WEBVTT - Does Mars Have a Liquid Center? 0:00:08.360 --> 0:00:11.840 Hey, Jorgey, I have a food engineering question for you. 0:00:12.000 --> 0:00:14.840 Food engineering. We're trying to melt ice cream with a 0:00:15.000 --> 0:00:18.040 particle collider, not yet, but now I'm gonna go try that. 0:00:18.239 --> 0:00:21.919 Now I'm wondering how they engineer foods with a liquid 0:00:22.120 --> 0:00:25.520 center inside. Okay, now you're trying to make our candy 0:00:25.560 --> 0:00:28.320 with liquid inside? Yeah? Or like, how do they make 0:00:28.440 --> 0:00:31.800 peanut butter vealed pretzels? That's a billion dollars secret. I 0:00:31.880 --> 0:00:35.000 can't just reveal it. We might get sued. Alright, I 0:00:35.000 --> 0:00:38.440 guess we should stick to revealing big science secrets. Yeah. 0:00:38.440 --> 0:00:40.720 I don't think we'll get sued for those. They're usually 0:00:40.760 --> 0:01:00.720 free and maybe also useless. You said it not mean. Hi. 0:01:00.760 --> 0:01:03.920 I am more Hammon cartoonists and the creator of PhD comics. Hi. 0:01:04.080 --> 0:01:07.440 I'm Daniel. I'm a particle physicist, and I do enjoy 0:01:07.520 --> 0:01:10.880 me a peanut butter field pretzel. Really, why can't you 0:01:10.880 --> 0:01:14.039 just put the peanut butter on the outside. It's a 0:01:14.080 --> 0:01:18.520 totally different taste experience, man, I mean this can't be compared. Plus, 0:01:18.680 --> 0:01:22.280 I admire the engineering. Somehow they baked this pretzel around 0:01:22.280 --> 0:01:25.640 the peanut butter. It's incredible. You think that's how they 0:01:25.680 --> 0:01:28.160 do it. They formed the bread around the peanut butter. 0:01:28.319 --> 0:01:30.160 Actually did some research about this. It was the basis 0:01:30.200 --> 0:01:33.520 of a big lawsuit. And there's a fancy co extrusion 0:01:33.560 --> 0:01:36.640 process where they have the pretzel dough around the peanut 0:01:36.680 --> 0:01:39.800 butter and then they bake it. Co extrusion. Wow, that 0:01:40.120 --> 0:01:44.360 sounds like a heavy duty physics term. You should google it. 0:01:44.360 --> 0:01:46.679 They used to find some really fun YouTube videos about 0:01:46.680 --> 0:01:50.680 the interior of these factories. Pretty fascinating food engineering. And 0:01:50.720 --> 0:01:52.760 by experiments, you mean you tried it at home a 0:01:52.760 --> 0:01:54.600 bunch of times, or you ate a bunch of pretzels 0:01:54.640 --> 0:01:56.760 with peanut butter. I ate a bunch of pretzels. I 0:01:56.800 --> 0:01:59.720 tried the chocolate covered versions, the non chocolate cover versions. 0:01:59.760 --> 0:02:02.120 I'm in the name of science. Have you tried coach 0:02:02.200 --> 0:02:06.680 twinging butter and pretzels? That's the next level heart attack recipe. 0:02:06.760 --> 0:02:09.120 You should sell that idea to Ben and Jerry's. But anyways, 0:02:09.120 --> 0:02:11.760 welcome to our podcast, Daniel and Jorge Explain the Universe, 0:02:11.840 --> 0:02:14.680 a production of I Heart Radio in which we extrude 0:02:14.840 --> 0:02:20.000 ideas about the universe into your head without breaking your skull. Somehow, 0:02:20.040 --> 0:02:23.480 we wrap your mind around the peanut butter field delicious 0:02:23.480 --> 0:02:26.040 secrets of the universe. We talk about all of the 0:02:26.120 --> 0:02:29.680 crazy stuff happening deep out in crazy space, and all 0:02:29.680 --> 0:02:32.320 the tiny stuff happening in between your toes and the 0:02:32.400 --> 0:02:35.560 smallest particles. We break down quantum mechanics, We talk about 0:02:35.560 --> 0:02:39.360 astrophysics and everything in between. Wait, I thought that the 0:02:39.520 --> 0:02:42.840 science secrets that we reveal our the pretzel part that 0:02:42.919 --> 0:02:47.000 surrounds the yummy peanut butter inside of our punts. It 0:02:47.040 --> 0:02:49.160 could be I was thinking of my brain is the 0:02:49.160 --> 0:02:53.280 peanut butter and my skull is the pretzel. You just 0:02:53.360 --> 0:02:56.360 ruined that vision of deliciousness for me. Every time you 0:02:56.400 --> 0:02:58.079 bite into one of those from now on, just think 