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THE SEARCH BAR

Why is the 2024 total solar eclipse a big deal?

| 57 minutes | Media Contact: University Communications

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Summary

Why is the 2024 total solar eclipse such a big deal? And, where and how can you see it safely? 

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

Summary 

In this episode of The Search Bar, Aaron LaCluyzé discusses the awe-inspiring experience of witnessing a total solar eclipse. He describes the surreal nature of seeing the moon pass in front of the sun and the feeling of being both special and small in the vast universe. Aaron shares his personal experience of almost crying during a total solar eclipse and emphasizes the indescribable beauty of the event. He encourages people to take the opportunity to view the upcoming total solar eclipse in 2024 and suggests taking the day off to witness it. The conversation concludes with a reminder to like and subscribe to The Search Bar podcast. 

Transcript

Chapters 

 

Introduction

Aaron: I'll be a hundred percent honest, I nearly cried. It was that awe-inspiring, that amazing, that… words failed me. I'm a guy — I teach, I'm literally paid to talk for a living, right? That's literally what I do for hours a day, and words didn't work. My mind could not form words during those two minutes.

Adam: Why is the 2024 total solar eclipse such a big deal? And where and how can you see it safely? Welcome to The Search Bar. I'm your host, Adam Sparks, and on today's episode we're talking about solar eclipses with Aaron LaCluyzé, a faculty member in the Department of Physics at Central Michigan University. Hi Aaron, thanks for coming in today.

Aaron: It's a pleasure to be here.

Adam: Super excited to talk about celestial bodies and how they're going to be vanishing from the sky soon.

Aaron: Of course. Yeah, it's a great time to talk about that.

Adam: It really is because we're about to have a total solar eclipse.

Aaron: That's right.

Adam: Which is not the same thing as a partial solar eclipse.

Aaron: Right, so —

Adam: So, probably talk about what an eclipse is.

Aaron: Yeah, we should probably get into the subtle differences between those.

Adam: Or, what are we seeing at all when we’re seeing that?

What is an eclipse?

Aaron: Right, right. So, that's a good question. So let's talk about eclipses for just a moment. There are two basic kinds of eclipses. You've got your solar eclipses and you've got your lunar eclipses. And in either case, what we're really talking about is having an object go through the shadow of another object. So just to refresh folks' memories, I'm sure no one's confused about this based on my experiences in my intro to astronomy classes, the moon orbits around the earth and then the earth orbits around the sun.

Adam: Prove it. I'm just kidding.

Aaron: I could. 

Adam: Different podcast. 

Aaron: I was going to say, it might be a different podcast. As the earth orbits around the sun and the moon orbits around the earth, occasionally the shadow of the moon will land on the earth, so the moon is blocking out the sun. And so, that's going to be a solar eclipse. But sometimes, the moon will go through the shadow of the earth, and since the moon doesn't really give off its own light in any meaningful way — for us moonlight is really reflected sunlight — so when the moon goes through the shadow of the earth, the moon gets blocked out. So lunar eclipses, those happen relatively commonly, and the reason I say ‘relatively commonly’ [is because] we don't have them all the time. It's not like every time the moon goes to that side of the earth, we have it blocked out, and every time the moon goes to the other side of the earth, we have the sun blocked out. The moon's orbit is slightly tilted relative to the Earth's orbit around the sun. So, sometimes the moon is a little bit too high to block out anything or to go through our shadow, and sometimes it's a little too low. But when it's just right — like, there are certain times of year when it's just right. So in astronomy, we refer to that time of year as being an eclipse season. It's a time of year when you have conditions favorable for having an eclipse. But in order for that eclipse to happen, you have to have the moon in the right phase for it to happen, because the phases of the moon happen because of the geometry of where the moon is relative to the sun as the moon goes around the earth. So, the lunar eclipses are more common and more commonly seen because the earth is much bigger than the moon, so the earth's shadow is much bigger than the moon’s shadow. So, you end up with anybody who's on the nighttime side of the planet when a lunar eclipse happens, pretty much anybody on the nighttime side can see that lunar eclipse, no big deal. It's easy because there's a big whopping shadow to go through. The moon on the other hand, being much, much smaller than the earth, has a little teeny tiny shadow. And so, even when the moon goes in front of the sun, when it passes right in front of the sun, its shadow only lands on a small part of the earth at any given time. And so, when that happens, you can see maps that will have this curve that goes across the earth where they'll say, “Oh yeah, this is the path of the eclipse.” Well, the reason that's the path of the eclipse is that's literally where the shadow is going to go over time. Because it's not like the moon's going to move in front of the sun and then just sit there. The moon's still moving. It's still moving in it's orbit, so it's going to block out the sun momentarily and then keep going on its merry way. But the way you see that from Earth is that it's as if the shadow of the moon is sweeping across the globe, and if you're standing in just the right place, you'll see it. So, that brings us to the idea of a partial versus a total solar eclipse. So, in a partial solar eclipse, from your perspective on earth, wherever you are standing, you're seeing part of the sun blocked out by the moon. So, it's not blocking it completely, it's not lined up just perfectly from where you're sitting. Maybe it's a little bit too high or a little bit too low, so it's only blocking out part of the sun. But if you happen to be in just the right place, everything will line up just perfectly and it'll block it out perfectly. So, a total eclipse is when you are in the area where the moon blocks the sun completely, and that part of the moon shadow is a thing called the umbra of the moon shadow. So you might see that phrase thrown around a bit. If you're off to the side, so you see only part of it blocked, well, you're still in the shadow of the moon, but not the deepest darkest part of the shadow, there you're in the part called the penumbra. So, the umbra and the penumbra. The umbra is the center of the shadow, the penumbra is the edges of those shadows. So, if you're in the penumbra, you'll see a partial. If you're in the umbra, you'll see a total. And the area where the total is, is much smaller than the area where the rest of it is, where the penumbra is. And so, if you see part of it, that's a partial solar eclipse that blocks out a bit of it, it's like a chunk is taken out of the sun. And that can be everything from just a little tiny sliver as the moon just goes barely in front of just the edge of the sun, to yeah, it blocks out most of it, like 80-90% of it. Where you want to be, absolutely hands down where you want to be, is right dead in the center. You actually want to see that total solar eclipse. It's way more interesting. So, when those happen, it's, like I said, a small chunk of the world that gets to see it, just a little strip where that occurs. It just so happens we had one back in 2017 that came through the US that was lined up just perfectly. And so, it went kind from the Pacific Northwest through the rest of the country to the Atlantic seaboard, although I think it went the other way. I got to think about this. I'm not sure which direction it went, but it was diagonal through the United States. This one is going to sweep from Texas up through Arkansas, and up into southern Indiana and northern Ohio, and then head up to the east coast and into part of Canada. We're not going to see totality from here in mid-Michigan, so that's the bad news part. The bad news part is we cannot see totality from where we are. The good news part is we don't have to travel far to get to totality. So, we only have to go to either Ohio or Indiana to catch that. That being said, you'll still see the partial from here.

