 And I mean, it's, it is the case and this applies to amateur astronomers too, that, you know, as you get older, you have more disposable income. And, and we, I'm 68 and I don't, you know, that's the new 50 right and so I myself is really energetic and I love to travel and, and I'm taking Vivian with me on my next trip. Yeah, nice. I don't even care where we're going. We're going to Antarctica. In December, I'm going to be leading an eclipse cruise. That is among other things we're going to the Falcon Islands and we're going to cromp around on Antarctica and scare the penguins. And then if we're really, really lucky. We'll see, we'll see the total eclipse on December 4. Wow. Yeah, it's a fingers crossed kind of situation. If you look at the climatology. Antarctica itself is great. It's going to be very clear there but the prospects out on the ocean where we're going to be and where lots of other ships. Is, is worse than 5050. And it turns out the South Orkney Islands, which are just barely in the path of totality, create little clearings and they have, you know, sort of, or, or a graphic clouds, you know, and how on the lee side, often there are no clouds on the backside of the islands. And that's what these little islands do they create little clearings and the otherwise thick clouds that pervade that part of the ocean. So yeah, we've got our fingers crossed that that will be the case. But in case it's funny you mentioned that I was just watching this like a documentary about working in Antarctica some six part series. And there's some talk about like how the West Antarctic Peninsula is like radically different climates on either side. There's a chance to go to Antarctica once. This is some years ago when I was still sky and telescope full time. I'm mostly retired down mostly. And, you know, I covered planetary science so I covered meteorites and the guy who headed the National Science Foundation team that goes there every Antarctic summer. It's basically this time. And we come along on one of our meteorite hunting expeditions. And the notion of living on the Antarctic ice in a tent that wasn't heated for six weeks, just did not appeal to me at all. What's not appealing about that. It was not for me. I'm from Central California. You know, warm winds blow course through my veins and and that was just not going to work for me. But look at all your fingers. What do you have, you can, you can a couple of them you could just lose the frostbite. That's right. Yeah. Yeah, I folks are. For everyone who's coming in. And you're putting things in the chat, please make sure that you go down to the bottom and select panelists and attendees. It defaults to just panelists and you want everyone to see what you're saying so and we are at the top of the hour so I'm going to go ahead and get started and so hello everyone and welcome to the January NASA night sky network member webinar. We're launching tonight's webinar from the astronomical society of the Pacific in San Francisco California. We're very excited to present this webinar with our guest speaker Kelly baby from sky and telescope magazine and the International Dark Sky Association. Welcome to all of you on the YouTube live stream. We're very happy to have you join us. These webinars are monthly events for the members of the NASA night sky network. There's more information about the NASA night sky network and the astronomical society Pacific. Hopefully I can convince Vivian to drop a couple of links into the chat. Before we introduce Kelly here's Dave prosper with just a couple of announcements. Okay, I just have several bits of news for everyone tonight. First off, as some of you have already sometimes posted pen orders are being shipped and are now being received around the country. All orders from November and December have been shipped in the past couple of weeks. You can see my extremely high tech shipping area. And the rest of the ones for January should be out by early next week and they'll be going out this weekend as well. And if you haven't ordered yet. That's not a problem because the order period is much greater this time around you got to like the end of March to do so. The free pins for clubs will be sent out by April, unless you order earlier and if you use something in the order form, you just be like I got the three free pins, you know, you don't have to pay. So, I'll put the link to the pin order in the chat. Just so you got that just basically just all the information and making sure you know your clubs qualified by posting two events from last year, if you could. Also, so also just thank you for joining our little webinar tonight. For next month, we're going to do something a little different. We're going to have a watch party. And so we're going to watch the coverage of the landing of Mars perseverance and ingenuity on February 18, and you'll be able to join us for that if as much or as little as you want. We're lining up some special guests and such right now. And so if you're going to watch NASA stream on that day and you want to bid a company pop on over at our stream. We won't be having the stream like actively in the background for us so you might need like another device to watch it. But it's sort of like a, if you're going to just look at us and not watch it is almost going to be like a night sky network and guests react to NASA coverage sort of look, you know, it'd be like that. But yeah, we're just having like a watch party basically. It'll be a lot of fun. And details will be posted in the February newsletter, which should be at early next week. And also on the night sky network website in the next couple days. And you can watch with us for as long or as little as you want and I'll just post a link to the registration in there in the chat and Oh, Kathy Moore is mentioning that that the Girl Scouts are in Idaho are planning a virtual watch party as well. That's awesome. And oh, I realized I just put the pin order link into just panelists so remember, make sure you've got a panelists and attendee selected. And last one. It's also time to nominate your favorite astronomer for an award from the Astronomical Society of the Pacific the ASP awards nomination process is open to all. For if you've got someone you know that's involved in research public outreach or active in the amateur astronomy community or teaching communities, please send in your nominations. You can check out the ASP awards website page for details on a nomination process and info about previous award winners, and we'll send this info in our newsletter again in early February as well. And it'll be on the main page in a couple days to and we know you have a favorite astronomer, maybe in your club, maybe a local university, maybe they presented to your club or they're your buddy, not made him for an award, make him feel loved. And yes, this year the ceremony will be a virtual one, but it will be as glamorous as we can make it. So, boom, link in the chat. And that's my brief news bit back to you by. All right, thank you very much Dave lots of good things there and so we're looking forward to that watch party in February. For those of you who are on zoom you can find both the chat window and the Q&A window, the buttons to reach those down at the bottom edge of your zoom window on your desktop. Please feel free to greet each other in the chat window, making sure to select two panelists and attendees, or else it would just go to the panelists. Also, let us know if you're having any technical difficulties you could put that in the chat or you could send us an email at night sky info at astro society.org. If you have a question for Kelly this evening, please type that into the Q&A window. If it goes in the chat, it's going to get lost and so put those in the Q&A window so that we'll be able to find those. And I think that that's about it on the preliminaries. So I want to again welcome everyone to the January webinar for the NASA night sky network. This month we welcome Kelly Beatty to our webinar. Kelly has been explaining the science and wonder of