What Major World Cities Look Like at Night, Minus the Light Pollution | Hacker News Reader

What Major World Cities Look Like at Night, Minus the Light Pollution

blogs.smithsonianmag.com

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If you were in New York City during Hurricane Sandy, in the lower half, at least, you got a taste of this first hand.

I had to walk home into the unpowered section of Manhattan every night from work. I took some photos during that time. Unfortunately, as it was still overcast, we never did get a chance to see the stars from downtown Manhattan:

http://tumblr.eyeheartnewyork.com/post/37636219209/i-finally...

Wow, those are really beautiful shots that you took. I did wonder what being in lower Manhattan was like after the storm and your photos capture that first hand. Thanks for sharing.

Those photographs are stunning – and haunting. Thanks for sharing them.

I remember being disappointed that it was overcast during the blackout. I was so hoping to get a chance to see stars.

A nearby city's lights are enough to hide much of the starscape so depending on how wide a blackout is you might not have seen much.

An interesting difference between your photos and the renditions linked here is that the buildings in yours are black silhouettes, while the ones here are fairly well lit up. That's the first thing that stuck out at me: if there is no light pollution, what is lighting the foreground buildings? If you look at the Hong Kong photo, for example, it looks like there is a ton of light pollution: all the buildings, plus the surface of the water in the harbor, are lit by a diffuse glow. The only exception is the sky, which is inexplicably not affected by the same glow, clearly giving away the Photoshopping.

Perhaps there's some combination of moon-lit conditions that would produce that effect, but it sure doesn't look right to me.

On a clear night without light pollution stars provide decent illumination. However, those photo's where clearly Photoshopped.

> However, those photo's where clearly Photoshopped.

That's pretty much what the entire article was about. :)

To get the kind of starry skies shown in those pictures, you'd need an exposure of at least tens of seconds if not more. With that long an exposure, the starlight will be quite sufficient to bring out detail in the environment.

I was in CT (just outside NYC) when Sandy hit. My area was out of power for about a week, and I remember sitting outside on our porch just after the storm started dying down, looking around and seeing... nothing. I hadn't realized just how many lights there were, even in my tiny little town. As much as that whole experience sucked (being without power, water, etc isn't fun), sitting on the porch and writing a song with my roommate that night is one of my favorite recent memories.

Makes me want to go out to the middle of nowhere for a while, just to experience the Real World (TM) again; it's been a long time.

I live 30+ miles from any town of any size and there's still sufficient light pollution seeping over the horizon to make the hills stand out black against the sky. I'm lucky I can see the milky way at all, although somewhat washed out.

Being in the lower side of Manhatten, there would still be sufficient light pollution from all the areas nearby that still had power, that I'd doubt you'd see more than a few stars. You can see the sky glow in your pictures; compare the sky, with its visible clouds with the full-black buildings.

It's basically impossible to get a proper sky anywhere east of the Missisippi.

I went camping on an island just off the coast of florida a few years ago. There was a bit of a glow looking back at the coast, but looking out over the ocean the view was pretty amazing.

Acadia National Park has a decent night sky. That's because Maine is very sparsely populated -- half of the population lives in the 10% of the land area that's closest to Massachusetts. It gets even better if you go farther. Take I-95 up, and exit about halfway between Bangor and Canada.

The Michigan Panhandle is also not too bad. It helps that two sides are surrounded by water, which leads to little light pollution.

Amazing photos! What is the streak of light in the sky of the Central Park (?) photo? An airplane or meteor?

Airplane, I believe.

There's still significant sources of light pollution all around in those pictures. I doubt that you'd have been able to see anything more than the handful of really bright stars on those nights.

They would look nothing like those photos.

The city would look much, much darker. You can really tell that those are day shots of the cities with the brightness and saturation reduced.

The sky would look much, much less impressive. Photographers like to perpetuate a fantastic idea of the night sky by taking overexposed pictures, and this one is no exception. I have been in the middle of the savannah in Africa, with no light around for miles, and I don't remember the sky looking anything like that.

