Latest / PlanetGeo: The Geology Podcast / Common Misconceptions Part I (GeoShort)

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Common Misconceptions Part I (GeoShort) · PlanetGeo: The Geology Podcast

• 0:02
  SPEAKER_00: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:15
  SPEAKER_00: All right, let's do it.
• 0:17
  SPEAKER_00: What's going on?
• 0:18
  SPEAKER_02: Not a whole lot.
• 0:19
  SPEAKER_02: How you doing?
• 0:20
  SPEAKER_00: Yeah, I'm doing well.
• 0:21
  SPEAKER_00: Doing well.
• 0:22
  SPEAKER_00: Hey, this is kind of fun.
• 0:23
  SPEAKER_00: This one right here.
• 0:24
  SPEAKER_00: This geo short we got.
• 0:26
  SPEAKER_02: Well, I don't know what we have going on, so I'll tell you if it's fun later on.
• 0:29
  SPEAKER_00: So so here's what we're gonna do for this gear short.
• 0:32
  SPEAKER_00: You've taught high school for a long time, and you've probably seen a lot of misconceptions.
• 0:38
  SPEAKER_00: Hey, did you notice how I held back from making a cheap joke about your own?
• 0:41
  SPEAKER_00: I did.
• 0:41
  SPEAKER_02: I was expecting it.
• 0:42
  SPEAKER_02: Yeah.
• 0:43
  SPEAKER_02: Like I could tell you kind of how long I've been teaching high school.
• 0:46
  SPEAKER_02: I I was expecting it.
• 0:47
  SPEAKER_00: You kind of went, mm-hmm, like you were expecting a comment.
• 0:50
  SPEAKER_00: I held back.
• 0:51
  SPEAKER_00: Hey, aren't I being nice?
• 0:52
  SPEAKER_01: Yeah.
• 0:53
  SPEAKER_00: I'm I'm being so nice to you right now.
• 0:55
  SPEAKER_00: Okay, so here's what we're gonna do.
• 0:56
  SPEAKER_00: I came across this paper, uh, actually on Twitter, and we'll put a link to it in the episode description right now.
• 1:03
  SPEAKER_00: But this is a compilation and review of over 500 geoscience misconceptions.
• 1:09
  SPEAKER_00: It's a 2013 paper.
• 1:12
  SPEAKER_00: You're laughing at your wife.
• 1:13
  SPEAKER_02: I'm right by the window, and Jenny just peered up out of the corner of the window and waved at me.
• 1:19
  SPEAKER_02: So that's cute.
• 1:21
  SPEAKER_00: Aren't you guys cute?
• 1:22
  SPEAKER_01: Very nice.
• 1:22
  SPEAKER_01: Yeah.
• 1:23
  SPEAKER_01: All right, keep going.
• 1:24
  SPEAKER_00: So we've got this paper that compiles and reviews over 500 geoscience misconceptions, common misconceptions, across all age groups.
• 1:34
  SPEAKER_00: So you've taught for a long time, and I think this would be kind of a fun exercise to kind of break this down into a couple of the highlights, things that struck me, and and I'll kind of interview you about whether you've come across these and how you approach them in the classroom.
• 1:47
  SPEAKER_02: Alright, let's go.
• 1:48
  SPEAKER_02: Does that sound good?
• 1:49
  SPEAKER_02: I haven't looked at any of it.
• 1:50
  SPEAKER_02: We haven't talked about any of this, so you're hitting me, and I have no preview.
• 1:56
  SPEAKER_00: Okay, let's do it.
• 1:57
  SPEAKER_00: So there's a lot of these.
• 1:58
  SPEAKER_00: There's over 500.
• 1:59
  SPEAKER_00: A lot of them have to do with plate tectonics and earthquakes and historical geology, weathering.
• 2:04
  SPEAKER_00: We're just gonna kind of give them an overview, alright?
• 2:06
  SPEAKER_00: So Chris, the first one, have you come across this misconception that most earthquakes only occur in hot climates?
• 2:17
  SPEAKER_00: No, I have not come across that.