astronomy to the public since 1974. An award winning writer and communicator he specializes in planetary science and space exploration as senior editor at Sky and Telescope magazine. Kelly enjoys sharing his passion for astronomy with a wide spectrum of audiences from children to professional astronomers, and you will occasionally hear him guesting on NPR, or the weather channel. He's served on for a decade on the board of directors for the International and Park Sky Association, and he's an officer for IDAs Massachusetts chapter so please welcome Kelly Beatty. Thank you very much, Brian. It's great to be here. I've been watching the chat and seeing all these many names that are familiar to me so I need a couple of shout outs. One is the St. Louis Club, which is going to have Ray Arvidson as a speaker he is one of my favorite people that is fabulous this is in the context of the perseverance landing. And the other is I better watch myself and we have instant back checking going on because one of the attendees tonight is no none other than Tim Hunter, one of the co founders of the IDA in 1988 and Tim writes a monthly column on light pollution for the reflector for the astronomical week. So Tim great to have you here with us. And I'm without further ado I'm going to get going at let's see I need to share my screen and we're going to go to my take that and we're going to start at the beginning. We got this far down I don't know but we're just going to back up and here we go. Okay, so I want to kind of set the tone here a little bit. I'm going to read this quote, which is something about the, the preciousness of the night sky that could have been written, you know, yesterday but it was actually written almost a century ago by a naturalist named Henry best in who spent a year in Cape Cod. And it sort of encapsulates the feeling that I have and what we what we have in the night sky is precious and so much of it has been lost. And it's been lost to light pollution, which is becoming more common certainly among amateur astronomers, we certainly all know this term but in the general public as well. It's basically artificial illumination of the night, and it has various forms of glare light trespass any disturbance of the natural landscape. And it, you know, so much of it is is wasted light wasted energy light that's not necessary. And I need to say here that the goal is not to have no light at night but to have the right light at night, and we'll get into how how that can be accomplished. In terms of terminology, we take the light that comes out of a fixture and we kind of subdivided into three general categories of, of where it's going. If it goes above horizontal, that is nowhere hitting the ground and up into space. That's known as up light, and the area that hits the ground and within a reasonable distance that's the useful light and then there's this slice just below horizontal which creates glare. That light eventually does hit the ground but it can be annoying in the meantime, if it should hit your eyes. Now, this is an interesting, I'll show you some pictures of earth from space and those pictures show light that's going up into the sky. And you would think that the light from a lamp that is going straight up like a searchlight hypothetical searchlight would be the worst and it's not. These three computer models show how much light scatter is created. When up here, can you, Brian or Dave, can or Vivian, can you see my Chris you're okay. Yeah, it looks good. Okay, this, this is, this is light that is basically shining straight up and I want you to know it's two things first of all it doesn't spread side to side. And while the amount of scatter that it creates is relatively relatively confined and limited, but does that light gets closer and closer to going out straight to the side and horizontally eventually down here, just within that slice within 10 degrees of horizontal just above that is where the most damages done. And so for any of you living in a, in a suburb of a big city. Yeah, I live 30 miles outside of downtown Boston, when I look straight up. I am literally experiencing light pollution created by bright lights, 30 miles away in Boston, that are streaming glancing overhead and passing through my Amster, the sky glow of me. So that's, that's where the real damage is done from the standpoint of sky glow for a few examples of you know the good and the bad of lighting of fortunately these are becoming less and less common. This is an old style street light, and the bulb is down here inside this kind of glass salad bowl. And that salad bowl is a lens that that takes the light from that single bulb and distributes it across the street. But some of that light ends up because the bulb is down here in the bottom some of that light ends up going above horizontal. Then about 1990 or so, many communities started using these fully full cut off lights, where the bulb was actually up here in the housing the bottom is flat. And all the light went down on the ground and that was the sort of first wave of improvement over or on street lighting technology. So over here I want you to notice this little thing right here. And for those of you who are seeing me in the in the corner this is one of them. This is the day night sensor on top of every street light. And it lets in light and in days gone by it simply caused the street light to come on at dusk and go off at sunrise. And that light was on, you know, every night all night. And that's because a lot of this lighting technology high pressure sodium mercury vapor whatever it might have been was driven by balance and these lights did not like to be turned on and off very often. So once a day was plenty. And so that the technology vault just have them beyond all night which is obviously a problem for us. Another really bad kind of light is the kind that gets slapped onto the side of a building with the intention of trying to light up a parking lot nearby. We call these wall packs. I consider them sort of public enemy number one, in terms of bad lighting. They, they, of necessity send out their light horizontally but also way more than that here's a here's a side view of a wall pack, showing the broad spread of the light both horizontally and up and it's just awful. Another thing that this is, I haven't seen too much of this out in California but maybe people can comment or ask questions or drop me a message. Here in Massachusetts, if you're a business and you and you don't want to have the expense of installing parking lot light yourself if there's utility pole outside your business. The utility will very gladly put up a light for you that shines on your parking lot. And they're not very well controlled as you can see and this is kind of what they look like at night. The fog here adds to the dramatic effect but they're they're just awful in and of themselves. So, so I'm going to take off five reasons why we should be concerned about light pollution. The one that we as astronomers worry about the most is the sky glow that it creates. I suspect if this is the demographic of a typical astronomy club, most of you are well old enough to have remembered the great blackout in August of 2003, which blacked out a great part of the Northeast. This is Southern Canada, South Eastern Canada, Toronto's dark, Ottawa's dark, a lot of Detroit's dark. Look at all these places that have no lights. The cutoff line was somewhere around here. And when that happened it was in August. This was taken by a guy named Todd Carlson who was in downtown Toronto. While the lights were off, he took a picture. This is August. So the Milky Way is up beautifully. And he took a picture toward the south. These are candles in his home. And it's this just beautiful starlit night. This is from basically downtown Toronto. And then the next night the lights came back on and this is the same view over here on the right. I'm showing you very dramatically what we've lost, what we do lose to light pollution in terms of the beauty of the sky. Now for many years the National Park Service