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LEDs’ potential to save our night skies

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Re: LEDs’ potential to save our night skies

#141

Post by throwaway173738 »

yonatan8070 wrote: post #93
throwatdem12311 wrote: post #64

All the car headlights for new cars in Canada are LED and it makes driving at night painful and dangerous. So many times I’ve been nearby blinded by them and I can’t see anything ahead. And it actually physically causes me pain.

But is that the fault of the LED? That sounds like the fault of whoever calibrated the LEDs' brightness and directionality. If the beams were the right brightness and pointed downwards, we wouldn't be having this issue.

There will always be situations where you’ll be under the cut point of a low beam. If there’s a small incline then a flat intersection the drivers opposite the incline get the fill low beam. It’s part of what makes HID lighting dangerous to pedestrians. It obscures the vision of oncoming drivers turning left or right. Also if an automatic headlight system doesn’t react to turn the high beams off it will blind people.

Re: LEDs’ potential to save our night skies

#142

Post by ssl-3 »

apparent wrote: post #109

> The use of solid-state technology gives the lights an extraordinary life-span, often measured in decades rather than years. I have found this not to be the case. They seem to last several years, but not an amazing period of time. Also, the ones that were installed in my home are quite expensive, something like $45 per can (the whole thing must be replaced), and the price to install is $30 per can because the compan…

At home, my solution to that is to use lighting fixtures have Edison sockets inside for a bulb to screw into, just like they always used to.

The fixtures last forever, and may have already been there for half a century. It doesn't need changed.

The bulb lasts as long as it lasts, but is easily replaced. It can be dumb, or it can be smart. It can be changed for different color temperature or CRI or protocol or efficiency rating or whatever.

Re: LEDs’ potential to save our night skies

#143

Post by Reason077 »

uv-depression wrote: post #25

Greenhouses here in the lower mainland of British Columbia have been devastating to the night sky. It's quite depressing how little society values the night sky, something that's been an important part of every human culture for longer than recorded history. I've taken friends out to thoroughly mediocre skies (Bortle 4-5) and they've been very impressed, because they're used to city lights (Bortle 9) where you can ma…

Wanaka, in the South Island of New Zealand, still has pretty good views of the night sky. You can see an awful lot more stars than you can from major cities.

But even here it’s under threat: a recent new retail development on the edge of the town (called “Three Parks”) emits so much light that it illuminates the nearby hills at night. The sad thing is that much of this light seems unnecessary to me: eg a hardware / garden retailer has enormous floodlights to illuminate their inner courtyard constantly at night, even when they’re closed.

The rest of the town has always been pretty good at minimising light pollution, with soft, modest and well designed street lighting in residential areas. But such considerations have been forgotten completely with the new development. Three Parks emits more light pollution than the rest of the town combined!

Re: LEDs’ potential to save our night skies

#144

Post by Reason077 »

qurren wrote: post #99
uv-depression wrote: post #25

Greenhouses here in the lower mainland of British Columbia have been devastating to the night sky. It's quite depressing how little society values the night sky, something that's been an important part of every human culture for longer than recorded history. I've taken friends out to thoroughly mediocre skies (Bortle 4-5) and they've been very impressed, because they're used to city lights (Bortle 9) where you can ma…

Starlink gets a lot of flax for it but as an avid night sky photographer myself (IG: @dheeranet) who regularly goes to Bortle 1 parts of the world, I haven't found them to be an issue at all. 1. They are only visible when they are spinning up to orbit 2. They are too dim to desensitize your eyes, and are extremely easy to remove with the most basic of outlier rejection techniques; netizens often amplifiy outliers by…

As a “night sky enthusiast”, as opposed to a real astronomer, Starlink and other satellites do not bother me much.

There’s certainly more of them than there used to be, but the satellites aren’t bright enough to affect your eyes or distract too much from the stars. If you do see one it’s a fun little exercise to try and figure out what it is!

Ground-based light sources are the real threat to night skies.

Re: LEDs’ potential to save our night skies

#145

Post by culi »

qurren wrote: post #99
uv-depression wrote: post #25

Greenhouses here in the lower mainland of British Columbia have been devastating to the night sky. It's quite depressing how little society values the night sky, something that's been an important part of every human culture for longer than recorded history. I've taken friends out to thoroughly mediocre skies (Bortle 4-5) and they've been very impressed, because they're used to city lights (Bortle 9) where you can ma…

Starlink gets a lot of flax for it but as an avid night sky photographer myself (IG: @dheeranet) who regularly goes to Bortle 1 parts of the world, I haven't found them to be an issue at all. 1. They are only visible when they are spinning up to orbit 2. They are too dim to desensitize your eyes, and are extremely easy to remove with the most basic of outlier rejection techniques; netizens often amplifiy outliers by…

Starlink has over 10k currently but has applied for at least 42k. And because it's now a US military technology, every other country is building its own. China is planning on launching over 12k satellites and Russia is working on their own.

