Light Pollution Rapidly Reducing Number of Stars Visible To Naked Eye, Study Finds (theguardian.com) 39
Research suggests if trend continues, view of Orion's belt will disappear due to glow from artificial lighting. From a report: "There is no light in earth or heaven / But the cold light of stars," wrote the poet Henry Wadsworth Longfellow. But for myriad writers and artists, that source of inspiration could be fading as research has revealed light pollution is rapidly reducing the number of stars visible to the naked eye. The study, published in the journal Science, suggests locations with 250 visible stars at present will have just 100 visible stars in 18 years.
"If these trends continue, eventually it will be very difficult to see anything at all in the sky, even the brightest constellations. Orion's belt will start to disappear at some point," said Dr Christopher Kyba, of the German Research Centre for Geoscience and first author of the research. The team write that the glow produced by artificial lighting grew exponentially over the 20th century with population growth, new technologies, and expansion of towns and cities. However the impact of a shift to light-emitting diodes (LEDs) in recent years is unclear. Satellites that can measure skyglow have limited resolution and cannot detect some wavelengths of light emitted by LEDs.
"If these trends continue, eventually it will be very difficult to see anything at all in the sky, even the brightest constellations. Orion's belt will start to disappear at some point," said Dr Christopher Kyba, of the German Research Centre for Geoscience and first author of the research. The team write that the glow produced by artificial lighting grew exponentially over the 20th century with population growth, new technologies, and expansion of towns and cities. However the impact of a shift to light-emitting diodes (LEDs) in recent years is unclear. Satellites that can measure skyglow have limited resolution and cannot detect some wavelengths of light emitted by LEDs.
In other news (Score:4, Funny)
Re:In other news (Score:5, Insightful)
There is no reason light pollution should be getting worse.
It is easy to put reflectors and motion sensors on streetlights, so the light is directed downward, and the lights are only on when traffic or pedestrians are present.
People can do the same for the outside lights around their homes. Motion sensors save energy and are a better deterrent to crime since the sensors can not only turn on the light but also activate a camera.
Reducing light pollution can be done, and it saves money. We need to make an effort and educate people.
Re:In other news (Score:5, Insightful)
There are two reasons light pollution is getting worse.
The first is that there are more people. More people means a larger part of the planet is developed, and development means light at night.
The second is that with the switch to LEDs, everyone seems to be thinking the extra efficiency should be pissed away by making everything BRIGHTER, rather than keeping illumination levels the same. Don't start me on the idiocy of having 6500K street lights at night, either, or having illumination that isn't directed entirely downward.
But the switch to LED illumination from low-pressure sodium for our streets is a serious problem for astronomers. With low-pressure sodium (the weirdly orange lights), only a narrow part of the spectrum gets stomped on. With LEDs (or high-pressure sodium, mercury, HID, etc.) a much more significant part of the spectrum gets washed away. Astronomers really need to step up their lobbying efforts because it's a hard climb at this point to get everyone to revert back to colors that don't impact so much of the spectrum.
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Or the same for headlights in new vehicles, or those who try to retrofit LEDs onto their car/truck/SUV.
One can't see the sky because they're blinded by the headlights.
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The second is that with the switch to LEDs, everyone seems to be thinking the extra efficiency should be pissed away by making everything BRIGHTER, rather than keeping illumination levels the same. Don't start me on the idiocy of having 6500K street lights at night, either, or having illumination that isn't directed entirely downward.
This is compounded by higher frequency light sources being preferentially scattered by the atmosphere making light pollution much worse at the same brightness vs lower temperature sources.
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There is no reason light pollution should be getting worse.
The prevalence of something cheap (e.g. bright lighting) combined with people who just don't give a fuck are very much a core reason why something like lightpollution should be getting worse.
Not only do people not care about the night sky, they actively promote more light, we [amsterdaml...stival.com] fucking [festival-of-lights.de] glorify [wfol.com] it [vividsydney.com].
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fucking [festival-of-lights.de] glorify [wfol.com] it [vividsydney.com].
The human ones are very much prettier than the natural ones. :-)
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Disagree, but then I'm fortunate enough to have regularly gone into the middle of nowhere where there actually isn't any light pollution. Seeing multiple galaxies unaided in the night sky isn't comparable to someone pointing a projector at a building.
