A few weeks ago, we took you along for a night walk through one of Germany’s brightest cities to find out what’s so tricky about LED lights when it comes to the environment.
In this episode, we bring you part 2: an in-depth look at a thought experiment about light pollution called “Rewilding the Night.” The group behind it counts ethicists and artists among its ranks. At the focus of this project is the “Light Clock” – it’s no ordinary time piece.
Interviewees:
Dr. Taylor Stone, program manager at Delft University of Technology in the Netherlands
Dr. Rupert Griffiths, researcher urban design, Lancaster Institute for the Contemporary Arts at Lancaster University
Dr. Nick Dunn, professor of urban design and executive director of Imagination, Lancaster University
Dr. Alison Powell, associate professor of media and communication, London School of Economics
Dr. Gina Maffey, writer, science communicator
Transcript
Kathleen: This is Living Planet.
Hey, this is Kathleen. A few weeks ago, we took you along with us for a night walk through one of Germany’s brightest cities to learn about light pollution from a leading expert named Chris Kyba.
For this episode, we’re bringing you part 2, so if you haven’t heard part 1, you can scroll back through our feed to hear that now. It’s called “Bright lights, big LED cities.”
To recap really quickly, our night sky has gotten 10% brighter over the past decade. One reason for this is the widespread adoption of LED lights. LEDs are more energy efficient so, in theory, that’s good news for lowering our energy consumption. But LEDs emit a higher percentage of blue light waves, the same light that helps regulate our circadian rhythms.
A brighter nighttime environment is a problem for mammals and insects because the majority of them are nocturnal. They survive and thrive in the dark.
Take the lowly vole, a rodent similar to a mouse. It’s starting to evolve into a creature of the daylight because bright nights make it easy prey. Or the black beetle that’s so distracted by LED garden lights that it forgets to forage and produce offspring.
Migratory birds are thrown off by brighter skies, too. A recent Canadian study found that birds exposed to artificial light for more than 10 nights over a 30-day period ended up migrating over a week earlier in the spring than they were supposed to – and so they ended up arriving at their breeding sites too early.
So that’s basically what we covered in part 1.
But we wanted to do a part 2 because there’s something really interesting going on with the research on light pollution. You see, it’s not just scientists who are trying to find solutions this issue has spilled over into other disciplines. Like art and, even, ethics.
Take, for example, this Canadian researcher. Dr. Taylor Stone.
Taylor: Yeah. So, I have a very interdisciplinary background. Every degree I've had has been in a different subject actually. I started in architecture and then did environmental studies and eventually ended up in the ethics of technology.
Taylor’s a program manager at Delft University of Technology in the Netherlands. He’s been working on an unusual light experiment with this man…
Rupert: I'm Rupert Griffiths and I'm based at Lancaster Institute for Contemporary Arts.
Rupert works in urban design, but his backstory zigzags across disciplines, too. He describes himself as a…
Rupert: … cultural geographer, design researcher and also a designer and artist.
Taylor’s interest in light started back about 15 years ago when he was working on his Master’s.
Taylor: When you talk with people who are very interested in in light pollution and darkness it's often about these transformative experiences of being in the dark, of being in these truly dark places.
But for me, what set me on this path was actually the opposite. Of the first time I had gone to New York City and gone into Times Square and it was in this sort of this, this sort of I thought something like Cathedral of Light.
And you sort of have this moment similar to perhaps seeing the Milky Way for the first time where you sort of step back and just say, wow, this is this is a space totally created by artificial light. Totally created and controlled by our technologies. So, we've, we've sort of chosen to create these spaces in these tunnels of light that have cut ourselves off from these natural rhythms and from this experience of the night sky.
Rupert: Light choreographs all life on Earth, it's driving everything. It's the kind of master clock, really for the Earth…
A few years later and halfway across the world Rupert was thinking about this, too. He was in Xian, China for a photography exhibition on time and light.
Rupert: It’s got an interesting identity cause it’s an ancient capital. and on the other hand, it's a tech hub and a center of innovation. So, it's a very brightly lit city, it’s incredibly light at night.
Rupert’s plan was to capture Xian’s night sky awash in artificial light. And then to travel to one of the darkest places on Earth – Tibet’s Ngari Prefecture – and make photos of complete darkness.
