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The World's Largest Refracting Telescope (with Dr. Amanda Bauer)

Dean chats with Dr. Amanda Bauer, Head of Science and Education at the historic Yerkes Observatory in Wisconsin. Listen in to learn about the largest refracting telescope in the world and Dean's tips for determining a telescope's "coolness factor." New episodes release every other Friday!

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Looking Up is transcribed using a combination of AI speech recognition and human editors. It may contain errors. Please check the corresponding audio before quoting in print.

Dean Regas: Edwin Hubble demonstrated the expansion of our universe. Gerard Kuiper defined the Kuiper Belt, a region beyond Neptune containing icy bodies. Subrahmanyan Chandrasekhar formulated the Chandrasekhar limit. These are just three of the countless astronomy legends who studied at the prestigious Yerkes Observatory in Wisconsin.

Today, we'll learn about the century-old telescope they all looked through and what it takes to keep it in working condition. From the studios of Cincinnati Public Radio, I'm your host, Dean Regas, and this is Looking Up, the show that takes you deep into the cosmos or just to the telescope in your backyard to learn more about what makes this amazing universe of ours so great.

So, there are just some observatories that are too cool for words. I'm really, really excited to talk about the Yerkes Observatory in Wisconsin. They are home to the largest refracting telescope in the world. This thing is 40 inches in diameter, so big hunks of glass that are 40 inches in diameter ground to this perfect shape that light will go through.

And the telescope has been there for more than 125 years. There's something about historic telescopes in general; at least they get me going. I don't know about you, but they get me going because I like to go back in time in my mind and think back like what it was like to work at these telescopes. I mean, imagine going to work, let's say the year is 1899 or something like that. What do astronomers do? What do they eat? Do they stay up all night? They sleep during the day? I don't know. I love thinking about this stuff.

Earlier in 2023, I got to go to the Yerkes Observatory. I got to give a talk there, and I got to stay in one of the astronomers' residences. So those are like the old astronomers' residence; they fixed it up, and it was kind of cool because man, it got dark at night. It got really dark at night out there. And, so I went out and just did a little walk around and he had this gigantic building there. That's barely visible silhouetted against the sky and the telescope that's in there. The main part of the building is actually three stories. The dome that we're standing in is 12 stories high from the top of the dome to the base of the telescope.

We look at telescopes like the one at Yerkes, and that's the biggest refractor. I mean, why didn't they make any bigger ones? Why not just make like a hundred-inch diameter or one or a 500-inch diameter. Why, why stop there? And that's the thing with these refracting telescopes. There is a size limit. They can only be so big. If you're thinking about looking through the classic telescopes, you put your eye at the bottom, you look through the whole length of the tube, the lens at the top can only be held on the sides. And so if you have a giant lens, it actually, the weight of it starts bending. And so the Yerkes refractor was kind of like the limit.

But what the modern telescopes do there, these are more reflector telescopes, and these are ones that use mirrors instead of lenses. And so reflectors are all the rage now because you can make them any size you want. Like the James Webb Space Telescope has those segmented mirrors. So you can make it almost any size you want. You support the weight at the bottom of the mirrors. The light comes in, bounces off the mirrors, goes to a secondary mirror, can go into any kind of instruments you want. Cameras, spectrographs, whatever you want. Reflecting telescopes can be any size. But, come on, they're not classically cool looking. I mean, when I go visit observatories, modern and historic, the big question is, where do I put my eye? If they laugh at me because nobody actually puts their eye up to telescopes, then they're like, oh, yeah, you know, that's where the camera goes, because cameras are way more sensitive than your eye. But if I say, where do you put your eye, and they say, right there, then I know that's a cool observatory. That's the kind of observatory I want to be at, where you can put your eye up to a telescope. Come on. Amanda, thanks so much for joining me.

Amanda Bauer: Today. My pleasure. It's always nice to chat with you, Dean.

Dean Regas: Oh man, is the Yerkes Observatory such a special place and you drive up that driveway and you see this gigantic building with these domes on it and then you get inside and you got the largest refracting telescope in the world. So what do you, what do you feel like when you walk into that dome and you see that telescope? What's it like?

Amanda Bauer: It never gets old.

It's always kind of a moment of awe as you walk in. And then you kind of hear the acoustics and the voice echoes and everything just feels very historical, mechanical. You, it's a lot of hands-on. There's not a computer in there that you get to touch. So kind of every time you really feel connected to all of the generations of astronomers of the past.

