SPEAKER_01 0:05

Please welcome to the stage. Milt.

SPEAKER_00 0:10

Thanks so much. Thank you so much. Thank you, Chris, for organizing such a wonderful day. So let's discover how we're going to play a planet. Space and music have had this long history, this bonding together. And there are some reasons I think that occurs. Firstly, there is this sense that music is universal, stretches beyond the earth. Ability to speak without reference to a language. There's a shared sense of mystery awe and transcendence from the earthly plane. And they're both built from the sort of raw fabric of the cosmos, that is, energy and time, or amplitude and frequency. There's also a sense of relativity. In music we think about we remember a melody because it's the same shape in pitch and time space, just as astronomers can make comparisons between um vastly differently sized celestial bodies. They behave in the same way because of their relationship to each other. And they both seem to harbor meaningful patterns writ large. Now, the attempt to represent uh space within music is usually done through a sense of distance, a metaphorical distance in uh harmonic space or in stylistic space or temperament, so that it feels like the other. But today I'm going to talk about something wholly different as where they meet together, space and music. And of course, this is an ancient idea. Pythagoras had noted that with his monochord, he could essentially listen to how the universe behaves with its shared language of harmonic ratios. What is simple mathematically is consonant musically. Essentially, we have these two domains, the objective, external, reason data about the external world, and this experience of music, this subjective internal sensory experience. And so there's something with space and music where they are brought a little closer. There's this bridging of the domains. So much so that they can swap instruments in order to understand each other. And by sharing instruments, sharing concepts, there's this idea that there is this bigger knowledge formed, which actually on the on the founding of Gresham College, I think there was a bet greater sense of before these our disciplines were so segregated. So sonification in a way is a bridging of these domains from the observable objective data through some kind of membrane into the sonic, into sound and perhaps music. Now it gets more complicated because what do we mean by data and what is a sonic domain and what is music and what is audio and so on. If you want to know more, uh someone wrote a book about it. But essentially, this is what's happening data to the sonic. And we to do so we should have some sort of rules. Now that there are these high and mighty descriptions of what sonification is, but I can distill them into the idea of seeing the world through your ears, and that in doing so, we have to be rule-based, repeatable, and reversible in the translation process. The data has to be relevant, we should be able to recognize different uh data forms in the sonic realm, and there should be a reason to do it, for example, in order to understand something about the world. It sounds like a uh modern invention, but uh we are surrounded by uh sonification. A traditional kettle is fitted with a device so that when it reaches boiling point, it whistles. That's a form of sonification. And if we wanted to abstract it, we could take that temperature gradient, assign it to a sine wave, and put a ping where uh it reached boiling point. T's ready. Um we don't need to do that because the traditional method works just the same, but that concept is actually useful. I had eye surgery a few weeks ago, and the surgeon used something called a Faker machine, which had a very audible sine wave to measure the pressure. So um I can see you all thanks to sonification. Some data forms are readily available, like seismic data. All you have to do is scale it up, speed it up, and we can start listening to earthquakes. Or we can do it to detect particles and so on. Musicians on the other hand are very greedy and are constantly reaching out to the external world for compositional sources. There's a long history of composers using their names in their music as melodic contours, but some go further, like the Brazilian composer Vila Lobos, whose symphony number six is based upon the contour of the mountains in his homeland of Brazil. And you'll see here that this melody by the Oba I track down the mountain follows the contour exactly. As the clouds fade, you'll be able to see it. And there's his sketch of the same mountainous range. So it mattered that shape to his music. We now have better data and better tools, and we can do all sorts with it. We can understand the behavior of pendulums by assigning a virtual keyboard to the right-hand edge and break the grid of conventional music notation. We can turn a spider web into a harp and let the wind blow through it. Not only is it musically interesting, but we also know something about the work the climate and also the construction of the web developer. We can take the Aurora and have its light frequencies slow down to set to sound. So those solar storms might uh have a different symphonic reaction. And we can even reach into artworks and turn them into new artworks. This is uh starry night, its colours being read through, converted to make a little starry night music. Can we just wait for till we get to the yellows?

unknown 7:37

Just what the moon.