has had a program, a team that goes around to National Parks and measures the darkness at night. They're called the night sky team. And they've made it to many of the National Parks across the United States. And what they do is they take all sky photos. Very carefully calibrated. This is the bottom is the sort of fish eye view. And then the top here is along the horizon and you can see a couple of small light zones from very distant towns but basically this big purple band here and the one going across here that's the Milky Way. And so this is a particularly dark place at Natural Bridges, dark sky place. Now this for comparison is from Mojave, Mojave National Park now I believe it is, and that big blob that you see in the distance is Las Vegas about 50 miles away. Very bad. And despite the fact so here's my point, Las Vegas is 50 miles away, and you can see how even directly overhead, the stars are pretty washed out from light pollution simply because of the scattered light coming from Las Vegas. This is an actual photo in that direction. And this beam that you see here is not some artifact it's actually the Luxor Hotel in downtown Las Vegas with this tremendously bright light up in the up in its dome beaming straight up into the sky. Really horrible. The East Coast, one of the most popular national parks is Acadia on Mount Desert Island. And it's, it's for any of you who've been back here it's becoming quite an astronomical destination because the town of Bar Harbor which is this little light dome right here. It has a lighting ordinance and they're going to a lot of trouble to control the lights because a lot of people come to Bar Harbor and come to Acadia be just for stargazing. And there's a huge annual event called the Acadia night sky festival held in September, October if you have a chance to attend it's really terrific. Now back over on the West Coast, some of these national parks, recognizing that their night sky is a resource, an environment to be projected just like the daytime is have gone to some links to to really correct their lighting. There's a big project going on in the Grand Canyon right now but this is Yosemite National Park and you can see that these are all pretty effective lighting examples down here these are amber LEDs, which are the most benign from the standpoint of wildlife. And you know the idea has one of its signature programs is the dark sky places program which certifies that places are are are dark and will stay dark, and the towns and regions that apply for this have to go through a fairly rigorous process in order to get this certification there are plenty of them in the Rocky Mountains there as you can see the one we're particularly proud of here, I'm from the Boston area so. Up here in northern Maine is a new night sky sanctuary that's the darkest of the dark. It's 90,000 acres of land that was donated to the government to create a national monument and in those 90,000 acres there's like six lights. So it is it is truly dark. Now what I want to do is is just for a moment here. I'm going to show you this is a new thing that I just found out about shortly ago. It's, it's a guy by the name of Suje Patil, who's in France, and he has created a database of dark places to go stargazing and I'm going to this is this is a sort of summary map and the. We discovered that this doesn't work so well if I don't, I just need to jump back in and and share my web screen. Watch a web screen. There with me just sec here. Okay, we'll go to point screen our point. Well, where are you just screen drive. Now, maybe we'll just skip that. Go back to this. So, the website is dark sky map.com. And what I want to encourage all of you to do. Suje isn't quite ready for this yet but all the dots that you see on that map are essentially observatories of one sort or another. But it obviously could benefit from having the input of amateur astronomers in various regions, you know Southern California or Colorado or, or New England, where we kind of know the territory and we know where places are that are good stargazing locations. And so he's going to create a kind of interface with his with his website so that you can submit to him probably in webs in like an Excel form, a list of dark sky viewing places and greatly expand this this database. It's just getting started there's also an app. There's a companion app it's called meet stargazers. And it's a it's a comfortable kind of map for for finding places to go stargazing. So I encourage you to go looking for that dark sky map.com. All right, the second thing is visual impairment this is nothing to do with astronomy it has everything to do with being able to see at night when the light is not strong. Just a little bit of physiology here if you didn't know this your eyes have two kinds of sensors, the cones which which provide your daytime vision and also your color vision, and then the rods which provide your vision at night. And, and I want you to notice that the rods are much more sensitive in general this is a log scale over here on the left. They're much more sensitive in general and they're more sensitive to blue light the peak is over here in the blue green section, and that that plays into important considerations later on. So, so here is a typical backyard in say oh I don't want to pick on any place in particular let's call it Tucson, and somebody has a security light all night on all night and if you're passing by your eyes react to the light coming from that light and they don't want to see that would ordinarily be dilating just shut down and make it very difficult to see what's really there which in this case is a bad guy standing in the gate there. You know just mining his own business in this particular case but but you couldn't see him very well at all you wouldn't have noticed necessarily that he was there. And so that's why even your security lights around your house need to be shielded in order to get the most effect out of them what I what I tell people is in your home in your living room or bedroom whatever the lamps that you have there have lamp shades on them for a reason because if you were just looking at the bear ball would be pretty harsh. And that would be with the the whole safety and security of being outside at night. Again, it's not that we don't want any light but that light needs to be down on the ground in the what we call the target area, illuminating illuminating the sidewalks and the streets and not shining directly in your eyes. So the environmental consequences are significant from light pollution and light in the night sky. You know there are a lot of creatures that that do their thing at night. They pray they eat they mate and and our lights at night are disrupting that and they're there are lots and lots of examples but here's here's just one that I want to point out to you. These are pathways of migrating birds are throughout the year. And here along the East Coast we have one called the Atlantic flyway which as you can see goes right up the coast and right over the Cape Cod in Massachusetts. The birds have these very sophisticated means of figuring out where they're going on their migrations. And one of the things they key on is lights and in a in a dark pristine environment they key on stars or the moon or glints off the water whatever it might be but if you introduce a bright source like a city in the middle of our migration route then instead of flying in a straight line to wherever they're headed. They start circling that light and and eventually they can they can literally circle a building, a lit building or a tower or something at night. All night they essentially become captured and fixated by it, and then they drop out of the sky of exhaustion or just dead where they become easy prey and tens of millions of birds die every year during their migrations because they get entrapped by by the lights of the city. And that's not so good. The fourth bullet point here are human consequences and this is an emerging area of science and I don't want to try to hit this too hard but it