How was the night sky taken from us?

| 46 minutes | Media Contact: University Communications


How is light pollution affecting the environment and our own well-being? And how can we mitigate light pollution and preserve night sky visibility? 

Guest: Aaron LaCluyzé, faculty member in the Department of Physics at Central Michigan University


In this episode of The Search Bar, Adam Sparkes interviews Aaron LaCluyzé, a faculty member in the Department of Physics at Central Michigan University, about light pollution and its impact on the environment and human well-being. They discuss the history of light pollution, its effects on the nighttime sky, and the importance of preserving dark skies. Aaron emphasizes the need to raise awareness about light pollution and make informed decisions about lighting, such as using shielded lights and turning off unnecessary lights. He also highlights the benefits of experiencing a dark sky and encourages listeners to visit dark sky parks or other remote locations to appreciate the beauty of the nighttime sky. The conversation also touches on the issue of satellite constellations and their impact on astronomy and space debris. Aaron concludes by urging individuals to act and advocate for measures to reduce light pollution. 




    Aaron: We, kind of, went a little wild with it. We just had more and more light everywhere, all the time, until suddenly started to drown out the nighttime sky. And for most people, something like 80 or 85% of the entire world's population is impacted by light pollution in one way or another. If you look at major population centers, if you look at places like the coasts, like New York, L.A., those sorts of places, you can't get away from that light dome from that city in any reasonable amount of time. And so, those folks who have grown up in an urban setting, they may have never seen a dark sky. Literally never seen a dark sky. 

    Adam: How is light pollution affecting the environment, and our own wellbeing? Welcome to the Search Bar. I'm your host, Adam Sparkes, and on today's episode, we're getting the lowdown on one of the least talked about pollutions, light pollution, with Aaron LaCluyzé, a faculty member in the Department of Physics at Central Michigan University. Well, thanks for coming in, Aaron. 

    Aaron: It's great to be here. 

    Adam: This is a topic that I don't feel like I know a lot about, technically, but I certainly have an opinion about. Just because I love the outdoors and I love wild spaces. And as I get older and appreciate quiet things more, as a loud person, I've become much more aware of what the night sky looks like. And I think it's something that a lot of us could either take for granted, in that, maybe, we live somewhere where we get to see the night sky often, or, maybe, we don't really know what night is at all. So, I thought that would be an interesting place to start the conversation, is, maybe, the history of it. As people, it hasn't been very long, this idea of night not being a very, very dark place and a very, very dark time of the day. I mean, this is a new concept, the idea of light pollution and us not experiencing darkness. 

    What is light pollution?

    Aaron: It very much is, kind of, a modern phenomenon. And for folks who don't really think about the nighttime sky and don't really think about light pollution all that much, the analogy I really like to give people to get used to it is the concept of noise pollution. That's something we all have experience with. If we're in an urban setting, or you live near train tracks, or you live near a freeway, there's this constant, low-level noise that's constantly happening. You, kind of, don't even notice it after a while until it's gone. And then you're like, “Wow, it's actually quiet, that's nice.” Well, light pollution is like that, but for light. And for most of human history, the vast majority of human history, going back thousands of years, you had daytime and you had nighttime. We didn't really have artificial light. We had candles, you had fireplaces, you had that kind of stuff. But I mean, that's a really small, contained sort of thing. And it wasn't until the modern era with the invention of the electric light bulb, which opened up huge possibilities and wonderful new things with that technology. 

    Adam: You could work past dark. 

    Aaron: You could finally work past dark, which, I guess, on the one hand is a good thing. On the other hand, now you get to work past dark, that's great. But we went a little wild with it. We just had more and more light everywhere, all the time, until [we], suddenly, started to drown out the nighttime sky. And for most people, something like 80 or 85% of the entire world's population is impacted by light pollution in one way or another. For those of us here in mid-Michigan, we can kind of take it for granted because we can drive half an hour and we've got dark skies. But, if you look at major population centers, if you look at places like the coasts, like New York, L.A., those sorts of places, you can't get away from that light dome from that city in any reasonable amount of time. And so, those folks who have grown up in an urban setting, they may have never seen a dark sky. Literally never seen a dark sky. There's an anecdotal story, which I unfortunately recently learned is not true, but back in the nineties, there was an earthquake out in California that knocked out the power to L.A. for a while. And so, suddenly, all these people went from the normal bustle of the city to suddenly it's dark for the first time ever. And the story goes — the part that's not true because that part's true — the part that's not true is that 9-1-1 was inundated with phone calls of all these people who are like, "What are these crazy lights in the sky? What's with these UFOs?" And it was the Milky Way. It was the stars. It was the things they had never seen. So, it was not 9-1-1 that was inundated, but local observatories were inundated with phone calls. So, the story got a little blown out of proportion, but there is a kernel of truth there. These people had never seen that. And even myself — I'm a professional astronomer, I've been doing this for 20-some years — even I, when I go to a truly dark location — like, not just a little bit dark, but a truly dark location — I get slightly confused as to what I'm seeing in the nighttime sky. So, I've been to some major observatories around the world, including down in Chile, on top of a mountain in the middle of nowhere, and there are no lights. It is completely dark on top of that mountain. And I can't find constellations anymore. I'm a professional astronomer and I can't find a constellation because there's too many stars to see. In a truly dark location, you can see thousands of stars once you're adapted to the nighttime sky, once you're adapted to the darkness. But most people who live in cities, they see a dozen, a couple of dozen, maybe, of the brightest stars, and that's it, and they never see the rest of it. And on the one hand, you can say, "Okay, big deal, who cares? You're not seeing the nighttime sky." On the other hand, you're missing out on an experience that, literally, for generations, we've had this ability to see the awe of the nighttime sky. The only thing that competed with it was the moon. And so, you just wait for the moon to be down, and you've still got your nice, bright sky. But now we have lights, lights absolutely everywhere, and a lot of them poorly designed. And that's really what's infuriating about it, is that you don't actually have to completely sacrifice the nighttime sky or give up lights. That's not what we're dealing with here. It's not one or the other. We can take steps and we can make it so that it's better, but we have to be willing to do so. And that's a little bit hard. I do want to mention, I should preface, I am not an expert in light pollution. I don't study this. There are people who do. So, I'm not an expert in it, but I am someone who has a vested interest in it as a professional astronomer and as someone who wants more people to experience the joy of space, the joy of the nighttime sky, to see the galaxy we live in, to see the Milky Way, to see the planets, to see the stars, to see all that stuff. 