What will the view of the solar eclipse be from Michigan?

Adam: How much are you going to see from here?

Aaron: Yeah, so, here in mid-Michigan, so, here in Mount Pleasant, I want to say it's about 92% of the sun will be blocked out at its maximum, which it's not like that's going to be not a show at all. It's going to be interesting. It'll be absolutely interesting. If you've never seen a partial solar eclipse, even that's worth seeing. But it's going to be a bit like twilight. So essentially, imagine that you take all the light from the sun and we just cut out 90% of it. Well, that kind of happens every day at twilight. It happens at sunrise and sunset. But imagine that sunrise came on rather suddenly in the middle of the afternoon, because that's what it's going to be like. 

What are the dangers of looking directly at a solar eclipse?

Aaron: Before we go any further, I do want to put a disclaimer way up front here, just in case people turn off the podcast, the most important thing to know is that if you're going to try and view an eclipse, you want to make sure you do it safely. So, anytime that you have anything but a total solar eclipse — so we'll talk about the total in just a minute — but, if you have a partial solar eclipse in any way, make sure that you're wearing or using appropriate protective devices to try and look at the sun. It's very dangerous to look at the sun. The sun is exceedingly bright, and the human eye was not really meant to stare at the sun. I mean, we use sunlight all the time. We're used to sunlight. But, looking at the sun is not a very good idea. Glancing at the sun, we've all done that. You're outside and you kinda glance up in the sky and you're like, "Oh, there's the sun." But you don't look at it for very long. You look at it for a split second because it's very, very bright and your brain tells you, "Hey, that's too bright. You probably shouldn't be looking at that." But during a partial solar eclipse, when the light is essentially damped down, you don't notice that you're staring at the sun, because it's not nearly as bright. And you're like, "Oh, that's not a problem." Well, here's where the problem comes in. I hate to sound like a downer, but what's so dangerous about looking at the sun is the ultraviolet light from the sun. So, the same part of sunlight that gives you a sunburn, that's still happening even when you're looking at the sun and 90% of it is blocked, you're still getting that ultraviolet light. Now, that's not so bad. You're like, “I can stand in the sun for several minutes and not…,” — if you're like me, easily 10 minutes I can stand in the sun and not get sunburned. The problem is the back of your eye has no pain receptors, and so if you're looking at a partial solar eclipse without protective equipment — if you're looking at a partial — you're essentially bombarding the back of your eye with ultraviolet light. You're giving the back of your eye a sunburn and you don't even know it. You can't feel it. You can't notice it. The first time you notice it is a few minutes later and you're blinking and it's like, "Oh man, I can still see a ghost image of the sun." You know how that normally happens? 

Adam: Yeah

Aaron: Well, that's no big deal. But imagine that that happened and never went away. Like, never went away. You can blind yourself doing this. So, I know that this sounds really ominous and sounds really creepy to say, “By the way, you're sunburning the inside of your eye.” But I really want to tell people that upfront because I want to make sure they take these things seriously. It's really, drastically important that you take care of your eyes. But if you're in totality, only in totality does this work, during the brief window of time — and it is a brief window. It can be anything from a few seconds up to a few minutes. During that brief window of totality, you can look at the sun with the naked eye, during totality itself. Not the moment before, not the moment after, but during totality you can. But any time other than that, you definitely want to be wearing eclipse glasses or using a solar filter of some sort, but make sure you have the right protective equipment.

How long will the eclipse last?

Adam: How long is totality? What’s that going to — I know it's different every time.

Aaron: It is different every time.

Adam: But I think we're getting a long one, aren't we?

Aaron: It's a pretty long one. So, it depends on where exactly in the shadow you sit. So, imagine — picture the United States, picture a map of United States. So, imagine taking a dime and just sliding it across the map, and what matters is which part of the dime — or let's call it a quarter, that's a little easier — but which part of the quarter did you slide through? Did you slide through just the edge of the quarter? Well, in that case, you're going to have, I don't know, 15, 20 seconds of it. So technically, totality is visible from the state of Michigan in one teeny tiny little corner down by Detroit for about five seconds. I think it's five seconds.

Adam: You don't want to risk that.

Aaron: Don't quote me on that number, but it's really, really small. It's not worth it. Just go — I hate to say this to people in Michigan, but just go to Ohio. It's right there. Just go over the border to where totality is really going to be good. The deeper you get, the closer you get to the center of it, if you're dead center in the shadow, so you're sliding through the middle of the quarter as it comes by, you're going to get just shy of four minutes for the eclipse. So, from when the moon completely blocks out the sun until it starts to slide enough that the other side of the sun, the sliver of the sun, starts to appear on the other side. Maximum you can get is just shy of four minutes with this one in this part of the country.

Adam: That's pretty good though, right?

Aaron: It is, it is. The first solar eclipse I ever saw myself was back in 2017, and there I had two and a half minutes. And, on the one hand, it felt like that moment was forever, and on the other hand, it felt like it was over in a split second. It was that weird, kind of, time dilation that you feel when there's something going on that you either really hate or really enjoy. You know that feeling when you're in the dentist chair and it feels like you've never known a life that wasn't being in that dentist chair? And then you get up and you realize, “Oh, that was 20 minutes. That wasn't bad at all.” It's that, kind of, weird time dilation that you get. So yeah, three and a half minutes, four minutes, that's actually pretty good for a solar eclipse.

What's the cultural history of eclipses?

Adam: You mentioned that the first one that you went and saw in person was in '17. Getting one in '17 and getting one in '24 is also pretty unique, too, right? Because we’re not scheduled for the one for a while.