Dean Regas: And so, uh, you have this scope that you can, you know, first off, you have to open up the roof, move the telescope around, and then how do you get your eye up to the eyepiece?

Amanda Bauer: That's right. So, it's tricky. The telescope looks so big. And some people think that there's this really historic wooden ladder in there that you have to move over, which you can use, but the biggest, most effective way to get up to the eyepiece is by lifting the floor, which is about 90 feet across.

As far as we know, it is the largest indoor elevator in the world, and that lifts us all the way up to the eyepiece of the telescope.

Dean Regas: And you walk in and it's like, you know, like the eyepiece is still like 10 feet above you and you're like, wait a second. So then you, yeah, you hold onto the handrail and the floor just moves right on up.

Amanda Bauer: Yeah, it's, it's quite a legacy.

So the elevator itself is hanging off of four cables that are connected to huge weights. And so there's a direct current motor in the basement of the dome that activates and pulls those weights down which lifts up the floor. There is another direct current motor that operates the dome itself. So the dome is 90 feet across and moves 360 degrees around.

So when you need to move that slight opening, it's about 11 feet across the opening in the dome, you have to move that all around from this DC motor,

line it up with where your telescope is pointing, and then you move the telescope either by hand, or there's another, uh, direct current motor inside of the pier that holds the telescope up, and that operates the right ascension. Motor.

Dean Regas: And so what's involved with keeping up with this telescope that's over 125 years old?

Amanda Bauer: So when I first took over this role, and it was kind of my job to assess how is the telescope working? Does it still work? What do we need to do with it? Uh, it hadn't really been used in probably five years, and we had done a lot of masonry work inside the building, so there had been some dust and particles up in the air.

So it was really, really difficult to move at first. I mean, we tried to move it by hand, but it turns out that three of us had to work together to kind of move it into the right direction, which is not very efficient for observing. So we finally learned from some of the old engineers and former directors who are still in the area where we need to grease and oil every point in the telescope and, you know, climbing up on ladders and crawling over things to get all of that grease and oil in the right place.

And then you just have to move it back and forth and back and forth. And so now I can move the whole telescope and point everything by hand, but we definitely have to stay on top of all of that greasing. It is just a very mechanical system.

Dean Regas: Yeah. I, I love the, the story here of the Yerkes Observatory also too, because it was started and owned and operated by the University of Chicago. And then it came into private hands. Talk a little bit about that, that transition from a university to being kind of independent. The observatory.

Amanda Bauer: The Yerkes Observatory in Williams Bay closed in 2018 when the University of Chicago didn't need it anymore. It has new owners now, local people who want to restore the observatory and give it a new purpose. That's right. The University of Chicago founded Yerkes in 1897 and then owned it all the way up until 2018 when they decided they did not want to own and operate the observatory anymore. Now in a statement, the university says the observatory no longer contributes directly to the school's research mission, adding it no longer makes sense from a program or cost standpoint to operate it. The school says it will include the Village of Williams Bay in its discussions about what to do with the property long term. So they made a pretty abrupt announcement to the community that said they were going to stop ownership in October 2018, and at that time, nobody knew what was going to happen to it. So there was some concern around the astronomy community, what would happen to the largest refracting telescope in the world, and what would happen to the collection of 180,000 glass plates that are images that had been collected from that observatory over the last 125 years that were still housed in the building.

There was a group of local folks who live in this area around Geneva Lake who were so passionate about the legacy of this observatory and the architecture of the building and the potential of what it could be that they got together and they formed the Yerkes Future Foundation as a nonprofit. The community of Williams Bay really thinks it's theirs. Because it's been here for so long that they feel it's just part of their fabric of their life and their culture. And they negotiated with the university to take over ownership, um, and stewardship of the facility, the telescope, the glass plate collection, and the 50 acres of Olmsted designed grounds that it sits on right next to Geneva Lake. So that transfer of ownership took place in 2020. And the building immediately went under some renovation. Completely replacing the roof, which had water pouring in. Um, we had to replace the entire electrical system inside the building. We put solar panels on the roof. We did a lot of renovations on the main floor, including the bathroom. Because if you're gonna, you know, renovate a building, you don't really need to keep that historic bathroom. In my opinion. Um, and then we finally, we opened up to the public. Last May, so, um, at the end of May in 2022, was the first time that we opened up to the public again.