    Adam: It's a little bit of awe that we're missing, right? 

    Aaron: Yes. 

    Is there a benefit to reducing light pollution?

    Adam: I think — I saw a video clip of a pilot in Alaska. He's a bush pilot. He’s a gentleman who has a business, and he was flying the bush plane. Or, it's not a bush plane, but what do you call the ones that...? 

    Aaron: The floatplane? 

    Adam: Floatplane, yeah. It was a float plane. He's flying a float plane. And he made a comment of, “You asked me if I ever get tired of this.” And then they show the shot out the window of the plane and he goes, "Does that answer your question?" And he's been flying these float trips for 30 years, bear watching and fishing and all these things in Alaska. And I actually watched this video last night and it got me to thinking about this conversation today, and we're kind of missing the mountain range a little bit, right? He knows that, “I will never get tired of looking out the window of this plane and seeing this vast, beautiful Alaskan wilderness.” And to some extent, that's a little bit of a wild world that's been kind of hidden from our eyes, right? 

    Aaron: Yeah, and for a lot of people, there was a choice that was made, and they didn't make that choice. The nighttime sky was taken from them by, essentially, society's actions over the past 200 years or so. And it's one thing if you decide, “I'm not interested in astronomy.” That's fine. Not everybody has to be interested in astronomy. But to have that completely taken off your plate, and not just your plate, but your children's plate and their children's plate, that seems such a shame. And so, it's important that we raise awareness about this. And that's kind of where I come from, the angle that I come to it from. The most important thing about fixing a problem is to realize that it is a problem. And so many people don't even know that it's a problem. They don't even think about it. They're not looking up because there’s nothing to see because all the lights are on. 

    Adam: Do you think that people should go look at it? Because I had this — and this is, again, a little bit of an anecdote. I'm a Detroiter, I moved to Mount Pleasant to work here at the university. You mentioned middle Michigan. you can drive about an hour, and you can be in a really dark location. When I moved here, I couldn't believe how many stars were in my front yard. I was blown away. Now, I was old enough by the time I moved here to recognize that — I went to high school close enough to a major automotive factory, one of the biggest ones in the state, where I can remember being with my high school girlfriend in her backyard at night and being [like], “Look at how beautiful this big pink glow is,” and it was just the bloom from the automotive factory at night. So, I grew up in an environment that not only was I'm in an urban and a suburban area that is just light polluted in and of itself, but even the local region had a separate lower bubble of bloom going on. And it's not that I had never seen a night sky, but when I moved here just walking out the front door at night to go just to the grocery store, I don't know what the first moment was. I just went, “Whoa.” And then it's persistently been such a drastic difference from what I grew up with and lived with for the first 36 years of my life before I came here. I feel like you should go seek that out. If you are living in that kind of a bubble, having a quiet moment with the sky will help you appreciate it. And it's free! 

    Aaron: Yeah, it is. It just takes a little bit of time, which I understand is precious. But it's like experiencing a flavor that you didn't know existed, right? It's like, imagine that you grew up your entire life and all you had ever had was vanilla ice cream, and vanilla ice cream's fine, it's great. But then one day, just suddenly, you taste chocolate ice cream and it's like, “Wait a minute, this is a thing that I didn't even know existed and it's amazing.” It's a whole new incredible experience. That's what it's like going from being in a city and seeing the nighttime sky and going to a small town or into a real rural area and seeing the nighttime sky. It is a sense of awe; it is a sense of wonder. It kind of settles you. It gives you a sense of place in the universe, that you're part of something bigger. 

    Adam: It's very centering. 

    Aaron: Yeah, it's amazing and it's relaxing and I love it. And I want everyone to experience it at least once in their lives, that they get a chance to see a dark sky. 

    How does poor light design contribute to light pollution?

    Adam: Shocking!

    Adam: What's the difference? I want you to tell me a little bit about what are the types of lights, what are the things that are — what's happening in our environment? Because, I would add to that note that when I go back home to where my mother still lives in the house I grew up in, that factory shuts the lights off at night. So some things are starting to change. It's darker than it was when I was a kid. What were we doing for a really long time before we started to have some awareness of this? 

