that's bathed in light that feels warm and safe it's like everything is suddenly muted and flattened as if reality went through a low contrast sepia-tinted desaturation filter. You feel like you see better but everything is muddled together in the sameness of uniform lighting.

The experience is highly cognitively dissonant and counterintuitive.


I'm glad that darkness is respected in some places. The need to live in constant light is, to me, unnerving. Light pollution, like noise pollution, creates a myopic dome of sensory oblivion, separating us from experiencing the sounds of nature, the splendor the night sky, the emotions of isolation. I think we'd be better off with a nightly reminder of the natural world and expansive universe beyond our city block.


People are afraid of the darkness.

I really wish that wasn't the case. But removing lights is an uphill battle powered by irrational arguments and doomed to failure even on the cases where it's clearly the best option.

Even dimming the lights is hard.


I've grudgingly come to admit that also people who don't have great vision love bright lighting. I can usually see perfectly well by starlight, but that's not the case for everyone.


I was once in the US Navy, and stood many a bridge watch. When it got dark, all outside lights except for the navigation lights (red light on port bow, green on starboard bow, a white light up top and another white light on the stern). And on the bridge, we used only dim red lights, to avoid affecting our night vision. None of the navigation lights was easily visible from the bridge. And you could see reasonably well, even on a cloudy night.


I'm a regular outdoor runner and also an extreme morning person, so I'm often out running at like 3 AM, and it is absolutely not safer to be in complete darkness. Surfaces are not perfectly uniform and unobstructed and the ambient light from the atmosphere and surrounding city, even dead in the center of a major metro area, is nowhere near enough to see everything you might hit. I've tripped many times and even broken my hand before. It is effectively impossible to ever go full speed.


if you're out running at night, perhaps you should also be carrying some lights? both to help you see your environment and to help others see you.


I run at night on trails (during the summer, when it's too hot to run during the day). I wear a headlamp, and don't trip any more than I do in the day--despite the fact that the trails have rocks and roots. The only issue I have is that because the headlamp is inches from my eyes, shadows are almost invisible.


Where I come from they did change the lights to LEDs, but they turn off 2/3rds or 3/4ths of them after midnight; still enough light to navigate, but much less power usage and light pollution. There's a bike lane outside of town whose lights were motion activated, iirc that was installed about 20 years ago.


I walk a lot and support this, even though I am not convinced it makes me more visible when not in front of the headlights. Typically, the danger happens when walking on the sidewalk perpendicular to a road. I can see the car, they cannot see me until I'm a few feet in to the crosswalk when I'm not lit up by a street light.


WTF? What about pedestrians? Are they walking in full darkness?

This seems to be totally oriented to cars. I find American cities incredibly dark by night. Walking around feels too dark and unpleasant.


> WTF? What about pedestrians? Are they walking in full darkness?

During a normal night, you get used to the darkness surprisingly fast, and if there even a slight sliver of moonlight, your eyes will within seconds adjust and let you see things again without trouble.

At least that's my experience growing up in the dark countryside in Sweden and seemingly retaining this as an adult, YMMV.


> During a normal night, you get used to the darkness surprisingly fast,

Then a car drives past and your sight instantly adjusts to that, but takes several minutes to adjust back. Then you're stuck in subjective total darkness for a while.

Or, if you're in an area with mixed lighting (e.g. you walk past a house that incidentally lights part of the street) then your eyes can never adjust and you have to walk through pools of total darkness. I know this experience from rare situations where a few streetlights go out in a row, and it's not as easy as you just portrayed it.

> At least that's my experience growing up in the dark countryside in Sweden

That's fair enough IMO. I don't think it's feasible or helpful to plaster every centimetre of every rural road in street lighting. But the comment we're replying to suggested removing them in cities "outside of ... active center areas". That's a different matter.


YMMV as you get older and lose that superpower.


What range/years are you specifically referring to? It seemingly is as good as ever, and I'm 32 now. I'm guessing that would start being around 40s, when the general eye-sight starts to decline?


Yep, right around your mid-40’s in my experience. Friends have said it started the day they woke up on their 40th birthday.


I don't think there is a rule for that? At least not in my case. My eyesight got worse really fast out-of-nowhere when I was like, 15 years old? And since then it didn't change anymore. I got myopia, after a few years of too much computer screen (the old CRTs).


While there was a suspicion of eyesight troubles in my late teens, it really kicked in during a period I was working on pretty crappy screens, that was in my late 20's. It's not much but enough to give me headaches when not wearing them.


How old are you? Most people experience worsening eyesight mid 40s.


I'm currently 37, I hope it doesn't start to get worse again anytime soon. I never used glasses regularly, btw. Always had the impression that would weaken my eyes long-term.