SPEAKER_00 7:41

Thank you. So that's the what of what sonification is, and that's the shortest I've ever explained it. Um but here we're talking about astro sonification, the stars, and what we can do to them. And in fact, it's a special kind of data, I think of as the royal sonification, because uhstronomical data embraces the huge spectrum of time, distance, and size, from the very small and fast to the electromagnetic spectrum, which is where music starts joining its music and sound. Then we move through the audible spectrum, to the rhythmic spectrum, to the length of a piece of music, some very long ones, until we get to astronomical time. So it feels like music kind of sits in this bridge of this wide span that astronomy occupies. And again, they share the same um fabric of amplitude, energy, frequency, and rhythm, distance and wavelength seems to be interchangeable in music, and so there's a rich source and uh powerful metaphors, if not uh shared concepts that can be forged from them. And so if we take the idea, for example, of uh Pythagoras's monochord, where uh distance in space becomes a wavelength which becomes a frequency, a frequency which becomes a pitch, we have this very clear sort of cosmic reading, and I find it really telling that we call them musical instruments, but they're scientific instruments also. So the instrument is one of discovery of the external world and also of the internal experience. And I've brought with me one of the most honest instruments I can imagine, which has just passed its centenary, actually. This is the most honest instrument. Ready? It's called, I wanted to do the reveal, a theramine. Here we go. A theremin has only two controls, so that's one of amplitude and one of uh pitch. Uh invented back in the 1920s. This one controls the volume, this controls the pitch. Do you want to hear it? Oh, might as well, since we've got it here. Quiet. Lovely, right? And it makes a lovely noise when you turn it off as well. Oh, thank you so much. So, what I thought I'd do is that we can actually read the universe using this instrument itself. Taking the idea of distance in space, using relativity to hear it. And for that, we need an expert theremonist. And luckily we have one. Professor Chris Lintot. Milt is lying. This is the first time we've done this or knew that this was happening.

SPEAKER_01 11:08

Yeah.

SPEAKER_00 11:08

So what we'll start with, what I've done is kind of reduced um various exp extra extract.

SPEAKER_01 11:15

I've never played an instrument on stage before.

SPEAKER_00 11:17

Well, this is a great place to.

SPEAKER_01 11:18

I was prevented from playing the triangle at school. Good. Okay, there we go.

SPEAKER_00 11:25

So we've got this um map here. Okay. And um what you'll get, we'll probably start at Neptune. All you have to do is sort of step away from here and place your finger on Neptune, and then should be able to move it. I'll just check this. Is it working? Okay. Okay. So if you put your finger on Neptune, please, you can you don't have to touch the paper, just below it and touch the there you go. There we go. Yeah, no. So Neptune, Uranus. Beautiful, yeah. You can even touch it, it's fine. Okay. Is it so it gives you a Uranus? And then we've got um yeah, that's your volume. Excellent. Good. Okay, so let's do the gas giants and let's play a melody with a gas giants. So Neptune, Uranus, Saturn, Jupiter. Yeah, yeah, slides. Slide is good. There you go, it's more expressive.

SPEAKER_01 12:15

They're an integer planet.

SPEAKER_00 12:17

Okay, then use the volume control.

SPEAKER_01 12:22

I mean you can add some asteroids in the earth. Yeah, we can add some asteroids for this. But yeah, Jupiter, Saturn. But you can hear that there's this sort of relation between them, right?

SPEAKER_00 12:30

There is, but what's extraordinary is what we never get from the images is how close the rest are.

SPEAKER_01 12:35

Yes. So could you please play us the rest? Okay, so from Jupiter to Mars, to Earth, Venus, Mercury, and then the Sun. They're really close.

SPEAKER_00 12:46

Yeah, there you go. So that's an interesting experiment, right? So we have that. Uh where would you like to go next? Um we've got Kepler's 11. Let's do the Jovian moon.

SPEAKER_01 12:57

No, well, this will be interesting, yeah, because the the four moons of Jupiter, the big ones, um, they have a very different relationship. And this is interesting scientifically. So um, right. I told you it'd be chaos. Right, so Jupiter's here, then Io, the volcanic moon, and then Europa, and then Ganymede. Lovely. I'm gonna guess Callisto's about here.

SPEAKER_00 13:22

Yeah, well, let's step back a little bit. Uh yeah, just watch out for the volume because if you're here there, you can track your distance. Think of it as a circle then.

