Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

LEDs’ potential to save our night skies

spectrum.ieee.org

Post reply on HN
Print view View original

181–190 of 200 posts

Re: LEDs’ potential to save our night skies

#181

Post by swiftcoder »

Jblx2 wrote: post #127
swiftcoder wrote: post #6

Earlier quoted context omitted.

> That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system” One of the biggest excuses for ultra-bright streetlights is crime prevention (usually shortly followed by CCTV). I'm not really sure why we continue to indulge that point of view, but if one is indulging it...

I know we can be all righteous and intellectual on HN. But the article pretty much glosses over the large number of people who are afraid of the dark. Not afraid of crime in the dark. Actual adults who are apparently having a visceral reaction to the dark. What percentage of people is this? What percentage of those would adapt in a positive manner?

Those people can carry around a cheap LED lamp if it so pleases them...

Re: LEDs’ potential to save our night skies

#182

Post by kakacik »

culi wrote: post #149
binarymax wrote: post #42

Our city recently went on a crusade on replacing all of the high pressure sodium bulbs with LEDs, with the justifications of driving safety and energy savings. I agree that these are important, but the LED bulbs they chose are actively hostile to homes and pedestrians. They are blinding. You can't look at them. I have one outside our house in the main viewing angle and we need to close our shades as soon as they are…

:rock: + :slingshot:

-> repair, if repeated police or company will maybe put on a little camera, and then suddenly your hobby lands you in jail with enough time in to ponder why childish behavior is ruining one adult's life

Re: LEDs’ potential to save our night skies

#183

Post by t-3 »

oblio wrote: post #180
t-3 wrote: post #162

Earlier quoted context omitted.

Many cities and settlements have been created intentionally rather than as a result of populations organically reproducing on the spot. Colonies, chartered towns/cities/etc, company towns, etc. It's a very common thing throughout history to the present day.

And... the people? Where do they come from? Mars? All you're describing is population redistribution, not population creation. Urban centers have very low fertility rates, which actually reduces populations...

Yes, the people come from other places. The "population center" is very often made by people with intention though. The global population is still rising, so conjecture about the effect of cities on fertility rates is irrelevant. Humans aren't going extinct any time soon.

Re: LEDs’ potential to save our night skies

#184

Post by oblio »

t-3 wrote: post #183
oblio wrote: post #180

Earlier quoted context omitted.

And... the people? Where do they come from? Mars? All you're describing is population redistribution, not population creation. Urban centers have very low fertility rates, which actually reduces populations...

Yes, the people come from other places. The "population center" is very often made by people with intention though. The global population is still rising, so conjecture about the effect of cities on fertility rates is irrelevant. Humans aren't going extinct any time soon.

Did you read my previous comment in detail?

People don't live in caves, they will create light pollution everywhere, anyway. Might as well put them in small and dense population centers.

I hate reading comprehension these days :-)

Re: LEDs’ potential to save our night skies

#185

Post by t-3 »

oblio wrote: post #184
t-3 wrote: post #183

Earlier quoted context omitted.

Yes, the people come from other places. The "population center" is very often made by people with intention though. The global population is still rising, so conjecture about the effect of cities on fertility rates is irrelevant. Humans aren't going extinct any time soon.

Did you read my previous comment in detail? People don't live in caves, they will create light pollution everywhere, anyway. Might as well put them in small and dense population centers. I hate reading comprehension these days :-)

You said: "Nobody "creates" population centers."

That's demonstrably false, population centers are created all the time. The fact that populations don't spontaneously appear is irrelevant.

Re: LEDs’ potential to save our night skies

#186

Post by jefftk »

thayne wrote: post #165
esikich wrote: post #158

Earlier quoted context omitted.

I don't see how this can be true especially if you have a fancy telescope tracking something, take 3-5 whatever many shots in succession and stack. It's astrophotography 101.

For professional astronomers, it really sucks if you only have, say, an hour of observing time on a big telescope, and then a few of your precious frames are ruined because of a satellite. And you don't always even know that the frame is ruined until later, or have the flexibility to take more frames if needed (because you submit the full observation plan ahead of time, and just get the results later), in which case…

Where is 10% coming from? If you're focused on something far away shouldn't the fraction be <<1%?

Re: LEDs’ potential to save our night skies

#187

Post by arijun »

fch42 wrote: post #135
Loic wrote: post #58

Earlier quoted context omitted.

The timing and brightness is well adjusted, it feels natural, like a friendly ghost taking care of you.

unfortunately they never are. Brightness-adjusted, that is. Everyone installing lighting fixtures these days believes they must be daylight-level bright. The only ghosts you see are afterimages if you happen to look straight at the streetlamp ... (I find it odd; dark-adapted eyes see a lot, including movement in shadows or low-contrast obstacles - after all, our bodies know how to see well at moonlight levels of illu…

Because

1) Humans night vision is significantly worse than your regular vision. Low light would cause more accidents, eg.

2) The elderly have pretty terrible night vision. Your idea would exclude them from half the day.

Re: LEDs’ potential to save our night skies

#188

Post by arijun »

teamonkey wrote: post #134
amiga386 wrote: post #98

Earlier quoted context omitted.

TFA doesn't even claim that. TFA links to an advocacy website trying to convince authorities to put out less light pollution. It claims improved lighting (presumably brighter) doesn't reduce crime, and it claims a reduction (but not elimination) of lighting doesn't increase crime. I would say that going from no lighting at all, to some lighting, on urban paths, improves safety (not tripping over unexpected obstacles)…

Nobody is trying to remove all street lighting. There are plenty of practical suggestions on here and in that document about how things can be improved without reducing safety.

From the comment that started this deviation:

> Wouldn't it be more reasonable to just expect people who want to walk places in the dead of night to wear a headlamp?

Re: LEDs’ potential to save our night skies

#189

Post by oblio »

t-3 wrote: post #185
oblio wrote: post #184

Earlier quoted context omitted.

Did you read my previous comment in detail? People don't live in caves, they will create light pollution everywhere, anyway. Might as well put them in small and dense population centers. I hate reading comprehension these days :-)

You said: "Nobody "creates" population centers." That's demonstrably false, population centers are created all the time. The fact that populations don't spontaneously appear is irrelevant.

I said a lot more than that and this entire discussion is in the context of high speed trains and light pollution.

Again, reading comprehension, context, and I guess, typical techie obtuseness.

Re: LEDs’ potential to save our night skies

#190

Post by michael1999 »

projektfu wrote: post #124
michael1999 wrote: post #7

We need much better engineering standards if we are going to fix night lighting. A simplistic lux-on-the-ground measure combined with cost minimization produces a few lights, with bare bulbs, up hight, with brutal intensity. These are all things that produce glare directly on the eyeball. You need much less light on the ground if the eyeball itself has no direct line to the hottest part of the lights. Instead, the ni…

I believe that is what TFA is about.

ctrl-F "standards" - zero results.

The fine article was more about the effects of bad lighting, and the motivation to change. It does not discuss the engineering and insurance standards that generate the bad choices. Perhaps you misread my comment. As long as the standards are left as-is, street engineers are going to keep doing as they are.

Post reply on HN