But it ended up being too hard to get into Tibet. So, he took a closer look at Xian.
Rupert: So, what I started to do was take photographs of the of the night sky […] Just taking many thousands of photographs every night
So, to be like, maybe 10,000 photographs. With a lens-less camera, so you just get a color filled image of the sky. So, a single color basically.
He starts chopping up those photos into single pixels of color and then he takes each slice of natural daylight and the night sky, all lit up, and arranges them into a circle.
Rupert: So, you've got a representation of 24 hours of changing light in that in that circle.
Rupert calls it “The Light Clock.”
A few years later, Taylor and Rupert meet through a mutual colleague -- and Taylor sees in Rupert’s artwork a way to move the discussion on light pollution forward.
Taylor says we’ve cut ourselves off too much from natural lighting. In urban areas we have light. In nature, we have darkness. But don’t we need the darkness too to be connected to the natural world?
Taylor: And we really have to break away from this because cities are where we live. It’s where humans are increasingly living. This is where we spend our lives. So if we really want to start changing our relationship to the natural world and really think about sustainability, not just as an instrumental idea of efficiency, but also what it means to reconnect with nature. We have to start thinking about our cities and how we bring these experiences into our daily lives.
By the time Taylor and Rupert connect, Rupert’s already been using his light clock to visualize data he’d been gathering in several places. There was one in Beijing, one in London, and one on a nature reserve in northern England called Leighton Moss.
You can see all of them on his website – including the one Taylor had him set up in Germany – in the botanical gardens in Bonn to be exact – as part of a project called “Rewilding the Night.”
Kathleen: So, I've pulled up this light clock and can you describe a little bit about what we're looking at because… it's quite a beautiful image, but I can imagine somebody looking at it and saying I don't understand how this is a clock. It doesn't, I can’t read it as a clock.
Taylor: Yeah, indeed. It's not meant to be read as a traditional clock of telling time. What it is basically we've installed different sensors, light sensors in the botanical gardens that are collecting data regularly and transmitting it. And what he's done is translate this into this thing he calls a “light clock,” which is meant to really show us the changing conditions of light in the space, […] So, when you look at this it, it is this, this spiral, right? And every circle is one day.
The image on the screen is of a tightly wound spiral against a black backdrop. The spiral starts wide and gradually narrows into a black hole in the middle of the screen.
Each rotation is made up of tiny, almost wispy circles of light – like the fine delicate links of a bracelet.
There are blue circles that represent daylight. As the day progresses the circles gradually turn a shadowy gold. The color of the nearby streetlights.
Taylor: And as we look deeper into it, we're looking back in time. So, you can actually start to see the changes of lighting quality daily, but also over the months over lunar cycles, seasonally, annually, depending on how long the light clock runs and how and how far back it can go.
And so this is how it's meant to read. It's meant to be more of an artistic interpretation of the conditions of lighting in these different temporalities that we deal with. And again, to re-engage with these qualities we may or may not actually pay attention to in our daily lives. And to sort of take a step back and look at these different conditions.
What’s so interesting about this data is that it’s not for a scientific study in the classic sense. Their goal isn’t to spit out numbers about light pollution.
Instead, it’s an invitation to really take it all in. For example, how the night sky in northern England is so dark that the phases of the moon come through in the light clock. In Bonn, the sky glow and nearby streetlights give the night a golden tinge. In Beijing, a light near the sensors appears to be giving off green light waves, even.
And these phases of light shift with the seasons too of course.
Rupert: There's been a lot of interest in in this way of representing the data. And I think that you know, people have looked at it from all kinds of different angles. Like from you know, from policy to people wanting to, you know, kind of look at how light might be affecting biodiversity in the back garden.
I mean one of the things that I’m particularly sort of keen on with this work is the way that it sort of as a as a timepiece situates you in this local and planetary understanding of time, it's specific to where you are, but it's also completely based upon the rotation of the Earth and its movement around the sun.
Rupert says artificial light has allowed us to become nocturnal beings in a sense.
Part of what he and Taylor are trying to do is to reframe the conversation around light pollution … to really illuminate the complexity of this issue.