• 2:19
  SPEAKER_00: Okay, on to the next one.
• 2:21
  SPEAKER_00: Have you come across the misconception that lava bursts out during an earthquake?
• 2:27
  SPEAKER_02: Yes, I have come across that.
• 2:30
  SPEAKER_02: Hollywood loves that misconception, so yes, that they have perpetuated that myth.
• 2:36
  SPEAKER_02: You think it's Hollywood's fault?
• 2:37
  SPEAKER_02: Okay, that's interesting.
• 2:38
  SPEAKER_02: I do, I I do, I blame Hollywood on that.
• 2:41
  SPEAKER_02: They Hollywood loves geology and they love to make geology really, really bad.
• 2:45
  SPEAKER_00: Oh, okay.
• 2:46
  SPEAKER_00: There we go.
• 2:47
  SPEAKER_02: Like, you know, we could do episodes on junk science in Hollywood.
• 2:50
  SPEAKER_00: That's true.
• 2:51
  SPEAKER_00: I mean, yeah, for sure.
• 2:52
  SPEAKER_00: For sure.
• 2:53
  SPEAKER_00: Yeah, but so how do you approach it in the classroom?
• 2:55
  SPEAKER_00: If you have students who are like, oh, you know, I saw on whatever movie that lava is coming out during an earthquake.
• 3:03
  SPEAKER_02: How do I approach it?
• 3:04
  SPEAKER_02: Um, I'm not very delicate about it.
• 3:07
  SPEAKER_02: Um, you don't say um yeah, it's funny, you know, you just kind of you look at these things and you laugh about it.
• 3:17
  SPEAKER_02: And you know, I I don't know.
• 3:19
  SPEAKER_02: I like to think that I create a very safe atmosphere and climate in my classroom where kids are you know at ease to say these kinds of things.
• 3:28
  SPEAKER_02: I welcome it, I welcome off-topic questions and things like that every single day.
• 3:32
  SPEAKER_02: And so we laugh at this kind of stuff, you know, like it's uh and you just kind of like, well, no, it depends on the plate boundary, and hopefully that you know at that point they've had enough like plate tectonics to know that not all earthquakes are gonna generate magma.
• 3:48
  SPEAKER_00: Okay, and so for the people listening who maybe share this misconception, what are you gonna say to them?
• 3:54
  SPEAKER_02: Um, yeah, no.
• 3:59
  SPEAKER_02: So delicate, Chris.
• 4:00
  SPEAKER_02: So delicate.
• 4:00
  SPEAKER_02: I know.
• 4:01
  SPEAKER_02: Well, that's yeah, no.
• 4:03
  SPEAKER_02: Um you know, you go back to our plate tectonics episode.
• 4:07
  SPEAKER_02: Only certain plate boundaries generate magma.
• 4:10
  SPEAKER_02: You know, you have divergent boundaries, you have where plates are moving away from each other, and those can generate magma, but most of those are in the middle of oceans.
• 4:19
  SPEAKER_02: There are some instances where they're in continental crust too, but not very common.
• 4:24
  SPEAKER_02: And then you have the transform boundaries like the San Andreas Fault, which is generally devoid of magma, uh, no magma associated with those, or very little magma associated with those.
• 4:33
  SPEAKER_02: And then you have the convergent boundaries, but those are volcanic, they can generate magma, but it's actually a long ways away from the plate boundary itself.
• 4:42
  SPEAKER_02: So yeah.
• 4:43
  SPEAKER_02: Yeah.
• 4:43
  SPEAKER_02: All right.
• 4:44
  SPEAKER_02: That's a good one.
• 4:45
  SPEAKER_02: All right, on to the next one.
• 4:46
  SPEAKER_02: I made a long story short.
• 4:48
  SPEAKER_02: No, I made us I made a short story long there, didn't I?
• 4:50
  SPEAKER_00: Yeah.
• 4:51
  SPEAKER_00: Well, you made a short story boring.
• 4:53
  SPEAKER_00: I don't know if you made it longer or not, but that's that's what I'm good at.