    Aaron: So, let's start with where the problem really is. And that is that we are usually, as a society, as humans, we're usually pretty lazy about how we do things with lights. It's like, “Okay, I've got a flag. I need to light that up. I've got this sidewalk. I need to light that up. I've got this road. I need to light that up. Let's just put up a bunch of lights.” Let's just not even think about it. Here's a light. Great. We'll just slap it up. It's not bright enough. Oh, we'll just add another. Well, yeah, but it depends on how you're using that light. Are you aiming that light? We need to light a billboard. Okay. Billboards are a really good example, the easiest one for people to see where the problem lies. So, as you're driving along the interstate, next time you're driving on a freeway, or whatever, and you see a billboard, I can almost guarantee you that that thing is lit from below, that the lights for that billboard are on the bottom and they're aimed up. And they're on the bottom and they're aimed up because that's easier. I don't have to run the cables as far. We can put them on the bottom [and] it's not in the way the rest of the billboard. We just put 'em on the bottom and aim 'em up. Yeah, but most of that light's not really going on the billboard. Most of that light is just going up. Most of that light is wasted from your perspective. It's not doing what you wanted it to do, you just wanted it to light up the billboard. So, that's just a simple design thing. And if you look at streetlights — as you mentioned, we're both photographers, so a couple of things I'm about to say, I'm of two minds about. So, streetlights, if I say the word streetlight to you, like a streetlamp, the first thing that you probably picture in your head is from an old movie, a big wrought iron thing with a beautiful glass base, like glass bulb at the top. But it's got no top on it; it doesn't have a lid on it. There's no hood on the top, because that looks neat and that looks picturesque, and I'd love to take a picture of something like that in some foggy conditions and it would look awesome. But a bunch of that light's going up not down. And we were trying to light the street with the street light, not the sky with the street light. And so we have this kind of spillover effect that happens with a lot of lights when they're poorly designed, when they're aimed up instead of down, when they don't have hoods, when they're aimed lazily, when they're just aimed in random directions. Because that'll happen too. You end up lighting the sky, not the ground. So, I guess we should take a moment. I'm going to take — okay, I'm going to digress and take a moment, if you'll indulge me. 

    Adam: I will indulge you. 

    Why does light pollution occur?

    Aaron: And let's talk about why you end up with fewer stars in a bright situation than in a dark situation. What's really going on there? So, at a fundamental level, your eye is able to see what it's able to see. It's always a matter of contrast. The thing that you're trying to see, how bright is it compared to the stuff around it? 

    Adam: I always tell my students, brightness is relative. 

    Aaron: Brightness is absolutely relative. The stars, they're out during the day. They're totally there. You just can't see them because the sky is too bright. Well, wait a minute, why is the sky too bright? Well, the sky's too bright because the sun is out, and the sun being out — light from the sun comes into the atmosphere and it scatters off all the stuff that is the atmosphere, and you end up with that nice blue sky that you see on a day, not like today. It happens to be quite overcast here in Mount Pleasant today, but on a good day, the sky is blue because that sunlight that's been kind of scattered in the atmosphere. So, we know, just from that little experiment there, that little thought there, that when light goes into the atmosphere, it doesn't always just go straight out. It can bounce around. And so, when we light things on the ground, that light goes up, but it doesn't just go out into space. It bounces around in the sky and comes back down. And so, you end up with what we refer to as ‘sky glow’. So the sky glows a little bit just because of those interactions that are happening. The more light that we put on the ground aimed up, the more sky glow we have, and the brighter that sky glow, you have a harder time seeing those faint stars. And so, eventually, you've made your sky so bright that only the brightest of stars can be seen. And that's what you end up with when you're in a city. If you go to New York and you look up, yeah, it's nighttime so the sky is ‘dark’ for a certain value of dark. 

    Adam: You can see clouds in New York at night, I mean… 

    Aaron: Right, yeah. I mean, they're lit up from the ground.  

    Adam: It's wild.

    Aaron: It's crazy. But if you're lucky, you'll see a couple of stars and they'll be like the brightest stars in the sky. Like, “Oh, there's the constellation of Orion because I can see two of its stars.” Okay, that's not great.

    How can we address light pollution?

    Aaron: So, our goal in all of this, our goal in bringing attention to light pollution and trying to fix light pollution is really about, let's take steps to make things… to use our light more appropriately so we don't get that spillover effect, that, like, excess light going up that we don't want. So, in the modern era, as we've started to figure these things out, we've started to take steps with that. So, you'll make streetlights with a hood on top, so at least the light that it's creating is going down, not up. You'll try and turn off lights when they're not needed. So, much in the same way that in a lot of the buildings — I don't know where you guys work, whoever's listening or watching this podcast — but a lot of buildings, they've got motion sensors. And so, when no one's there, it turns the lights off. Well, why does it do that? Well, you don't need the lights on at that moment. Let's just use lights when we need them, not when we don't need them. So late at night, sometimes lights are turned off at factories or at a parking lot that doesn't need its lights on. So, those sorts of steps, they're very simple, they're very easy things, but they can just chip away at that light pollution that we've got going on to try and make life a little bit — as strange as it's going to… — a little less bright for everyone around. We don't want to make your life brighter, we want to make it less bright, actually, ironically, so that you can see the nighttime sky. 

    What other factors contribute to limited night sky visibility?

    Adam: I want to go back a little bit, too. I think, if you live in a major urban area as well, that skybloom you're talking about is often exasperated by other particulates in the air. So, if you live in an area where there is more air pollution — so we talked about L.A., which has a famous smog situation — I think you see even less sky in L.A. than you do in New York.

