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LEDs’ potential to save our night skies

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Re: LEDs’ potential to save our night skies

#111

Post by adamsb6 »

qurren wrote: post #105
uv-depression wrote: post #102

Earlier quoted context omitted.

(1) Considering there are now multiple companies planning to launch their own fleets of tens of thousands, satellites need replacing, etc, even if this was completely accurate, this will be a continuous and ongoing issue as it has been for years. (2) The standards for astrophotography and for professional astronomical measurements are somewhat different! Also, I think you meant median stacking; mean stacking doesn't…

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…

My wife's hometown in China used to have two options to reach from Shanghai - high speed rail (top speed ~ 200MPH) that takes about six hours or a roughly one hour flight.

Rail travel has stops and slowdowns in more populated areas that make it a bit slower than the advertised top speeds.

Re: LEDs’ potential to save our night skies

#112

Post by RetroTechie »

kccqzy wrote: post #44
throwforfeds wrote: post #33

Earlier quoted context omitted.

I hadn't been out to a dark sky in years so I went out to a deep part of Joshua Tree (Bortle 2-3) one night not too long ago just to see some stars. Wow, I was not expecting that many Starlinks up there.

National parks in California are indeed amazing. One time during a group trip to Death Valley, people were so amazed by the night sky that half decided to sleep outside the tents just to experience falling asleep while looking at the stars.

> people were so amazed by the night sky that half decided to sleep outside the tents just to experience falling asleep while looking at the stars.

Where I live, it usually impossible due to nights being too cold (okay, you can use sleeping bags/extra blankets etc), clouds, or... mosquitos.

But when/where it's not: highly recommended! "Spaceship Earth" in progress.

Re: LEDs’ potential to save our night skies

#113

Post by aidenn0 »

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…

Yes, I was wondering if they really last longer than sodium-vapor lamps, which last about 5 years at a 50% duty cycle.

Re: LEDs’ potential to save our night skies

#114

Post by [deleted] »

adamsb6 wrote: post #111
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…

My wife's hometown in China used to have two options to reach from Shanghai - high speed rail (top speed ~ 200MPH) that takes about six hours or a roughly one hour flight. Rail travel has stops and slowdowns in more populated areas that make it a bit slower than the advertised top speeds.

[deleted]

Re: LEDs’ potential to save our night skies

#115

Post by GrinningFool »

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.

Not really. When incandescent headlights are mis-aimed, it is generally not nearly as blinding or painful [for standard car headlights]. Mis-aims happen - it shouldn't be a risk to other drivers when they do.

Re: LEDs’ potential to save our night skies

#116

Post by dfxm12 »

Hilliard_Ohiooo wrote: post #69
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…

It's not that big a deal for MOST people. I was on navy ships transiting the Pacific it's as dark as it can get on deck and sure, it's magical and spectacular (especially the NUMBER OF SHOOTING STARS!) but even in the middle of the ocean 99% of my fellow sailors could not have given less of a shit. I'd sit out there for hours and they all though I was a weirdo for it. So, while amazing, most people don't understand o…

Depends how far back we go for "first place". Stars are an interesting intersection of social sciences, hard sciences, and even some woo for a very long time. We must consider their interaction between religion, astronomy and astrology going as far back at least as history lets us.

Re: LEDs’ potential to save our night skies

#117

Post by apparent »

aidenn0 wrote: post #113
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…

Yes, I was wondering if they really last longer than sodium-vapor lamps, which last about 5 years at a 50% duty cycle.

I imagine they last longer than some other types, but it hasn't been an order-of-magnitude difference that was advertised. Also the cost/hassle is much more than expected.

We've put some smart LED bulbs into some fixtures, and those have been fine. But they've only been in for a few years, so we don't yet know their lifespan.

Re: LEDs’ potential to save our night skies

#118

Post by RetroTechie »

Loic wrote: post #58
fhdkweig wrote: post #12

Earlier quoted context omitted.

Those things drive me nuts. There is a walking path that I frequent, and I can't use it at night because they are spaced every 20-30 feet. When I am not under them, they are off and my eyes adjust to the darkness and as I pass under one it flips to full daytime brightness and blinds me. As soon as I walk away from it, everything goes dark again, but my eyes had adjusted to the daytime brightness of the lamps. And I k…

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

Your Park May Vary (YPMV).

Re: LEDs’ potential to save our night skies

#119

Post by oblio »

qurren wrote: post #105
uv-depression wrote: post #102

Earlier quoted context omitted.

(1) Considering there are now multiple companies planning to launch their own fleets of tens of thousands, satellites need replacing, etc, even if this was completely accurate, this will be a continuous and ongoing issue as it has been for years. (2) The standards for astrophotography and for professional astronomical measurements are somewhat different! Also, I think you meant median stacking; mean stacking doesn't…

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…

> but if there aren't population centers, you'll have to have plans to create them in order to support the rail system itself.

This is such a misanthropic point of view.

Nobody "creates" population centers. People aren't created out of raw clay, they already exist.

If population centers are "created" it's because people already exist and want to live in a specific place, often time urban.

And if they wouldn't go to these population centers they wouldn't live in caves in the dark. They would be spread over many more places, yes, creating lower levels of light pollution but lots more of them, covering a lot more land.

Re: LEDs’ potential to save our night skies

#120

Post by retired »

Hilliard_Ohiooo wrote: post #69
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…

It's not that big a deal for MOST people. I was on navy ships transiting the Pacific it's as dark as it can get on deck and sure, it's magical and spectacular (especially the NUMBER OF SHOOTING STARS!) but even in the middle of the ocean 99% of my fellow sailors could not have given less of a shit. I'd sit out there for hours and they all though I was a weirdo for it. So, while amazing, most people don't understand o…

In parts of The Netherlands is simple never gets dark due to light pollution. It feels like it is always dawn. Pretty bad for your sleep cycle.

Some pictures: https://milieufederatie.nl/nieuws/6-op-de-10-nederlanders-wi...

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