0:02:58.240 --> 0:03:03.359 I'm eating Daniel's head, not mom goodness, let's please hitit 0:03:03.480 --> 0:03:05.919 that out. But anyways, we do like to talk about 0:03:05.960 --> 0:03:09.480 the universe and all of it's amazing goodness inside and 0:03:09.520 --> 0:03:11.640 everything that you can quote through it, inside of it, 0:03:11.760 --> 0:03:14.040 and all the things that you can discover because it's 0:03:14.040 --> 0:03:17.400 the big cosmos and there are wonderful things out there 0:03:17.480 --> 0:03:20.000 hiding in plain sight, that's right. And the more we 0:03:20.080 --> 0:03:22.600 look out into the universe, the more we discover these 0:03:22.600 --> 0:03:25.760 surprises and the more questions we have about exactly how 0:03:25.840 --> 0:03:28.720 things work, what layers they're in, and how they're organized 0:03:28.760 --> 0:03:31.000 and how they got that way, right, because we can 0:03:31.000 --> 0:03:33.760 see the universe and touch it and probe, but who 0:03:33.760 --> 0:03:36.600 knows what's line underneath the surface, what is at the 0:03:36.680 --> 0:03:40.119 core of the universe and how it works. And everything 0:03:40.160 --> 0:03:43.600 that's out there has a history. The Moon, the Earth, Mars, 0:03:43.640 --> 0:03:48.000 every planet, every star has a sometimes billion years long history, 0:03:48.200 --> 0:03:50.800 a crazy story that tells us how it got to 0:03:50.840 --> 0:03:53.600 be the way it is today. And unraveling that story 0:03:53.720 --> 0:03:57.840 is like the biggest, most delicious detective mystery in the universe. 0:03:57.920 --> 0:04:01.120 Figuring out what exactly happened to the object. Can we 0:04:01.160 --> 0:04:03.360 tell just by looking on the outside or just by 0:04:03.360 --> 0:04:06.600 looking through a telescope, exactly what the story is of 0:04:06.640 --> 0:04:09.840 this heavenly body? Yeah, because we want to know, right, 0:04:09.920 --> 0:04:13.680 the species as human beings, were curious about where things 0:04:13.800 --> 0:04:15.800 came from and how they got to be the way 0:04:15.840 --> 0:04:18.760 they got to be, and that's all part of their history, 0:04:18.800 --> 0:04:22.760 and it's all they're inside of the things for looking at. Yeah, 0:04:22.839 --> 0:04:25.240 we showed up in this universe basically the last minute, 0:04:25.240 --> 0:04:27.400 and a lot of stuff happened before we got here. 0:04:27.720 --> 0:04:30.080 So it's fun to unravel those stories and figure out 0:04:30.279 --> 0:04:32.240 have things looked this way for a long time? The 0:04:32.360 --> 0:04:34.640 things used to be really different. Does that mean things 0:04:34.720 --> 0:04:36.919 are going to change? It's all just part of like 0:04:37.279 --> 0:04:40.240 becoming conscious beings and exploring the world that we find 0:04:40.279 --> 0:04:42.840 around us. So today we'll be talking about one of 0:04:42.880 --> 0:04:46.279 these mysteries. Line underneath the surface of our own neighborhood. 0:04:46.360 --> 0:04:48.960 It's something that we can see almost every night, but 0:04:49.320 --> 0:04:51.480 that is kind of hidden from us, right, that's right. 0:04:51.480 --> 0:04:53.880 We have questions about what's beneath our feet, and we 0:04:53.920 --> 0:04:57.359 have questions about what's beneath the feet of potential neighbors. 0:04:57.560 --> 0:05:00.560 You mean the actual neighbors. Like is your neighbor sitting 0:05:00.560 --> 0:05:02.760 on top of a giant oil well or something? Yeah, 0:05:02.800 --> 0:05:05.080 maybe there's like a huge peanut butter deposit under my 0:05:05.120 --> 0:05:08.240 neighbor's house and I could sell that to that factory. Yeah, 0:05:08.640 --> 0:05:13.400 instead of liquid gold, that's liquid saturated fats. Well, it's 0:05:13.440 --> 0:05:15.599 peanut butter technically a liquid or is it a solid? 0:05:15.680 --> 0:05:18.440 I guess it depends if it's smooth or what's the 0:05:18.480 --> 0:05:22.240 other one crunching? What is the phase diagram of peanut butter? 