Rupert: Yeah. And I think another thing is that it doesn't, it doesn’t like dictate a position to people. Like it doesn't say light pollution is bad or like or artificial light at night is good. It just presents what’s in the environment. […] I think this was an important part of the way that I was thinking about this when I was developing it doesn't have an aim to change people's perspectives.
It's more to situate people within the environment in a way that they, um, you know, the way that people can't experience in many ways because it's, you know, it shows the night which many people aren't going to experience the the whole night.
It's striking to see how much artificial light shows up on the Light Clock. Even in a place like Bonn’s botanical gardens, where the night is almost pitch black.
Their sensors picked up the yellowy glow from nearby streetlights and skyglow over Bonn.
Taylor and Rupert want this to be a conversation starter about something more, though.
As they remarked in their paper about the Light Clock in late 2024, making urban lighting more environmentally-friendly isn’t just about energy efficiency.
It’s about starting a much more radical conversation about why we even use light the way we do. Is it for safety? Is it for beauty? Are we afraid of the dark? And how is light keeping us from connecting with the natural world at night?
On this particular night, they’ve invited their team members to go on a walk. They start at their research institute about 30 minutes away, getting away from a busy street
Then cut through a neighborhood lined with early 20th century townhouses. Well-lit of course
And then follow the lights of the boulevard lined by chestnut trees that leads the Botanical Gardens…
Before we set out, Taylor asked the group to pay attention to the quality of darkness they’re experiencing on this walk. This is supposed to be a conversation for everyone to share in.
Kathleen: So, my ears perked up earlier this evening when you were telling people, you know, this is a lot about stories. What do you mean by that? Why exactly stories?
Taylor: Well, there's a there's a philosopher in a paper really like about urban philosophy, and in the paper’s a lot about urban restoration. And one way you can think about that is indeed planting trees, greening cities. These sorts of things.
But another way to think about it is. Urban restoration is about finding stories and finding new stories about our cities and our lives and cities that we find meaningful or good, and then maybe have fallen away or fallen into decay and trying to think about how we can bring these back. So, part of this project and this event is to ask what sort of stories about darkness and about urban nights we want to. And why?
The Botanical Gardens are situated behind a baroque palace, the focal point of this particular neighborhood. Bright lights illuminate its yellow ocher façade. This is where I can finally catch up with Dr. Nick Dunn, who seems to have been chatting with one person or another for the whole walk. He’s Taylor and Rupert’s collaborator from Lancaster University.
Nick: Light and dark have been cast in opposition to each other for as long as people have been on the planet. And darkness often comes out worse in that kind of equation. We tend to think of it and associated with negative things. What we're doing with this project and the impact we've already seen is getting people to think differently about how they might adopt different policies about thinking, even about nature after dark you you know we tend to think about green spaces in the daytime, we think about nature in cities. But encouraging people to think about our near neighbors, our non-human neighbors when we're in a place like this after dark becomes really important.
Kathleen: I mean, aside from the fact that. Two of the people, the main people on this project together, Rupert and Taylor, can you give me some other examples of how you've seen or had during conversation seeing how you know how people have really started to think about this in a completely different way?
Nick: Sure. So even this evening, as as walking us, chatting to a gentleman and his his son. And he was describing the idea that his favorite animal was a nocturnal one. But he hadn't appreciated about four-fifths of collective life on the planet is nocturnal.
It moves around at night and because we close our curtains, we close our blinds, we don't necessarily think about the living world. This isn't just a civic issue. It’s not just about cities.
Darkness is dwindling all around the planet, and with satellites up in the sky, we're actually taking light pollution around the Earth. Not even a terrestrial issue to do with lights being fixed because they're out there in outer space as well.
So, helping people to understand why darkness can be valued, how we can have an inclusive, sustainable, and sort of convivial atmosphere in places after dark and understanding where darkness should be and where it shouldn't be. You know to make sure that we have the kind of atmospheres and ambiences that encourage us to sort of live in the world rather than always chasing that next thing in a fast quick fix.
Kathleen: So, you're an architect, right?
Nick: I originally trained as an architect. I’m a professor of urban design.
Kathleen: And yeah, what did you learn about light versus dark when you were studying, or what role does darkness play in your discipline?
Nick: So actually surprisingly little. We did a lot about daytime studies and this is the thing even now. Most contemporary architecture education doesn't speak about the night at all. We talk about light, form and shadow, but we don't talk about the night. And architects, generally speaking, are very poorly trained.