    Aaron: Absolutely. 

    Adam: Because they're in a valley and that, kind of — if you're from California or if you've been there a lot, there's major air quality issues there. And it can be, like, even at night, it can look just hazy when you're there. You don't have to be an expert to observe it. It's there. It's just there. 

    Aaron: Right. And another thing, on that subject, that people might be familiar with, the past couple of years, we've had a lot of really bad wildfire seasons. And the particulate from the wildfires get into the atmosphere and they block out the sky as well. It makes it grayer, if you want to think of it that way. Speaking of Beaver Island, which I'm sure we're going to talk about in a few minutes here, but a couple of summers ago I was up there, and we were trying to observe. It was nighttime, it was clear, it was dark… 

    Adam: We couldn't see the sun. We were there. 

    Aaron: And we couldn't see the stars at night because there was too much wildfire smoke in the atmosphere. It's not just light pollution that affects what happens in your atmosphere, it's pollution that happens in your atmosphere. 

    How does light pollution impact wildlife?

    Adam: This is one of those things where it's a lot of — it really is a death by a thousand paper cuts type of a problem, right? Our own personal light that trespasses into spaces that it shouldn't be creates a lot of noisy light. It really does add up. So, this is one of those things where you can do your part, correct? I mean… and if you don't care about the night sky, there's a lot of other stuff out there too, right? I mean, bird strikes are affected by evening lights being on. And I read something, and I don't know if this is verifiable, so bear with me, I'm going to say it anyway. I read something yesterday that something like a billion birds are killed and sometimes — it might be annually, just by window strikes alone. 

    Aaron: That would not shock me. 

    Adam: It's like a wild amount. Just a wild amount. 

    Aaron: It is. And actually, just, if you think about the numbers, it is a disturbing amount of wildlife that is killed from just running into windows where lights were on, quite frankly. Sometimes running into windows when lights weren't on. I mean, windows are actually — windows and windows design, building design, is actually a huge problem for birds, straight up. But there are a lot of different impacts, not just with our enjoyment of the nighttime sky, but there are physical ramifications for both human beings and for wildlife to having this much light pollution. We did not really evolve over millions of years, the animal life on earth didn't evolve over millions of years, with artificial lighting. This is a relatively new thing, and it changed extremely fast, and they haven't really learned how to cope yet. Kind of the poster child for this sort of thing is sea turtles. So, when sea turtles — their eggs are laid in the sand on the beach and eventually those eggs hatch and then the newly born sea turtles have to make their way into the ocean. Well, how do they find the ocean? How do they know where to find the ocean? For a long time, just because of how it usually goes, sea turtles lay their eggs so that they hatch at a certain moon phase. Usually a round full moon tends to be typical, as I understand it. Again, I'm not a sea turtle expert here, although I love sea turtles. 

    Adam: Everyone loves sea turtles. 

    Aaron: Everyone absolutely loves sea turtles. For a long time, we thought that they essentially navigated by moonlight, that they were drawn to the moonlight and that took them out to the ocean. But then if you think about that for just a little bit longer, it doesn't make any sense because was the beach facing south, east, north, west? Where was it facing? The real answer is that they used the contrast, essentially, between the light out at the ocean, so moonlight reflecting off the ocean, and the darkness behind them, because the darkness behind them was just the beach, the trees, the foliage, whatever's back there. 

    Adam: Nothing was lighting it up. 

    Aaron: There was nothing lighting it up. And so, it's not that they went toward the ocean, it's that they went away from the darkness. But as we've gotten areas that are much, much more light polluted, the sea turtles are born and have no idea where to go because there’s no darkness behind them anymore. And so, that tends to be a problem. So that's kind of the easiest one to point at and go, “Look, right there.” We can point at it. You can see all these sea turtles that can't make their way to the ocean. They die on the beach. That's terribly tragic, and everyone loves sea turtles. But there are a lot more subtle ones. So, you alluded to birds. There are a lot of birds that fly, migratory birds, that fly at night, and they fly at night because it's less stressful, it's not as hot. It's easier for them to maneuver long distances without getting tired. But as we've added artificial lights, they don't know where to go anymore. They get confused in their navigation. They can't find their way around and you end up with migratory birds in places that they don't belong, or running into things that they weren't running into before because the lights are distracting to them. They didn't evolve that way.

    How does light pollution impact humans?

    Aaron: But there are impacts to us as well. So, if you've ever tried to get a decent amount of sleep on an airplane, you know that there are a couple of problems with that. One, the seat's just too uncomfortable. It's not great. But the other one is noise. The sound of the plane is terrible. So the most — just a life hack from me to you, get yourself some noise canceling headphones and wear those on a flight, and then on the return flight, don't wear them and see how you feel. Just compare and contrast those two things. Having all that sound around you all the time leads to a worse quality of sleep than if you don't have that sound. So, there's a sound pollution way. Light does the same thing. Human beings are meant to sleep in darkness. That's how we evolved. That's what we did. And it used to be that nighttime was dark, but now nighttime's not dark. Now, nighttime is bright because you've got all these lights in your bedroom, or you've got the lights of the city coming through your window, so you don't get as much sleep, you don't get as deep of sleep. It's just bad for you overall to be in those sorts of environments. To go even more subtle than that, your body clock is kind of gauged to that. It used to be that as the sun was setting, the character of the light changed, because the sunlight during the day is nice, bright white, blue skies, you've got all those sorts of things. But then, your body took as a cue — as the sun went down, the light got different, the sky got paler, the sky eventually got dark, the light got oranger, then redder, and then it went away and you went, “Oh, it's time for sleep.” And so, your body's kind of normal, natural rhythm happened, and you would get sleepy. But now, what happens when the sun starts to go down? “Oh, it's getting dark in here. I'll turn on a light.” And so you turn on a light, or you turn on a TV, or you're staring at your screen the entire time. So you're just blasting your face with light all the time. And so, it's no wonder that we all have problems sleeping and that we all have terrible quality of sleep. Well, we are essentially doing that, again, death by a thousand paper cuts. We're doing that to everyone else with all of the lights that we have on in our environment. 