0:05:22.279 --> 0:05:24.240 Can it sublimate into a gas? I wonder. I don't 0:05:24.240 --> 0:05:26.960 know if anybody's ever done that experiment. You mean, like 0:05:27.080 --> 0:05:29.720 go straight into a gas form of peanut butter, like 0:05:29.760 --> 0:05:34.040 you can invade peanut butter. Not recommended, folks, not recommended. 0:05:34.240 --> 0:05:36.920 Our lawyers have not vetted that statement. Please do not 0:05:37.040 --> 0:05:40.320 vape peanut butter. You could clog through your lungs directly 0:05:40.320 --> 0:05:42.360 with peanut butter. But if you do vape peanut butter, 0:05:42.480 --> 0:05:45.880 tell us about it, because we're curious that may will 0:05:45.880 --> 0:05:48.480 be another billion dollar industry who knows, or a billion 0:05:48.520 --> 0:05:50.680 dollar lawsuit. We're about to get hit with people who 0:05:50.760 --> 0:05:55.240 use it to cure their pretzel addiction, and then they'll 0:05:55.320 --> 0:05:58.880 need some patches, some peanut butter patches. Anyways, Yeah, we'll 0:05:58.920 --> 0:06:02.240 be tackling one such mystry in our own solar system, 0:06:02.279 --> 0:06:04.640 so to be on the podcast, we'll be asking the question, 0:06:09.839 --> 0:06:13.760 does Mars have a solid or liquid core? I guess 0:06:13.800 --> 0:06:17.320 the question is Mars hardcore or softcore? Is it a 0:06:17.360 --> 0:06:20.440 hard boiled egg or a soft boiled egg? Exactly? I 0:06:20.440 --> 0:06:23.080 think it's a super fascinating question, and it's fun for 0:06:23.120 --> 0:06:26.040 me because I think about like when people were asking 0:06:26.080 --> 0:06:28.839 this question about the Earth, you know, for a long time, 0:06:28.880 --> 0:06:31.160 we didn't really know, like, hey, what's the Earth made 0:06:31.200 --> 0:06:33.000 out of? It's just one big rock? Or is there 0:06:33.120 --> 0:06:36.400 something crazy going on under our own feet? And now 0:06:36.400 --> 0:06:38.040 that we have a little bit of a sense of 0:06:38.040 --> 0:06:40.120 what's going on inside the Earth, we can ask similar 0:06:40.200 --> 0:06:43.680 questions about other planets, and so it's fascinating to wonder, like, 0:06:43.720 --> 0:06:45.800 are they different, are they the same? What's going on? 0:06:46.040 --> 0:06:49.160 I guess just to verify, the Earth has a softcore. Right, 0:06:49.279 --> 0:06:52.200 The inside of our planet is molten, right, It's like 0:06:52.320 --> 0:06:54.480 melted rock. Yeah, there's some melted rock and a lot 0:06:54.520 --> 0:06:58.120 of melted metal, melted iron, liquid nickel, all this kind 0:06:58.120 --> 0:07:00.760 of stuff flowing underneath our feet. It's part of why 0:07:00.800 --> 0:07:03.760 we have, for example, a magnetic field. I see now, 0:07:03.760 --> 0:07:05.840 I guess, is it possible for a planet of our 0:07:05.880 --> 0:07:09.600 size to have a solid core? Like, wouldn't all that pressure, 0:07:09.640 --> 0:07:12.120 gravity pressure eventually kind of I don't know, melt the 0:07:12.120 --> 0:07:14.720 stuff inside. Yeah. The reason that we do have a 0:07:14.800 --> 0:07:17.440 liquid core is because of all that temperature and pressure, 0:07:17.640 --> 0:07:20.440 and that comes from both the gravitational pressure and also 0:07:20.520 --> 0:07:22.840 the decay of the isotopes inside the Earth that helped 0:07:22.920 --> 0:07:24.840 keep it hot. But it's not going to be that 0:07:24.880 --> 0:07:28.280 way forever. You know, we got a certain spoonful of Earth, 0:07:28.320 --> 0:07:31.000 and eventually it's gonna cool off. I think we estimated 0:07:31.080 --> 0:07:32.680 once on this podcast that it's going to take more 0:07:32.680 --> 0:07:36.000 than a hundred billion years before the Earth cools, So 0:07:36.120 --> 0:07:38.000 we got some time, and you know, the Sun is 0:07:38.040 --> 0:07:40.680 going to go red super giant before that, so it's 0:07:40.680 --> 0:07:42.960 not going to be our number one problem. But other 0:07:43.040 --> 0:07:46.080 planets are different sizes and so they will have different 0:07:46.120 --> 0:07:49.160 cooling off times. It's gonna be a while before we're cool. 0:07:50.160 --> 0:07:52.040 I can relate to that. Hey, we're gonna be young 0:07:52.040 --> 0:07:53.880 and hot for a long time. Think about it that