Aaron: It is, yeah. So, these things go in a cycle, okay. So, let's talk a little bit — and it might not be where we were headed originally — but let's talk a little bit about eclipses historically, how these things happened. So, human beings have known about eclipses pretty much since there have been human beings, because it’s kind of hard to miss when they happen. But they were unpredictable long ago. We didn't really know what was going on. We didn't have a really good idea of exactly how the orbits of the earth and the moon really interacted as they went around the sun. We didn't know these things. And so, lunar eclipses, those happened, and lunar eclipses, they're kind of neat. They're fun. They're a thing that happens. They're slow. I mean, even solar eclipses are slow from start to finish. They take several hours, and you have, kind of, the neat thing in the middle when you've got the totality that's actually happening. But the whole thing takes a couple of hours. And those happen at night. Most people were asleep. You didn't have to worry too much about your lunar eclipses. But solar eclipses were terrifying for ancient peoples because if you were actually in the path of totality, you thought the world was ending. Because suddenly, in the middle of the day, the sun went away. It just went away, and that is really strange. In a few minutes, I'd like to talk about that 2017 eclipse, and I'll try and explain why it was so terrifying. But most of these cultures, they had no way to predict them. They didn't know.

Adam: It was like a bad omen, or…

Aaron: It was a bad omen. They thought of it as like a sign of displeasure from some supernatural being or god that was trying to punish them for something.

Adam: Yeah. “This is it, guys.”

Aaron: That's right. “Here it is, the end of the world.” In Chinese culture, they felt that it was a great dragon was devouring the sun. And so, they developed these, kind of, cultural traditions that when in eclipse happened, you had to bang pots and pans and make noises to try and scare off the dragon so that it would cough back up the sun so that we wouldn't all die. So, there are lots of different cultures around the world that had these sorts of beliefs that came up around eclipses. 

How do modern-day scientists predict eclipses?

Aaron: As time went on and we started to understand better and better and better what was going on and came up with better models of how the earth and the sun and the moon moved through the cosmos, we started to get a better ability to predict these things. But our predictions were kind of like, yeah, we expect one in this area, because there were patterns to them. There's a repeating pattern that happens in them that takes place over about 18 years or so that they happen, but — it's about 18 years, it's not perfect. So, there's a little bit of a lag there. And that lag means the area of the globe that gets an eclipse the next time around, that 18-year cycle, they won't necessarily be in exactly the same spot. It'll move a little bit. And so, they had a pretty good idea of how to predict lunar eclipses, but predicting solar eclipses, because they're in such a smaller spot that you can see them, that took longer before we could do that. As we go towards modern times, we now do it with computers, right? We've got a computer model that keeps track of where the moon and the sun are in the sky relative to us. We measure the moon's position very, very precisely. When we landed on the moon, we left behind some mirrors that we can bounce lasers off of to get perfect distances between us and the moon. So we can do all of that in a computer model now very, very well. And so, we can predict to the second exactly where it's going to be on the globe. And so, that's what we do now, so we can predict them. But it is relatively uncommon to have one area have two of them back to back like this in such a short period of time. It sometimes happens, just the cycles line up so that you go, “Okay, we got one here, now we got another one here.” And then we don't have one for a long stretch. And then you might get a couple more, but they kind of come in batches here and there. We are not going to get another one that's visible from the United States. I mean, we had these two back to back, and so some of our younger listeners might be a little bit jaded and go, “Oh, well, these things happen all the time.” No, no, no, no, no. We're not going to have another one visible from any reasonable part of the continental US until sometime in the 2040s. And that's kind of a long way from now. So, if you have an opportunity to see this one, definitely go see this one. And it's right there. It's right next door. The one last time, because of the path that it took, you kind of had to drive very far south or very far west to actually catch it. This one? Yeah, it's Ohio or Indiana. It's not so bad.

How was the experience of viewing the 2017 eclipse?

Adam: It's not too bad. Where did you go to see the 2017 one?

Aaron: So yeah, several of my colleagues went out west to kind of the middle of nowhere in the middle of a field out someplace. My aunt lives in Greenville, South Carolina and totality went right over her house. 

Adam: Oh, wow. Awesome. 

Aaron: So, I went to Greenville, South Carolina, and I just hung out there. So it was August, it was like August 17th, something like that...

Adam: In South Carolina?

Aaron: ...in 2017. And August in South Carolina is not a good time, honestly, particularly not for a Midwestern or like myself.

Adam: Who can only be in the sun for 10 minutes.

Aaron: Who can only be in the sun for maximum of 10 minutes. But the good news is she has air conditioning and we baked cookies. So like I said, an eclipse, if you want to go from start to finish, takes several hours from when the moon just begins to block the sun just a tiny bit. You're talking hour and a half or so until you hit totality. Then you've got the amazingness of totality, then another hour and a half or so as it goes back out. So we set up some things to view it. I set up a camera with a solar filter on it, and we would go outside and we'd look at it for 10 or 15 minutes till we got too hot, and then we'd go inside, we'd bake some cookies, we'd have some cookies, we'd go back outside, and it was great. It was a fantastic experience, quite frankly. Perfect.

Adam: What kind of cookies?

Aaron: They were chocolate chip.

Adam: Yeah, that's the route.

Aaron: Yeah, just the standard. Actually…

Adam: That's not the standard. That's the benchmark.

Aaron: Okay, the benchmark. I mean, if we really want to have the cookie throw down, the answer is oatmeal chocolate chip. Not oatmeal raisin, oatmeal chocolate chip. It combines the best of oatmeal raisin cookies and the best of chocolate chip cookies fused into one. And I think that's the best cookie.

Adam: I can get behind that, actually. 

Aaron: Yeah. 

How so you prepare to view a solar eclipse?

Adam: I think that brings up a good point, in a way, in roundabout — when we're making segues, this brings up a good point. 

Aaron: That's right.

Adam: Which is: planning for one of these things can be quite an undertaking, right? Not everyone's going to have access to their great aunt's house, their aunt's house, who's right in the path of totality. There's a whole economic system that is fueled by these things, and there's a lot of people that are out trying to do it. What do you need to do? What kind of plans do you need to make to kind of see this?

Aaron: Yeah, so the most important thing is to make a plan. Don't just wing it. Don't just think to yourself, “Oh, yeah, that's a thing that's going to happen in April. Oh yeah, it's going to be fine.” By the way, Monday, April the 8th of 2024 will be this eclipse, just in case it's not on anybody's radar.