basically boils down to this during the day, you're supposed to be away and during the night you're supposed to be asleep and when it's dark. There is a little gland in your brain called a pineal gland, which gets a signal from your eye having nothing that that sensor in your eye has nothing to do with vision it literally tells the pineal gland it's dark, make melatonin. Melatonin is a compound that's been shown to be very effective in as an immune as part of your immune system and your overall well being. And at night your body normally makes lots and lots of melatonin, and you get enters your bloodstream. But if you interrupt that cycle by turning on the light. So you make a raid of the fridge or you know hit the bathroom in the middle of the night and flip on the switch. You interrupt that cycle you and your melatonin protection comes crashing down and it's, it's, it's not good for you. In fact, the late Richard Stevens who died just a year or so ago. Decades ago realized that exposure to light at night suppressed melatonin and may lead to a risk, increased risk for breast cancer in women and prostate cancer in men. We're not talking about just, you know, the light from the streetlight entering your bedroom window we're talking about, you know, graveyard workers and nurses, working overnight. They're, they're the ones who, who really had their circadian system really messed up. It's, it's true for all of us that light at night disrupts our circadian system, and not it's been a more than a decade now that this disruption due to light has been considered carcinogenic to humans and and this is a fortunately these lights aren't here anymore but but can you imagine having to try to go to sleep with these glare bombs outside your bedroom window, not good. And more recently the American Medical Association has gotten into this, this activity on light pollution and has found that, you know, light pollution and sky glow is potentially harmful. And more recently, they, they concluded that it's actually a hazard to seniors. As we get older, our eyes the inside of our eyes get more cloudy and our lenses get cloudy. And so the glare from bright lights at night creates a lot of scatter in the eye makes it very difficult to see well. The last thing I want to touch on is energy waste. You have all seen, I'm sure, images of the earth taken at night from space. And here's one of the eastern seaboard. Just to set the stage here's New York City, here's Boston up here where I am. This is, let's see, this will be Philadelphia, and this is Baltimore, Washington, I think this is Richmond down here. Over here, this is, this is Toronto, I believe the Chicago is not quite in the picture. So, here's a, here's a picture of the Boston area and you would think that the interstate highways would be the worst, some of the worst places for showing, you know, for having lights along them. But actually, if you think about interstates are not really lit continuously. It's the state highways and here are a couple of examples root nine and root one in the Boston area that are lined with, you know, businesses, all night gas stations and McDonald's and parking lots that stay lit all night even though the stores themselves are closed. And it represents a tremendous waste of energy. These data right here are a little bit dated, but when this map was taken when this image was taken that the amount of waste just from the greater Boston area was 15 million kilowatt hours a year which was millions of dollars. And I'll show you in a second how that situation has improved, but it's not improved everywhere. This is a picture of downtown Chicago in aerial view taken for National Geographic. And if there's any city in the US that's over lit it's Chicago and Chicago was over lit by design for decades the mayors and the city councils intentionally over lit every bit of the city ostensibly to make it safer. Okay, so I'm going to take just a break here I'm going to jump into the Q&A section. Darien says I use a green laser do you know if it's possible to obtain permission to have a light switch paste at the base of public streetlight. As far as I know Dave Darien the answer is no streetlights are almost always unmetered. So, even if it were possible to install a streetlight, which generally is not, I am sure your town would say, rightly or wrongly, that having that streetlight turned off increases danger to the public community. There are solutions and I'll get to them down the road here so let's see we have what can be done to change the lights here in Chicago that which is exactly right. Let's see, Joe that Joseph that light is. I think Chicago has now finished a retrofit to LEDs. And I would I don't know off the top my head is whether those LEDs are connected our computer controlled or not. But Chicago is a very tough situation we try to engage them and they read with the idea did and they just did not want to listen to it at all. Alan asks, is there who lives in Allen lives in Wyoming. And he wants to know how, how to get a dark sky expert. So how you can become a dark sky expert. I'm sorry Alan. Yes, I think that the solution Alan is to become an advocate of the idea of the International Dark Sky Association. And there's a series of webinars that advocates that is to say, you are maybe your club. The Center Wyoming Astro Society wants to become more engaged, or you yourself can be a become an advocate and and as an advocate you have access to a whole bunch of webinar webinars and how to use that that we have that can bring you up to speed. The other way is just to listen really, really carefully and take lots of notes during my presentation tonight. But, but you, you know, I am not a lighting expert and I now know really an awful lot about lighting systems and what works and doesn't, and it's all self taught. Let's see Debra asks, whether it's possible to add new improved non glare design for best visibility regarding dark sky lighting. It's, it's a long question Debra. Basically, she's saying that police departments want much faster, but I mentioned dark skies. Alright, so the problem is dark skies right at the turn off for a lot of people they think that you want to make it dark. I've started talking in terms of instead of dark skies. The night sky conservation. You know it's not just about being an astronomer. It's, it's the biology is the human stuff the kinds of stuff I'm talking about here. If you're if you're police chief can get and you're the people that you're trying to approach can get past the notion of dark skies being all the lights shut off and realize that that There are better ways to do it. Brian I see you jumped in here does this mean you want to say something. No, I'm good. Okay says Brian would like to answer this question live sorry. Let's see do I know what the legend is from the dark for the dark sky map no I do not. I don't know what each of those little symbols means. If you go I couldn't get to the website to sort that out. I encourage you to go to their dark sky map or.com, and I'm sure it's explained it Spencer says that a coffee cans can host up to the top each has a red LED with the battery that's great that that's a very nice non destructive way. The term so back to Deborah, the term non glare is what we need it's not about just glare, Deborah as we'll get into it. It's, it's a bunch of factors, including the intensity of the lights, the color temperature of the lights and I'll get to those in term. Alright, I'm going to keep going now. I get my. So let's see if I can get this to work again, because this is this, this is really important. Our, our sophistication in being able to map out where light pollution exists has gotten much much better with a new series of satellites with with improved nighttime centers that have better spatial resolution and not to pick on any city in particular but here's Las Vegas. So we'd like to try to do stargazing from, and, and there is a website called light pollution. My own light. Let's see. It's called. There we go. Light pollution map dot info. And I'm going