There’s a new-ish body of research that suggests aging is non-linear/happens in “cliffs,” and that the first big decline is mid-40s. Something to look forward to.

https://www.technologyreview.com/2024/08/15/1096799/aging-hi...


About the time you start needing reading glasses to see your phone or computer screen. Between 40-50 years for most people. You will develop an appreciation for the people who complain about small fonts and low-contrast color schemes. And yes, adapting to darkness takes longer.


> people who complain about small fonts and low-contrast color schemes.

I already do this at this point, so guessing that's a club I'm in already, even if my eye-sight is perfect :)

Well, I guess I'll report back in 10-20 years and I can finally have this confirmed for all of us.


It's not usually possible to reply to decades-old HN threads.


This is a car-centric ableist take.

Not everyone has excellent vision. In addition to those who are actually visually impaired, your eyesight simply gets worse as you get older even if you had perfect vision when you're young.

And even if you can adjust to the night, which is Moon and cloud-dependent anyway, that completely goes away every time a car goes past with its LED high beams.

LED lights have way more capacity to be directional. There's absolutely no reason why street lights can't mostly point down to light the street and sidewalks with minimal light pollution to any nearby houses.


> This is a car-centric ableist take.

Growing up on a island with 700 people where the most common mode of transportation is probably bicycle (besides walking, or possibly moped), it really isn't :) People are really eager to jump on the "ableist" accusation, aren't they?

> And even if you can adjust to the night, which is Moon and cloud-dependent anyway, that completely goes away every time a car goes past with its LED high beams.

It really doesn't, at least it didn't for me. It's true that for some seconds you'll see less, but your eyes will adjust faster after that than the initial adjustment when you go from a fully lit environment to unlit, even without direct moonlight.

I'm not arguing for completely dark cities, that'd be bananas. I was just giving another perspective about how we can (usually) adjust to darkness if we let our eyes be used to it. Of course we should have lights in cities so everyone (not just us with good night-sight) can navigate without issues.


I am night blind, among other things and cannot drive. If an area doesn't have street lights it's much more inaccessible to me, I become fully blind and I usually end up not going. Lights off is bad for me, end of story. Whether my ability to walk around at night is a factor here is a subjective decision. I understand people in my situation are a minority.


Wouldn’t a headlamp or a flashlight achieve the same purpose?


Also it's terrifying for safety; way too easy to assault someone in complete darkness.


I suspect your terror comes from lack of familiarity with natural light outdoors, and is a product of always having the lights on plus not being out of a house often.

The night is not 'complete darkness', we can generally see fairly well.

Also, I suspect your presumption on assault risk and assault rates comes from media, which is designed around building fear. Fear sells.

So I agree that you find the natural world terrifying, I just wish you didn't. Because the natural world is what we are fit for.


> Because the natural world is what we are fit for.

Good thing we live in cities then!


Let's put it this way. The fear is someone hiding in the shadows to jump a person, and then dragging the victim back into the shadows.

Bright lights on the street create more shadows. All you have to do is step out of the streetlight and no-one will see you, because the light-level contrast between the lit street and the surrounding space.

If there aren't any streetlights, so the surrounding space has the same illumination as the roadway, then that space is more present in more passerby's visual awareness.

So your proposed solution, "Streelights on every street" actually increases the risk you are so concerned about.


Completely the opposite.

Numerous studies show crime goes down when streetlights are turned off.

Simply put, you don't get scrotes hanging about in groups up to no good without lights, and anybody who is walking around is carrying a torch, making it obvious what they are doing (e.g. if you are breaking into a house, needing a torch instead of using a streetlight makes it obvious to everybody what you are doing).

No to mention a lack of streetlights makes if harder for somebody to hide in the shadows.

The real question to ask, is why people like yourself are 'terrified' [sic] of the dark. Statistics show the real truth of what you should be worried about.


> The real question to ask, is why people like yourself are 'terrified' [sic] of the dark.

Statistics show that people don't care about statistics but about confirmation bias and the media is eager to feed it.


I'm don't see why this is downvoted, I think it's an honest and legitimate question. What are pedestrians supposed to do when there's no car passing them right this moment? Carry their own torch? Rely on ambient light from the moon and reflected from nearby lit streets? Are we assuming there's such a high volume of cars that there's never a gap? I'm genuinely confused.


Where I live, even with streetlights, most people I see walking after dark carry a torch.

It’s easier than ever to carry one.


Honest question: Do you mean that most pedestrians are actually using (not just carrying on their person) a torch while walking along lit streets? I have essentially never seen that where I live, except some joggers have lights attached to their clothing but that's just so others can see them better. I can't imagine street lighting in an urban/suburban area being so bad that that would be necessary. That's a terrible state of affairs which, in itself, is a gross anti-pedestrian move.

(Or did you just factiously mean that people have smart phones on them which can function as torches?)