way. 0:07:54.080 --> 0:07:57.080 That sounds very hard corn, all right, But they were 0:07:57.080 --> 0:08:00.160 asking questions about Mars. Does Mars have a solid or 0:08:00.280 --> 0:08:02.920 liquid core? And it's kind of a big deal, right 0:08:02.960 --> 0:08:06.040 because it might tell us whether or not Mars is 0:08:06.080 --> 0:08:09.000 still you know, sort of young and active, and it 0:08:09.080 --> 0:08:11.200 might tell us also what our future might be for 0:08:11.640 --> 0:08:13.680 that's right. And I think it's just a question that 0:08:13.720 --> 0:08:15.760 people have when they look up into the sky and 0:08:15.800 --> 0:08:18.240 they wonder, you know, is that planet over there a 0:08:18.240 --> 0:08:21.280 lot like our planet or is it totally different? And 0:08:21.320 --> 0:08:23.800 what does that mean about the nature of planets and 0:08:23.840 --> 0:08:26.840 planets in other solar systems, and it's to me just 0:08:26.880 --> 0:08:30.880 really connects with this basic, simple initial curiosity we have 0:08:30.960 --> 0:08:33.040 when we look up at the sky, we wonder what 0:08:33.160 --> 0:08:36.680 those things are like. Hey, but before we answer this question, 0:08:36.960 --> 0:08:39.920 we wanted to answer a question from one of our listeners, 0:08:39.960 --> 0:08:43.320 perhaps our youngest listener. That's right. You may remember last 0:08:43.320 --> 0:08:46.120 week we talked about Hannah, who was home sick from school. 0:08:46.240 --> 0:08:47.800 She's two and a half years old. She lives in 0:08:47.840 --> 0:08:50.960 Australia and she wanted to hear Daniel and Jorge. So 0:08:51.000 --> 0:08:53.080 I reached out to her dad and asked him, Hey, 0:08:53.200 --> 0:08:55.720 does Hannah have any questions she wants us to answer 0:08:55.880 --> 0:08:59.360 while she's homesick? And he asked her what questions she 0:08:59.440 --> 0:09:03.000 had for day own Jorge, and she said, monkey, wait? Monkey? 0:09:03.120 --> 0:09:06.720 Is her question? Was her first question or answer to 0:09:06.760 --> 0:09:09.000 the universe and everything in it? I don't know. It's 0:09:09.000 --> 0:09:10.240 hard to get in the mind of a two and 0:09:10.240 --> 0:09:12.920 a half year old sometimes. But then he asked her again, 0:09:13.280 --> 0:09:18.480 and so here's Hannah's real question. How and how my 0:09:18.760 --> 0:09:26.040 land home? Why is the Larne shine? Oh that's adorable. 0:09:26.320 --> 0:09:28.920 It's like a little tiny little nerd. Yeah, and she 0:09:29.000 --> 0:09:31.920 has the same curiosity. Today we're talking about Mars and 0:09:31.960 --> 0:09:33.480 what's in it, But you know, she's looking up in 0:09:33.559 --> 0:09:36.320 the sky and she's wondering, why is that thing up 0:09:36.360 --> 0:09:39.559 there glowing at me? It has the same root of curiosity. 0:09:39.800 --> 0:09:42.120 I see you're saying that it taps into that same 0:09:42.240 --> 0:09:44.680 like looking up at the sky and wondering what's going 0:09:44.720 --> 0:09:47.440 on out there? Yeah, exactly why is that thing up 0:09:47.440 --> 0:09:50.400 there doing that thing that it's doing? Well? Really quickly? 0:09:50.440 --> 0:09:52.640 Then what is the answer for Hannah? Why does the 0:09:52.760 --> 0:09:56.080 moon shine? Yeah, Hannah, the reason the moon shines, especially 0:09:56.080 --> 0:09:59.280 at night, is that it's actually reflecting light from the Sun. 0:09:59.720 --> 0:10:02.120 Even though you can't see the sun at night, the 0:10:02.200 --> 0:10:04.959 sun can see the moon, and so the Sun's light 0:10:05.000 --> 0:10:08.160 bounces off the moon and down to your eyeball. So 0:10:08.280 --> 0:10:11.120 at night you're kind of seeing the sun by seeing 0:10:11.120 --> 0:10:13.920 it reflect off the moon. So moonlight is all just 0:10:14.080 --> 0:10:17.440 reflected sunlight. Right. Do you think she's asking about moonshine 0:10:17.480 --> 0:10:21.040 as well? Why does my dad drink so much moonshine? 