I've seen sky that looked pretty close to that--about like this video. (Probably a bit less bright, but still more impressive actually being there.)

http://www.youtube.com/watch?feature=player_embedded&v=p...!

I remember that it was different enough that I was blown away by the contrast.

> The city would look much, much darker.

Not unless it was a moonless night. Even a quarter moon can be surprisingly bright once your eyes have adjusted to the night.

I agree that this takes it a bit too far, but it is possible to clearly see the milky way on a moonless light. You can't really see the details of the colours (you need a long exposure picture for that), but you can clearly make out light and dark patches and patterns (such as the milky way) in the sky.

My parents live in a small village on the south coast of England, the nearest town is 15 miles away, so I saw it regularly when I was younger.

Was it cloudy? Obviously stars wouldn't shine like this through clouds, but if the sky is clear, they could

I love driving up into the mountains here in Colorado on a clear night. The stars are just..dazzling. They very much look like one of those photographs.

I doubt I'm the only one who read the article with the hope of finding some new technique to remove light pollution from images to show off the stars... and was mildly disappointed to find out the beautiful images were just cut-n-paste jobs (albeit outstanding ones).

I'm wondering what kinds of techniques exist for removing light pollution?

Spectrum sensitivity? Spectrum filtering on exposure? Post processing?

You most certainly are not.

I wonder if you could get it done with some kind of manual HDR: tracing out the skyline to explicitly say "stuff below the line should be from the low exposure photo, stuff above from the high exposure photo."

Disclaimer: I know nothing about photography.

The problem with light pollution is that the light bounces off of water, dust, and smog in the atmosphere, and back down into your eye/camera. So when you look up, the sky isn't darker, it's a lot brighter! You would need a way to subtract the extra light.

Theoretically, it would basically be just a matter of subtracting the "general" light background, and then apply a deconvolution to the remaining "signal" to reduce blurry areas of light into point-like stars.

However, deconvolution is one of those things that's great in theory, but almost impossible to pull off in practice, except under extremely controlled circumstances. And in this case, considering just how much dust/smog/etc. is in the atmosphere, and how it is non-uniform, I expect it would be simply impossible.

There's a lot of that kind of stuff that goes into signal-cleaning in observatories, especially those located near major cities (like the Lick Observatory outside San Jose). But it tends to be pretty site/telescope-specific, full of in-house custom code, so I'm not sure if there's anything good that a regular photographer could use to produce the same effect.

Though it won't help our eyes any time soon, something along the line of "Adaptive Optics" [1] could possibly address at least some of the issues you mentioned when creating images. Getting tech from the world's beset telescopes into consumer/pro camera gear might be asking a bit much at the moment, but eventually it could become possible. If it was done, a big issue would be having countless people shining lasers into the sky.

[1] http://en.wikipedia.org/wiki/Adaptive_optics

Tucson, Arizona uses sodium vapor lighting for all its street lighting specifically to allow the nearby observatories easily filter the light pollution.

I attended a conference in Tucson last fall and...being jetlagged, did a nice walk at 4AM in the desert behind our resort. It was really amazing, I hadn't seen shooting stars in decades.

It's only a couple hours from Tucson to the Kitt Peak Observatory, where they have astronomy programs for the public. I talked my wife into doing it when we were there visiting friends last year.

I highly recommend it. The astronomy is fairly basic, but the experience is incredible: You're up on a big mountain, surrounded by gigantic telescopes, in the middle of a vast desert wilderness. It's freezing cold outside after dark. When the program is over, you have to drive down the upper half of the mountain without headlights to protect the observations that are happening.

I went to scout camp in the Chiricahua mountains in SE Arizona and experienced the same thing. I'd sneak out if my tent at night to look at the night sky (until my scoutmaster chased a bear out of our camp...the guy was psycho!).

Similar situation in San Jose, CA: http://mthamilton.ucolick.org/public/lighting/Cooperation2.h...

I grew up in Tucson, I do remember amazing stars at night. I also remember seeing an observatory on Mount Lemmon. Never made that connection tho.

It helps that sodium lights produce more lumens/watt than the alternatives.

