15 years ago, I co-authored my first paper in the field of #LightPollution studies: https://doi.org/10.1371/journal.pone.0017307
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@skyglowberlin I teach large university science courses. Hundreds of fairly privileged students in the room. It has been my habit to ask them to raise their hands if they have ever seen the Milky Way.
The results have always been disappointing. Over the past 20 years it has gotten worse and worse. Recently many students don't even know what I mean by the question, and I have to explain what a dark sky looks like.
"Raise your hand if you have ever been awed by a clear dark sky full of countless, countless stars." Always less than 5%.
@jameshowell @skyglowberlin I grew up in Chicago. In college, I took a class on the history of astronomy (great class), and I was puzzled how all those naked-eye astronomers could make their observations. Then I went on a road trip through the western states with a roommate, and at some point around 3 AM in the middle of New Mexico, he pulled over and said “get out.” I got out. He said “look up.” I looked up. And I got it.
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@skyglowberlin When I teach about retinal physiology, it breaks my heart. Often there isn't a single student who has ever experienced vision after true dark adaptation.
It turns out that—it takes time, but it's real—you can see by starlight. And the faintest stars you see? That's a single rod cell detecting A SINGLE PHOTON. Your retina is that sensitive.
Before 1879 this was an absolutely universal human experience. Now it's exotic, unimaginable.
@jameshowell @skyglowberlin if you talk to people who experienced the three-day power outage in Ontario in a big city you’ll often find that is one of their most profound memories of the event.
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@jameshowell Yup. If I won the lottery, one of the studies I would love to fund would be to see whether adults who grew up in rural settings have superior night vision to those who grew up in the city.
If you never train your visual system to see with rods only, does it still develop normally?
@skyglowberlin @jameshowell I’ve been an amateur astronomer since I was 11 and had a home darkroom for photography soon after. I’ve let people know what can be done and seen in low light.
One time, winter hiking in New Hampshire, my flashlight batteries died and I hiked another 2 miles under just the illumination of a clear night sky. Mars was the brightest thing out.
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@skyglowberlin @jameshowell I’ve been an amateur astronomer since I was 11 and had a home darkroom for photography soon after. I’ve let people know what can be done and seen in low light.
One time, winter hiking in New Hampshire, my flashlight batteries died and I hiked another 2 miles under just the illumination of a clear night sky. Mars was the brightest thing out.
@glasspusher @skyglowberlin Hiking by marsshine
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@skyglowberlin @jameshowell I’ve been an amateur astronomer since I was 11 and had a home darkroom for photography soon after. I’ve let people know what can be done and seen in low light.
One time, winter hiking in New Hampshire, my flashlight batteries died and I hiked another 2 miles under just the illumination of a clear night sky. Mars was the brightest thing out.
@glasspusher @jameshowell There's a path through the woods in Brandenburg that I've walked several kilometers along on starlit nights without a moon. I couldn't actually see the ground because of the foliage, but I could follow the path because of the lighter areas between the trees.
This isn't a great idea, though - if someone had dug a big hole in the ground I would likely have fallen in. But it shows what's possible when you know the area and the pathway is flat.
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@skyglowberlin I teach large university science courses. Hundreds of fairly privileged students in the room. It has been my habit to ask them to raise their hands if they have ever seen the Milky Way.
The results have always been disappointing. Over the past 20 years it has gotten worse and worse. Recently many students don't even know what I mean by the question, and I have to explain what a dark sky looks like.
"Raise your hand if you have ever been awed by a clear dark sky full of countless, countless stars." Always less than 5%.
Went on vacation with some friends to a beach on the gulf coast. We're out one night and one of them says "what is that in the sky?"
He meant the Milky Way.
He'd never seen it and thought the name was just a metaphor for something. Or just a candy bar. I was floored. He's not a young guy.
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@glasspusher @jameshowell There's a path through the woods in Brandenburg that I've walked several kilometers along on starlit nights without a moon. I couldn't actually see the ground because of the foliage, but I could follow the path because of the lighter areas between the trees.
This isn't a great idea, though - if someone had dug a big hole in the ground I would likely have fallen in. But it shows what's possible when you know the area and the pathway is flat.
Yes, when I did the above hike, I could see the trail in front of me- footsteps in the snow.
Back when I lived in Oakland, one night I walked my regular jogging trail through a park( very narrow). I was under tree cover which made it darker, as I was looking for luminescent mushrooms. I found I could keep on the path by feeling, as I walked, that the ground was harder on the trail than the edges.
Pushed the limits of what I could see in low light, and noticed that my other senses were filling in the experience more.
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@jameshowell @skyglowberlin I grew up in Chicago. In college, I took a class on the history of astronomy (great class), and I was puzzled how all those naked-eye astronomers could make their observations. Then I went on a road trip through the western states with a roommate, and at some point around 3 AM in the middle of New Mexico, he pulled over and said “get out.” I got out. He said “look up.” I looked up. And I got it.
@adamrice @jameshowell @skyglowberlin I also have fond memories of nights with numerous stars and a clear Milky Way. Living in the Netherlands, that is something special for me. But for all humans until a few generations ago this was absolutely normal. You might not see it every night (clouds/moon) but very often. That's a staggering loss. Can you imagine that in a few generations 95% of all people will have never seen a forest? This seems similar but hardly anyone realises that.
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@skyglowberlin I teach large university science courses. Hundreds of fairly privileged students in the room. It has been my habit to ask them to raise their hands if they have ever seen the Milky Way.
The results have always been disappointing. Over the past 20 years it has gotten worse and worse. Recently many students don't even know what I mean by the question, and I have to explain what a dark sky looks like.
"Raise your hand if you have ever been awed by a clear dark sky full of countless, countless stars." Always less than 5%.
@jameshowell @skyglowberlin I thought you meant that as a trick question. Technically, everything we see is part of the Milky Way.
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Yes, when I did the above hike, I could see the trail in front of me- footsteps in the snow.
Back when I lived in Oakland, one night I walked my regular jogging trail through a park( very narrow). I was under tree cover which made it darker, as I was looking for luminescent mushrooms. I found I could keep on the path by feeling, as I walked, that the ground was harder on the trail than the edges.
Pushed the limits of what I could see in low light, and noticed that my other senses were filling in the experience more.
@glasspusher @jameshowell Yes, walking slowly and feeling the ground your feet is very important in such a situation.