• 4:56
  SPEAKER_02: Everybody's but everybody has to be good at something.
• 4:59
  SPEAKER_00: So all right, on to the next one.
• 5:00
  SPEAKER_00: All right, let's go.
• 5:01
  SPEAKER_00: Chris, have you come across the misconception that the crust and the lithosphere are synonymous terms?
• 5:07
  SPEAKER_00: Or are they?
• 5:07
  SPEAKER_02: Oh, yeah, all the time.
• 5:09
  SPEAKER_02: Absolutely.
• 5:10
  SPEAKER_02: This is very, very common.
• 5:11
  SPEAKER_00: And how do you answer the misconception?
• 5:14
  SPEAKER_02: Um, so I guess I describe the crust as like a a sheet of wax paper over top of a bowling ball.
• 5:21
  SPEAKER_02: That's more like on a scale of what the crust is.
• 5:24
  SPEAKER_02: And the lithosphere is it includes that, it includes the crust, but it also includes the upper part of the mantle.
• 5:32
  SPEAKER_02: But the lithosphere is compositionally very different because it includes the like this ultra mafic mantle part, but both of them, the crust and the lithosphere, are cold, crunchy, and brittle.
• 5:48
  SPEAKER_02: I don't know.
• 5:48
  SPEAKER_02: I I guess that's kind of where I draw the line.
• 5:50
  SPEAKER_02: The lithosphere is much thicker than the crust, and it includes like parts of two layers.
• 5:57
  SPEAKER_00: That's right.
• 5:57
  SPEAKER_00: And it is they they kind of behave together, they move around together that crust in the upper mantle that is the lithosphere.
• 6:04
  SPEAKER_00: Yeah.
• 6:05
  SPEAKER_00: Um another one in this theme of the interior of the earth is that the asthenosphere is liquid.
• 6:11
  SPEAKER_02: Yes, yeah, that happens all the time.
• 6:14
  SPEAKER_00: And what do you say when you come across that misconception?
• 6:17
  SPEAKER_02: Um, you know, like the we don't know a lot about the asthenosphere.
• 6:22
  SPEAKER_02: This is a layer of the earth that is a part, it's a um it's in the mantle, it's below the lithosphere, which is what we just talked about.
• 6:31
  SPEAKER_02: And it is this layer of rock that is like at or just above, or maybe just below in certain places, the melting point of rock.
• 6:42
  SPEAKER_02: So it's it's kind of like soft.
• 6:44
  SPEAKER_02: It has properties of both rock and a very like thick viscous fluid all at the same time.
• 6:51
  SPEAKER_00: Yeah, that's right.
• 6:51
  SPEAKER_00: So it can kind of you you have this analogy.
• 6:53
  SPEAKER_00: I'll never I always remember this from sitting in your class where it behaves like hot plastic, it can flow, it does, but it needs a lot of stress for it to flow.
• 7:02
  SPEAKER_00: Um okay, one more in the interior of the earth.
• 7:05
  SPEAKER_02: Only one more.
• 7:06
  SPEAKER_00: Oh well, no, one more in the interior of the earth theme.
• 7:09
  SPEAKER_00: Chris, have you come across the misconception that the interior of the earth can be understood in terms of drilling, digging, and sonar?
• 7:21
  unknown: Wow.
• 7:22
  SPEAKER_02: All right, it's a strange misconception, isn't it?
• 7:24
  SPEAKER_02: Yeah, you caught me with that one.
• 7:26
  SPEAKER_02: Oh, I love it.
• 7:26
  SPEAKER_00: But basically, I think that I think the misconception is that like we have like samples of all of the interior of the earth.
• 7:33
  SPEAKER_00: I think maybe I can summarize it that way.
• 7:35
  SPEAKER_02: Yeah, I think, yeah.
• 7:37
  SPEAKER_02: Um, again, Hollywood has is to be blamed for this one, I think.
• 7:41
  SPEAKER_00: Um, you really we're not trying to get any Hollywood sponsors for the podcast here, are we?
• 7:47
  SPEAKER_02: Uh no, we're not.