SPEAKER_01 13:29

Yeah, okay, I'm gonna think of it. Um, can go home. I'm gonna do this. But what you can hear is there's not the hierarchical resonance. Like as we moved out in our solar system, we got they got further and further apart. Whereas here it's much more even. And they're they're actually a crammed system, they're all very close to Jupiter.

SPEAKER_00 13:49

So, question to you is um is there any benefit for a regular laying out of sections that are cramped and so one of the things we've learned at as we're demonstrating is that solar systems are chaotic.

SPEAKER_01 14:03

Yep. Right? In fact, there's even some sense that our solar system may not be stable, and so that in the future Mercury may spin into the sun, or we know that in the past Jupiter and Saturn interacted. So if you form a regular pattern, then those interactions are less likely to happen. And so once you hit a resonance, so for example, a planet that goes around twice for every time the inner planet goes around once, then those are a bit more stable.

SPEAKER_00 14:25

It's bad news if you that's orbital period, but not necessarily distance.

SPEAKER_01 14:29

That's right, but the two are linked, right? So Kepler told us those two are intrinsically linked. So if you know the period, you know the distance, and and vice versa. That's just gravity. Um but what's interesting about these is these these moons from Jupiter, so the fact they're in this sort of pattern means they c interact in a complex fashion. So they line up all the time, and gravity of one moon affects the other. And so one of the things we don't understand about the Jovian system is how this is happening. There are two probes, the European Juice and the American Europa Clipper, that are on their way there now to have a look at these moons.

SPEAKER_00 15:03

Lovely. Can you try out Kepler 11? Because it has a very interesting pattern as a musician. So they Okay.

SPEAKER_01 15:09

Um, I'm just going to play the planets and then you talk about the pattern. Yeah, okay, go first. And then we'll we'll talk about the physics. Okay, Kepler 11, right. Star, Kepler 11 B, D, E, F, G.

SPEAKER_00 15:23

Now notice the gapping is actually close to um what in Indian classical music are called the shruti, which are quite rational divisions of the octave. It does it does sound familiar, but yeah, exactly. So um do me a favor. Do you want oh you're gonna play on that? Yeah, I'll play on that. You can um you can keep playing if you want to.

SPEAKER_01 15:43

It doesn't make a I think I'm a duet might be beyond me.

SPEAKER_00 15:47

What's interesting is that that gap there is an arbitrary length of of time, right? So uh of of I'd say time, pitch, and also of distance.

SPEAKER_01 15:57

Yeah.

SPEAKER_00 15:57

So um we could call that an astronomical unit, which is just an arbitrary thing.

SPEAKER_01 16:02

MILTS we'll call it MILTS astronomical unit. Exactly.

SPEAKER_00 16:05

But it that just happened to be the tuning of that instrument plus the A4 printout that happened at my home printer, which always prints things too small. So that's a very arbitrary thing. Right. And so is an AU.

SPEAKER_01 16:17

Yes, that's true, which is our distance from the sun.

SPEAKER_00 16:19

Yep. I think what's different though with music is that because of our biologies, we have decided that a musical unit is an octave, right? There's something about this division that almost all uh music cultures call the same name when it when it doubles in frequency. Right. But we can still map these objects to um these distances to musical units here. So if you take, for example, um this uh uh the solar system, it would have we can track it uh over an octave. So I'll take you something like uh Kepler 11, which we just listened to. Okay. We can drop it and see its relationship. I haven't got a screen here, but we can see its relationship to a musical scale, which is something.

SPEAKER_01 17:07

This is just the just from the distance of the planet. This is just distance.

SPEAKER_00 17:10

We'll get to period later, but this gives us a um uh a root, a sort of sharp uh sharp second, a minor third, a sharpened fourth. It's really nice on the um the one the Jovian moons, which you can replay if you want to. It won't sound the same, but I'm gonna enjoy it. Okay. Is uh good? It's this super augmented.

SPEAKER_01 17:47

I think we got something there. I think that'll work. I I reckon that the full version of that track takes about three and a half hours.

SPEAKER_00 17:54

Yeah, you wait for our album and we'll get there to it. But um, what's beautiful though is that space is big. Space is big. That's the only thing I remember from earlier. And so we found they augmented this beautiful Jovian chord that I can now call it, because we don't have enough names for things in music now. And then we have these scales that emerge from it. But there must be, for example, in blues we have these in-between um notes somewhere between these. They not don't obey these equality.

SPEAKER_01 18:28

And they feel they they feel that slight, not wrong, but they they they feel slightly spice, right?