When we think about how to light buildings up, we're often using lots of up lighters, throwing light all across the surfaces. So, there's more that needs to be done there in terms of education and information. And I became fascinated when I was studying architecture to help support myself, I became a freelance crime scene surveyor. And I was working at night seeing a very different city at night.
Kathleen: Wait, but speaking of danger…
Nick: Yeah?
Kathleen: I mean that would make me want to turn the light on immediately.
Nick: And that's fair enough, but what became very apparent to me is the daytime city of which I was a student, moving around, doing all the things they did, doing the long hours in architecture studio was a very different thing at night and so I've been fascinated for over 30 years now in what makes this change, how identities shift, what can be valued in the night.
So, it's all about these preconceptions and the sort of cultures and histories that we have, the stories that we tell ourselves about what darkness is, who the night is for and who we share it with that become really interesting to me.
As we go around the bend down the gravel path along the moat, the street lights still feel a bit intrusive, but the darkness of the gardens and a few stars are finally visible in the night sky.
A Canadian researcher named Dr. Alison Powell has been talking this evening about the role civic engagement needs to play in rethinking urban lighting. She’s a professor of media and communication at the London School of Economics.
Alison: Light can be used to include and exclude, and we're walking through actually, what is a pretty well-lit part of Bonn which has street lighting, which I think creates lots of pools of comfortable appearing light.
But because there's so much social inequality, lighting can be used as a weapon to exclude people from public space because of things like gendered assumptions about safety.
Kathleen: Could you expand on? Maybe I don't know if you have a personal experience with that particular comment.
Alison: I mean, I don't personally experience a lot of darkness-related fear or anxiety, but I think that some of the most interesting research in this space comes from Iona Data's work.
She studied gendered infrastructure in India. And she examined how the design of different kinds of lighting schemes allowed women to only have access to certain kinds of public space at certain times when lights were on or during the daytime, and also created a kind of sense of exclusion from public spaces when lights were off or it was dark at night time.
Kathleen: So you said you're from Western Canada in a place that from a place that is darker at night than here, and you live in London. I'm just wondering how do we? Yeah. How would you compare it to here in terms of like, do you perceive this as really dark or somewhere in between? I I imagine London is brighter.
Alison: Uh, it’s pretty bright here. I came to Bonn to do another night walk a couple of years ago we wrote about this and it had just snowed and it was very cloudy and it was like the brightest night walk I've ever been on. […] But what I noticed about bond is that it has a different temperature, color, temperature of its lighting, so many of the lights in London are LED lights and they are more on the blue spectrum.
They're actually quite bright. These ones seem to have a color temperature that's more similar to like old fashioned gas lamps more yellow. So, it feels very calm and it doesn't feel super bright. Nor does it feel dark.
Right now we're walking through some trees into the Botanical Garden and I can see the colors of the jackets of the people in front of us. So, to me this doesn't appear very dark, but I have spent a lot of time in dark places walking around when it's dark out.
Kathleen: Could you give me an example of one of those really dark places?
Alison: Well, I spent a lot of time camping as a young person, so I spent a lot of time like trying to figure out how to, like, walk around in forests at night or in twilight.
And I was thinking about this the other day I went camping with my daughter when she was about 7:00 or 8:00 and she really hadn't never seen a beaver before. She really wanted to see a beaver and I said, well, we have to go at night because beavers are nocturnal, they don't have the same time scale as us we have other creatures with us in, you know, on the planet that that are different than us. So, let's go for a night forest walk to go see the beaver.
So, we put on infrared headlamps. And we went for a walk in the forest, in the dark to go and find the beaver. And we were really surprised that when we got into the middle of the forest where the beaver pond was, that we could actually see the beaver. Even though it was actually what we might think of as really very dark.
Kathleen: And do you think that already kind of started to shape your daughter's relationship to being in the dark and feeling safe or or not feeling scared?
Alison: Well, certainly she became less scared of the of being out in the forest or she knew that she could navigate out in, you know, out in in the world by herself. The city is different. You know, things are the things that are risky are not necessarily about dark and light.
They might be again about like the relationships that we have with other people and also about the assumptions about what is OK or not OK for people to do in space. Like a forest, if it doesn't have other people in it, it's actually pretty safe.