Dean Regas: Yeah, it was, it was one of those stories that I was following here from Cincinnati, anything going on with historic observatories, and I was like, oh man, this is, this could be trouble. I mean, this could be the end of the observatory when they were gonna sell it. University of Chicago, did I not accept my offer? I offered them 20 bucks for it, and they said no. Well, I know part of the, uh, the taking over of Yerkes is you get to uncover some things that maybe nobody has seen for a long time in the archives, up in the attic, down in the basement. Are there some really cool, like, finds, some relics and tools, treasures that you've found and uncovered?

Amanda Bauer: Yes, we just recently opened up this vault. They had a vault that they built into the original building to store papers and documents of high value. And so over the century, the decades, they've, you know, changed the types of things they've stored in there. And so we finally decided to pull it out piece by piece. And I uncovered this really gorgeous. scale, like set of scales with the like tiny little metal things that you put on one scale to weigh the other side that probably came from about the 1920s or 1930s. Um, one of my other favorite finds was one of the early astronomers, his name was Storys Beres Barrett, who helped found astronomy and helped find. The site for Yerkes Observatory, he kept these little daily calendars for a few years. And so I found a set of four of his daily calendars that had this really cool like art deco design on the outside. These are from 1901 to 1904. And every day he just kind of writes things off like Send, uh, invoice to Dr. Barnard and pick up light bulbs and send this to Chicago. So it was just a really fascinating insight into like the details of the daily routine at the very beginning of the observatory in, you know, the beautiful script that he had at that time.

Dean Regas: So now to be the caretaker of this 126 year old telescope, is it kind of awe inspiring to be, you know, part of history, all these famous people have looked through the telescope and worked there, uh, Carl Sagan, Nancy Grace Roman, Edwin Hubble, all those folks, what's it feel like to be in that same building with the same equipment?

Amanda Bauer: It is really inspiring to know that so many creative minds were able to kind of start their career trajectory towards this thinking about asking big questions in the universe, and being able to open up cabinets and kind of uncover these little relics or tools or bits of history that have been sitting there for the last hundred years and try to put together who used it for what purpose and how it got reused over time. And I think the exciting thing too is taking that legacy and reinventing it, creating something new that is really continuing to drive research and asking those big questions, but also combining that with culture, with art, with training for students, with outreach and education in a way that is at the core of all that we're doing. It's not a research institution with a little side of outreach, and it's not a museum with, oh, there's a research group here. At the core of everything that we're doing is really bringing together those concepts of astronomy and exploration with the art and expression of all of those big ideas at the same time.

Dean Regas: Well, I mean, there's the, the giant refractor, but there's also several other telescopes are on the facilities. What kind of research could be done, is being done, uh, things you're looking forward to?

Amanda Bauer: Right. There are two large reflecting telescopes as well in the building. It was designed with three domes, the big dome for the great refractor and two smaller domes. Currently, we have. A Bowler and Chivins 1967 24 inch reflecting telescope in one dome, and then we have a 41-inch reflecting telescope in the other dome. And so, with the weather that we have here in Wisconsin, which let's see. Be honest is not great for astronomical site combined with it's it's not bad as far as dark skies go in the Midwest either, but they're not the darkest I've seen, and we're not really at that high of elevation.

So all of those things are kind of working against us from a research perspective, but that's not stopping us from doing things like looking at transiting objects. When an object passes in front of another one and blocks its light a little bit, um, and also transient phenomena. So other Aspects when an object will get brighter or dimmer or change its position for some reason. So those are the types of research projects we're doing right now. We are ramping up our digitization of the glass plates because these are the history of what happened to astronomical objects over the last hundred years in ways that we have no other way to determine. This is called Time Domain Astronomy.

Dean Regas: So this is a field I don't know very much about, but talk to us a little bit about Time Domain Astronomy.

Amanda Bauer: It's a kind of new field. Time Domain Astronomy is the study of things that change over time. And so the project that I was Yerkes Observatory is called the Vera C. Rubin Observatory. And it's a modern eight-meter telescope that's being built in Chile right now. And when it comes online, it will look at the entire sky visible to it. Every three nights or so, it will look over and over and over. And once it has kind of a template image of what a part of the sky usually looks like, when it takes a new image, it can subtract the new image from the template, and anything that's left over is something that changed. So it got brighter or fainter or moved or appeared or disappeared. Um, and they can track those things. And what they're estimating is that every single night, they will send out ten million alerts. Ten million things changing overnight that we hadn't previously detected. The fascinating thing about that is we've never looked at the universe with those kinds of eyes before. We've assumed many things just kind of stay the same. Like my Ph.D. research was on 250 galaxies, but I only saw a snapshot, one picture, not how they changed over time. And so how I tie that to Yerkes is that we have this 180,000 glass plate collection of images over the last 125 years. And so we can compare things that are happening now that the Rubin Observatory will be detecting in the next couple of years and say, what did that look like 100 years ago? How has that changed on that time scale? And so that's what the time domain Study is, how do things change over time in a way that we up to this point have not been able to study in-depth.