    Adam: Probably including all the little, cute animals. 

    Aaron: Yeah, absolutely. It definitely screws up a lot of things with nocturnal animals. 

    Adam: Yeah, picture the cutest animal you can think of. 

    Aaron: Yeah, whatever your favorite animal is, light pollution is affecting that animal.  

    Adam: Probably. 

    Aaron: Every single one.

    What kind of light bulb creates the most light pollution? Why?

    Adam: You said something they want to touch on, which is blue light, right? You're talking about your computer screen, your TV, your iPad, that cool blue — particularly since the advent of LED lights, too. It's my understanding it's a lot worse. 

    Aaron: Yes. So, again, not a light expert, not an expert on all of this, but I read things too, and yeah… LED lights; LED lights are, on the one hand, a godsend and a curse. So, old school lighting, the way your parents and your grandparents did it — if you're listening to this podcast, it was at least your parents. The way they did it is they had all incandescent lights. And an incandescent light is literally a toaster behind some glass. It's a little thin piece of wire that you heat it up and it glows. But if you heat it up and it glows, it glows, kind of, equally… not quite exactly, don't… Look, I apologize to my intro physics students for the thing I'm about to say, but it glows, kind of, equally in, kind of, red, green and blue. It glows in all of those. And so, you get a nice kind of warm, balanced light from a light bulb, typically. But as a lighting source go, they're terrible because most of the energy that you're putting into that really comes out as heat. I mean, I'm not really kidding when I say the light bulb is basically a toaster, because it is. Old school light bulbs, you put your hand near them, they are hot. 

    Adam: They started fires all the time. 

    Aaron: All the time, absolutely. But as time went on, we got other technologies. We got the dreaded fluorescent light bulbs.  

    Adam: Beautiful. 

    Aaron: Which anyone who has lived through… 

    Adam: But they spiral like a soft-serve ice cream cone. 

    Aaron: Yeah, that's right. They were great. Everyone loved them. There were no problems whatsoever, and they certainly weren't filled with mercury. But we eventually got LEDs. And so, LEDs work with a completely different technology, and essentially most of the energy you put into an LED comes out in the color of light you wanted it to be. But they're kind of skewed to be very blue, for the most part. That kind of lighting tends to be bluer than other kinds of lighting, which on the one hand is good because the human body perceives those bluer colors as brighter even when they're not. So we can make a light bulb that's energy efficient and we don't need to generate as much light. But on the other hand, it's also bluer, and we just talked about how blue is not necessarily great because, again, your body associates blue light with daytime and redder and oranger lights with nighttime. So, it tends to screw things up there. So, I do love LED lights conceptually, but… The other thing that's happened is, as we've invented these LED lights, they tend to be brighter than other kinds of lights just because they're much more energy efficient. So, for the same amount of energy, we can make a way brighter light. So, what drives me crazy is when they replace a streetlight with an LED streetlight but don't redesign the light at all. And so, you end up with this light that is overwhelmingly bright for its application. And so, we had a streetlight that was already creating light pollution, and then we essentially souped up the light that we put in it and just made the light pollution that much worse. 

    Adam: Look how much brighter it is, though. 

    Aaron: Yeah, look at it, it's great. Think of how much safer everything is now that we have this thousand-watt light pointed up. 

    Adam: And I think everyone's probably experiencing this as LED headlights become more common, which is that — they are just wild. My car, guilty, my Subaru has LED headlights, and it was the first vehicle I have ever owned that had them, and I noticed that people were flashing me as though my brights were on and they weren't. Because it is an Outback, it's not that high off the ground. It is just substantially brighter than any previous headlights I’ve owned. 

    Aaron: Yep. Same with mine. I have a Toyota, it has LED headlights, and I get the flash of the brights all the time. It's so bad that the last, not last time, but one of the times I had it in for servicing, I'm like, "Can you guys check? Are my headlights pointed too high up?" And they're like, "Nope. That's exactly what they do. We know exactly what you're talking about. Sorry, there's nothing to fix." 

    Adam: I feel like if you've bought a car in the last, I dunno, let's call it three years, four years, LED headlights are like standard at this point. 

    Aaron: Yeah, they are, they are. They're brighter. People tend to prefer them. But again, there's ramifications to that. There's knock-on effects. So, it's tough. 

    How can we mitigate light pollution and preserve night sky visibility?

    Adam: So, let's talk about things that are happening that are mitigating this. So, this is something that we're talking about now, and I think most people who are listening have probably heard about dark sky initiatives, things like that. They're becoming more prevalent, although they're not new. I mean, I think it's something that's been going on for better than half a century now. There's been at least some effort to acknowledge this and maybe have rules to combat the brightness. Tell us a little bit about your understanding of those and what the benefit of having dark sky spaces, or even just light pollution regulations in your area might be. 