If you ever have the opportunity to go into true darkness, during new moon, and give your eyes an hour or two to properly adjust to the point where you can walk around and make out features of the terrain based only on the starlight, you may be awestruck at the
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You're right that in remote areas the stars are more visible and the "light pollution" (which really just light trespass) was nonexistent. When I was 18, I rode my bike on a lonely mountain rode with no moon and could only tell where I was by the silhouettes of the telephone poles against the stars. The road was black asphalt and could not be seen.
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If you ever have the opportunity to go into true darkness, during new moon, and give your eyes an hour or two to properly adjust to the point where you can walk around and make out features of the terrain based only on the starlight, you may be awestruck at the beauty.
I've been hiking by starlight (no moon). Yes, humans can really do that...
You can't expect the unwashed masses to do it though. Ignorance/numbers will always win in the long term.
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False. Water makes (most) other things wet.
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It's as if there might be some connection... (Score:5, Insightful)
'"If these trends continue, eventually it will be very difficult to see anything at all in the sky, even the brightest constellations. Orion's belt will start to disappear at some point," said Dr Christopher Kyba, of the German Research Centre for Geoscience and first author of the research'.
At a time when there is so much concern about CO2 and other emissions, and so much desire to reduce fossil fuel consumption, isn't it a little odd that so many lights are burning (many of them to no useful puspose) that we can't even see the stars?
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Not really. Light keeps getting cheaper, so Jevons' paradox [wikipedia.org] kicks in.
It's wrong, but it's not odd.
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isn't it a little odd that so many lights are burning (many of them to no useful puspose) that we can't even see the stars?
You're begging the question. Why does a light serve no useful purpose? Streetlights exist for a purpose. Artistic lights exist for a purpose. And that's before we talk about the single most light polluted country in the world is such due to the proliferation of greenhouses to grow food for us.
As an amateur astronomer myself I hate light pollution, but I wouldn't dare claim that most of it is caused by lights which serve no useful purpose.
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But according to the armchair experts on the interwebs, the most efficient way to live is to build MORE densely and pack ourselves like sardines into ever tighter spaces. Because all those studies showing overpopulation leads to both mental and physical difficulties in animals can't possibly apply to humans, right?
One thing I miss about farm life is late night crop time. If you shut down for a bit to take a nap and had no tractor lights on, you could see the night sky so damned clearly. People that don't st
Re:Um...too late? (Score:4, Interesting)
Re:Um...too late? (Score:4, Interesting)
Re:Um...too late? (Score:4)
I'd like to thank my fellow commenters for allowing us one moment of joyful sharing amid the constant bickering, bitching, and in-fighting. Thanks guys. Virtual hi-fives all around. And I'll secretly hope I get to experience both of those views before I expire.
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If you think the sky's clear on the Moon, you should see what it's like in intergalactic space. No stray particles from lunar surface outgassing, no zodiacal light, no absorptive dust. Just clean cosmic microwave background in all directions.
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If you think the sky's clear out in the country, you should see what it's like out at sea. The best night sky I've ever seen was when I was in the Navy and my ship was on the Gun Line in Tonkin Gulf back in '72.
Hate to say it, but it's rubbish compared to out in the country. The sea creates some pretty horrible viewing conditions, as do land areas near the sea. Mist, humidity, turbulent air, all of which are pretty damn bad viewing conditions.
Been out at sea many times, it's dark, but it's no where near as clear as in the country especially if you can get some elevation under you, and there are still places in the world which are as dark in the country as the middle of the ocean.
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Sigh... (Score:2)
Stargazers say world-famous night skies have been ruined by dazzling lights from new Shell petrol station [walesonline.co.uk]
Space Telescopes (Score:1)
Why are we worried about astronomers? In fifty years time, I bet most telescopes would be in outer space, and astronomers would talk to them via the solar systems Internet.
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It's crime (Score:2)
Re:It's crime (Score:4, Insightful)
The problem is that lighting does much less to deter crime than people think, and most "security" lighting is done poorly and not as a substitute for well-planned ways to make a built environment safer.
Even studies that seem to show positive correlation between more lighting and crime reduction are highly situational:
https://www.cnn.com/2022/04/28... [cnn.com]
Other studies have shown increases in crime related to lighting (because people can more easily congregate and do illicit things).
https://popcenter.asu.edu/cont... [asu.edu]
And in any event, the best answer is rarely what people do. They go get poorly targeted lights that generate a lot of glare and deep shadows, which are just as likely to promote crime as to reduce it.
So now there's light pollution, wasted power, sunk costs on ineffective infrastructure, ill effects on human health from disrupting our physiological response to darkness and light, but relatively limited effect in abating crime.