I read it as a brilliant and elegant hack, a sort of real-world magic. As Vi Hart said (referring to how she builds her comfortable-looking fast-cut accelerated videos of handwriting) it's "tricking your brain into seeing what was actually there."

Here's a shot of the Milky Way over Los Angeles, taken over Los Angeles [1]. The first comment explains the technique. There's still cut-n-paste going on, because the exposure lengths for stars and for city lights are so different---and also the stars are moving. But you might consider it slightly more "honest."

[1] http://www.flickr.com/photos/magneticlobster/5941836830/

After living in Alaska for several years, I don't really think that is how cities would look at all. With just stars and even the aurora borealis, it is incredible how pure darknesss looks. I really didn't know how much light pollution effected the sky until living there, but even in small towns and other less populated areas the light from various sources changes the skyline.

Whew. I was wondering if I was the only one who has been out in the mountains and other rural areas, but have never seen a night sky like these.

If there is literally no light pollution in your vicinity (like in the middle of northern canada, hundreds of kilometers away from the nearest small town) on a very very clear night it does look something like this.

I've never seen the milky way with that much color, but the amount of stars and the star clouds of the milky way are not that far off.

The title is not just removing light pollution, it is removing most of the atmospheric interference. On clear cold nights you can get something close to this if you're truly in the middle of nowhere. Emphasis on clear and no towns within a few hundred kilometers.

I remember the Milky Way looking very ... milky. It's just a dim white haze -- much dimmer than the stars surrounding it.

The reason it doesn't really look like the photos is that we don't have CCDs in our eyes. When things get dim enough, we lose a lot of color perception. (That's why night scenes look practically monochrome.)

Having spent some time in the White Mountains in northern New Hampshire, the sky I saw looked a lot like those pictures, I think they are fair depictions. I definitely remember it as being my first and only time when I could actually see the Milky Way.

(it's also a little freaky being above a thunderstorm at night)

The summer I was 13 I went to summer camp in Minnesota, and one clear night the counselors took us in a bus out away from the camp, to a hilltop, and we lay on our backs and looked up. I could see the band of the milky way across the sky, and so many colors. I have never seen a night sky like that before or since. It was as vivid as these images depict.

The stars look like this in the fall, in the western US, 60+ miles from the nearest city, and above 5000 ft. I've spent a lot more nights camping on the east coast and while you can see the milky way if you're remote enough, the altitude or the humidity or something makes the stars dimmer.

Yeah, my brother lives outside Flagstaff, which has strict light pollution laws and is at 7000 ft. On clear nights the view from his front yard is ridiculously gorgeous.

I grew up in rural New York and once, when camping, we stayed up very late with all the lights off. You would be amazed at how much your eyes eventually see after a couple hours in darkness. We could see Satellites, the Milky Way, and even the "Horse and Rider" (https://en.wikipedia.org/wiki/Horse_and_Rider).

Nowadays, with phones and ipod, it's nearly impossible to let your eyes adjust that long without light. But it's worth it.

There's probably an app (that has probably been done) in there for making the screen show in hues of red. Or, if not an app then a screen protector that's a gel (https://en.wikipedia.org/wiki/Color_gel).

There's an app for that: http://stereopsis.com/flux/

t also helps to give your eyes time to adjust to the darkness. I've spent a few nights in the Australian outback, about 100km+ from any population greater than half a dozen or so. Initially, the view seems ho-hum, but stay outside in the dark for half an hour or so and it becomes amazing.

And do stay away from _any_ light at least during that half hour. Rods take that time to fully adapt to the dark (http://en.wikipedia.org/wiki/Adaptation_(eye)#Dark_Adaptatio...; I think some experts claim even longer times). Since light adaptation goes much faster, even a short glance at a light means you need minutes to get fully dark adapted again.

I spent a summer in Haiti. There were blackouts every night... The skies looked just as beautiful as the ones linked.

I find it rather an epiphany to realise that our distant ancestors must have seen the sky like this all the time, rather than the vague haze most of us experience. No wonder then that the movement of the stars and planets played such a cultural and religious impact on their lives.