    Aaron: Sure. Let's start with the one and we'll transition to the other. One of the questions that will come up is, “Hey, guys, I agree with you. This is great. You've convinced me. I'm 100% on board. What can I do?” Well, okay, step one is raise awareness, which is what we're trying to do here with this discussion, with this conversation. Step two is, any chance you get to give input about lighting, do that. So, I know, myself, my house is in a neighborhood. My neighborhood has an HOA. The HOA occasionally has meetings. Sometimes those meetings are about such mundane questions as streetlights. When that happens, talk about it. Talk to your neighbors, talk to the people in the HOA, talk to everybody. Let them know, "Hey, I'm not against streetlights, but let's just do it right. Let's think about this." There are communities that have implemented ordinances or rules about what kind of lighting can go in, what the directionality of that lighting is. Do they need to be shielded, not shielded, those sorts of things. The way I was first introduced to this, the first time I really thought about it, I was grad school, and I had an opportunity to go observe at Kit Peak, which is just outside of Tucson, Arizona. And there's a small town nearer to the observatory, and they have rules there. And I think in Tucson itself they now have rules about how the lighting has to be designed to not impact the observatory. Now, that's nice because there's an observatory right next door and they're trying to minimize their impacts on it, but there's not an observatory everywhere. But, there are people everywhere. And so, people should try and think about those sorts of things. Something else that's happened more recently, as time has gone on, as we've recognized that the nighttime sky is a vanishing resource that needs to be conserved. Because that’s really what we're talking about here, is trying to preserve areas where people could experience a dark sky if they wanted to. Organizations have popped up, and I think the big one right now is, I think, now just called Dark Sky. It had a previous name when it was first founded back around 2000, 2001, sometime in there, but I think it's now just called Dark Sky, and I think their website is And they, essentially, fight for this sort of thing. They raise awareness, they try and get rules and regulations implemented. I know nobody wants more rules and regulations, but we're going to mark off this area and we're going to say this is now a , and we're going to try and make it so that we prevent any new lights from going in here. We try and minimize the impact of the lights in the surrounding areas, and we'll try and make these places close enough that people can get to them, but far enough out that they're not impacted by nearby cities, is, essentially, what they try and do. And so, here in Michigan, I believe that there are six dark sky parks. Several of them are associated with some of the state parks. And so, there's like an area of the state park where they've gotten rid of all the lights, essentially. So there's six dark sky parks, and there are, I believe three, maybe four actual internationally recognized dark sky preserves. And so, that's kind of the next step up from a dark sky park, where they're more remote, they're more away from lighting. And so, we've got 10 different places you can go here in Michigan where you can reach those sorts of things. They are a little out of the way. I mean, Michigan is not that big. Well, okay, maybe it is. I actually had reason recently to wonder about, as another digression, to wonder about how big is Ireland?  

    Adam: That's perfect.  

    Aaron: How big do you think Ireland is? 

    Adam: Oh man, Ireland's got to be the size of Ohio. 

    Aaron: It's actually slightly smaller than the lower peninsula of Michigan, by land area. So the entire country of Ireland is Michigan. So, there's always this kind of push/pull that goes when you talk to Europeans about — they don't quite grasp the size of the United States because it’s just so big. But, well, you can get anywhere in the lower peninsula in a few hours. That's not so bad. So there are several dark sky parks. Most them are kind of on a coast. And you might go, “Well, why do we build them on a coast?” Well, because that way you could only have city lights behind you.  

    Adam: There's only so much light you can get on the water, right?  

    Aaron: That's right. We're not building cities on the water, yet. But at least for now, we're not. So, there are several, kind of in the upper part of the lower peninsula up near Mackinaw, up in the thumb. There's at least one that's up in the U.P. But we do have these places set aside that a person can go and actually experience the dark skies for themselves to see what the fuss is all about. One of them that is interesting… So for those who don't know, whoever might be listening to or watching this, Central Michigan has a biological research station on Beaver Island. And so, Beaver Island is the largest island in Lake Michigan. A lot of people don't know about it. It's one of those hidden secrets. But the island itself is not heavily populated. Kind of the northeast corner of the island has a little town, and there are some other things scattered about the island, but most of the island is relatively undeveloped and most of the island is shockingly dark. And so, they are currently undergoing the process to get a big chunk of the island declared as a international dark sky preserve. I don't know where they are in that application process. I know that they're getting there, and I have no doubt that it is going to get declared that. But if you really, truly want to experience dark skies and you're in Michigan and you've never been to Beaver Island, because a lot of folks haven't — 

    Adam: It's a great trip. 

    Aaron: First of all, you should do it because Beaver Island is an amazing place. And secondly, you'll actually get a chance to see those truly dark skies on Beaver Island.  

    How is light pollution measured?