• 7:49
  SPEAKER_02: Um, yeah, I actually this is a a common misconception, I think.
• 7:54
  SPEAKER_02: I've had this time and again.
• 7:56
  SPEAKER_02: We have no direct sampling of the interior of the earth.
• 7:59
  SPEAKER_02: Everything that we know about the interior of the earth is from indirect evidence, you know, using things like analysis of seismic waves and density and uh looking at space too, looking at meteors and and things like this that tell us about the composition of the interior of the earth.
• 8:17
  SPEAKER_02: No direct sampling, and nor do I think that will ever happen.
• 8:21
  SPEAKER_02: That's right, not even close.
• 8:23
  SPEAKER_00: I think you know, we have samples.
• 8:25
  SPEAKER_00: What are the deepest samples that I know of?
• 8:26
  SPEAKER_00: We have samples of some diamonds that come from like 500 or 600 kilometers depth, but that's but they were brought to the surface.
• 8:34
  SPEAKER_02: We didn't go get those.
• 8:35
  SPEAKER_02: No, exactly.
• 8:36
  SPEAKER_00: That's that's geologic sampling, and um, you know, that is less than one-tenth of the total radius of the earth.
• 8:45
  SPEAKER_00: So we don't have access to most of the earth.
• 8:48
  SPEAKER_00: Okay, moving on, Chris.
• 8:50
  SPEAKER_00: Have you ever come across the misconception that oil only formed millions of years ago and is not forming today?
• 8:58
  SPEAKER_02: Yes.
• 8:59
  SPEAKER_02: That's something that well, I don't know if like so that's a difficult one.
• 9:05
  SPEAKER_02: Most of the time, students don't come with that misconception.
• 9:08
  SPEAKER_02: Most of the time you come with that misconception, you come across that misconception that this is an ek like an extinct process.
• 9:16
  SPEAKER_00: Okay.
• 9:16
  SPEAKER_00: And how do you answer that?
• 9:18
  SPEAKER_02: So you you know, you talk about uh renewable and non-renewable resources, right?
• 9:22
  SPEAKER_02: And and non-renewable resources are resources where the processes that form them are either no longer occurring anymore or occurring at such a slow rate that they're non-renewable, you know.
• 9:35
  SPEAKER_02: So I guess that's the way I answered the question.
• 9:36
  SPEAKER_00: Yeah.
• 9:37
  SPEAKER_02: Does that make sense?
• 9:38
  SPEAKER_00: That's a great point.
• 9:39
  SPEAKER_00: And you can go back to our, I think, greenhouse gas episode that kind of talks about the long-term carbon cycle and the short-term carbon cycle and the sort of differences there.
• 9:48
  SPEAKER_00: But yeah, I know that's a that's a great way to answer it.
• 9:51
  SPEAKER_00: That oil is being formed today, but at a slower rate than we're consuming it from ancient oil.
• 9:57
  SPEAKER_02: Yeah, just a wee bit.
• 9:59
  SPEAKER_00: A little bit, a little bit.
• 10:00
  SPEAKER_02: Yeah.
• 10:01
  SPEAKER_00: Okay.
• 10:02
  SPEAKER_00: Have you come across the misconception that all radiometric dating is carbon dating or radiocarbon dating?
• 10:08
  SPEAKER_02: Oh, yes, that is a really, really good point.
• 10:12
  SPEAKER_02: Absolutely.
• 10:13
  SPEAKER_02: Everything about radiometric dating is carbon dating.
• 10:18
  SPEAKER_02: That's it, man.
• 10:19
  SPEAKER_02: Oh, yeah.
• 10:19
  SPEAKER_02: And then, of course, all of the problems that go along with carbon dating.
• 10:24
  SPEAKER_00: So I have a question for you on this front, because you know, radiocarbon dating is actually only good for about 50,000 years.
• 10:31
  SPEAKER_02: Right, about 10 half-lives, yeah.
• 10:32
  SPEAKER_00: Yeah.
• 10:33
  SPEAKER_02: Because after that, there's so little of it left.
• 10:35
  SPEAKER_02: Yeah.