Adam: It's my birthday.

Aaron: Oh, well, fantastic. We did it just for you.

Adam: Thank you. Appreciate that.

Aaron: You're welcome.

Adam: Tell the astronomers’ guild that I'm happy that they rotated the flat earth for me.

Aaron: That's right. We fired up the jets to rotate the flat earth so it'd be perfectly aligned just for you. 

Adam: Cheers.

Aaron: The most important thing is to have a plan. Just any plan at all is better than no plan. Don't just wing it. And the reason I say don't just wing it is there are kind of a lot of population centers that are in driving distance of the path of totality, and the path of totality is not that big. So, I don't know where you think you're going, but you better think about it now. You also want to go early, so you might think to yourself, "Oh, I'm just going to drive in the day of. That'll be fine." Well, if you're going to do that, give yourself extra time because everyone else is doing that too. And so, traffic is going to be a nightmare. It's going to be even worse afterwards. So, I'm going to say, actually, plan to go early, but also plan to stay late, because as soon as the eclipse happens, everyone's going to try and go back home and however long you think it was going to take you, it's going to be longer.

Adam: Every parking lot in the path of totality will be coming and going to a Beyonce concert.

Aaron: Pretty much.

Adam: Pretty much. 

Aaron: And I know a lot of people are probably thinking, “Oh yeah, I'll just drive to a Meijer or a Walmart that's in the path of totality.” 

Adam: No, you won’t.

Aaron: Hey, guess what? Everyone else thought of that. They're planning on that too. So, if you're going to do that, go for it, but stake it out early. Get there before dawn and park your car in that Walmart parking lot. But yeah, have a plan. If you're going to try and go someplace, if you can go a day or two early, that's great, but good luck with that because all of the hotels are probably already sold out, and if they aren't, they're jacked up in price. And so, expect that to not do well. If you have any relatives or friends along the path of totality, that's a great idea. Go just mooch off of somebody's couch. That's fine. Have a plan B, though. And I mentioned that because weather is a thing, and if it's cloudy where you were planning on going, you're not going to see it. That's not the way — the clouds will get dark. That is what will happen. The clouds will get dark and then they will get light again, and that was everything that you will see. Try and stay mobile if you can, have a plan B, know which way you're going to go. And as far as getting back out again, that's the tough part. So, like I said, I went to visit my aunt and we went down a couple of days early, because I was visiting family. We had a nice time down there, but we had to leave immediately because my wife had to be back to work the next day. And so, that eclipse happened to be in the mid-afternoon. This one is as well, we'll talk more about that in a minute. And normally to drive from South Carolina back up here to mid-Michigan is about 12-13 hours. Depends on how many stops you make. It took us, I think, 22 to make it back from that.

Adam: Oof. And that's eclipse traffic?

Aaron: That was eclipse traffic because everybody was in that strip, and even if they trickled in for the days before, once it was over, they were all trying to get home. And so, however fast you think you're going to drive, you're not going to, and you're probably thinking to yourself, “Well, wait a minute, I've got an iPhone. I can totally just have it punch up directions for me and it'll direct me around traffic.” Yes, you and everyone else with an iPhone. So, the plan to get off the freeway, you'll notice there's like 20 cars ahead of you and 20 cars behind you also getting off the freeway to go around on that ‘shortcut’. So yeah, be ready for that.

Adam: Gas and snacks.

Aaron: Yeah, make sure your car is actually fueled before you go in so that you're ready for that. And make sure you've got some snacks on board.

Adam: Maybe some cookies.

Aaron: It may be some cookies, for instance, I think is a great idea.

Adam: Oatmeal chocolate chip, if you can swing it.

Aaron: That's right.

Adam: That'd be a good one. It feels like it's the type of event where you have to plan for kind of a long, relaxing experience. If you're going to go into it and try to make it something that you're going to do with an awful lot of efficiency, or you're thinking you're just going to watch that, in this case, four minutes of totality, it's not that. It's a get the lawn chair out and really soak it in type of thing.

Aaron: It is. Yeah, it's a lead up and a lead out, okay. This is not watching a five second TikTok. This is watching the Lord of the Rings, all the movies back-to-back. Okay, it's a long thing. Get settled in. That's fine. That's totally okay. It's fine to slow down. It's actually good to slow down to see one of these. And you might think to yourself, “Okay, that's all interesting and that's neat, but, wow, that sounds like a lot of trouble. Why would I do that?” Why would I drive to a crowded area and maybe sit in a sunny parking lot with no shade? And, I mean, I do have my oatmeal chocolate chip cookies, which is great, but what else? Why am I doing this? Well, let's talk about 2017 if we could. Let's tell the tale. 

Why is a total eclipse worth trying to see?