    Aaron: And if you really want to get a grasp for how impacted your location is by light pollution, I think maybe the easiest way to do it — because, you know, measuring light pollution is a little complicated. It's a little tricky if you truly want to quantitatively measure it. There are special devices you can use to measure the sky brightness. There are ways to look at the faintest stars you can see and look at that brightness. There are satellites that do that sort of thing. There's a whole group that actually studies light pollution from space that look down with satellites. But I think just kind of as a general rule of thumb, if you want to figure out how it is, wait until it's cloudy, wait until it's a completely overcast day or an overcast night, and then go outside and just look at the difference in the color of the sky in the directions you look. So, if you're in a truly dark location and you look up and you see basically nothing, you're truly dark. You're seeing nothing when it's overcast. If you're in a place that's impacted by light pollution, you'll see the clouds themselves. You'll see a glow in the sky that's coming from the lights around you, and sometimes you can actually identify —like the city, like the town — it's over there. You can see, kind of, an orange glow just completely covering that chunk of the sky in that direction. And so, I think a cloudy night will give you a very quick rule of thumb as to whether you're dark or not. 

    Adam: And you're probably not that dark. 

    Aaron: You're probably not. Yeah, I mean, statistically speaking, if you're listening to our voices, you're amongst the 83% of the world that is impacted by light pollution. 

    What are the cultural impacts of light pollution?

    Adam: There's a lot of cultural touchstones about these night skies, and if you're carrying that tradition in your family, you might be losing it depending on where you live. And I think that's certainly an important sensitivity that we should probably have when we're having these discussions as well. 

    Aaron: Oh, absolutely. Absolutely. The nighttime sky was a part of who we are as human beings. It was baked into our culture. The stars, the constellation, the moon, its phases, all of that was tied to culturally who we were. The movements of the nighttime sky, the movements of those constellations, it was how we told time. It was how we figured out what part of the year we were in. We didn't have an iPhone that told us, “Oh, by the way, it's time to plant crops.” 

    Adam: There were always iPhones.  

    Aaron: That's not the way it worked. So, to deny that link to a whole other generation behind us seems like such a waste. It seems like such a terrible crime to take away the sky from everyone, which is essentially what's happening. One other thing, while we're on this topic of decisions being made that you might not actually have any influence on, I want to touch briefly, without opening too big of a can of worms, I want to touch briefly on satellites.  

    Adam: Oh yeah.

    What concerns arise with the proliferation of satellites?

    Aaron: So, satellites are another issue. So right now, there have been tons and tons and tons of launches of Starlink, which is SpaceX's mega constellation of satellites. 

    Adam: It's tens of thousands, isn't it? 

    Aaron: Uh, yeah. 

    Adam: Or it's getting there. 

    Aaron: So, the idea behind Starlink, its whole point in life, is to provide internet to rural areas without having to lay copper or fiber optic cables to those areas. 

    Adam: Which feels altruistic. 

    Aaron: Which is great. I understand the drive to do that. But I always ask number one, at what cost and number two, who decided this was okay? And at what cost, it seems to be, well, at the cost of the nighttime sky. And who said this was okay? Well, it wasn't us. We were not asked for permission. But there are now somewhere around 8,000 Starlink satellites in orbit. There are more Starlink satellites than every other kind of satellite combined currently in orbit. And this is just one company who has put these satellites in orbit. There are two or three others who are lined up to do the same thing, and each one is going to have tens of thousands of satellites. The ultimate goal for Starlink, eventually, I think, is 40,000 satellites in orbit. 

    Adam: That was what I was thinking. Yeah, that's wild. 

    Aaron: They're on their way there. If you've ever seen what's now called a satellite train — a phrase that did not need to exist until very recently — if you've never seen one, it's — for a brief moment, it's awe inspiring. So, if you get to a dark location and you look at the nighttime sky, you've got your stars, you might have some planets up, you might have the moon up, you might see the Milky Way, you might see those beautiful sites. And then you'll see a thing that's moving relative to everything else. And you're like, “Oh, look, a satellite, that's neat, that's unique, that's odd.” A wait, another satellite right behind it, and another one, and another one. And you'll see just a string of 15 little dots just going across your sky all at once. And so, on the one hand, you can say, “Well, look, okay, they're just dots in the sky.” It's no big deal. You're still seeing the stars. I'm not blocking those stars outright. Well, you're doing a couple of things here. The first thing you're doing is you are interrupting astronomy. So, there are astronomers who are trying to look at that sky with very sensitive cameras, with very powerful telescopes, who are taking very long exposures. And my very long exposure that might've been 10, 20, 30 minutes of exposing at one spot in the sky, suddenly I have a whole string of streaks that went through that frame. And so, now, I have to find a way to get rid of those. And I have to hope, I have to pray, that they didn't go right in front of the thing I was trying to look at. It's kind of like if you were in a movie theater and you're trying to watch the movie really intensely, and there's a guy in front of you with a flashlight that just keeps shining it in your face occasionally. That's really what those satellites are doing to astronomy. But if I was in this dark location, gazing at the nighttime sky, trying to ponder my place in the universe and being awed by the wonder of it all, and now suddenly I just have a line of satellites going through, and that kind of changes the connection I was trying to make there just a minute ago. They're not just optically bright. They don't just reflect a lot of sunlight. They're radio bright as well. They give off a lot of radio waves that they shouldn't. So, it's impacting radio astronomy as well. So, it's kind of like the equivalent of — we've got these radio telescopes that are listening for the quietest noise possible, and somebody runs through the room screaming, is essentially what it's like. 

    Adam: Gosh, it might've been just a couple of years ago, but it might've been the year that we were both up at Beaver Island. I had somebody challenge me to go look for them. Then I went and laid on top of my Jeep and looked up just in my front yard here, and you can see 'em. 

    Aaron: Oh yeah. 