I'm surprised nobody has mentioned the International Dark Sky association [1]:

  > Once a source of wonder--and one half of the entire
  > planet's natural  environment—the star-filled nights of
  > just a few years ago are vanishing in a yellow haze.
  > Human-produced light pollution not only mars our view of
  > the stars; poor lighting threatens astronomy, disrupts
  > ecosystems, affects human circadian rhythms, and wastes
  > energy to the tune of $2.2 billion per year 
  > in the U.S. alone.

You may want to check out their Practical Guide [2] for homeowners who want to reduce their light pollution.

[1] http://darksky.org/ [2] (PDF) http://www.darksky.org/assets/documents/PG3-residential-ligh...

"minus the atmosphere and with eyes that will absorb stars luminosity for 20s straight" let's not confuse it.

This is somewhat of a repost: https://news.ycombinator.com/item?id=5205058

Kinda surprised nobody else said that yet...

While the US is relatively good at keeping the air and water clean (relative to some places I've been), both light and noise pollution are a big problem - almost unregulated.

I've seen the night sky (moonless) from out in the Arizona desert and watched the Aurora Borealis from a stone outcropping on Sarah Lake in Quetico National Park.

It is a wonder to behold. I wish it looked like these photos. It doesn't.

You can clearly see the band of the Milky Way in both places. At first you think it's cloudy. But as your eyes adjust it becomes apparent the sky is clear and that's when the wonder of it all occurs to you.

Cool photos tho'. I'd buy one for my workspace.

"“It is impossible not to read these pictures the way the artist wants them read: cold, cold cities below, cut off from the seemingly infinite energies above.”

I see unity: humanity's improbable citadels cradled by the beckoning infinity of the universe. Not everything has to be framed in conflict.

I had a feeling of coziness and was reminded of human cohesion looking at what I presumed to be millions of people coming together to sleep at the same time preparing for the next day. It seemed so peaceful.

Is that what the sky literally looks like with no light pollution, or are they time lapsed at all?

Those must be long exposures with post processing. A clear sky without light pollution doesn't look anything like that, but it's beautiful. Go see one!

I've always wondered what it would be like if there is a total black out in a big city. Now I can see it in these pictures. If the blackout isn't exactly simultaneous, would the stars slowly emerge one by one? How cool would that be!

Yes, they would. If you're in the middle of a remote desert during the day, you would be able to look up and see only blue sky. As the sun sets and the night becomes darker, you'll gradually see more and more stars until you see as many as you'll be able to when the sun is on the opposite side of the earth from you.

What surprises me is the difference in nature between brazilian cities and the others. I would like to see one of those pictures of Porto Alegre, where there's almost one tree per person.

Even though they look a bit fake, I like these photos. The atmosphere reminds me of Alan Weisman's book "the world without us". The cities appear as ghost cities, everything dark, allowing natural light to be visible again. It's like the early stages after humans deserted it, before the forces of nature (combined with lack of maintenance) break through and crumble the buildings.

This is how it would look through a special lense on a camera. Anyone who has been in true wilderness knows it looks nothing like this.

Reminds me of the dialogue in Kurosawa's Dreams movie in the part where there is a conversation with an old man in a treadmill village (I wouldn't like night so bright you could not see the stars) http://www.youtube.com/watch?v=w1FIps--PGg

from the article: “It is impossible not to read these pictures the way the artist wants them read: cold, cold cities below, cut off from the seemingly infinite energies above. It’s a powerful reversal, and one very much in tune with a wave of environmental thinking of the moment.”

NOOOOO! What a load of bollocks. This is the _opposite_ of what I felt about these photos, until this bonehead art critic stepped in and told me what to feel. To hell with all commentators of art. Art does not tell you what to feel, and I resent anyone saying that any reaction is "impossible". Bah!!!

These are beautiful. I would love to have one of these framed in my house.

If we didn't have light pollution, a window frame would be sufficient to have this kind of view on every clear night.

Wow, these are neat pictures. Interesting way of showing the night sky sans artificial light.

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