to try this one more time to see if I can get this website up. I'm going to go back to that first light pollution info dot map. Okay, now. I'm going to go try to go back to sharing my screen. And let's see if I can share this. Are you seeing a map of Europe. Yes, yes. Okay, great. I got to work so let's go over here. And let's pick. This is, this is, this is really, I'm going to show you how you can use light pollution map dot info is the website. And so this is what these giant colorful puddles will take St. Louis because they're very active they have a very active club and I know some of you are here tonight. And this is, you can see up here at the upper right this is the world atlases of 2015 back in 2015 the data that we had to work with was from a series of meteorological satellites from the Defense Department that had relatively poor spatial resolution on the ground so you see that it's kind of resolved but mostly St. Louis is a blog. If you go here to this drop down menu I hope you can all see that you can pick I can show you this this new generation of satellites. You can see what it looked like in 2012 you can see the resolution is a lot better this is the, the, the light pollution map in St. Louis in 2012 now here's what it looked like in 2020 for comparison. And you can change and jump to different years and you can, you know you can use these sliders to increase the amount of the background that you see. Here's an example you can and these work make for fantastic presentations and you can go anywhere in the world and call up these maps. But what I want to do instead is show you, I should just leave there. Let me do that. Now I'm going to go to a different website. Now you should also see a map of the world. Right. It's Aurora's. And I want to show you a really kind of horrible situation. In the decoders. That's Winnipeg Canada that's not where is it. Here it is. Okay. These are the fracking fields of North Dakota. And this, this is a place where two decades ago there was no light pollution whatsoever to speak of and now it's this giant wasteland of 24 seven, you know, extraction from the ground. Again, the website here is not the same as the one before it's light trends dot light pollution map dot info, write that down because I'm what I'm about to show you is magic over here at the upper left is a little, a little geometric icon, click on that. And I can draw a box around this. You see me drawing that box. And having done that. It's too big. All right, I'll make a smaller box. The area is too big. It's size of a part of the state than down here having drawn that box around that area down here at lower left I'm going to generate a chart. And here's the chart. And it shows in graphic and gory detail. Over time, how much the light pollution has increased in that location. The, the, the, you know, the, the numbers here, the fact that I've got six significant digits seven significant digits here. That's an awful lot of light per square kilometer in that area. Now you might think that light pollution has increased throughout the country over time, but that's not necessarily true I happen to discover this today I'm going to zoom in on Boston, my hometown. And I'm going to do the same thing around basically downtown Boston. Right. And now I'm going to create a map, a chart and what I want you to notice that in Boston proper. Light pollution is actually trended down. Yeah, I can, I hope you can all see that chart. Okay. This is fabulous for your location to demonstrate what your situation is and because the data has good spatial resolution, you can you can pick the entire city, a little suburb, a big business development outside the town whatever it might be. And you can show very graphically how much the light pollution is increasing down here, down here in the bottom. It tells you what the trend line is right and how much the how much it's increasing. What I want you to notice, especially about Boston, this is something to be wary of. You notice how we get these peaks near the beginning of each year. And that's because of snow cover on the ground. Light pollution always goes up the scattered light in the sky goes up a lot when there's no cover on the ground. Okay, that's all light trends dot light pollution map dot info for that. And now I'm going to go back one more time to this chair. So I show from. Okay, good. Okay. So, there's, there's an example here's, here's an example from a little town population 4300 called milanocket main. Why this is important is that milanocket is right on the edge of the newest night sky sanctuary in northern and this is a place where it used to be where they used to be giant paper mills operating day and night. The paper mills have shut down they've left town. And so this town has an opportunity to really correct decades of light pollution growth you can see that the trend has has been slightly increasing but it's not bad and they're working to do better. Okay, I'm going to take another break and see if anybody has questions. Let's see. All I'm seeing here. Does it look like we have any fresh questions. Okay, good. Well, let's move on then. I'm going to go back to this. The promise of LEDs. So, on the left, I'm showing a bunch of different classic kinds of lighting sources, many of them will look familiar to you. We have we have incandescence which are which are not very very inefficient 90% of the light of the energy used in incandescent bulb escapes his heat, much better or fluorescent mercury halide fluorescent bulbs. They're all that over the time we've gotten better at generating light from electricity, but none of them can touch the energy efficiency of light emitting diodes which are shown that shown there on the on the right. And I just checked today. There are there are LEDs now that create 250 lumens or which is a measure of quantum of light output per watt of electricity. The theoretical limit is around 300 lumens per watt but it just blows away all these other traditional sources. So LEDs have been a fantastic development from the standpoint of lighting technology. It's going to revolutionize the way we light the night and maybe our indoor spaces as well. But there is a problem that we need to all be aware of when it comes to LEDs. And that is something called color temperature. So color temperature is is a way of describing the, the spectrum of a light source based on its temperature if it were a black body radiator and I want don't want to get into that but but let me just give you a common everyday example. Imagine a candle's flame and the flame out of a gas grill or a or your your stove. The blue light that comes off of gas flame is telling you telling your brain this is a much hotter flame than the yellow color of a candle flame. And so the higher the Kelvin the higher the color, the higher the temperature, the bluer the light source. And I'll give you a good example let's see if this will, this will show. Yes, alright so this is a sort of step wise representation of color temperature. And you can see that the lower the number the lower the temperature the yellow or the warmer the light. And so, as you get up to, you know, 5000 that's the temperature of the sun, the surface temperature of the sun is about 6000 Kelvin and so that's that's daylight and it can get even bluer than that. The problem is that a lot of early LEDs and the cheap ones that you, you can buy at the hardware store in the flashlight are very high temperature they have a lot of blue in them. And blue at night is very bad. So now when you go down to buy lighting at your store. You can see on the label in addition to telling you how many watts it uses and how many lumens it puts out. And how many lumens per watt it puts out it also gives you the color temperature that's this number here 3000 and if you're really lucky, it will give you a little colors color bar like this. And this is what we might call warm white. And when it comes to lighting at night, we want the color temperature to be as warm as possible that is to contain as little blue light as