    Adam: They are going by and they're going by with regularity. You don't have to wait half the night. You can go up as soon as the sun's been down for an hour and just watch 'em go every couple of minutes. And sometimes, like you were saying, in little clusters, and that's naked eye laying on my back. You can see ‘em, there's no question. 

    Aaron: And if you wanted another reason to think about this — and I don't want to terrify anyone, necessarily — but if you wanted another reason, if you wanted another reason to think about this, even if you don't care about the nighttime sky — let's say that's not your worry. You don't care. You're jaded, you're bitter, you're not looking up. That's fine. Okay. There are now 8,000 satellites in orbit that have a limited shelf life. They will die. They will eventually become obsolete, and we're going to have to do something about them. There's a plan for that. Okay? Again, there are regulations. If you put a satellite in orbit, you have to have a plan for what do with it when it's done. And the normal operating procedure is that you aim it back at Earth and you point it into the atmosphere at an oblique angle so that as it comes in, it heats up, it breaks apart, it disintegrates. Okay, sure. But we wrote those regulations when you had 5, maybe 10 satellites. That's not a big deal. Earth is a big place. Its atmosphere can probably take it. Yeah, there are 8,000 car-sized lumps of metal, glass and circuitry that we're just going to plunge right into the atmosphere. And we literally do not know what happens when we do that, when we dump that much material in the upper atmosphere. No one's done that research. 

    Adam: It sounds wild. 

    Aaron: We didn't have to, right? Because that was unthinkable. Who would do such a thing? Well, now we know who would do such a thing. Satellites in orbit — there are lots of reasons to have satellites in orbit: communication, weather forecasting, all kinds of wonderful things that you can do with satellites in orbit. But one of the things that you do with satellites in orbit is spy on other countries. And so, countries don't take kindly to that, and they'd like to be able to defend themselves against that. So one of the things you can do is if there's a satellite that is spying on your country, you could blow it up. You could just go ahead and do that. There are downsides to that because once you blow up a satellite, you've created, instead of one thing flying through space, you now have thousands of tiny things flying through space, which is not necessarily good for the other satellites that are up there. And so, a few years ago, China blew up a satellite from the ground just to prove that they could. Now, this was a big flex, I get it. I understand why they did it. But at the same time, the rest of the world was pissed because they just made a big debris field, is what they did. And as we get more and more satellites up there, this becomes a bigger and bigger and bigger problem. Because if you break apart enough of them, you create enough shrapnel that it hits other satellites that hit other satellites that hit other satellites, and you eventually just have, essentially, a cloud of debris around the earth, and then you can't launch any more satellites because they would hit the cloud of debris. 

    Adam: And there's a downstream effect to that too, which is, I assume, being able to launch space shuttles and things like that.  

    Aaron: Yes, absolutely.  

    Adam: And sometimes when we talk about these things, it is — as existential as it might feel, we have to think about what this looks like in a hundred years. And, certainly, we are not going to live through that, I don't think. Maybe.  

    Aaron: We hope.  

    Adam: But yeah, if space junk becomes a thing that we can all sit and look at the same way we can look at the Starlink satellites, we're probably not in a good place, and probably… 

    Aaron: We're definitely not in a good place. By the way, that thing I just described is a thing called Kessler Syndrome. So if you want a really terrifying evening, just go find the Wikipedia article on that, and that'll be some light bedtime reading for all the listeners. 

    Recap and conclusion

    Adam:  Awesome. Well, I hope that we haven't freaked anybody out. If you could, to wrap this up, if you could give everybody one quick piece of advice for a thing they can do to help out with light pollution and a thing they can do for themselves to enjoy a dark sky. Go ahead. Give us one reason. 

    Aaron: Yeah. So the number one thing you can do is raise awareness about it. That's the number one thing you can do. Any single human probably doesn't — any single person listening to this probably doesn't have the influence to fix it. But if enough people know about it, if enough people are concerned about it, the people who actually have that power can do those sorts of things. If you get an opportunity to install lighting in your own home or around your own home, or you get influence with your HOA or town council or anything like that, just make people aware of it. Try and think carefully about it. Try not to have lights pointed in places that they don't need to be pointed. That's the number one thing that an individual can do. As far as the nighttime sky itself, as far as experiencing it for yourself, take the time to do it. Actually make a plan. Say to yourself — don't put it off. Life is short. You never know what's around the next corner, and I want to make sure that every person who can, experience a truly dark sky at least once in their lives. So go camping. Here in Michigan, we are absolutely lucky to have so many wonderful state parks and recreation areas. Just go someplace dark. Wait for the sun to set. Wait for your eyes to adjust. Give yourself about 20 or 30 minutes. Know that it's going to be a slow down, is what that's going to be. We have this fast-paced life where if a webpage takes more than three seconds to load, we just close it. We just go to something else. 

    Adam: Way too long. 

    Aaron: No, no, no, no, no. Pump the brakes. Take a minute. Take a deep breath. Actually talk to the people you're with. Put down your devices. You don't need those, you're looking at the sky. And look at the sky with someone you care about and just take the time to see it. It's like the most important thing you can do. 

    Adam: That sounds like an awesome plan. Aaron, thank you so much for coming in. 

    Aaron: Thank you for having me. It’s been a pleasure. 

    Adam: I look forward to talking again soon. Thanks for stopping by the Search Bar. Make sure that you like and subscribe so that you never have to search for another episode.

    The views and opinions expressed in these episodes are strictly those of the host and guest speaker.