Dean Regas: What do you hope that the That telescope and others will at Yerkes help teach the future observatory visitors?

Amanda Bauer: That's a good question. I hope that visitors are able to see how You can make historic objects relevant today. It's not that we're gonna put these things away and just look at them. We're really trying to use them and kind of teach people an appreciation for them, but also an interpretation of what they see, and that can be combined with other aspects of the observatory, observation within our apiary, where we've got bee boxes out there, and we've planted a pollinator garden, and we have students coming through who get to learn how to use telescopes on these big facilities, and we have Nobel Prize-winning astronomers and astronauts coming through that are speaking to the public, um, and we had a U.S. Poet Laureate who came through, Tracy K. Smith, last year, and so all of these aspects of people asking really big questions inspired by the architecture and history and legacy of this building, bringing that into a future where we are going to need to combine lots of different aspects of thinking in order to figure out solutions for the big problems like climate change. So I'm hoping that people come away inspired and that they feel capable of making contributions in whatever area that they have the most interest in.

Dean Regas: Well,it's amazing the work that you all have done out there. I was lucky enough to visit during COVID right after the sale and the, the restoration work had just barely begun. And the, what you all have accomplished in such a short amount of time, the restoration, the scope work, and the education programs, it's, it's amazing. So, uh, kudos. Thanks so much for doing what you do.

Amanda Bauer: Thank you. It's, it's really rewarding. It's really challenging. And it's unlike anything I've done in my career so far. So I'm up for the challenge.

Dean Regas: Well, thanks so much for chatting with me today.

Amanda Bauer: Thanks for having me, Dean.

Dean Regas: One of the other really, really cool things about the Yerkes Observatory is the architecture. And boy, I wish we could have had more time to talk about it, but it is a wild, Looking building, uh, it sits at the back of this, uh, this long approach, this long park, like drive up to it and the building is massive, but then when you walk around it, there's these weird little. Touches and flourishes and details like there's columns out there and the, the, the, the stone is so well done and intricate that in some of the pillars they carved in little flourishes, little flowers, little stars and little faces.

They have moon phases that are depicted in stone around there. The detailing is, is really incredible. So, uh, if you haven't been, you should check it out, and we'll post some pictures, uh, kind of what this looks like from the outside and just some of the details on the building. It is incredible. And the amount of work that they had to do to get the building like open to the public is far out. I was joking with, uh, uh, Dr. Bauer about the. bathroom.

Um, I remember touring the Yerkes Observatory back in the day and I don't know what it is about astronomers and bathrooms. They're not interested in any detailing in a bathroom. There's a few things just for advice out there. If you come across an astronomer, do not. eat anything in their fridge because that has been there for way too long and know that their bathroom is going to be disgusting. Those are just astronomer traits. That's how it is. And so, um, thank goodness they've actually improved the bathroom there.

The inside is just amazing as well. Thinking about all these, uh, you know, historic telescopes. And the part that kind of struck me was the pictures. She mentioned the glass plates. They have this glass plate collection. And the pictures are so incredible, these glass plate slides of galaxies and nebulas and star clusters.

So, I want to give you a little homework assignment. The show's called Looking Up. We want you guys to do some looking up too. So, I want you all to try to get your own picture of the sky. Use your phone, use your good camera, whatever you got. Uh, mess around with your exposure levels because I have a pretty cheap phone, but it has this thing that can do an exposure, like a longer exposure of the sky, and you can actually take pictures of stars and constellations that will show up. So that's your homework assignment. See if you can take some pictures of the sky, the moon, stars, planets, whatever it is. Post them on social media and tag us, you know, do #LOOKINGUPPOD. I'd be curious to check them out.

Looking up with Dean Regas is a production of Cincinnati Public Radio. Ella Rowen is our show producer and cosmic paparazzo. That's a singular paparazzi? Who knew that? That's pretty good. All right, I learned something. Marshall Verbski assists with our audio production and discussions of scientific discoveries. I know, I mean, it's like we have like long, long talks. I mean, way too long talks. Our theme song is Possible Light by Ziv Moran. I'm Dean Regas and keep looking up.