• 10:35
  SPEAKER_00: So in your class, how much time, you know, instructional time or lab time do you spend on radiometric dating as a sort of a field?
• 10:43
  SPEAKER_00: And how much of that is radiocarbon dating?
• 10:47
  SPEAKER_00: Do you have a rough estimate for me?
• 10:49
  SPEAKER_02: So uh you're dealing with you're talking what you're talking about is what I call in my class absolute dating.
• 10:55
  SPEAKER_02: And I spend at least a week on absolute dating.
• 11:00
  SPEAKER_02: So we talk about, you know, radioactive decay and the modes of decay.
• 11:05
  SPEAKER_02: We talk about half-life, you know, the time it takes for half of the isotopes to decay.
• 11:09
  SPEAKER_02: And then we talk about each of the common isotopes that decay and the methods that are used.
• 11:16
  SPEAKER_02: And then we also talk about the errors.
• 11:18
  SPEAKER_02: And we talk but but to me, equally, maybe most importantly, are the assumptions that are made about radiometric dating.
• 11:30
  SPEAKER_00: Okay.
• 11:31
  SPEAKER_00: Gotcha.
• 11:32
  SPEAKER_02: So yeah, coming back to your question, yes, that is a very common misconception that everything radiometric is carbon dating.
• 11:40
  SPEAKER_00: And it is a misconception because there is a lot of other methods and a lot of better methods for determining the ages of things way back till the beginning of Earth history.
• 11:50
  SPEAKER_02: Right.
• 11:51
  SPEAKER_02: We can only use carbon dating for dating young things, young geologic things.
• 11:56
  SPEAKER_02: You know, we can't use radio or carbon dating for dinosaurs and things like that because there's none left.
• 12:02
  SPEAKER_02: They're too old.
• 12:03
  SPEAKER_00: That's right.
• 12:03
  SPEAKER_00: And so in my class, I spend maybe a lecture and a half on all of radiometric dating or absolute dating.
• 12:10
  SPEAKER_00: And, you know, I'm mentioned I have maybe have two slides on radiocarbon dating.
• 12:15
  SPEAKER_00: So it is a small fraction of absolute geochronology or radiometric dating.
• 12:21
  SPEAKER_00: It's a very small component.
• 12:22
  SPEAKER_02: So well, I, you know, I'm rather proud of myself because I I wrote a lab because this is something that's really important to me.
• 12:28
  SPEAKER_02: You know, when you talk about age of the earth, it's just a topic that is close to my heart.
• 12:33
  SPEAKER_02: Uh so I wrote a lab on uh you know radiometric dating and basically just coming up with uh the composition of a rock and telling the kids what the composition of the rock is, and then having them tell me what the initial composition of the rock was before radiometric dating took place.
• 12:54
  SPEAKER_02: So they have to go back, you know, and walk it back using the math and normalization processes that you all use when you do this to tell me what the and I'm the only one that knows what the original composition of the rock is, and they have to tell me what it was.
• 13:07
  SPEAKER_02: That's cool.
• 13:08
  SPEAKER_02: I like that.
• 13:08
  SPEAKER_00: That's a good exercise.
• 13:09
  SPEAKER_00: Yeah, all right, moving on.
• 13:11
  SPEAKER_00: This one is kind of interesting to me because I just came across it two days ago when I gave a lecture on plate tectonics and the structure of the earth.
• 13:17
  SPEAKER_00: Chris, have you ever come across a misconception that oceans are responsible for oceanic crust?
• 13:26
  SPEAKER_02: Yes.
• 13:27
  SPEAKER_02: Yeah, I it's a great one, isn't it?
• 13:29
  SPEAKER_00: And this is like this is our fault.
• 13:31
  SPEAKER_00: This is geologists' fault for using the terms, like for using oceanic crust as a definition.
• 13:37
  SPEAKER_02: Yeah.
• 13:38
  SPEAKER_02: So when we teach, we teach uh, you know, about the oceans and we teach about oceanic crust.
