The World According To Sound: A Sonic History Of Astronomy

JOHN DANKOSKY: This is Science Friday. I’m John Dankosky. Looking into space can be pretty daunting. How do we make sense of staring into the vast expanse above our heads, the millions of stars we might be able to see and the billions more we can’t? Now how about listening to space?

That’s the task that Sam Harnett and Chris Hoff gave themselves for their podcast series Cosmic Visions. They’re the team behind The World According to Sound. It’s a podcast that’s brought our listeners close to the sounds of science over the past few years. Now, this new series is part of a humanities project called Ways of Knowing that takes listeners through the history of astronomy and the study of the cosmos, from ancient Babylon to the Hubble telescope. Sam Harnett and Chris Hoff, welcome back to Science Friday. Thanks so much for joining us.

SPEAKER 1: Thanks for having us.

SPEAKER 2: Thanks for having us.

JOHN DANKOSKY: So let’s start with the idea behind this project. It’s part of a podcast about the humanities. Now, science and humanities are often on different sides of the table or at least different sides of the campus. How did you think about telling space stories through this lens?

SPEAKER 2: Well, I think that’s the point is that they shouldn’t be on different sides of the table, really. That was the impetus for the project, which is, for some reason in our society, science and the humanities have been split. And the point of the project is to show that there really are unsplittable if you look at the history of science.

JOHN DANKOSKY: Now, we’re going to be hearing some of the space sounds you were working with in just a minute. But maybe the both of you can take me through how you decided on the stories about the history of astronomy that you wanted to tell here.

SPEAKER 1: Yeah, we actually had some help from the Johns Hopkins Humanities Center. They’re called the Alexander Grass Humanities Institute. And they have people in the humanities and astrophysics there that kind of helped us create this list, and then we kind pared it down to what we wanted to do.

But really, it became clear to us that we had to do a kind of expansive history of it, and like starting from ancient times and going up to the modern times, to really show this evolution of how the humanities were intertwined with astrophysics since the beginning of the written record all the way up to now to 2024.

SPEAKER 2: And I’d add that, yeah, the goal was to pick stories throughout history that showed different ways that major scientific breakthroughs came about and to show that science doesn’t happen in one way. Again, I think there’s a trend to separate humanistic thinking from scientific inquiry, and really, they’re married. But they’re also everything from philosophy and religion to literature and art has all been part of the story of the history of astronomy.

JOHN DANKOSKY: Yeah, and this whole idea of ways of knowing, this is actually something we’ve explored quite a bit on the program as well over the years. It’s this notion that this Western ideal, this academic version of how we might look at something as broad as the cosmos, this isn’t the only way people have been looking at it throughout the centuries and centuries.

SPEAKER 2: Right. In the Dante episode, here you have this Italian Renaissance poet in the 14th century about God. And the way he describes the universe is eerily similar to the way scientists in the 20th century started observing the universe through telescopes.

[AUDIO PLAYBACK]

– This is an excerpt from the Divine Comedy. The narrator has just come out of purgatory, and he’s gazing up at the heavens. Everywhere he turns, he feels like he isn’t looking outward at space but, instead, inward, back in time toward the same point, the beginning of creation– God.

– [ITALIAN SPEECH]

– This description of the universe is remarkably similar to what would be observed in telescopes some 600 years later. Just replace God with the Big Bang.

[AUDIO PLAYBACK]

SPEAKER 2: Now, at first that seems just like a crazy coincidence, just a quirk. But actually, the reason that the two are so similar is because, cosmologically speaking, if you’re trying to conceive of a universe that is not infinite but there’s nothing outside of it, the only way to do that is to curve space. And modern telescopes show us that space is curved, and Dante in his imagining of the universe also curved space. So that kind of coincidence between two things, a highly religious poet in the 14th century and modern telescopes, they’re kind of dealing with the same problem.

JOHN DANKOSKY: I think one of the most beautiful ideas in that episode, though, is flipping the notion of what we’re looking at when we look into space. When we started this segment, I talked about the difficulty of looking into space and comprehending what you’re seeing. And the way that a lot of modern society thinks about space is we’re on Earth. We’re looking up at what’s out there. But you use this Dante example to really tell a beautiful story about how, in ancient times, people had this notion really flipped.

SPEAKER 1: Yeah, I think that sort of idea of perspective is also central to the series. It’s sort of to me, even still, even after having worked in this episode for hours, and hours, and hours, this notion of thinking that when you look out into space, you’re not looking out. This notion that you’re looking in towards something is really hard to comprehend if your entire life has been spent thinking in this opposite way. So I find, yeah, that getting back to these ideas that were from 500 years ago, 1,000 years ago really can change your perspective on these truths that you thought you knew.

SPEAKER 2: Well, and that’s– dealing with something like the universe, we think, oh, modern science, we have all these telescopes. We have all this technology, advanced physics.

But the universe is still incomprehensible. We still– you can’t wrap your mind around it. It’s impossible to wrap your mind around it.