possible, because it's that blue light, which has higher energy for photon that is most disruptive to our nighttime environment. And I want to take you back I showed you this before but I'm going to show you it again in the context of now LEDs. At night are we rely on the rods for our night vision, and our rods are very sensitive in the blue part of the spectrum. That's why using a red flashlight at night when you're trying to read a star chart or whatever it might be is a good thing because our rods are very insensitive to that red light. And, and you, you, you probably know that over time, when you're exposed to darkness at night, your, your eyesight improves, both because your pupil enlarges, and also because your rods, a secret, your retina secretes are a compound called rhodopsin, sometimes known as visual purple, which essentially put your rods on steroids and causes them to be super sensitive. And as soon as you expose those rods to a blast of white light or blue light blue rich light. The rhodopsin gets bleached out and you have to start all over any of you that spent any time out with the telescope know exactly what I'm talking about. Alright, so here's the deal. These by and large are replacing throughout the world throughout the United States probably in your towns and cities street lights that used high pressure sodium bulbs. They have that sort of characteristic peachy color that is pleasantly warm and high pressure sodium is that color because it has virtually no blue light in it as you can see from the spectrum it's got a series of very sharp line emissions that combine to create that peachy color very little blue light the effective color temperatures about 2200 Kelvin. Remember that number. By contrast, LEDs have blue light in them, and even when, even when they're sort of cranked down to be at a lower color temperature that's happening because the LED bulb has a phosphor that coats the inside of it. It absorbs this intensely blue and ultraviolet light that the the native or new naked LED puts out and and then creates it at a warmer spectrum as you can see between these two comparisons. So 3000 Kelvin has a fairly small spike of blue most of the blues been absorbed and re-rated and at other color at other longer wavelengths, whereas a 5000 Kelvin has a very distinct strong peak. If you were to see a 5000 Kelvin light at night, it would seem very harsh to you, because your your rods just they overload on this and this kind of shows that story, but that this heavy black line is the emission of a 5000 Kelvin LED. And for comparison, I have two other curves. The solid curve here. This is your daytime vision or what's called photopic sensitivity. This is your, your date, your, your eyes, the cones in your eyes. This is their response curve. And then at night the dashed line is your circadian sensitivity. This is the light at night that would disrupt your sleep that would keep you awake. The light doesn't correspond exactly to the response of the of the rods, but it's close and you can see that the strong peak of an LED is right in the wheelhouse of your circadian sensitivity. This is really bad. It's not just human. It's, it's all animals as well are completely disrupted by these strongly blue LEDs. So what's the solution. Well, not to have blue LEDs. So if I hear as, as you go and talk to people about LEDs, especially if they're city officials or something, or lighting people that really don't know what they're doing. I have heard it said many times the 4000 Kelvin LEDs are just like moonlight and if it's good enough for the moon it's good enough for us and that's just not true. I'm going to come. This is the real comparison. The 4000 Kelvin do match moonlight in the sort of red part of the spectrum but in the blues part it's it's it's completely skew. In fact, blue light is closer to a 2200 Kelvin spectrum, then it is, then it is to the 4000 so blue light moonlight itself is actually quite warm. And lots and lots of cities and towns are converting to LEDs and why wouldn't they, because they're, they're highly efficient. They can be controlled in amazing ways. But in Cambridge mass not far from me, which is a very densely packed place. They put in 4000 Kelvin lights, and I for one would not be the owner of this house and have this streetlight shining into these windows. I will say in partial defense of the Cambridge system. Every streetlight in Cambridge is has an IP address, it is wired through Wi Fi to a computer system. And so if the owner of this house says, Wow, this lights way too bright can you turn it down. A few clicks on a keyboard can turn this down to 50% 30% whatever and in fact in Cambridge, all of the streetlights power down to 50% of their normal output after 10pm by computer control. This is something you can do with LEDs that you just cannot do with any other kind of light source so it's, it is really a good thing. Even so, blue light that's in LEDs is a problem. It is, it is, it's, it's, it's a problem both for humans and you know all those, all those lighting maps that I was showing you taken from space, the new generation of satellites are relatively blind to blue light. They're picking up mostly the rest of the visible spectrum but not the blue light so they're under representing how much blue light is actually showing on the ground. The United Medical Association several years ago came out quite strongly against LEDs as a above 3000 Kelvin as a possible health hazard. Now we're getting near the end of this talk and I'm going to have to leave a lot of time for feedback and questions. And when I got started in this game, banging the drum for for better lighting at night and LEDs didn't exist yet really. I was kind of an odd tree hugger environmentalist whack job, but now I'm still all those things but now, you know, a lot of people know about light pollution there's a growing awareness of it, especially in mainstream media. There's also a geographic cover from several years ago now, a decade ago, and that is downtown Chicago. And, and so a lot of places are now paying close attention. And in fact, just within the last year, the International Dark Sky Association and the illuminating engineering society. The national organization that sets the lighting standards for the United States partnered together after years of kind of dancing around to create what are called the five principles of outdoor lighting that lighting should have be useful have you can see them should be useful should be targeted should be no brighter than needed should be used only when you need it, and should be the warmest possible color that you that you can get away with and it's really great to have the, the people who, who are listened to for lighting advice and lighting levels finally coming around to partnering with the idea to control light pollution, and we're very hopeful that in the years going forward that that together this partnership will will create new pathways for for reducing having having that lighting the be smartly applied. But really the bottom line is, no matter what the light source, whether it's the color temperature. The bottom line is to light, only when you need it, only where you need it, and just the amount necessary. As Tim Hunter as one of the founders of idea and Dave Crawford the other founder would say, no, no, no more everything else is waste. I want to call your attention before we close. First of all the idea is website is dark sky.org. And there's a lot of information there if you've not checked it out. We have a celebration coming up in April called international dark sky week that I hope you and your clubs will participate in in some way. It's a little challenging during the pandemic of course, but one of the resources on the website is a little public service video called losing the dark and you can see the URL for it down there at the bottom. The video is professionally produced. It's about seven minutes long, and it essentially touches on all the themes that I've been talking about here for the last hour, or so, and condenses them in