0:10:21.080 --> 0:10:22.560 I don't know. I think that's a question for her 0:10:22.640 --> 0:10:27.200 dad and his father. There nothing wrong with moonshine, nothing 0:10:27.200 --> 0:10:29.480 wrong with the little moonshine. All right, well, Hannah, that's 0:10:29.480 --> 0:10:32.240 to your answer. The moon shines because it bounces light 0:10:32.280 --> 0:10:34.000 from the sun, so it looks like it glows, but 0:10:34.080 --> 0:10:36.760 really it's just kind of like a mirror, just reflecting 0:10:36.880 --> 0:10:39.840 and getting lit up by the sun. That's right, all right, 0:10:39.920 --> 0:10:42.520 Well back to our question, those marks have a solid 0:10:42.600 --> 0:10:45.280 or liquid core? This is a pretty interesting question, and 0:10:45.320 --> 0:10:48.480 we were wondering, as usual, if people out there and 0:10:48.520 --> 0:10:51.680 new the answer to this billion year question. So thanks 0:10:51.679 --> 0:10:54.760 to everybody who volunteered to answer this question as usual. 0:10:54.840 --> 0:10:57.840 If you'd like to participate for future episodes, please write 0:10:57.840 --> 0:11:00.480 to me two questions at Daniel and Jorge dot com. 0:11:00.559 --> 0:11:02.960 Think about it first. Second, do you think Mars is 0:11:03.080 --> 0:11:07.200 solid or liquid on the inside. Here's what people had 0:11:07.240 --> 0:11:11.960 to say. Yes, they might be a big diamond inside it. 0:11:13.040 --> 0:11:18.080 Now I think Mars has hot liquid. Yes, it does 0:11:18.520 --> 0:11:22.959 completely solid, because Mars doesn't have any radioactive isotopes inside 0:11:23.000 --> 0:11:25.719 the core. Keep it hot and keep it liquid. I'm 0:11:25.720 --> 0:11:28.400 going to say, yes, Mars has a solid core of 0:11:29.200 --> 0:11:33.640 iron or nickel or some other heavy element, just like Earth. Yes, 0:11:33.800 --> 0:11:39.360 Mars has a solid core. It has no obvious plate 0:11:39.400 --> 0:11:43.600 tectonics going on it obviously had some sort of tectonic 0:11:43.720 --> 0:11:49.080 activity going on at some time, and the magnetic field 0:11:49.120 --> 0:11:53.360 is almost non existent. So I think if we were 0:11:53.440 --> 0:11:55.960 to dig deeper, I think we'd find it does have 0:11:56.040 --> 0:11:59.440 a solid core. I don't think Mars has a significant 0:11:59.480 --> 0:12:04.040 magnetic field because solar radiation is a concern for explorers. 0:12:04.880 --> 0:12:07.120 I would say it cooled down at least a billion 0:12:07.200 --> 0:12:09.480 years ago to a solid all the way through to 0:12:09.559 --> 0:12:15.440 its core. Yes, I think it has and used to 0:12:15.480 --> 0:12:22.280 be more powerful and active. But judging by the strength 0:12:22.400 --> 0:12:28.680 of the magnetic field and the atmosphere, it weakened in time. 0:12:29.840 --> 0:12:34.200 Probably that will happen to Earth to I don't know 0:12:34.320 --> 0:12:38.480 for sure, but kind of this is the way I 0:12:38.520 --> 0:12:42.120 think it would go. Mars does have a solid core. 0:12:42.400 --> 0:12:45.040 End of story. I see you remember you saying in 0:12:45.040 --> 0:12:49.760 an earlier podcast that Mars does not have um an 0:12:49.760 --> 0:12:54.880 electromagnetic field protecting it because it doesn't have a solid core. 0:12:56.480 --> 0:13:01.080 So I'm going to say no, all right, some pretty 0:13:01.120 --> 0:13:03.880 definitive answers here. I feel like people were pretty confident 0:13:04.280 --> 0:13:07.559 about their answers here. They're like, yes, definitely, this, definitely, 0:13:07.600 --> 0:13:11.320 that definitely peanut butter, A big hot diamond. I like 0:13:11.400 --> 0:13:13.200 that one. Why do you think people are so confident 0:13:13.280 --> 0:13:14.800 this time? I think that a lot of people have 0:13:14.920 --> 0:13:18.600 heard that Mars is smaller and cooled faster, doesn't have 0:13:18.679 --> 0:13:21.960 volcanoes on the surface or a magnetic field, and so 0:13:22.040 --> 0:13:24.440 I think that leads people to suspect that it might 0:13:24.520 --> 0:13:27.680 just be a big lump of hard rock, unlike the 0:13:27.760 --> 0:13:31.240 Earth and the story. All right, thanks for joining us, um, 0:13:31.280 --> 0:13:35.520 But there's more, I see, there's more to the story. 