> except some joggers have lights attached to their clothing but that's just so others can see them better.

Yes, generally the purpose of the light is so others can see you.

My god, we spend all of our lives blasting lights into our eyes (some people call these lights "screens"), we've forgotten how to live without it!


I use the flashlight on my phone to flash at drivers to increase the likelihood that I am seen.


I mean I quite often see people holding a torch (or maybe a lit up phone) while they're walking.

I'm in an urban area, but it's not as well-lit as a downtown environment. There's street lights every 2-3 houses and they're not super bright.

I personally prefer this over a downtown-like bright environment since it makes it easier to sleep and the ambience is just better at night.


Clearly you have lived your entire life in a city under streetlights.

Here, if you go the the pub at night as the streetlights are turned off at midnight, so you take a torch (your phone as a backup). Its perfectly commonplace. To suggest this is "anti-pedestrian" is a bit silly. Rather, it's anti-light pollution.


> Carry their own torch

You state this like it is a bad idea.

If you have a cell phone, you have a torch.

If you are walking in a place where there are cars, having a light on you is a great way to reduce your risk of being hit. So yes, you should absolutely be carrying a torch if you are walking near streets after dark. Nordic countries teach this in kindergarden.

When I'm crossing a street after dark, I always flash my torch at potentially oncoming cars. Even if I'm at a lit crosswalk.

If you are walking in a place without cars, then the place probably doesn't have the infra to provide street lighting. You may want a torch, depends on the phase of the moon and your comfort level with dim lighting.


You are starting an unrelated conversation.

This comment chain started with someone suggesting that in cities lighting be turned off almost everywhere, and someone replied that pedestrians won't be able to clearly see where they're going without a torch (and I agreed). Where I live, no pedestrian in a city would ever need to use a torch to see where they're going.

You've posted a couple of replies saying that pedestrians should carry a torch so that cars can see them. Well, maybe, maybe not. But that's a different matter.


Get a flashlight?


> The experience is highly cognitively dissonant and counterintuitive.

Hitting the next homeless person and throwing them 10 meter in the space will be quite the experience.

Honestly, this is not shitty experience because of regulation, this is just councils cutting costs everywhere except their salaries. Los Angeles these last couple days has showed what it means to do that. You'll literally be on fire some day.


OK but blinding blue LEDs are most common substitutes, because it's the lazy default, and because people do not care. That's the point of the article.


Blue-white LEDs have become the replacement for High Pressure Sodium [HPS] traffic lights because that's what the LED light companies have to sell. In the early years of the transition to LED streetlights they had to sell blue-white LED streetlights because warmer LEDs were not competitive with HPS on the basis of lumens-per-watt.

Most of the people who understood the advantages of blue-free amber HPS light over white metal halide lights retired, and this little tidbit of information didn't get passed to the next generation of city employees.

> and because people do not care.

People care, but they don't know why they hate the blue-white LED replacement lights. I've complained to the city about their new lights, but have not gotten any responses about why they haven't deployed LED lights with a safe spectrum of color.

This comment about unsafe blue-white headlights got a few upvotes: https://news.ycombinator.com/item?id=42444111


Blue light is safer for cars - it gives slightly faster reaction times, and lower the chance of drivers falling asleep.

The problem is that for pedestrians, the reaction-time is irrelevant, they're butt-ugly, and plenty of people go on night walks because they can't sleep but want to.

Half of this article is basically about cities being overly car-centric.


In some ways, car-centric cities are like that because people don't care. "I'll just take my car, whatever". They don't care about traffic, pollution, accidents, etc.


Or maybe they care about getting to their destination in time and not wasting half a day just going from point A to point B on foot/by (shitty) public transportation, or they'll be fired.

Daily reminder that we live under capitalism where you're not allowed to just "take your time".


I’m not well-read on the old lighting research, but I’ve come across some explanations for why humans actually do much better with amber outdoor lighting than white. One of these points relates to how our pupils expand and contract with the amount of light available.


My impression was that HPS lighting became so widespread not because of the supposed advantages of its light spectrum, but because it was simply the most light-efficient technology available at that time. Here in Germany, only main/multilane streets requiring more lighting were using HPS, residential streets mostly had lamps with white fluorescent lights, so switching those to LEDs wasn't as much of a change. But still, I'm wondering: what about curtains, window blinds etc.? It's not as if people are forced to endure the intrusion of street lighting into their bedrooms?


> But still, I'm wondering: what about curtains, window blinds etc.? It's not as if people are forced to endure the intrusion of street lighting into their bedrooms?

Of course. But that's the problem -- now black-out curtains are required. And maybe you hate those because you really enjoy waking up with the sun streaming in, and now you have to wake up every morning in blackness until you go open the curtains.