Aaron: I am a professional astronomer. I have been for several decades. I've been doing this for a long time, and I had never seen a total solar eclipse until 2017. I'd seen partials and partials are cool. I enjoy partials. I like — if you can't see anything else, at least catch the partial. But I had never seen a total. I'd seen pictures of total solar eclipses. I'd seen them in textbooks my entire life, and I always thought that those pictures of the total solar eclipses, that they were using some sort of long exposure technique or special filters to make it look like that. I always thought that that's what it was like. I really truly believed that. And then I went and saw this eclipse, and I was not fundamentally prepared for what it was going to be like. It was such a different experience. There are a lot of things that were weird leading up to an eclipse. The eclipse itself is great and awe-inspiring. But just leading up to it is strange because the sun is high in the sky. I mean, we're going to block out the sun with the moon’s shadow, the sun was high in the sky for us. It was mid-afternoon, two, three o’clock, and it was just getting dimmer. I was just getting dimmer and dimmer and dimmer. You know, we're used to that at twilight. That sort of thing happens every day at twilight. But when that happens, other things occur that are kind of subtle cues to you that this is normal. The sun is getting lower in the sky, and so the sun gets oranger or redder as it goes down, and all of the shadows that are around you get kind of longer and longer and longer as the sun gets lower in the sky. But that's not what's happening here. What's happening here is it's just getting dimmer. And so the shadows are still sharp and the shadows are still what you would expect, but the light is dimmer. It's as if you're wearing sunglasses that have a little dial on the side and somebody's turning the dial up and just making them darker and darker and darker as time goes on. And it feels really weird. And it's not just you that's reacting that way. Everything around you is as well. The animals, the insects, they all think it's sunset. They don't know. So, the crickets kicked in at some point, and they just got louder and louder and louder, and there were cicadas at the time, and they kicked in. And then the birds that eat insects at dawn and dusk, like barn swallows, those sorts of things, they came out and they started doing what they're doing. And then all the streetlights turned on because all of our modern streetlights have a sensor on top that looks at the light level and turn on when it's dark and off when it's light, and they all turned on, and that was weird. And then looking in every direction, it looks like sunset in every direction. You get that kind of red glow on the horizon as if the sun is just below the horizon, but it's doing that in every direction, not just where the sun is, because the sun's high in the sky. And so, that's really, just, weird. It's just bonkers. And we're getting closer and closer and closer. And finally, totality happens. Now, up until this point, we're of course wearing protective eclipse glasses. So, every time you look at the sun, you're seeing that it's getting dimmer, but you're looking at it through eclipse glasses. But then totality happens, and you can take off the eclipse glasses. Now, I am a photographer as a hobby. So I had set up a camera with a solar filter on a tripod with the longest lens I had. It wasn't a very good lens, but it was the longest lens that I had, and I wanted to get the best view that I could. And I was taking pictures, and I knew that it was going to be about two and a half minutes of totality. But I also knew that I didn't want to experience the eclipse looking through the camera. I mean, that is an experience, but it separates you from the — I know that you know what I'm talking about. 

Adam: I know it very well.

Aaron: It separates you from the experience. And I didn't want to do that. I thought that would be a disservice to me since this was the first, and maybe the last, eclipse I would ever see. Who knows if I'd make it to any others, or if the weather would cooperate, those sorts of things. So what I did was I set a timer on my watch for 30 seconds and I said, I get 30 seconds of taking pictures, and then after that, I cannot touch that shutter button. And so, I had a solar filter on up until totality happened, and I was clicking away as it got closer and closer, and then I pulled the filter off and I fussed with my exposure, because exposure changed, and I took some pictures for 30 seconds until my alarm went off, and then I just stopped, and I looked at the sky. And it's difficult to put into words what I saw. It's almost a quasi-religious experience. It really moves you on a deep and fundamental level, because you're seeing something with your own eyes that you've never seen before, and maybe we'll never see again. This moment of perfect alignment between the sun, the moon, and you. And when it happens — you know, we think of the sun as being this giant thing in the sky, and it's not. We think of it that way because it's so bright, we don't look at it. There's kind of like a whole region of the sky that we kind of avoid with our gaze much of the time. But once you block it out, you see that the sun is actually quite small in the sky. It's only about half a degree in size. In fact, it's about the size of the full moon. That's why eclipses work, right? They're both about the same size in the sky. Not because they're the same size, because the moon's much smaller, but the sun's much further away. So, it's really small in the sky, but at the same time, we think of the sun as kind of this little disc of light. We've seen it at a sunset. You can glance at the sun at the sunset, no problem there. Or at a sunrise, if you're up at those terrible hours. I'm an astronomer, not a big fan of being awake early in the morning. When you block out the disc of the sun that we normally see, there's a part of the sun called the corona, which is the outer bits of the sun. It's kind of like a halo around the sun. It's there all the time. It's just that it's very dim compared to the disc of the sun that we normally see that it's just drowned out. You don't see it. But once you cover it up with the moon, you can now see that solar corona, and it's this big, extended, beautiful, dynamic, shimmering halo around the sun, and it extends much further away from the sun than I was ready for. I totally didn't expect that. It's like the pictures in the textbook that I thought you had to do a special photography technique to get. You don't. You can just see that with your naked eye, and if it's in totality, you can look at it. You can look at it with your naked eye. And the spot that isn't the corona, it is — the best way I could describe it is, it looks like someone took an ice cream scoop and just took a perfect scoop out of the sky and just left this perfectly empty black round hole right in the middle. Because it’s now kind of drowned out by that halo of the corona that's around it. And I can't put into words what it really was like to see it. And then, suddenly, it's gone because it's moved on, and the sliver of the sun starts to appear again, and now you can't stare at it anymore, and the corona's gone. I did not expect the corona to come on that fast and that bright, because your eyes are adapting to the darkness during that time as we get the sun blocked out a little more and a little more and a little more, your eyes are adapting to that. And so, once the corona appears, your eyes are ready for it, essentially. So it's totally worth seeing. Everyone I've met who has seen one once to see another. And there are people who, once they've seen one, they essentially spend the rest of their lives chasing it.

Adam: They're chasing…

Aaron: Right? It's this weird moment. There are these experiences that you have that are etched into your brain forever. The day you get married, you know that. The day your first child is born. You know these things, they're just etched into your consciousness. You will never forget about them again. That is what this is like.

Adam: Aaron's a scientist, and there's a lot of scientific things we haven't even hit that are probably happening in that moment.

Aaron: Oh, yes.

Adam: But the thing that seems to be the most impressionable for you is this parallel experience that you probably had to those ancient ancestors of yours that probably had no damn idea that a god wasn't plucking the sun out of the sky.

Aaron: Right, exactly. If I didn't know what I know and this suddenly happened, I would also be terrified. Absolutely terrified. Even knowing what I know, I was shocked to my core at what it looked like. It was so unreal. And it's one of those things that you see it and you're like, this looks like a special effect from a movie. This is ILM. ILM did this. But no, they didn't. You're seeing it with your own eyes live in real time, and you're sharing that experience with the people around you. You don't know what's going through their head because you're all just going, “Oh my God, I can't believe this,” which is basically what I did for five minutes.

Adam: There's probably not a lot of chatter going on.

Aaron: Okay, two minutes. And on the one hand, it felt like time stopped for that moment as I was experiencing this, but it was over so fast. It was over so fast. But people will spend the rest of their lives flying around the world to remote locations just to catch the next one, and the next one and the next one. Well, we had one and we're going to have one again in such a short period of time. We owe it to ourselves to try to see this. And the next one for us in the U.S., like I said, is in the 2040s. So, if you get any kind of an opportunity to do this, do this. And here's the thing that I'm going to say. I'm going to say it. I'm at a university, I'm a professor, I teach classes, but I'm going to say it. Students, don't go to class that day. I don't know what your classes are. If you don't have an exam, don't go to class that day. Cut class, get some friends. Go to Ohio. Go to Indiana. Go anywhere. Catch this eclipse. Is that important?