SPEAKER_00 18:34

And the spice only comes because of our the happenstance of our cochlear membrane and how it deals with frequencies. So if we embrace fully the cosmos, um when we take the a blue spectrum, it looks like this. In fact, they're ridged, which makes sense because they're they move slightly.

SPEAKER_01 18:52

And they do move slightly under the gravitational influence of each other, yeah.

SPEAKER_00 18:56

So there must be exoplanetary systems that match the blue scale. I like the idea of a planet. A planet that plays the blues is just brilliant. Well, that's what I'm gonna go hunting for. So um I'm starting to make this catalogue of of uh so of um exoplanetary scales, cosmic scales, which are genuine and you know, I genuinely think there is more things in heaven and earth that can be jumped off in musical imagination, you know. Do I like it with this? Doesn't it? Yeah, okay. You can turn it off if you don't, but it's a nice, you can keep going. Um I think I'm I'm I'm feeling very attached to it. I'm just gonna turn it off. There we go. You didn't get the whop because you didn't turn it on and turn it off with the volume up because we want to hear it.

SPEAKER_01 19:35

Oh sorry. There we go. You're happy now? What I was gonna say is that I think we're obviously playing about, but I was really striking when you introduced sonification in in 30 seconds. You said there had to be a reason for it.

SPEAKER_00 19:50

That's one of the definitions I don't ascribe, but uh but that's one of the just fine things what sonification is.

SPEAKER_01 19:57

But this is what makes sense to me about these planets. So so I I I've learned to love sonification after meeting Mill because I used to rant about it, mainly because I felt like it was a shortcut to people's emotional heartstrings. So, for example, the European Space Agency sent a probe called Rosetta to a comet called Cherimer Garisamenca. Uh, we called it comet Chewy Gooey for a while, and then we met Cherime Garisamenka and decided they deserved a full name. But anyway, um, we did a marvelous sky night program. We put a huge amount of effort into um getting a program out four days after the probe arrived at the comet. So it had a lander that bounced around called Philly, and then we got images from this comet that showed the spectacular snowy nucleus. Um, and we put it all together. I flew back from mission control to do the final voiceover, and the team in the edit had put down the final thing. They'd taken the readings from a plasma instrument that were measuring high-energy plasma around the nucleus, and the final line of the episode was, and now we leave you with the sound of a comet. And it sounded a bit theremen-esque. Yeah. And the trouble is that people listening to that thought that's in some way that's what you'd hear if you stood there. And it's what you'd experience if you were a plasma instrument that had ears, which is a different proposition. But here we're it's really the physics of the system that's driving.

SPEAKER_00 21:18

Yeah, we can, I mean, there's there's a very long conversation, but often those sonifications are um quantized, which means they they clip notes so that they are, and it's not even more consonant, they're just more familiar. So we've we're in a world where there are uh usually most of us are used to a musical system where there are 12 divisions to the octave, and also their own rhythms are evened out, and things are played on harmonic instruments. If you heard the raw data, which I often do, it's challenging, but then I like challenging music also. So um we are for what what in their defense when we look at a graph, we can't see microscopic things, we can't. Nuance, so we simplify. That's true.

SPEAKER_01 22:02

Yeah, yeah.

SPEAKER_00 22:02

So we're so used to having a graph as all as a portal, knowing that it's not the truth, but it's some way of understanding the truth. These are sonic graphs. Now, saying it's the music of is a bit misleading because what it is is the sounds of the data put through this system and so on. Right. And also, if you put the data of, let's say, um uh how what times I have breakfast in the morning, it will probably sound something that uh you'll produce something similar because it's just data coming in and nice sounds coming out.

SPEAKER_01 22:31

I'm interested in being able to differentiate and feel and so hence having the different planets that all the different planetary systems, because we have found there are these resonant systems.

SPEAKER_00 22:40

Oh, yeah. Well, that was really great, a great segue that we hadn't planned at all. But that was such a great segue. So um say something about that was I Yeah, so so so this was a surprise.