• 13:44
  SPEAKER_02: And to us it's so automatic that we don't think about what might be going through the minds of a 15 to 18-year-old kid that they're not differentiating between ocean and what the ocean crust is.
• 14:00
  SPEAKER_00: Yes, and I actually just had a conversation with my father, who's a biologist.
• 14:03
  SPEAKER_00: And in biology, the names mean something, right?
• 14:06
  SPEAKER_00: In biology, almost all the terms have a root that is based on some Latin term that if you piece the roots together, the term makes sense.
• 14:14
  SPEAKER_00: In geology, that is not the case almost ever.
• 14:17
  SPEAKER_00: There's no roots to geologic names.
• 14:19
  SPEAKER_00: So oceanic crust does not really mean anything apart from its crust beneath the ocean.
• 14:24
  SPEAKER_00: And it they the two don't have a ton to do with each other, actually.
• 14:28
  SPEAKER_02: Well, other than it lies beneath the ocean.
• 14:32
  SPEAKER_02: It's just a distinction that we need to draw.
• 14:34
  SPEAKER_02: The one thing I do love about geology, though, is that I I think a lot of our terms are not steeped in that you know, the Latin history or the Latin roots, you know, and for a lot of kids in biology, that can be very difficult because it's almost like learning a foreign language.
• 14:49
  SPEAKER_02: Well, that's true, Chris.
• 14:50
  SPEAKER_00: But also, but also I mean, you know, some of the rock names have there's they're just pulled out of thin air.
• 14:56
  SPEAKER_00: They're named for some town in Sweden, you know, where they were first discovered or whatever.
• 15:00
  SPEAKER_00: And like that's super confusing too.
• 15:02
  SPEAKER_00: So I mean, I see your I see your point.
• 15:05
  SPEAKER_00: So can we come back to why are there oceans over oceanic crust?
• 15:09
  SPEAKER_00: Like that, let's let's kind of clarify this misconception.
• 15:13
  SPEAKER_02: Well, so it it really comes back to the difference between oceanic and continental crust.
• 15:20
  SPEAKER_02: Oceanic crust is much thinner, therefore it it's thinner, it's denser, and it lies lower.
• 15:28
  SPEAKER_02: And so it gets flooded by the ocean.
• 15:31
  SPEAKER_00: So the oceans are on oceanic crust just because it's lower, and so that's where the oceans end up.
• 15:36
  SPEAKER_00: That's where we have water on the surface of the earth, they end up in the oceans.
• 15:39
  SPEAKER_00: So, totally.
• 15:40
  SPEAKER_00: Okay, cool.
• 15:41
  SPEAKER_00: I I came across that one two days ago, and I was like, oh, it's interesting.
• 15:44
  SPEAKER_00: Yeah, interesting.
• 15:45
  SPEAKER_02: It's one of those things you don't think of very often, actually.
• 15:47
  SPEAKER_02: So go ahead.
• 15:48
  SPEAKER_00: No, exactly.
• 15:49
  SPEAKER_00: Okay, Chris, have you ever come across the misconception that Earth's tectonic plates are separated by empty gaps?
• 15:59
  unknown: Yes.
• 16:01
  SPEAKER_00: Okay.
• 16:02
  SPEAKER_00: When you when you hold on, hold on.
• 16:04
  SPEAKER_00: When you laugh like that, I it makes me think you have it like a particular student in mind when you're laughing or something like that.
• 16:10
  SPEAKER_02: I sometimes I do, sometimes I do have particular instances that just hit me.
• 16:15
  SPEAKER_02: Yeah, my students sometimes think that at a divergent boundary that you can walk up to the edge of the boundary and then see into the guts of the earth.
• 16:25
  SPEAKER_02: Yes, that is for sure a misconception.
• 16:29
  SPEAKER_02: Yeah.
• 16:31
  SPEAKER_00: I mean, I just had this question in class, which was actually kind of a good one.
• 16:34
  SPEAKER_00: I was defining the lithosphere as the crust and the mantle, and then I defined mid-ocean ridge, like in Iceland where that the plates are spreading apart, and somebody raised their hand and said, Hey, I've been to Iceland, I've looked there.