Adam: You heard that here first.

Aaron: That's right. I would say I'll deny it, but I mean — I'm going to say it's on tape. It's not, it's digital. But still, I stand by it. I've already told my students, because I’m teaching classes on Mondays this year. It is a Monday that it happens. I've already told my students, we're not having class that day. I will give you a video lecture and I will post it. Watch it whenever you want, but don't be in class that day. I know I won't be.

If I've seen en eclipse before, should I still see this one too?

Adam: Now, are you going to experience it different this time? Because the religious experience might not occur.

Aaron: Right. Well, I don't know. I think it's going to, quite frankly. I mean, it's hard not to be overwhelmed by that experience, right? It's kind of like— here's a weird analogy, I don't know that it will appeal to everyone — but it's kind of like saying, you know, you thought your wife was beautiful yesterday, do you think you'll think she's beautiful tomorrow? Well, yeah, she's just as beautiful. It's just as amazing. This kind of a thing doesn't become any less overwhelming. I mean, maybe if I saw an eclipse every day, I might eventually get tired of it. But, I mean, the last one was in 2017. Kind of a lot has happened since 2017. I could totally use another eclipse right about now. 

Adam: Yeah, that feels right, huh? Imagine if you only get to see a sunset every seven years or something, right?

Aaron: Yeah. It's kind like that. I mean, you can have a particularly beautiful sunset that you're like, oh yeah, everything came together. That was an amazing sunset. I really enjoyed that. But if you see another one a month later and it's also a beautiful sunset, it's not like you don't notice that it's not a beautiful sunset. It's still a beautiful sunset. So, they're just infrequent enough that I don't think the shine ever wears off, but they are frequent enough that you can try and seek one out. You can catch another one. So it is absolutely worth it. You should absolutely do it. If you're going to do it, there is some planning, like I said. You got to go to where it's at. You got to be in the right place at the right time. This particular one, I believe totality happens right between 3:00 and 3:20 in the afternoon, Eastern time, for that kind of stretch of Ohio that I'm kind of thinking ahead into. If you want to go to Indiana, the timing is slightly different. Again, it's sweeping across. It's a shadow that's sweeping across the globe. So, you got to get the timing just right. 

What equipment do I need to view or photograph the eclipse?

Aaron: You also want to plan to have the right equipment with you. So, you want eclipse glasses so that you can look at it. I want to caution people, be careful about buying eclipse glasses. There's lots of places on the internet to buy them. I cannot guarantee that all of them are actually actual eclipse glasses rather than someone trying to cash in on that. So, this is one of those cases where I encourage people — I'll name a couple of specific names, but I'm not sponsored by anybody — but I encourage people to use a reputable source for them. This is not the kind of thing that you just go on Amazon and buy the cheapest one you can find. No, no, no, no. We're talking about your vision here. Unless you want to roll the dice on being blind for the rest of your life, it's probably worth it.

Adam: Sunburn cones or whatever.

Aaron: Yeah, exactly. That's another thing that you want to do. There are a couple of places that I like to use. There's a place called High Point Scientific, and they sell a lot of astronomy gear, so they're a good one. Use somebody reputable, like find a place that specializes in optics or camera gear, photography gear, or astronomy gear. They're going to have, kind of, the specific things that you want to do.

Adam: Yeah, I imagine Nikon or Zeiss or some of these companies probably have something like that.

Aaron: Yeah, and not all of these things are created equal, as well. So, there are companies that make solar filters for your camera that use that same kind of thin film mylar that goes in eclipse glasses. It looks like you've got aluminum foil on your eyes. It's not. But these thin film ones, they block specific wavelengths that are dangerous to the eye, and so they're safe for looking at the eclipse long-term. Other kinds you can find are essentially really, really strong neutral density filters. They're like an ND 10,000 or something. They're really, really high neutral density filter. Those are usually not actually rated for long-term use with the sun. You can use them, and they're fine on your camera.

Adam: They're sunglasses, basically.

Aaron: But they're basically sunglasses, and you want one that's actually rated for that sort of a thing. But the ones that you can buy from a photography supply that your standard filter places will make it, it'll be like an ND 10,000. They'll say solar filter, and then you'll read the little blurb at the bottom that's like, “By the way, this is not actually rated for long-term use with the sun.” You can still use it for your camera. And that comes to a question, a lot of people like to try and take pictures of these things. You can still use that kind of a filter for your camera. The point of that disclaimer is you're not supposed to just stare through the viewfinder at it the whole time. That's not good for your eyes. But yeah, if you're going to buy those things, if you're going to buy eclipse glasses or buy filters for your camera or whatever, you want to buy those early. If you're listening to this podcast now, you should do that now, because it's coming fast, and you want to make sure you can get that stuff to you before time runs out. So, plan ahead is really the way to go.

Adam: At least for me, when it comes to doing anything, I like to spend money on unnecessary gear and equipment. I kind of know that you're the same, actually, on this stuff.

Aaron: A little bit, yeah.

Adam: So, what I would love for you to do is, in terms of planning for my solar eclipse, what's the fun stuff I can have and then what's the DIY stuff I can have?