It's too much

Re: LEDs’ potential to save our night skies

#146

Post by culi »

parl_match wrote: post #140
garbagewoman wrote: post #130

Earlier quoted context omitted.

Both are real issues, to be clear. LEO satellites are a real and increasing issue.

Yes, but one is a vastly smaller issue than the status quo issues. Starlink gets a lot of attention because it's new, and because it's run by a polarizing guy who sucks. Meanwhile, the airplane and streetlight situation has been destroying night sky photography for decades, to the point where photographers consult charts and have communities tracking the best times of years to minimize the hours of driving you have t…

It's an exponentially growing issue. Starlink's current fleet of ~10k is expected to grow to at least 42k. And since its been used for military uses, China and Russia have realized they also need their own competition. China's SpaceSail plans on launching 15k satellites by 2030. The EU's ambitions are much smaller than both of them, but if every developing nation continues to build their own platform, where does it end?

Re: LEDs’ potential to save our night skies

#147

Post by qurren »

computably wrote: post #139
qurren wrote: post #105

Earlier quoted context omitted.

Some good points. However: > replacing the majority of air travel with high speed rail I absolutely LOVE high speed rail, but I will note that it is correlated with far more light pollution than air traffic. I say correlated because typically high speed rail is routed through high-density population centers, but if there aren't population centers, you'll have to have plans to create them in order to support the rail…

That's a backwards argument. Flights in California between SF and LA will obviously travel a continuous line across California. Yes, the populated areas have light pollution, but that's because they're, y'know, populated areas. HSR itself would add nearly no light pollution outside of the existing population centers, in contrast to flights.

Right, the California HSR route doesn't travel through any really dark sky regions anyway.

My point was that if you want replace, say, San Francisco Las Vegas with HSR you're going to inevitably have to wreck a chunk of Bortle 1 dark skies in the Sierra or Death Valley.

Doesn't mean I'm against HSR but it has to be done thoughtfully.

Re: LEDs’ potential to save our night skies

#148

Post by culi »

amiga386 wrote: post #36
trollbridge wrote: post #19

Earlier quoted context omitted.

Wouldn't it be more reasonable to just expect people who want to walk places in the dead of night to wear a headlamp? They're cheap, easy to recharge, and can be adjusted for various brightness levels.

The problem is not just with people who want to walk places, but people who want to mug/murder/rape those that do. As an example, in the UK, councils are expected to light commonly-traveled paths, both so path users can see where they're going, and to reduce crime. Unlit paths in city parks are still traversed, and are often a haven for crime. "Dead of night" isn't the right image. 5PM in winter with clouds (as is ty…

I hesitate to even engage in a conversation about organizing our entire infrastructure/society over such a rare incident, but I'll bite.

Powerful lights are known to actually increase safety risks. Our nightvision is reduced and the shadows of the lights are the most dangerous parts. Perhaps more dangerous than no light at all.

Once city (I can't recall which) had a really cool solution to this where they installed string lights. Lots of small, dim lights don't negatively impact your nightvision, keep the path pretty visible, and don't cause too much light pollution

Re: LEDs’ potential to save our night skies

#149

Post by culi »

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:

Re: LEDs’ potential to save our night skies

#150

Post by NooneAtAll3 »

qurren wrote: post #99
uv-depression wrote: post #25

Greenhouses here in the lower mainland of British Columbia have been devastating to the night sky. It's quite depressing how little society values the night sky, something that's been an important part of every human culture for longer than recorded history. I've taken friends out to thoroughly mediocre skies (Bortle 4-5) and they've been very impressed, because they're used to city lights (Bortle 9) where you can ma…

Starlink gets a lot of flax for it but as an avid night sky photographer myself (IG: @dheeranet) who regularly goes to Bortle 1 parts of the world, I haven't found them to be an issue at all. 1. They are only visible when they are spinning up to orbit 2. They are too dim to desensitize your eyes, and are extremely easy to remove with the most basic of outlier rejection techniques; netizens often amplifiy outliers by…

> They are only visible when they are spinning up to orbit

> and are extremely easy to remove with the most basic of outlier rejection techniques; netizens often amplifiy outliers by max-stacking instead of outlier-rejected mean-stacking to make Starlink look much worse than it is

my understanding was that they are a problem on much bigger scale than yours "one dude with mobile telescope (or maybe just a camera?)"

sure, we don't have many film observatories anymore (where max-stacking is literally only thing they can do), but a lot of lower-to-medium scale observatories get polluted observations with not enough funding to clean up easily or too small FoV for cleanup to matter - frame gets ruined, observation needs to be longer for effect

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