SPEAKER_01 22:56

So so I was talking about 17th century astronomy earlier, and and people may have heard of Bode's law. So the idea is if you take Mercury, Venus, Earth, Mars, Jupiter, Saturn, the naked-eye planets, they're sort of in a resonant pattern like this. You get this nice harmony of the spheres, and there's a lot of writing at the time about why the planets don't precisely line up in nice perfect fifths or something like that. So they were almost expecting a musical representation. Then Uranus comes along and doesn't fit at all, and Neptune comes along, which really doesn't fit. And so this idea when I was growing up was in textbooks as sort of a discredited, silly hypothesis. Why would you think that the planets would have a regular pattern of distance?

SPEAKER_00 23:37

Let's stop there for a moment because what I've managed to do is can you see it there, some sort of system there? So what I've managed to do is build a way of actually listening to those orbital periods. And so remember that um continuum there. We've got these things going round every few days or years in our at home. That's a frequency. If we speed that up enough, then we'll start to hear a rhythm. A year becomes a second. Um and if we speed it up in more, that's where we get those harmonic relationships three against two. So here's the solar system. I'm gonna, I should be able to just hear.

SPEAKER_01 24:12

So this is on, I'm just checking, yeah. So look at this screen. Yeah.

SPEAKER_00 24:16

Um, so right now, uh There we go. Let's speed this up a little bit.

SPEAKER_01 24:28

So they're sounding as they move. Is that the idea?

SPEAKER_00 24:30

Yeah, yeah, that's the idea. Let me get some. Oh, let's get this window up. Maybe it's that is that better if we see this. Okay, lovely. So we've got the um these moving around at a certain speed. I'm gonna get some faster notes and there we go. And then we we'll get some rhythm going.

SPEAKER_01 24:50

You can hear it, is you can hear what I said, right? That there is this.

SPEAKER_00 24:54

And there's the harmony that happens. Now, I've not quantized. Okay. This is what it would sound like quantize. There we go. And but I don't prefer the quantize version. No, no, no. I'm so used to hearing these pictures here. So let's talk about uh harmonic systems.

SPEAKER_01 25:14

Yeah, so as we found other planets, we realized that these patterns are actually pretty common, that Bode was onto something.

SPEAKER_00 25:23

It's Kepler 60, which I discovered just yesterday. Oh, it's pretty.

SPEAKER_01 25:29

That's nice. So, what's this two-planet system? No, three planets in in a so these are again nearly resonant, and one of the things that keeps happening is that they aren't just two to one, two to one, two to one. They don't quite line up. They're slightly off. And that's telling us something about the physics.

SPEAKER_00 25:47

Yeah. Uh which was the one that has that series?

SPEAKER_01 25:50

Hey, uh, well, the um hang on, what have you got? Oh my god, there's so many of them. Um I do sleep sometimes. Yeah, yeah. K2138's the one that my team found with a bunch of citizen scientists online. So this is a oh I love this one, yeah.

SPEAKER_00 26:05

This is a real jam, this one.

SPEAKER_01 26:08

So this is a series of uh how many have you got in here? Six planets. And they're a three to two, three to two, three to two, three to two, three to two resonance. So it's the longest resonant chain that we know about.

SPEAKER_00 26:20

We can we can hear it in different ways, like and focus on on its um rhythmic activity, you know, maybe just some just some drum crews, or you can just listen to the harmonic relationship between Yeah, and you can really hear there.

SPEAKER_01 26:38

That sounds different from the other systems that we've been listening to because this is actually in resonance. And so these planets must have formed and moved together, and that's what you're hearing in this pattern.

SPEAKER_00 26:49

Gorgeous. Uh this is a oh, this one's quite extraordinary.

SPEAKER_01 26:52

We did find a seventh planet in K2138 that doesn't fit the pattern, but I know that Milt hasn't included that one. It's been musically rejected, like me playing the theramin.

SPEAKER_00 27:02

Um actually, I went up to eight. Was it the eighth one? I'm sorry about that. Yeah, yeah, no.

SPEAKER_01 27:06

I'll add it. I don't want to reject this is a recent one, recent discovery.

SPEAKER_00 27:12

Yeah, it's gorgeous, and it I just want to and so these I'm starting to use to compose with. Um just why not? And it's really gorgeous. And what's lovely is that we can separate speed, we can slow down time or speed it up and focus in on any aspect of it.

SPEAKER_01 27:32

But the I but whenever you're doing that, you're keeping the relationships between the planets.

SPEAKER_00 27:35

Exactly, and also I can do I can change the pitch relation. If you see those notations, like I'm moving through the spectrum, so I can tune in to their moments there, which is quite lovely.