Aaron: Sure. So, what to do when you're planning for an eclipse. So, probably the most important thing you can have for an eclipse, like the number [one], if you're only going to buy one thing, you should get yourself a pair of eclipse glasses. And so, they don't look like much. They look like just a piece of cardboard with some aluminum foil in it. I promise you it's not aluminum foil. This is actually a very specific foil that blocks out like 99.999% of the light that would go into your eyes, and they're safe for solar viewing. You want to make sure you buy them from a reputable place. Find a good online retailer. Don't just use Amazon. Thousand Oaks Optical made these. They're a well-known manufacturer of optical equipment. And anything that you buy, make sure that it carries an ISO certification to be safe for solar light. So, there's a specific specification you want to look for. But these are your number one thing. And these you'll wear anytime that the sun isn't completely blocked. So, if it's a partial eclipse or if it's not quite into totality yet, you got to have these to keep your eyes safe. If you're going to step up from there, let's say that you're a photographer, they do make the exact same thing, but in filter sizes. So, this is, again, that same kind of foil that's in these eclipse glasses. You want to be careful with these. They're very, very delicate, and if they are scratched or punctured in any way, don't use them. Just get another pair or get another filter. So, that's something that you can use. If you get one that's as big as your biggest lens, you can then get step-up or step-down rings to attach it to other lenses on your camera. If you want to try and look at it with a telescope, they make ones that will actually go on a telescope. Again, that same kind of filter material that's in there. And anytime you look through these, when you're looking at the sun, it will give you a view that — it's a little bit orangey-red because it's trying to block out the wavelengths that would harm your eye, and it just gives it a nice kind of warm cast. It looks really good. The other thing you can get is filters, again, specifically for a camera. This is essentially a really, really strong neutral density filter. This happens to be like an ND 10,000 filter, might be a hundred thousand. It's a lot of zeros. This is fundamentally different from these. This is essentially really, really strong sunglasses. I'm not saying buy really strong sunglasses, that's not what I'm saying. But this will block out, again, the vast majority of the light, and that's safe for a camera. You wouldn't want to use one of these with just your eye. Only use this on a camera. These you could look through with your eye. They're just a big version of the solar sunglasses, the eclipse glasses, excuse me. If you want to step up a little bit, like each of these is slightly more expensive than the last one that I held up, but if you want to go real expensive, I can get yourself a pair of solar binoculars or a solar telescope. These happen to be manufactured by Celestron. They're a well-known telescope brand. And these, you can actually look at the sun directly with these binoculars. I did it just the other day in my office, because there was a beautiful sunspot that was on the sun. But these, the lenses look like they're black and they are useless for looking at anything other than the sun. It's just way too dark. So, these are a great thing to have. These are probably going to run you $100-200 to get a pair of solar binoculars, but they're a fun thing to have even when it's not an eclipse time. So, that's kind of a cool thing to have. Incidentally, on any of these, I really recommend testing them before you use them on the sun. And the way I do that is, I'll take my solar glasses and if I want to make sure that they're still good, that I haven't scratched or damaged them in any way, I'll find the brightest light bulb in my house, put them on and stare at the light bulb. And if I can't see it, they're still good. And so then I can take 'em outside and do what I want to do. But if you want to go the real DIY route, we'll just set all of this stuff to the side. If you have a cardboard box and you have a pair of scissors and some adult supervision, you can make yourself a pinhole camera or a pinhole projector. So, I have one over here that's partially built, made with a random box I found in my office. And so, what I've done is I've cut two holes. There's the empty hole that you're going to look through, and then the hole over here has some aluminum foil over it, and the aluminum foil, I've taken a pin and made a tiny hole right in the center of that aluminum foil. And then I just taped it to the inside of the box. And on the other side of the box, like the opposite side, I've taped on a piece of white paper. And so, then you'll just close it all up and you'll point this end at the sun, and you'll look through this end. So, you're kind of looking over your shoulder at the sun, and it will project a little disc of the sun on the inside of the box. And it's safe to look at while the eclipse is going on. You can actually look at it while not the eclipse is going on. This is perfectly safe, pretty much any time of year to do that sort of thing. So, you can watch as the sun gets more and more and more blocked. Now, if you're in totality, you can stop using this as soon as totality occurs. So this is one method of making a pinhole projector. Another method that you'll see, and there are lots of online tutorials for making pinhole projectors, I made a second one with another box. The longer the box is, the bigger the image you get. So, here's one where I have just the hole for the foil, and then over on the side I've cut a little flap. And so, you're looking into the flap at the projection that's on the far side of this box. And so the longer the box is, the bigger the image of the sun you're going to get. So try and get a long skinny box to do this sort of thing. But I mean, it doesn't have to be enormous. But right now is the perfect time to look around your house and see if you've got your empty Amazon boxes or whatever's been shipped to you. Find one that's suitable, grab some tape, grab some aluminum foil, and just go to town. And it's a great way to get a DIY project that lets you view the sun safely.

Adam: Thanks so much for letting us know how to do that. 

What scientific phenomena can be observed during a solar eclipse?

Adam: What are the scientific things that are happening that become observable, that aren't otherwise observable? Because I think the thing that sounds wild to me, when I've heard other astronomers or physicists talk about this, are just all of the stuff on the sun that suddenly becomes accessible without a whole lot of additional preparation or equipment.

Aaron: Sure. So, the sun is a really dynamic place. The surface of the sun, there's stuff going on it constantly. It's basically a giant plasma. It's a giant ball of charged gas that's interacting in really weird ways. So, there are solar flares and there are prominences and there are ejections of material from the surface. It's really wacky, the stuff that's going on in the sun. And in fact, it's a lot wackier right now because the sun happens to be in a solar maximum when there's a lot of activity on the surface of the sun. But at the very edges of the sun, when you block out the sun with the moon, at the very edges you can start to see some of those eruptions, those flares, those prominences, things that just wouldn't be visible otherwise without really expensive hardware. I mean, they make solar telescopes that are useful for looking at the sun at any time. That is not true of every telescope. So don't just grab a telescope at Walmart and point it at the sun. That is a recipe for burning your eye out. So do not do that. But they make specific solar telescopes to do that. But they tend to be very, very expensive. And they're so expensive because that's what we're doing to make them safe. It takes extra technology and extra effort to make them safe. So, you can see some of that solar activity normally, but once we block it out with the moon, you can just see it. It's right there. You can't miss it. And so, there are people who study the sun. I should mention as an astronomer, people tend to think of astronomy as a monolith. If you're an astronomer, you know everything about anything astronomy-related. Yeah, no, that's not true at all. I'm not a solar physicist. I don't study the sun. The sun is a star, yes, but it's way too close for me to care about. So, I look at stars much more distant than this. Being able to study those flares and prominences, being able to study the corona, right? The corona, there's a lot we don't know about the corona because it's very difficult to study because the rest of the sun is right there the rest of the time, and it's so bright that it drowns it out. So, there are lots of scientists who study those sorts of things, who study the dynamics of the surface, who study the corona, that they're going to spend the time of the eclipse doing that, that they're definitely going to be taking measurements and taking data to try and better understand that star that's right next door.

What can scientists learn from viewing a solar eclipse? What can the average person learn?

Adam: So, it's a tremendous learning opportunity for folks who are specializing in that area, right?