• 16:46
  SPEAKER_00: How thick is the lithosphere right there?
• 16:49
  SPEAKER_00: Which is a great question.
• 16:51
  SPEAKER_00: Like, so so how do you I mean there is something intuitively interesting about this question?
• 16:56
  SPEAKER_00: So why are the earth splits not separated by gaps?
• 16:59
  SPEAKER_00: And like what defines the gaps between the plates, if there are any?
• 17:03
  SPEAKER_00: Like what or what defines the boundaries between the plates?
• 17:06
  SPEAKER_02: So this was Iceland, correct?
• 17:09
  SPEAKER_00: The question was about Iceland, yeah.
• 17:11
  SPEAKER_02: So Iceland is a you know, it's a hot spot and it's a divergent boundary, and so it's extra volcanically active, right?
• 17:19
  SPEAKER_02: But that divergent boundary that runs through the basically the middle of Iceland, as a sthenosphere material, as that hot mantle rock comes up and and conveys the two parts of the plates apart from each other, that rock cools and and becomes a part of the oceanic crust.
• 17:41
  SPEAKER_02: It so that mantle material becomes crustal material as it comes up onto the surface and kind of like welds itself to each diverging plate.
• 17:51
  SPEAKER_00: Actually, the lithosphere right at that point of separation is probably very, very thin.
• 17:57
  SPEAKER_00: Like very, very thin, but it's still there, and you don't just go down into the mantle.
• 18:02
  SPEAKER_00: There's no big gap that you can kind of look down in the interior of the earth.
• 18:06
  SPEAKER_02: Because that rock comes up and solidifies.
• 18:08
  SPEAKER_00: Exactly, because there's always magma is always you know interacting with the atmosphere and cooling and it forms a rock.
• 18:14
  SPEAKER_00: Wherever magma is around, it forms a rock pretty quickly.
• 18:16
  SPEAKER_02: So I do have a picture that I show because this is a very common misconception, and I have a picture of a diver in the rift valley of a mid-ocean divergent boundary.
• 18:28
  SPEAKER_00: So can you paint us a picture of what that looks like?
• 18:30
  SPEAKER_02: Uh, sure.
• 18:31
  SPEAKER_02: You know, it looks like a diver that is in a slot canyon.
• 18:34
  SPEAKER_00: Can you describe what this slot canyon?
• 18:36
  SPEAKER_00: What's a slot?
• 18:37
  SPEAKER_02: Yeah, so this diver, all you see is really steep rock going above the diver, and you can see the floor of the rift valley.
• 18:45
  SPEAKER_02: And the diver can almost reach out with the wingspan of his arms and touch both lithospheric plates, yeah, at the same time, which can you imagine how cool that would be?
• 18:58
  SPEAKER_00: That's totally cool.
• 18:59
  SPEAKER_00: But there is no like super deep gap beneath him.
• 19:02
  SPEAKER_00: There once was magma, but there's solid rock.
• 19:05
  SPEAKER_00: You go down there and there is some solid rock.
• 19:07
  SPEAKER_02: There's solid rock, there's definitely a floor, yeah, for sure.
• 19:10
  SPEAKER_00: All right.
• 19:11
  SPEAKER_00: Well, Chris, I mean, that's all we're gonna go through today.
• 19:14
  SPEAKER_00: There's a lot of misconceptions.
• 19:16
  SPEAKER_02: Oh, are you serious?
• 19:16
  SPEAKER_02: You're cutting it off right there.
• 19:18
  SPEAKER_02: Well, do you want you want one more?
• 19:20
  SPEAKER_02: I do want one more.
• 19:21
  SPEAKER_02: This is every time you I get excited when you start reading because I don't know what's gonna come out of it.
• 19:26
  SPEAKER_02: Okay, all right, all right.
• 19:27
  SPEAKER_00: Give me one minute.
• 19:28
  SPEAKER_00: I'm gonna find one here.
• 19:30
  SPEAKER_00: Let's let's find one in the category of river misconceptions.
• 19:34
  SPEAKER_00: Oh, okay.