The onus shouldn't be on the residents. It's the same as saying, sure it's noisy but why don't you just wear noise-canceling headphones all day long?

Government services exist to serve the people, not make the people work around them.


Low pressure sodium lights were more efficient, but they emit a single wavelength of orange light. These lights were strongly disliked by people who liked to admire their car in the streetlights (I suppose).

> residential streets mostly had lamps with white fluorescent lights,

… they used CFLs? The spiral fluorescents were invented in the 1980’s, I guess. I speculate the residential street lights used mercury vapor bulbs, which had a longer expected lifespan than fluorescents.

> But still, I'm wondering: what about curtains, window blinds etc.?

You need a good blackout curtain to deal with light pollution through your window.


Decades ago, my junior college's parking lot was lit by low-pressure sodium lighting. I recall the light being an absolute monochrome yellow, to the point that you had to be careful to remember exactly where you parked your car, because you weren't going to find it by color.

I can't vouch for Germany, but there used to be long, high-output fluorescent tubes and fixtures for street lighting in the US. They seem to have largely disappeared by the 1980s. They weren't very common, but some cities used them. They tended to be used on main streets when I saw them.


> they used CFLs?

Nah, the lamps used (I assume) standard fluorescent tubes. Although honestly I don't know how widespread they were. They were (and still are in some areas) all over the place in Munich (and also e.g. here https://maps.app.goo.gl/M3RPqkN5MHZuPG7f7). Hamburg (https://maps.app.goo.gl/fPGfeEwWXtUGFnTL7) and Berlin (https://maps.app.goo.gl/kSemA2Md84AEJ9Py8) also have similar-looking ones.


Here in Baltimore the city seems to have purchased a huge batch of defective LEDs that are actually purple. It’s disturbing when you encounter one.


Nitpick: "are actually purple" makes it sound like they came out of the factory purple, but they're actually changing from white to purple over time as the phosphor coating fails.


Just to be clear, these are about 1-3 years old. So yes they probably weren't purple on the day they were installed, but this is a defect and not normal aging. https://www.reddit.com/r/todayilearned/comments/136nz3b/til_...


They'll be near-UV LEDs with a phosphor to produce white, high efficiency, low cost, but garbage long term.




The city employee who bought them is probably a massive Ravens fan...


i mean who wouldn't be the way they're playing


Might be so that they don't interfere with a certain species of wildlife. We have deep blue ones near me that aren't visible by a protected bat species.


They’re purple (blue is the other option) because veins are harder to see under purple light. They’re used to deter drug use, from my understanding.

Edit: final clause


Not true, they're just defective and degraded quickly, resulting in the odd color.


Agree, but it's more expensive and less energy efficient[1]. Personally, that seems worth it to me [EDIT: "it" being using slightly less efficient lights that are more comfortable for people], but thats a difference in values not in how much I "care" about the problem...

[1] https://www.scientificamerican.com/article/streetlights-are-....


> that seems worth it to me

How much more energy efficient is it? If it's a tiny efficiency gain vs the negative effects of blue heavy white light then I would suggest it's a bad tradeoff. Some studies have suggested that blue light doesn't affect sleep [1] but the psychological effects of cold vs warm light has been used by lighting designers for decades. Cold light is less comfortable and discourages hanging around, the positive spin is "energizing", it's often used in supermarkets and budget stores that value faster browsing, and impulsive decisions under a greater feeling of urgency. Warm light has a relaxing effect and is used, for example, in luxury stores and restaurants where people are intended to take their time. [2] For outdoor areas where people are intended to enjoy relaxing after dark activities warmer light would be far superior an experience than colder light.

1. https://www.medicalnewstoday.com/articles/blue-light-may-not... 2. https://www.tcpi.com/how-lights-impacts-psychology-mood-in-r...


sure - for your house. For lights all over the city that will be lasting years?


In my town, when they replaced the old mercury arc and high pressure sodium lights, they picked a pleasing neutral white for the side streets that's far better than the bluish-white mercury arcs they replaced, while using 40 watts each instead of 175. Win-win in my book.

The main streets have a different LED with a slight yellow cast, but not the ugly orange of high pressure sodium. Yes, we can have nice LED street lighting.


In the netherlands I have seen green street lights with motion sensors. Only on smaller streets and pedestrian paths, though.


That sounds cool.


Any way to test my light's spectrum? e.g. a cheap home spectrometer


Use a CD disk - really - it disperses light similarly to a dispersive prism. You can then see and estimate the amount of red, blue and green in a light. It works very well if you just want to check blue light sources at night. And you can even make a DIY spectrometer with it! https://youtu.be/p3MzQ1OF3lk


Take a photo


Implies no white balance shenanigans


A sheet of paper will generally manage ok for white balance calibration. A 3 tone grey card would be better, but a single, simple white will suffice




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