Aaron: Oh, absolutely. 

Adam: Yeah. 

Aaron: There are also some other more subtle things that are kind of interesting about solar eclipses. There's this scientist, I don't know if you've heard of him. I mean, he didn't make much of a splash. A guy named Albert Einstein…

Adam: Never heard of him.

Aaron: …who talked about, among other things, his theories of special and general relativity. Well, general relativity actually tells us some things about how gravity really works. We all tend to think of gravity as, “I drop an object, it falls.” Like, gravity pulls stuff down. Well, kind of. Without getting too technical, without spending two or three more podcasts getting us to the point where we can really have this discussion, what really happens is that anything with mass warps space-time, and that when you drop an object, what's actually happening is it's taking a straight-line path through space-time. Well, the sun is kind of a big mass, and so it warps space-time quite a bit. And so, what actually happens is stuff that's just behind the sun, so if there's a star way off in the distance but behind the sun from our point of view, the light from that star can actually get bent around the sun because the sun is warping space. So, this was a prediction that was made by Einstein's theory of general relativity in the early 1900s. And when it was predicted, people are like, that is crazy talk. I mean, there’s a lot of both special and general relativity that the first time you read it as a physicist, as someone trained in this, you go, that's crazy talk. Well, they tested it. So, when a solar eclipse happens, it dims the sky enough that you can actually see those stars. And so, they knew that that was going to happen. And so, after that prediction was made, a bunch of scientists went, "Well, you know, there's this eclipse coming up and I'll bet we could test this." And they did, and it passed with flying colors. Every test we've thrown at general relativity for over a century, every single thing that you went, “That's crazy,” when we tested it, it worked. This was one of them. And so, we actually proved, at least that aspect of Einstein's theories, just by observing a solar eclipse and knowing that we needed to look for a star that it'll look like it's just on the other side, just to the side of the sun, even though we know it's behind it, is essentially what happens.

Adam: For myself, when you read about these big general relativity things, or just these astrophysics things, thinking about things like gravity or things like light, they seem intangible in a way that my brain isn't hardwired to understand at all. So, I think for a lot of people, the reason it feels like nonsense, and the reason it feels like witchcraft is you're like, “Light's not stuff, it just is.”

Aaron: It just is, yeah. Just a thing that happens.

Adam: But light is stuff.

Aaron: Yeah, light is stuff, yeah. It's kind of like — you know when you've got a glass of water and you stick a straw on it and if you look at it from the side, the straw looks kind of bent like it's in the wrong place. And you're like, “Huh, that's weird.” Well, that's because your brain is used to light working in a certain way. You look in a direction and light goes straight in a direction. That's all it does. Well, no. No, it doesn't. It bends. It bends a lot. My glasses are proof that it bends a lot.

Adam: I can see at all because of refraction.

Aaron: That's exactly correct. But you can think of these things like special relativity, and, well, general relativity in this case, it's bending light, but it's bending light not because the light is going through glass instead of air, or in my case, plastic instead of air, but because it's actually getting bent through space itself, right? Because that's what masses do. And it is a really weird way to think about things. And you're right, it does seem like either crazy talk or witchcraft until you start to fundamentally understand it. There's this great quote, and I think it was Ernest Rutherford, who is another big name in physics, not quite as big of a name as Einstein, and he said that all of physics is either impossible or trivial. It's impossible until you understand it. And then it's trivial once you do. And this is one of those things that like, okay, if you understand the physics, well, of course it does that. And if you don't understand the physics, you're like, it can't possibly do that.

Are there any philosophical implications of a solar eclipse?

Adam: It feels like an awesome thing to think about, too, where if you're getting to observe this thing, that there are sort of these phenomena that govern the way that our universe just is, that they're laid a little bit more bare for a couple minutes right there, too. And maybe that adds to that feeling of awe…

Aaron: It does.

Adam: …and that feeling of being small.

Aaron: We tend to think of both the sun and the moon as just things that are, there are things that just happen like sunrises, sunsets, moon rises, moon sets. It's just a thing that happens. Don't even worry about it. There it is.

Adam: What's to know?

Aaron: It's just a thing. But when one gets in front of the other, a weird thing happens. You're like, “Holy crap, wait a minute.” The space is three-dimensional. There's stuff in front of other stuff. It's not just the moon is in the sky and the sun is in the sky. It's that, well, the moon's much closer and it just went in front of that other thing that I know is really big and really far away, and they lined up for just an instant. And that is, wow, that is just awe-inspiring.

Adam: The moon is doing that for you, in a way that you can never ask for or hope for. It's just happening and it's just such a wild thing to think about.

Aaron: And it, kind of, simultaneously makes you feel special and small at the same time, which is kind of a neat trick, right? Because you feel special, because you are in just the right place to see it, but you feel small because it's like, wow, the universe is much bigger than I am. It's much bigger than my problems. It's much bigger than my petty arguments about what's the best kind of cookie. None of that matters. But at the same time, look at this brief window of time, this three minutes of my life that I got to spend in the shadow of the moon.

Adam: Again, I want to really reiterate, we're sitting here — Aaron probably understands what the sun is and what he's seeing more than anybody, and he's — keep in mind, he led off here by letting us know that it just puts your jaw on the floor.

Aaron: I nearly cried. 

Adam: Yeah.

Aaron: I'll be a hundred percent honest. I nearly cried. It was that awe-inspiring, that amazing, that — words failed me. I'm a guy… I teach. I'm literally paid to talk for a living. That's literally what I do for hours a day, and words didn't work. My mind could not form words during those two minutes.

Conclusion

Adam: Aaron, thank you so much for taking us through your eclipse experience. I really appreciate your time today. It's been super insightful. I'm kind of excited. It's my birthday. Maybe I'll take the day off and try to take a look at it.

Aaron: Oh, you deserve it. Absolutely. I was happy to talk about it. The more people I can get to see it, the happier I will be.

Adam: Yep. Don't go to class.

Aaron: Don't go to class.

Adam: April 8th.

Aaron: You heard it here first, kids.

Adam: Everybody. Elementary school, high school, college.

Aaron: Cancel 'em all.

Adam: Cancel 'em all. Don't go to school.

Aaron: That's right. Don't go to work either.

Adam: Awesome. You got your permission here. Thank you, Aaron.

Aaron: Thank you.

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