You need metaphors. You need analogies. You need ways of thinking and interpreting that the humanities and art are very comfortable with. And again, I think the Dante example is a great one.

The average medieval man in Europe, in some ways, had a more accurate understanding of the structure of the universe than a modern person today because, when we look out into the space, it’s very difficult to not feel like we’re staring out into the void and to really think, oh, we’re looking back in time at the beginning of it all, which was the common conception of Christians in the Middle Ages. So this idea that we’re more advanced in certain ways, but we’re dealing with some of the same problems. And we’re thinking about things in some of the same ways that people have done since the beginning of time.

JOHN DANKOSKY: I think another important way that you can make something as vast as space comprehensible is to put it into some sort of terms that we might understand. And this is where a lot of the sounds that you use come into play.

One of the episodes in the series is about gravitational waves and Black holes colliding. It’s actually sounds that we’ve played on Science Friday in the past from your podcast. Let’s actually listen to that sound here.

[INCREASING WHOOP]

SPEAKER 1: What I love about that sound is, well, first of all, it’s such a whimsical, almost absurd sound for such an incredible cosmic event. You have two Black holes colliding, and it makes this whoop. But what I love about that sound is it’s not just a stunt to get attention. There’s actual scientific information encoded in that sound, and that sound actually helps scientists who are working on these problems have some kind of reference, like the auditory. It’s some way of envisioning this thing that is really not envisionable.

SPEAKER 2: Right, and without the sound, they actually wouldn’t know some of those things. So it’s an interesting situation where the sonic information embedded in this phenomenon actually tells them something that they wouldn’t know otherwise.

SPEAKER 1: Well, I think they– I think they could know it, but it’s not immediately graspable.

SPEAKER 2: [LAUGHS]

SPEAKER 1: Yeah, I think it’s more that–

SPEAKER 2: It’s just so immediately obvious, like the oscillating ones versus the regular ones. They just know immediately, oh, this is an x black hole, and this is– you’re right. Yeah.

SPEAKER 1: And it just gets to that point that you think of astrophysicists as these highly rational– they’re doing math, and everything is very concrete. But they as well need to think in metaphors and analogies. They need to use the ways of knowing from the arts and the humanities to approach their subject.

Science never has been and is not divorced from that kind of creative, imaginative thinking. And the scientists that we interviewed in that episode, he talks about it frankly, saying, I can’t really say that I understand this stuff, conceptualize it. He needs metaphors.

JOHN DANKOSKY: And just to be clear, the sounds that we heard, it’s a representation. It’s the sonification of data. This isn’t actually the sound of two black holes colliding because we don’t know what the heck that actually sounds like. Maybe you can explain exactly what the scientists are doing to create the kind of goofy sound that we hear.

SPEAKER 2: So what’s wild about these sounds, first of all, it is the data. It is the actual gravitational waves, which are ripples in space time. When two black holes collide, they happen to generate gravitational waves that are in the same frequency as sound waves in the human range of hearing.

So they don’t change the frequencies. They just shift it from gravitational waves to sound waves.

[INCREASING WHOOP]

So what you’re actually hearing is the two black holes colliding in real time, and this is actually how fast it takes for the two black fl to swirl around each other about the speed of a blender and come together. The only change that’s happening is that the sounds are being translated from gravitational waves to sound waves.

JOHN DANKOSKY: So you have an episode called “Picturing the Universe” that’s about the story of the Hubble telescope. And of course, with the launch of the James Webb Space Telescope and some of the amazing images we’ve seen over the last year or so, a lot of people have maybe forgotten a bit about how groundbreaking Hubble was. What drew you to the story of the Hubble telescope?

SPEAKER 1: We came across at one point that there was this person that had a whole theory of outer space looking like American Western landscapes. That just blew– that was just like clear to us, like, oh my God. And this has been around for 15, 20 years, this woman’s theory, Elizabeth Kessler at Stanford University.

[AUDIO PLAYBACK]

– If we think of the famous pillars of creation, the background is bluish green. These clouds of gas and dust are yellowish and brownish. So they look sort of like buttes in the desert Southwest kind of rising up from the bottom of the frame.

– Kessler is talking about the famous image from 1995 taken of the Eagle Nebula. It really does look like something out of Monument Valley or Arches National Park, familiar yet otherworldly.

The Pillars of Creation was created by Jeff Hester and Paul Scowen, two American astronomers. These men, along with the other image processors on the Hubble Heritage Project, seemed to favor saturated colors and high contrast. They turned the raw data from Hubble into images that resembled majestic desert rock formations.

– And it struck me that these astronomical images resembled landscapes and not just any landscapes but a particular set of landscapes, those that depict the American West in these kinds of very romantic ways, that emphasize the sublimity of that scene, that emphasize the kind of size, and scale, and drama, and majesty of those landscapes.

[PLAYBACK ENDS]

SPEAKER 1: But it makes a lot of sense. And we spoke to her, and she’s just really convincing and really articulate about this idea that, yeah, most of the pictures that Hubble takes, it’s of data that isn’t in the electromagnetic spectrum that humans can see. And so if that’s the case, then we’re all making interpretations about it. And if that’s the case human beings are interpreting this based on something.

