51–60 of 146 posts
You'd think they'd do better at containing the light from the grow houses, so more ends up on the plants and less making it to space. Like, foil or something?
It really surprises me, too. I guess the sheer size of these operations make it difficult or impractical. The cost must be greater than that of the wasted light. Too bad, because that is a lot of wasted light.
Ah yeah, in the post's first "unknown light pollution" example, I figured it must be a greenhouse. I was driving through a relatively small town one time and was a bit freaked out by this ominous yellow glow off in the distance. Like, the whole sky was glowing [0]. I ended up driving out to try to find the source, and discovered it was a huge greenhouse/farm. Luckily not an extraterrestrial landing zone or so on ;) […
Yellow glow is understandable, but check out this purple one https://www.cbc.ca/news/canada/windsor/not-northern-lights-g...
Ah yeah, in the post's first "unknown light pollution" example, I figured it must be a greenhouse. I was driving through a relatively small town one time and was a bit freaked out by this ominous yellow glow off in the distance. Like, the whole sky was glowing [0]. I ended up driving out to try to find the source, and discovered it was a huge greenhouse/farm. Luckily not an extraterrestrial landing zone or so on ;) […
Yellow glow is understandable, but check out this purple one https://www.cbc.ca/news/canada/windsor/not-northern-lights-g...
https://en.wikipedia.org/wiki/File:LED_panel_and_plants.jpg https://en.wikipedia.org/wiki/File:Led_grown_lights_useful.j...
> with an enormous array of yellow lamps Do they really need yellow? Plants do not really need green light (that's why leaves usually reflect green they don't need), so they'd probably be ok with red/blue lamps only. So why yellow? https://en.wikipedia.org/wiki/Grow_light
I was looking at light pollution maps just the other day, trying to find places to do astro-photography, and was blown away by how much light pollution there is. Really sucks, because I'd have to drive about 90 minutes out to get into a dark zone.
> Kiluaea (sic?), as an active volcano, regularly has literal glowing lava occupying the caldera. Not anymore, sadly: https://www.nps.gov/havo/planyourvisit/lava2.htm > Beginning in May, 2018, the lava lake that existed inside Halema‘uma‘u crater disappeared and lava flows from Puʻu ʻŌʻō crater have ceased. There is no molten lava or lava glow to see anywhere in or out of the park. (I would still recommend visiting:…
I wonder if there are some other places in the world I could visit reasonably expecting to see molten lava and all that dramatic looking stuff.
Earlier quoted context omitted.
Light perception is logarithmic. There might well be 99% of the light hitting the plants leaves, and 1% escaping to the environment, yet that 1% will only appear a bit dimmer than the original light source.
That's fine, but I'm still curious about the costs involved.
Some of the challenges include excess heat (HPS emit ~80% as heat) and moisture.
I haven't found anything that breaks down the costs. It seems the primary motivation is bylaw compliance.
Ah yeah, in the post's first "unknown light pollution" example, I figured it must be a greenhouse. I was driving through a relatively small town one time and was a bit freaked out by this ominous yellow glow off in the distance. Like, the whole sky was glowing [0]. I ended up driving out to try to find the source, and discovered it was a huge greenhouse/farm. Luckily not an extraterrestrial landing zone or so on ;) […
I've lived relatively close to one and hadn't seen night's sky for the whole duration I stayed there. Actually the whole town's sky was filled with light polution from one cucumber farm.
Constellations of fishing boats can also be a significant source of light when viewed from space. Here are examples from NASA of fishing boats off the coasts of Argentina [1] and Thailand [2].
[1]: https://earthobservatory.nasa.gov/features/Malvinas
[2]: https://earthobservatory.nasa.gov/images/92152/fishing-in-gr...
To the east, it is mostly bright areas with islands of dark. To the west, it is mostly dark areas with islands of bright.
If you look at a regular map, nothing really stands out to explain the difference. It is not like there is, say, a mountain range or difficult to cross river or something running down the boundary that made travel or settlement westward much more difficult at that point.
So why did patterns change there?
I asked about this once before, and received a few answers. I'm not sure if any of them are the actual explanation or not, though [1].
