APOD: Country Sky versus City Sky (2020 Apr 08)

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APOD: Country Sky versus City Sky (2020 Apr 08)

Post by APOD Robot » Wed Apr 08, 2020 4:05 am

Image Country Sky versus City Sky

Explanation: Dark skies are disappearing from the world. With modernization comes artificial lighting that brightens the night. While these lights allow modern humans to see, much light is wasted up into the sky. This light pollution not only wastes energy, but, when reflected by the Earth's atmosphere back down, creates a nighttime brightness that disrupts wildlife and harms human health, while doing very little to prevent crime. Light pollution is also making a dark night sky a scarcity for new generations. While there is little that can be done in large cities, rural country areas could benefit from lighting that is fully shielded from exposing the night sky where it is not needed. The featured panorama contains 6 adjacent vertical segments taken from different locations across Slovakia -- but with the same equipment and at the same time of night, and then subjected to the same digital post-processing. Although no stars are visible on the left-most city sky, the right-most country sky is magnificently dark. You can help protect the wonders of your night sky by favoring, when possible, dark sky friendly lightning.

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heehaw

Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by heehaw » Wed Apr 08, 2020 10:05 am

I remember, decades ago observing on Kitt Peak, one VERY cloudy night: such total clouds that walking outdoors I literally could not see my (Caucasian) hands held up in front of my face. David Crawford of KPNO led the effort to preserve dark skies. And I remember years earlier at a motel in California going out and looking up at a sky so dark that I could not pick out the constellations that I knew so well!

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by orin stepanek » Wed Apr 08, 2020 11:02 am

It is hard to see the MW from aa position within a city! Actually; all these were taken outside the city! 8-)
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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by JohnD » Wed Apr 08, 2020 11:07 am

Dark sky friendly lightning is indeed an exciting concept!

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by E Fish » Wed Apr 08, 2020 1:04 pm

There are a couple of places here in Idaho where they are designated dark sky preservation areas. In fact, central Idaho is a recognized dark sky reserve.

Low population density really helps. :)

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Imagineer » Wed Apr 08, 2020 2:19 pm

Which is more problematic for astronomers; artificial ground lighting or orbiting space vehicles and junk?

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Chris Peterson » Wed Apr 08, 2020 2:23 pm

Imagineer wrote:
Wed Apr 08, 2020 2:19 pm
Which is more problematic for astronomers; artificial ground lighting or orbiting space vehicles and junk?
Satellites are almost no problem at all. Light pollution significantly limits where observations can be made, although quite a lot can be done under light polluted skies. Light pollution is most problematic, I think, not to astronomers, but in terms of loss of the sky to everyone.
Chris

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Chris Peterson » Wed Apr 08, 2020 2:26 pm

heehaw wrote:
Wed Apr 08, 2020 10:05 am
I remember, decades ago observing on Kitt Peak, one VERY cloudy night: such total clouds that walking outdoors I literally could not see my (Caucasian) hands held up in front of my face. David Crawford of KPNO led the effort to preserve dark skies. And I remember years earlier at a motel in California going out and looking up at a sky so dark that I could not pick out the constellations that I knew so well!
When I lived in southern California, I knew the constellations well. The sky looked a lot like one of those basic constellation charts. When I moved to Colorado, I had to learn the sky all over. Other than a few standouts like the Big Dipper or Orion, most constellations are lost in the surrounding stars. And not much has changed here in 20 years. I can still see the Milky Way out of the windows even with lights on in the house. That's the primary reason I moved here.
Chris

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Cousin Ricky » Wed Apr 08, 2020 5:51 pm

Bortle scale 5 is the best I can get on a remote peninsula on my 21 km long island. While shielding of streetlights is becoming more common, the overall light pollution seems to be getting worse.

Of course, nowadays I’m restricted to my yard. The back yard is inaccessible due to ongoing construction, and the front yard is lit up by streetlights from 2 directions. Shielding a streetlight doesn’t help when you’re below it. The ideal time to observe would have been after Hurricane Irma, when we had no streetlights for almost 3 months; but we were all too traumatized to do much astronomy. (I did managed to nail M75 on one night, though.)

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Pikov Andropov » Thu Apr 09, 2020 4:21 am

Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific. It read more like a post from a politically-driven environmentalist blog than an explanation from a professional astronomer. I assume the grammatical errors and awkward writing style (clunky in places) are due to a language barrier. (Is the "text" credit for the author of the explanation, or for the text in the image?) At any rate, so many disjointed, irrelevant, and unsubstantiated claims made in the paragraph seemed more to detract from the message the images were offering rather than supporting or explaining it. The left-most image is itself somewhat dubious it its validity. Most disconcerting of all was the claim that, "You can help protect the wonders of your night sky by favoring, when possible, dark sky friendly lighting." I was not sure whether I was reading from APOD or AMWAY. Can someone please explain how anything humans do could possible harm the wonders of the night sky? Yes, I fully realize that it is harder to see with light reflecting off of surfaces, and it would be sad to lose our ability of observing the night sky, but really? Can we just get back to actual science please?