SPEAKER_01 27:50

Really tempted to imagine an alien version of you doing this with our solar system.

SPEAKER_00 27:54

Well, there's so many space is big. We covered that. Yeah, yeah. And so, you know, we can even have mythical ones.

SPEAKER_01 28:03

Well, the circumbinary is interesting, because yeah, we've now found these planets that go around double stars. So that these are weird orbits. So you have two stars in orbit. It is, but we've now found the real versions of these. To the great delight of university press officers. I'm sure. Because we say we've found Tatooine again. Um, but yeah.

SPEAKER_00 28:21

Okay, so we like this. But um there are all sorts of orbital happenings in the world, uh, in the cosmos, and one of them are pulsars. Tell us about pulsars.

SPEAKER_01 28:32

Sure, so pulsars are the dead cores of slightly massive stars, and because they're the core of something that used to be very large, they spin very fast. Um, and as they do so, they have powerful magnetic fields that, due to physics, we don't really understand. But if I wave my hands around, maybe that'll do. Um there are astronomers don't understand magnetic fields. There are jets of material that comes out of these things, and so as they spin around, often several thousand times a second, this jet light swings round the cosmos like a lighthouse. And so we see them as pulses of radio waves discovered by Jocelyne Melbene. What do we need that they uh pulse is audio range level? Yes, that's right. It's sort of seconds to milliseconds. There you go. So this is our map of pulsars in the galaxy.

SPEAKER_00 29:17

There we go. With the uh I think distance and um uh and the rate pulse rate is uh has been mapped here. So you it's quite nice, right? There we go. Oh, it's pretty.

SPEAKER_01 29:35

The fun thing is that we monitor whole thousands of these things because we're looking for gravitational waves passing through the cosmos. So the ripples in space and time can be detected by listening to these cosmic clocks. And when you hear a change in pitch or a glitch, it's perhaps because a gravitational wave came through.

SPEAKER_00 29:52

That is so beautiful. We should plan these next years.

SPEAKER_01 29:56

Next year.

SPEAKER_00 29:57

No, never mind. Um this is fun, and no one knows about it. So, Villa Lobos, remember him from earlier? Uh he took these uh mountain ranges and turned them into melodies. So we can go to anywhere in earth, let's say, um, I don't know why I'm picking Madrid. I was gonna do Greece, but we don't need to do Madrid, and we uh we don't need to do there. Well, and so what we can do here is because we have the data, we we have good data, I could take some section here, let's do raw audio, and I could just start drawing a little journey around Spain, and what we generate is the contour of landscape, which is gonna sound something like this as we walk around. Okay. Now for us to uh understand it, perhaps we should let's get it to a um turn it into let's uh let's say a voice like this, a sine wave, uh make musical, and now we have this passage through um through Spain that actually follows a real contour.

SPEAKER_01 31:14

Okay.

SPEAKER_00 31:16

Would you like to go to Mars? Yes, very much. Where would you like to visit?

SPEAKER_01 31:20

Uh let's go to Olympus Mons, which is the giant thing straight in front of you. It's the largest volcano in the solar system.

SPEAKER_00 31:26

Let's assume it takes a little moment to.

SPEAKER_01 31:28

It's so so high it sticks out into space. Oh, that's this is where we're gonna put our observatory in.

SPEAKER_00 31:33

Uh now we can take all sorts of um walks through it. I quite like the radar, the spiral through, because it gives us the contour over areas. So what I can do is uh how wide is it?

SPEAKER_01 31:46

Oh, it it's about the size of France.

SPEAKER_00 31:48

Oh, damn, this is big enough. So I'll go.

SPEAKER_01 31:50

So you've got the call what you've got on screen now is that's the caldera, that's the crater on the top.

SPEAKER_00 31:54

Oh, is that a drop-down then?

SPEAKER_01 31:55

Yes, it does.

SPEAKER_00 31:56

Oh, right. Okay, well we should be able to see.

SPEAKER_01 31:57

So this is you're looking down onto the top of a volcano, and one of the great mysteries is that um this is a shield volcano like the ones in Hawaii, but on Earth, plate tectonics carries the plate over the hotspot in the mantle, and so you get a string of volcanoes, which is what the Hawaiian islands are. On Mars, there's no plate tectonics for reasons we don't really understand. And so it just sits there and this volcano grows over over time, may still be growing yet.