0:13:35.720 --> 0:13:37.920 There is more to the story, Yes, exactly. I think 0:13:37.920 --> 0:13:41.280 there's some really interesting nuances here that these listeners will learn. 0:13:41.480 --> 0:13:43.720 All right, well, let's dig into it. First of all, Daniel, 0:13:43.720 --> 0:13:47.400 why is this question interesting to you, I guess and 0:13:47.440 --> 0:13:50.079 to physicists and generally to the public. Why should we 0:13:50.120 --> 0:13:53.679 care whether Mars is hardcore or soft and squishy on 0:13:53.720 --> 0:13:56.160 the inside. Yeah, Well, for me, there's sort of two 0:13:56.240 --> 0:14:00.000 levels there. One is just inherent curiosity, like I have questions, 0:14:00.080 --> 0:14:02.840 is about what's inside stuff. You know, you ever get 0:14:02.840 --> 0:14:04.400 a rock and you crack it open, you find a 0:14:04.400 --> 0:14:08.080 crystal inside. There's like a joy there discovering something you 0:14:08.120 --> 0:14:10.360 didn't expect, and so you always want to like look 0:14:10.400 --> 0:14:13.440 inside stuff to see what's there. Maybe there's something hidden, 0:14:13.480 --> 0:14:15.880 maybe there's a mystery. You know, that's why we explore 0:14:15.920 --> 0:14:17.840 the universe. We don't just sit back and think about 0:14:17.880 --> 0:14:19.920 it in our minds the way the Greeks do. So 0:14:19.960 --> 0:14:22.120 we sort of want to know what's out there because 0:14:22.160 --> 0:14:24.760 we could be shocked, we could be surprised. Mars couldn't 0:14:24.760 --> 0:14:27.360 be like hollow on the inside and filled with aliens 0:14:27.440 --> 0:14:29.840 or something. So we definitely want to go look and 0:14:29.880 --> 0:14:32.560 see what's inside this stuff. But also I think there's 0:14:32.560 --> 0:14:35.160 a question about just sort of the nature of planets, 0:14:35.280 --> 0:14:38.240 Like we have an interest in how many planets are 0:14:38.240 --> 0:14:40.440 out there, how do they form, what do they look like? 0:14:40.680 --> 0:14:43.760 Are their potential homes for humanity out there? And to 0:14:43.760 --> 0:14:45.640 get an answers to that, we really need to know 0:14:45.720 --> 0:14:47.800 like how planets warm and what they're made out of 0:14:47.840 --> 0:14:49.200 it that will give us an answer to like what 0:14:49.280 --> 0:14:51.200 they're like on the surface. So we got to know 0:14:51.240 --> 0:14:53.160 how the insides work if we want to figure out 0:14:53.240 --> 0:14:55.760 how the outsides look. Yeah, because you know, it's still 0:14:55.920 --> 0:14:59.360 kind of a big mystery in astrophysics and in science 0:14:59.560 --> 0:15:01.600 is how do the Solar System form and out of 0:15:01.680 --> 0:15:05.160 these planets specifically form in in an early version of 0:15:05.160 --> 0:15:07.000 the solar system, right, and it's still kind of a 0:15:07.000 --> 0:15:09.920 big question. We're still running simulations and trying to figure 0:15:10.040 --> 0:15:12.480 that out. Yeah, we talked about on this podcast we 0:15:12.480 --> 0:15:15.680 don't even really understand how our solar system came to be, 0:15:16.000 --> 0:15:18.920 Like we run models about our solar system doesn't really 0:15:19.000 --> 0:15:21.760 quite make sense, Like why is Mars so small? And 0:15:21.960 --> 0:15:24.560 why do we have very few planets close to our 0:15:24.560 --> 0:15:27.280 Sun whereas many other solar systems have lots and lots 0:15:27.320 --> 0:15:30.600 of planets in between the distance between our Sun and Mercury. 0:15:30.720 --> 0:15:32.400 So we want to know the answer to that question, 0:15:32.440 --> 0:15:35.320 like what is the story of our solar system? For me, 0:15:35.360 --> 0:15:37.560 it drives me crazy to think that there's an exciting, 0:15:37.600 --> 0:15:40.480 traumatic story something that happened here and we just don't 0:15:40.520 --> 0:15:44.960 know it. Maybe were coextruded by the great planet factoring 0:15:45.000 --> 0:15:48.000 the sky, a new creation myth folks born here today 0:15:48.000 --> 0:15:53.440 on the podcast, co extrusion sounds like a good novel name. Yeah, 0:15:53.520 --> 0:15:55.480 And you know, there are folks who do that kind 0:15:55.480 --> 0:15:58.120 of study, like look for other planets and other solar systems. 