Once we enter the Gardens, the streetlights recede into the background beyond the bounds of this oasis. The night sky opens above us like a gigantic dome.
A starry night, if a little bit cloudy. It’s a new moon, unfortunately, so no moonlight tonight.
The pungent smell of exotic plants and trees permeates the air. The group continues chatting. Ducking from time to time as the occasional branch seems to come out nowhere along the garden path.
They stop from time to time to hear short presentations from the different researchers.
There’s one story in particular that stands out. A woman named Dr. Gina Maffey says a few years back, she and her husband decided to do a “Wild Year” – an entire year of living outside.
Gina: And before that, I had studied in nature and conservation topics and sustainability. But spending that year outside made me realize how much of our interaction with the natural world is typically during sunlit hours. You know dawn to dusk. And forcing myself to spend that time outside during the night shifted my relationship and my understanding of the natural world and how dynamic it is during the nighttime.
But one of the things that was very clear during the year was this this idea of transition. And how readily we accept in, you know, in at home, in urban settings that to turn off and to go to bed, we switch the light out and that's it. You know, light to dark, straight away and then actually when you're when you're outside during all seasons, there's this period of transition. That you kind of, you start to feel yourself slowing down and it's like, OK, we need to prepare ourselves for sleep. We're getting ready to go to bed now and it's a very, um, eh yeah, it's very difficult to ignore that when you're really in it.
Kathleen: So what happened with time? Did you? Did you start to? I don't know, dread having to go back to normal life? Did you consider just living that way permanently?
Gina: Yes.
There is this this saying that culture is three days deep. And and it became really noticeable that the crunch points were when you really blurred the lines between nature and culture. So when you walked from the woods into the into the office. And increasingly, there were feelings of like, oh, I don't want to do this.
I want to keep it separate and I think societally, that's what we've done very comfortably. You know, you kind of, you can keep natural areas or nature as something recreational and separate.
Kathleen: (00:12:01) And how did that change your relationship to the night? I don't know the night sky or just what it means to be outside at nighttime?
Gina: So, what happened was the Wild year was, you know, it was really a way for us to explore our interaction with the natural world. What we found along the way was the difference it made to our social interactions as well. Like sharing these spaces with friends, and family and colleagues and a lot of that was linked to the night because that's where we've always shared these spaces.
That was where we would come together and we would make a fire and we would share stories and we would drag our poor friends and families out on cold nights to camp fires.
And there was something about that social interaction, which was surprising because that wasn't the goal of the year, but it demonstrated how valuable it is to have this kind of communal interactions within natural settings.
Kathleen: Did anybody in your social circle say, well, I want to try this, too?
Gina: Yes. Yeah, we had. We had a friend who went on and did her own year and lived outside.
Kathleen: So, we're standing in this, yeah, in this darker space in the city, do you feel more comfortable in the setting chatting then if we were like, I don't know, inside somewhere having a drink? Though maybe we wouldn't be having a drink over an interview, but…
Gina: Oh I don’t know. I'm still quite uncomfortable in urban settings, so you know a lot of my interaction during the year with the night was in, you know pretty much, you know what would be categorized as natural areas.
I think what happens with the light in natural areas is there is something comforting to it as well, and I I find in urban areas because a lot of the lighting casts a lot of shadows and this kind of stark contrast between the light and the dark and you kind of you don't, you know, you then can't see what’s in the shadows. You don't have that as much in in natural areas.
So, I feel that, I always have still have a fear in the night. Not of the night, but in the night. But that fear is greater in urban areas.
Kathleen: So, you've been rewilded you've essentially rewilded yourself?
Gina: Still, it's still a work in progress.
We’ll be right back.
This episode of Living Planet was produced by me, Kathleen Schuster and edited by Neil King. Our sound engineers were Jürgen Kuhn and Gerd Georgii.
If you want to check out Rupert’s Light Clock, you can visit his website: luminousnights.org.
This was the second of a two-part episode on light pollution. You can hear part one on Apple, Spotify or wherever you get podcasts.
What did you think of this episode? We’d love to hear your thoughts so send us message. Our email address is livingplanet@dw.com.
Living Planet is produced by DW in Bonn, Germany.