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Ann » Thu Apr 09, 2020 4:58 am

Pikov Andropov wrote:
Thu Apr 09, 2020 4:21 am
Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific. It read more like a post from a politically-driven environmentalist blog than an explanation from a professional astronomer. I assume the grammatical errors and awkward writing style (clunky in places) are due to a language barrier. (Is the "text" credit for the author of the explanation, or for the text in the image?) At any rate, so many disjointed, irrelevant, and unsubstantiated claims made in the paragraph seemed more to detract from the message the images were offering rather than supporting or explaining it. The left-most image is itself somewhat dubious it its validity. Most disconcerting of all was the claim that, "You can help protect the wonders of your night sky by favoring, when possible, dark sky friendly lighting." I was not sure whether I was reading from APOD or AMWAY. Can someone please explain how anything humans do could possible harm the wonders of the night sky? Yes, I fully realize that it is harder to see with light reflecting off of surfaces, and it would be sad to lose our ability of observing the night sky, but really? Can we just get back to actual science please?
Well, Pikov, that was an interesting post of yours, the first one ever you have posted here. I am not absolutely sure that it is in your, or our, best interest that you make more posts here.

Lets see, you used a lot of negative expressions and adjectives to explain why you dislike the caption of this APOD so much: it is pseudo-scientific, contains grammatical errors,displays an awkward writing style (clunky in places), is disjointed and irrelevant, puts forth unsubstantiated claims, and is disconcerting.

If nothing else, you have demonstrated the fact that you possess a large English vocabulary. You have not, however, offered many examples of what exactly it was in what words or passages in the caption that roused your ire.

Perhaps it was the expression "dark sky friendly lighting" that provoked you. Therefore I ask you to take a look at the light sources in the picture below and decide for yourself which of them are dark sky friendly and which are not.

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by TheZuke! » Thu Apr 09, 2020 1:57 pm

Ann wrote:
Thu Apr 09, 2020 4:58 am
Pikov Andropov wrote:
Thu Apr 09, 2020 4:21 am
Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific. It read more like a post from a politically-driven environmentalist blog than an explanation from a professional astronomer. I assume the grammatical errors and awkward writing style (clunky in places) are due to a language barrier. (Is the "text" credit for the author of the explanation, or for the text in the image?) At any rate, so many disjointed, irrelevant, and unsubstantiated claims made in the paragraph seemed more to detract from the message the images were offering rather than supporting or explaining it. The left-most image is itself somewhat dubious it its validity. Most disconcerting of all was the claim that, "You can help protect the wonders of your night sky by favoring, when possible, dark sky friendly lighting." I was not sure whether I was reading from APOD or AMWAY. Can someone please explain how anything humans do could possible harm the wonders of the night sky? Yes, I fully realize that it is harder to see with light reflecting off of surfaces, and it would be sad to lose our ability of observing the night sky, but really? Can we just get back to actual science please?
Well, Pikov, that was an interesting post of yours, the first one ever you have posted here. I am not absolutely sure that it is in your, or our, best interest that you make more posts here.

Lets see, you used a lot of negative expressions and adjectives to explain why you dislike the caption of this APOD so much: it is pseudo-scientific, contains grammatical errors,displays an awkward writing style (clunky in places), is disjointed and irrelevant, puts forth unsubstantiated claims, and is disconcerting.

If nothing else, you have demonstrated the fact that you possess a large English vocabulary. You have not, however, offered many examples of what exactly it was in what words or passages in the caption that roused your ire.

Perhaps it was the expression "dark sky friendly lighting" that provoked you. Therefore I ask you to take a look at the light sources in the picture below and decide for yourself which of them are dark sky friendly and which are not.

I was wondering if his comment was an advertisement for Amway! :ssmile:
https://www.amway.com/en_US/

One of the electricians in our manufacturing plant was telling me of the time he installed LED lighting in the lot of an automobile dealer one evening.
He said someone drove up and told him to adjust the lights better, as one was shining in his eyes while he was driving a half mile away! 8-)

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by TheZuke! » Thu Apr 09, 2020 1:59 pm

orin stepanek wrote:
Wed Apr 08, 2020 11:02 am
It is hard to see the MW from aa position within a city! Actually; all these were taken outside the city! 8-)
I suspect the camera is more sensitive at "seeing" The Milky Way in "the city" than human eyes are...

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by Chris Peterson » Thu Apr 09, 2020 2:38 pm

TheZuke! wrote:
Thu Apr 09, 2020 1:59 pm
orin stepanek wrote:
Wed Apr 08, 2020 11:02 am
It is hard to see the MW from aa position within a city! Actually; all these were taken outside the city! 8-)
I suspect the camera is more sensitive at "seeing" The Milky Way in "the city" than human eyes are...
The Bortle scale is normally used in regards to visual astronomy, and this APOD image does not accurately represent visual seeing at all. None of these sky images resembles what we see visually. It does give an excellent indication of the impact of light pollution on imaging, and is still a good general purpose infographic about light pollution in general.
Chris

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Re: APOD: Country Sky versus City Sky (2020 Apr 08)

Post by TheZuke! » Thu Apr 09, 2020 3:27 pm

Pikov Andropov wrote:
Thu Apr 09, 2020 4:21 am
Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific.
How about an article from an accredited electronics journal?

https://www.edn.com/zener-enhanced-dark ... -per-watt/
8-)