a way that is very approachable. The videos a little dated now it doesn't really go into LEDs at all, but it is, is definitely worth a watch. So in closing I just want to show you that these are the your go to places I list the Massachusetts chapter there because I am in Massachusetts why not. And there's my contact information on the bottom I welcome any of you who have questions about lighting your clubs want to get involved I think every honestly. I'm gonna tell you an anecdote. I give a lot of talks. I used to give a lot of talks in person to astronomy clubs. I would ask at the beginning no matter what the topic I'm talking about black holes or whatever it might be. At the beginning I asked for a show of hands of how many members in that club. This is an astronomy club are members of the idea. And I would get a handful. I certainly wouldn't get an audience full. And the sad reality is that if you take the number of members of idea and they take the estimate of the number of amateur astronomers in the United States. There's probably only three out of every hundred amateur astronomers that's a member of the idea. It's really pretty pathetic because we as a as a group as a group of hobbyists, we have as much to lose as anyone. If we can, if we can't control the lighting. And so I encourage all of you to when this is done to please go to the idea website sign up becoming a member. It's the it's $35 a year it's comparable to your club dues. You will help us. You know we have an idea I'm not on the staff obviously but idea has a staff of maybe eight people. And we're trying to change the world. And there are so many projects that we want to task get get on to here in Massachusetts we're trying to pass state legislation that would control lighting for state and municipally funded projects. We're trying to change energy codes around the country. We're trying to intervene in cities like Chicago and Tucson, where, where they're about to install LED lighting, the idea volunteers in the Phoenix area. Phoenix has a roughly 100,000 street lights. A couple of years ago they were about to install 4000 Kelvin street lights throughout the city. The city staff and volunteers interceded spoke to the city council, convinced them of the wisdom of using 3000 Kelvin, and in a nine to zero unanimous vote, the city council of Phoenix now the only adopted 3000 Kelvin as its standard for street lights, but agreed to move and substitute 3000 for the ones street lights that they had already installed. One person can make a difference. The idea can make a difference and we can't do it without your health we can't do it without your, your support out in the trenches, we can do it without your dollars helping through your dues to allow us to undertake the programs that we would like to. And I think I'll stop my, my petition with that, stop sharing and maybe let's let's have a bunch of questions here. It looks like we've got quite a few questions there so. Alright, I can see them now. Where can I find Danny asks, where can I find out what kind of lighting my city has well Danny I'm going to assume that there's. Let's find out if they've converted to LEDs yet or not. For those of you who have not yet had your town or city convert to LEDs, it is coming. There hardly will be a place in the country in the US in five years that doesn't have led street lights. It's the economics are just so compelling. Let's assume that that if you haven't converted to LEDs yet, you'll know because the lighting is probably has that peachy color that I was talking about. Those are high pressure sodium and that's good because that means that they haven't made the conversion yet and you can find out, you know, what what is planned and ask hard questions and, and maybe make a difference in the lighting in your city. If you've already had an LED replacement. Then you can probably go to your either your planning department or your department of public works that usually the people who are responsible for the conversion and and find out what the specifications were of that light. The things that you want to know most importantly are what's the color temperature of the lighting that got installed or will be installed and how bright are the new lights going to be or are they a lot of times towns and cities that don't really know any better will take a light that puts out a certain amount of light, you know, 3000 lumens, which would be typical for a 50 watt high pressure sodium street light and they'll replace it with an LED that also puts out 3000. We call that lumen for lumen replacement and that's BAD bad because of the blue light that the LEDs have you your eyes will see the even though the amount of light is equivalent, your eyes will see that light is being considerably brighter. So you want to find out what the color temperature is you want to find out what the what the lumen output is compared to what was there before. And if you're bothered by a street light. It's very possible that that light can either be controlled, or maybe they can install a shield so it's not shining in your face. Darien says that having checked I guess you checked the light pollution info that Chicago is trending down for light pollution very interesting that's probably true. Remember though, Darien that those. Those new satellites are relatively insensitive to blue light. So, you might not be getting the whole picture and he continues to ask. Oh yes is there a light advisable to have on at night while he's sleeping, or should all lights on his bedroom be turned off. A great question. So, Darien, I'm going to assume that you're an amateur astronomer, and you probably use a red light up by your telescope. Well you should use a red light in your grandson's bedroom. Take a standard little, you know, nightlight and and buy one of those teardrop shaped, maybe a red led or a red bulb from from a Christmas after Christmas sale or something. That's what we use in the BD household. We have red lights all over the place at night. And that way when you get up at night, you can see but your, your, your, your melatonin production won't be disrupted by that. Let's see, Deborah wants to know if idea can feature more good quality warm LEDs and action on its website. Hmm. Okay, that's a good point. One of the issues is that photos don't really show well the difference in color temperature. It's something that your eye sees in a way that the camera does not it's one of the one of those cases where the eye is actually better than the camera. So yes, it's certainly possible. And in fact the idea every year has prizes that are awarded for parks and whatever that have installed good lighting. Gary asks we live in Sedona. Many of the homes are non compliant. It's jumping around here they said you just enable blue light LED for business lighting which we do well Gary first question is, do you have a lighting ordinance in Sedona, I don't know the answer to that question but that would be the first thing to check. And the second thing is to talk to the. It's not so much the homes that are probably going to be the problem with the businesses. And so you should, I don't know how you would approach the businesses you in some sense you need to be brave and just go out there and talk to them. Do they leave the lot parking lights on all night does the city in Sedona itself, you know, parking lots don't need to be lit at night when there's nobody there. It's a great way to reduce lighting. If you want Gary, I would like to continue this offline but you know in Sedona, in particular, there are huge groups of IDA supporters both on either side of you in Phoenix and also in Tucson. I would go there first but but I would be happy to help if needed. Bernard wants to know if the presentation of slides will be available with our communities. Bernard I guess the answer is yes. If you go to the Massachusetts, well, yeah I need to update but on the on the Massachusetts chapter of the IDA website. I have posted this talk, and I'll work with Brian and Dave to see if we can get it and Vivian this we