0:15:58.120 --> 0:16:00.640 They look for exoplanets, and then there's a whole community 0:16:00.680 --> 0:16:03.400 people who just study like the planets in our solar 0:16:03.440 --> 0:16:06.320 system and what's in them. People who dedicate their entire 0:16:06.400 --> 0:16:10.320 research careers to like this question what's inside Mars, And 0:16:10.360 --> 0:16:12.400 you're saying that there might be parallels but the Earth 0:16:12.440 --> 0:16:16.400 as well, Like knowing what happened to Mars might help 0:16:16.480 --> 0:16:19.360 us understand what's happening here in Earth and let us 0:16:19.360 --> 0:16:22.560 study things like earthquakes and what we can expect in 0:16:22.600 --> 0:16:25.200 the future. Absolutely, you never want to just have any 0:16:25.200 --> 0:16:27.320 equals one, right. You don't want to base all of 0:16:27.360 --> 0:16:30.600 your conclusions about how planets work from one example. You 0:16:30.640 --> 0:16:31.840 want to look at a bunch of them. You want 0:16:31.840 --> 0:16:34.240 to population so you can get a sense for what's typical, 0:16:34.360 --> 0:16:37.040 and you can also see the future, Like if Mars 0:16:37.360 --> 0:16:40.560 is smaller and colder than Earth, then in some sense 0:16:40.560 --> 0:16:42.720 it might be what the future of Earth looks like, 0:16:42.880 --> 0:16:45.480 you know, in millions and billions of years. But it'd 0:16:45.480 --> 0:16:47.720 be good to get an understanding of how these processes 0:16:47.760 --> 0:16:49.720 work because we rely on the Earth to have these 0:16:49.800 --> 0:16:53.320 layers in order to have our civilization and our society function. 0:16:53.440 --> 0:16:55.280 So it would be good to know, like the factors 0:16:55.320 --> 0:16:57.880 that control that, What are the forces at play? Are 0:16:57.920 --> 0:17:00.560 things rising or sinking or cooling or eating or what's 0:17:00.600 --> 0:17:03.080 going on inside. So absolutely we want to get a 0:17:03.120 --> 0:17:06.320 better handle on the interior mechanisms of our planet. And 0:17:06.359 --> 0:17:09.240 it's all right there, hidden under the surface, bubbling up 0:17:09.359 --> 0:17:11.840 or maybe just chilling out. Let's get into whether or 0:17:11.840 --> 0:17:15.800 not Mars has a solid or liquid core and whether 0:17:15.880 --> 0:17:31.440 we'll ever know. But first let's take a quick we're 0:17:31.440 --> 0:17:34.520 talking about whether Mars the planet, right, not the Mars bars, 0:17:34.560 --> 0:17:36.760 because we know those have a newgat center, right, But 0:17:37.000 --> 0:17:41.119 isnt a liquid or a solid? Oh no, another you 0:17:41.119 --> 0:17:45.080 have a whole episode on strange matter from in candies. 0:17:45.359 --> 0:17:48.639 Daniel vapes various candies. That's in my new podcast series, 0:17:49.200 --> 0:17:53.119 one episode long. You just blew my mind vaping. What 0:17:53.160 --> 0:17:55.760 does that even mean? Oh my goodness, how could it 0:17:55.760 --> 0:17:58.080 be possible that nobody's ever tried that before, you know, 0:17:58.960 --> 0:18:01.760 after raping other stuff, since somebody must have had that idea. 0:18:02.080 --> 0:18:05.920 Oh man, I think you're in the run business, Daniel. Alright, 0:18:05.920 --> 0:18:07.840 So we're trying to figure out whether Mars has a 0:18:07.920 --> 0:18:10.880 solid or liquid core, not just for curiosity about what's 0:18:10.920 --> 0:18:13.360 going on there, but I might tell about the history 0:18:13.480 --> 0:18:16.399 of our planet and the whole Solar System. And so Daniel, 0:18:16.400 --> 0:18:18.480 you actually went out there and talked to an expert 0:18:18.560 --> 0:18:21.439 on this topic. Right, that's right. I called up a 0:18:21.480 --> 0:18:24.320 colleague of mine, Katherine Johnson. She's at the University of 0:18:24.320 --> 0:18:26.959 British Columbia, and I asked her why she was so 0:18:27.000 --> 0:18:30.040 excited about this particular question. Here's what she had to say. 0:18:30.400 --> 0:18:32.920 So then it's my pleasure to introduce to the program 0:18:32.960 --> 0:18:36.560 professor