And if you’re an American, you’re going to interpret it based on stuff that you know. And maybe if you’re Japanese, you would interpret it on stuff that you know. But the point is Americans are making these decisions, and to me, that’s just such a delightful idea.

SPEAKER 2: And I think the deep idea of that episode is everything in science is filtered through social perceptions, metaphors, analogies, the way that we envision things and think about things, we’re drawing on–

SPEAKER 1: Human bias.

SPEAKER 2: Yeah.

SPEAKER 1: Sorry, to interrupt, but human bias. That’s a major– that’s what interpretation is. It’s essentially human bias, is it not?

SPEAKER 2: Right. Well, and you can’t get away from interpret– interpretation is part of the whole process. And here’s a very clear example of these pictures from space, which are so iconic. They’re an interpretation of data that are then put into an image that makes sense.

And I think that that is a very powerful part of that episode is realizing, oh, these images could have looked different. They could have been different colors or zoomed out to different degrees if they were made in a different culture. And to be like, oh, that’s playing out in science all over the place, how we decided to depict images and what analogies and metaphors that we use to try to convey something.

JOHN DANKOSKY: What are the big things that each of you learned in this whole process? Because I’m sure you learned an awful lot about the history of astronomy. But what are some real takeaways for each of you that you say, yeah, I understand this a little bit better than I did before?

SPEAKER 1: Huh, well, that’s a good question.

SPEAKER 2: I would say that, on a fundamental level, it is that it hasn’t been this steady, forward progress of ideas towards a better understanding of the universe and that the understanding of the universe is really– it requires all these different ways of knowing, and you can’t get a picture of the universe just through one way of knowing. I think that was the premise at the beginning.

And it became more clear as we went through of like, oh wow, like you can’t wrap your head around this without thinking about it in lots of different ways. And in terms of science, there’s tons of stuff that I did not know or had learned but I had forgotten. For me, the episode we did about the Mayans and their use of zero was really illuminating, just, again, thinking of zero as a concept that was something humans didn’t always have.

And it had to be invented. And zero has different meanings and different cultural contexts and the way zero allows for certain kinds of math that allow for certain kinds of understanding. That’s a story that I did not know well that was– kind of blew my mind.

SPEAKER 1: I’d say that– I’ve always had a lot of respect for science, and this project kind of just taught me that, yeah, it is an extremely useful and important tool. But it’s definitely not the only game in town when trying to make sense of the world.

SPEAKER 2: Maybe one other thing I’d add that I didn’t know that I also thought was really wild is I didn’t know how many scientists or how many people who made great discoveries about the universe had really kind of wacky ideas or wacky approaches to their work. And I think of Johannes Kepler. I remember learning about Johannes Kepler in an astronomy course, this towering figure of European astronomy.

And he wrote this fantastical science fiction story about a trip to the moon with a daemon. I didn’t know that story. So this idea that a lot of these great thinkers were just thinking in all these really different ways was something I learned throughout the project.

JOHN DANKOSKY: I have just one last thing for both of you. Your final episode in the series is called “Sounds of Space”, and you say that there’s a lot to hear in outer space if you change the way you listen.

So I don’t know. What are your favorite space sounds? You’ve gotten a chance to listen to a bunch of these things. What are just some sounds that you really love?

SPEAKER 1: Yeah, well, some of the things won’t be space sounds, but I love the sound of Dante’s Inferno being read by an Italian person.

[AUDIO PLAYBACK]

– [ITALIAN SPEECH]

I love the sounds of comet dust hitting a probe.

[VIBRATING SOUND]

That’s actually been captured. That is a very nice sound, which is in the space sounds episode.

SPEAKER 2: I really like, in the final episode, it’s a montage of all this different electromagnetic radiation that’s been translated into sound. And there’s a ton of stuff in there. But I like the pulsars, like the spinning pulsars, that make this little blip sound.

[WIND-LIKE SOUND]

Again, this is data. That’s data that’s being translated into sound sonified. And I like there’s also the pulse of the Earth’s magnetic field that has been sonified. That’s really fun to listen to. But really, I think the deep throb of cosmic background radiation.

[DEEP STATIC]

It’s just there. It’s everywhere in the sky. And it’s just this static that pervades everything, and I think that’s like– the sound itself is not that spectacular, but the concept behind the sound, it really kind of– yeah.

JOHN DANKOSKY: There’s a lot of big concepts and a lot of big sounds in this series. It’s called Cosmic Visions. Sam Hartnett and Chris Hoff are the creators of the World According to Sound, and this new series is part of a humanities project called Ways of Knowing.

You can find it wherever you get your podcasts. And we’ll have links to some of the stories from the series on our website sciencefriday.com/soundinspace. Sam and Chris, always good to talk with you. Thanks so much for joining us. I appreciate it.

SPEAKER 1: Definitely.

SPEAKER 2: It’s a pleasure being here.

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