SPEAKER_00 32:24

Okay, so this is that, sorry, that's that's Spain. Let's have Spain.

SPEAKER_01 32:29

So you're dipping down into the Caldera at high speed here.

SPEAKER_00 32:33

Yeah, let's make it a uh I'm gonna make it.

SPEAKER_01 32:35

It'd be the most disappointing place for mountain climbers. Oh, is it response? Because it's basically a gentle slope for for it's about that for about 200 miles. And so climbing the biggest mountain in the solar system is really easy. But you can hear the drop there, right?

SPEAKER_00 32:52

Exactly, and you can see it on this pattern, on this pattern here. And it comes with a sequencer, so you can start mixing together sounds from anywhere in the universe. Uh uh moon, shall we get some data from let's do one more of these, yeah. Uh there's some asteroids here. Okay, we'll feel. Tell me about Vesta because I don't know anything.

SPEAKER_01 33:10

Oh, Vesta's fun. So Vesta's a large asteroid or a small dwarf planet. We've actually got bits of Vesta on Earth, so it's one of the largest things in the um asteroid boat, but it's had a violent past. There are fragments of Vesta floating around the solar system, and several of them crash into Earth. And um it seems to have had a watery past. So it either had ice or water in the past based on the mineralogy, but it's got an old surface, which is why you're seeing all these craters, which have caused by impact. Well, that's interesting you say that.

SPEAKER_00 33:44

First of all, a surface provides uh a contour, which is a contour can become um a timbrel. So this would be the sound of um let's see if it's working here. Uh it's not coming out here. Talking about something else.

SPEAKER_01 34:00

Yeah, yeah, okay. Um so we didn't know anything about Vesta until a spacecraft called Dawn went there, and it was Dawn's study of the surface that allowed us to match the mysterious meteorites that had an unknown origin to Vesta. And it's adding to this um theory that I think we're embodying of chaos in the solar system. So the old clockwork universe idea seems to have disappeared, and we now have, for example, a theory that says that in the inner solar system early on, there are about 20 things the size of Mars knocking around. Two of them may have collided, and what the remnant of that may be Vesta, but that's also put forward as an explanation for why Mercury has a very large core, and maybe it's lost its outer layers. We'll find out more about that when the Beppe Colombo spacecraft gets there in a couple of months.

SPEAKER_00 34:47

What's beautiful about this is that we can generate how water would flow on that surface, depending on the contour. And that too would have its own it would have its own contour that moves through that um that you're sort of tracing the surface gravity. Yeah, and we can just essentially drop these uh pathways down, and these all combine to make um uh to give us just incredible sources, but also I think that's what's interesting is that um when I'm talking to someone like you about um subjects I don't know about, I translate them into musical terms. The idea of phasing, the idea of gravity, of connection, of relationships. And um, music is a very useful metaphor, but then you know I think that we have this opportunity to share language. Yes, exactly. Um ultimately there's these watts of astro sonification, which are about rule-based, repeatability, relevance, recognizability, and why we use it. Some people don't class data music like the example you gave as sonification at all because it's not to inform, it's to inspire.

SPEAKER_01 35:59

Yeah, yeah, yeah.

SPEAKER_00 35:59

With no shade, but there is some shady element to that. Um, I I like to operate on the cusp, and I find inspiration from hard sonification and music in the rorous data. But I think the whys of astral sonification should be uh investigated more fully. We had five R, so again we have five C categories. Communication and insight, we understand. Hopefully, everyone understood something about planetary spacing in a way that's visceral and immediate.

SPEAKER_01 36:31

And memorable.

SPEAKER_00 36:32

And memorable, that it gets under your um your various skin layers. Also, there's an idea of collective concepts and collaboration. We're sitting here because of that. Um I get a huge range of compositional insights and creative constraints by writing the Jovian moon symphony. Already you have a reference that you would not think about in our limited imaginations. And there is a connection and cathartis. I do a lot of this for people going through illnesses, and to hear their illnesses, uh silent suffering sounded out is very cathartic. Um, but finally, I think the why not is the most interesting to explore, to embrace curiosity for its own sake and this shared sense of discovery about the world.

SPEAKER_01 37:27

We've certainly done that, and Milt, your curiosity continues to be inspiring. So please thank, join me in thanking Milton Mercadis, and I think that's a good idea.