Katherine Johnson. Catherine said hello to our listeners and 0:18:36.560 --> 0:18:40.120 tell them a little bit about yourself. Hi. So it's 0:18:40.160 --> 0:18:43.520 pressure to be here. And I'm a faculty member at 0:18:43.520 --> 0:18:46.680 the University of British Columbia in Vancouver and also a 0:18:46.720 --> 0:18:50.439 scientist at the Planetary Science Institute a Tucson and I 0:18:50.520 --> 0:18:54.639 work in geophysics in uh sort of planetary science. So 0:18:54.760 --> 0:19:00.080 I'm interested in understanding the interior state and evolution of 0:19:00.080 --> 0:19:04.640 of the planets, moons, and asteroids in our Solar system. 0:19:04.680 --> 0:19:06.960 And tell me why that's exciting for you. What is 0:19:06.960 --> 0:19:09.840 it about the interior of Mars, for example, that makes 0:19:09.840 --> 0:19:12.360 you curious, that makes you wonder what's going on inside there? 0:19:12.640 --> 0:19:14.960 So you know, one of the reasons that I like 0:19:15.080 --> 0:19:17.560 to think about other planets is really to try to 0:19:17.640 --> 0:19:20.000 understand our own planet better. I think you know, for me, 0:19:20.160 --> 0:19:24.080 that's one of the major motivations to try to understand 0:19:24.080 --> 0:19:26.960 planets in our own solar system, especially in the inner 0:19:27.000 --> 0:19:31.840 Solar system right where we have Mercury, Venus, the Earth, Mars, 0:19:31.840 --> 0:19:35.120 our own Moon, and they're all completely different from each other, 0:19:35.320 --> 0:19:38.280 even though they started in somewhat similar at least with 0:19:38.320 --> 0:19:41.600 the exception of the Moon, started in somewhat similar ways. 0:19:41.800 --> 0:19:44.119 And so a lot of this really has to do 0:19:44.640 --> 0:19:47.679 with their interiors and how they are interiors of like 0:19:48.240 --> 0:19:52.840 shaped their histories. All right, Thank you, Katherine. And so 0:19:53.040 --> 0:19:55.359 you went and chatted with her about this topic, Yeah, 0:19:55.359 --> 0:19:57.840 I did. We had a really fun conversation after all 0:19:57.880 --> 0:20:00.440 about it. Learned a lot of gory details of how 0:20:00.440 --> 0:20:04.040 the project works and the politics of getting her instrument 0:20:04.119 --> 0:20:06.159 up and on Mars and how that all works. It 0:20:06.240 --> 0:20:07.960 was a lot of fun. Thanks Catherine very much for 0:20:08.080 --> 0:20:11.440 educating me about your research. She has an instrument on Mars. 0:20:11.480 --> 0:20:16.160 She does exactly. She helped design and build this seizedmometer 0:20:16.280 --> 0:20:17.840 that they have on Mars, which is one of the 0:20:17.840 --> 0:20:21.359 ways they figure out what's inside. Interesting because that is 0:20:21.400 --> 0:20:23.080 sort of a way they do it here on Earth. Right, 0:20:23.200 --> 0:20:25.840 we haven't actually like dug a hole or a little 0:20:25.840 --> 0:20:28.159 people to the center of the earth. We have just 0:20:28.320 --> 0:20:31.720 models and kind of sound and sound wave detections on 0:20:31.720 --> 0:20:33.600 the surface, right, that's right. We have dug in only 0:20:33.760 --> 0:20:37.440 very shallow holes relatively speaking, into the earth, and so 0:20:37.520 --> 0:20:40.960 we have not actually probed physically the center of the Earth. 0:20:41.000 --> 0:20:43.200 But we do have a pretty good picture of what's 0:20:43.200 --> 0:20:46.880 going on inside the earth because of earthquakes. Every time 0:20:46.920 --> 0:20:49.520 there's an earthquake, it's like the earth rings sort of 0:20:49.560 --> 0:20:51.840 like a bell, and the waves they don't just like 0:20:52.040 --> 0:20:55.080 shake the outer crust, they propagate all the way through 0:20:55.119 --> 0:20:58.280 the interior. And when waves cross a threshold, like when 0:20:58.280 --> 0:21:00.639 you go from solid to liquid, or the quit to solid, 0:21:00.680 --> 0:21:03.480 or one kind of metal or to another, you get reflections. 0:21:03.480 --> 0:21:05.480 Just like when light hits a piece of glass, most 0:21:05.480 --> 0:21:07.679 of it goes through, but some of it reflects. So 0:21:07.760 --> 0:21:10.560