can get it on the night sky network somewhere. Yeah, I agree. Brian wants to know. Wait just one second I just want to say that I know that it's after the top of the hour and we never go long on our talks but this is so important and we're having such a good time we just understand if people have to leave because it's late some places but I'd like to just keep talking if, if you don't mind. We'll go for another five minutes or so. Brian wants to know about Starlink satellites which is that it's a specific very specific kind of light pollution. There is some hope. The American Astronomical Society just had its biannual meeting and Starlink and other companies were represented there. Brian, I encourage you to go read about this on the sky and telescope website we have two articles about this that were just posted. Alright, so David in LA says, there's a new housing development near Fraser Park, a sacred space to be sure. How can we get them to pay put amber and and down lighting in this new large community what can we do to get developed to install correct lighting. Would IDA be able to help. Yes, for starters. There is a chapter in California but I think it's up in the Sacramento area so I would I would contact Tucson specifically. I'm a little bit far away from you I certainly know where Fraser Park is. If the if the plan is not too far along, try to find out David who the who the municipal authority is that's approving that development and work with them as well. One of the strongest just generally for all of you, you know it's very difficult to get a light changed once it's installed. It's relatively easy to get the specifications for lighting changed before something is built. And so the time to be proactive is to keep an eye on, as you have developments that are just being proposed or just being discussed. And so that's one of those cable access planning board meetings and see what's coming down. So I think the answer is if they're not too far along there certainly is hope. You need to get the conversation going. Lots and lots of times. People install bad lighting not because they do so intentionally but they just don't know any better. And it only takes one person like you or me or an IDA rep to educate and to to illuminate and inform them and the outcomes are awfully good. Okay. I'm going to try to get a couple, couple of people who haven't asked yet. Andrea wants to know. What about equipping street lights with integral motion sensors wouldn't be all the time say Zarendra you're absolutely right Andrea. And in fact this has been tried in Europe. And the thing about street lights is, what are they there for. I mean, why, why are there street lights in your towns at all. Often they're installed at intersections, which are, are complex zones or there are places where pedestrians and cars tend to congregate there might be a crosswalk or something like that. And so that is a sort of place where a, a sensor could be used. Until LEDs, it was not possible to have such sensors. LEDs don't mind being turned on and off or dimmed up down sideways multiple times per second you can do anything you want to them. And so, and so consequently, having a motion sensor on some of those street lights would be a good thing. So a little impractical the electronics would be really expensive to do that for every street light, but it is possible. One of the things to look for, for all of you, as you go out and try to find out what street lights are being installed, find out if they have something you remember this thing here this little this little doohickey. The new ones have seven pins, they're seven pin connectors, and there might not be equipped with it at the outset but those connectors allow you to install electronics that can dim the street lights later on at night, or have them be computer controlled. That's something to watch out for. Produced by Dracula Handcliffe does she asks, what about headlights, for example. Yes, headlights do affect the night sky and especially the new ones that are super bright and blue, but they are really not the main culprit here it's the street lights and area lights and parking lot lights that we need to really attack. Okay, the last question I think we'll make this the last one for the night. Are lighting manufacturers helpful in recommending the purchase of warm LEDs in lieu of high temperature LEDs. Well that's a really good question Greg. And in years gone past the idea has been at odds in conflict with in battle with the illuminating engineering society and other lighting organizations. The realization has come that, guess what citizens prefer warm color temperature lighting at night. They prefer 3000 over 4000 they prefer 2700 over 3000 and the new wave coming up, which, which is not coming soon enough to suit me. There's a new generation of LEDs that are called PC amber PC stands for phosphor coated. So it's not, it's not an innate emission at warm lights but it's a very warm color temperature 2400 2200 very much like the high pressure sodium that they're replacing. And, and so I think that in the next you know three or four years or so, you will see because because the public is demanding these lower color temperature lights. There is no place hardly, at least in terms of a municipal street lighting program that no place is doing 5000 Kelvin anymore, though they were 10 years ago. Very few places are doing 3000 4000 anymore that American Medical Association pronouncement had a chilling effect around the country and so lots of places that were already planning 4000 K switched abruptly to 3000 K because the AMA told them to. And that's a that's a really good thing. And you have for that you have Mario mother to thank met some of you know Mario's name. He is was former president of the Massachusetts Medical Association, cardiologist by training. He is a key figure he's on the Council of the American Medical Association, and he's an amateur astronomer with a 32 inch telescope on top of his house. Go figure. So, I think Vivian and Brian and Dave will will perhaps call it a night. And, and again, my email is really easy in terms of dark sky stuff it's kbd. That's kb at TTY at dark sky.org, I would love to engage any or all of you. Either generally or specifically about your situation and how you can help I'll tell you this. Those of you who are here have invested an hour to learn about light pollution and I really thank you for that. But one person can make a difference. One person with a well time presentation to your planning committee or your board of select your select board or whatever your authority is whoever will get to listen can change the outcome of the lighting in your city. It only takes one person saying hey I have an issue here that I'd like to bring your attention you can do it, and I and others on the idea or here to help here to help you do it. So, Dave and Brian and Vivian back to you. Well, thank you very much Kelly for joining us this evening and thank you everyone for tuning in. So everyone will be able to find this webinar if you want to use this webinar to help advocate with some of your local groups who didn't have a chance to join us this evening. Thank you to see this on the night sky network website in the outreach resources section, and it will also be on our YouTube channel we should actually that should be up there now but we will update the website tomorrow. But it's up there on the on YouTube, pretty much right away because we've been live streaming it. You can also join us for our next webinar on Tuesday, March 23 when Dr Kelly lepo I'm not sure how to pronounce the name of the Space Telescope Science Institute will bring us up to date on the James Webb Space Telescope. Next month we have a special event as Dave mentioned at the top of the program night sky network members can join us for a perseverance landing watch party on Thursday, February 18 and so stay tuned for information on that. So keep looking up, and we will see you next month. So good night everyone. Thank you Kelly that was fabulous. That was. Join the idea.