• 19:35
  SPEAKER_00: All right.
• 19:35
  SPEAKER_00: How about that?
• 19:36
  SPEAKER_00: Okay.
• 19:38
  SPEAKER_00: Here we go.
• 19:40
  SPEAKER_00: Rivers do not carve valleys, but only passively flow down them.
• 19:45
  SPEAKER_00: That is the misconception.
• 19:46
  SPEAKER_00: Have you ever come across it?
• 19:49
  SPEAKER_02: No.
• 19:50
  SPEAKER_02: No, I I can honestly say have not come across that misconception.
• 19:54
  SPEAKER_00: Okay.
• 19:55
  SPEAKER_02: Um yeah, like I don't that's it's an odd one.
• 19:58
  SPEAKER_02: It's uh it's a popular misconception.
• 20:01
  SPEAKER_00: That's it's a popular one, but I think it I mean, I think it makes some sense the misconception that rivers are just flowing along.
• 20:07
  SPEAKER_00: The rivers are not doing anything.
• 20:08
  SPEAKER_02: Yeah, they're just static, yeah, yeah.
• 20:10
  SPEAKER_00: But actually, see a lot of change.
• 20:12
  SPEAKER_00: But rivers are doing a ton.
• 20:14
  SPEAKER_00: I mean, rivers are doing all the work here.
• 20:16
  SPEAKER_00: Rivers are actually cutting down through.
• 20:19
  SPEAKER_00: And we talked about this with our Grand Canyon episode a little bit, right?
• 20:22
  SPEAKER_00: Um, uh well, that was a bit of a dud.
• 20:28
  SPEAKER_00: Let me find another one here.
• 20:31
  SPEAKER_00: Okay, here's a good one.
• 20:32
  SPEAKER_00: Here's a good one.
• 20:33
  SPEAKER_00: Earth's plates cannot bend, and this is a very popular one.
• 20:37
  SPEAKER_00: Earth's plates Earth's tectonic plates cannot bend.
• 20:41
  SPEAKER_02: Huh.
• 20:43
  SPEAKER_02: Um, all right.
• 20:44
  SPEAKER_02: I don't know that I've come across that as a popular misconception in my classes, but I will say this that do you remember the first fold you saw in rock?
• 20:56
  SPEAKER_00: Ooh.
• 20:57
  SPEAKER_00: No, I don't because don't you really?
• 21:00
  SPEAKER_00: Because I saw folds a lot before I knew actually what they were.
• 21:05
  SPEAKER_00: So I remember the first time I kind of realized what the story they tell is, and that was on the field trip in your geology class when I was in high school, when we went to the upper peninsula of Michigan, and we sat on this black outcrop of rock right along Lake Michigan.
• 21:22
  SPEAKER_00: So we're kind of on this peninsula of rock that kind of gradually slopes into Lake Superior.
• 21:28
  SPEAKER_00: Sorry, I said Lake Michigan, I meant Lake Superior, that slopes into Lake Superior, and there's water lapping up along the edges, and we're looking at this rock, and there's all these white veins going through it, and those veins have folds in them, and some of the other veins cross-cut some of the folds, and your exercise was figure out the history of this rock, and then it was like, Oh wow, a light bulb went off.
• 21:50
  SPEAKER_00: That was like, Wow, when it folds, that means that there was like three events in there that the vein was intruded, the vein was then folded, and then another vein came and cut across it.
• 22:01
  SPEAKER_00: Like, that's so cool.
• 22:03
  SPEAKER_02: Yeah, and then later in the day, we went and saw a major anacline along the side of a freeway.
• 22:08
  SPEAKER_02: We pulled off alongside, I think it was raining out, and we, you know, it was like a from it was 30 feet across, you know.
• 22:16
  SPEAKER_02: And when you look at that, you and like so.
• 22:19
  SPEAKER_02: I don't know if that's a popular misconception or not, but I will say this that every time I show students a fold in rock, where in by the way, you know, when we talk about bending of rock and we refer to them as folds in geology, it's not like a folded piece of paper, it's just a bend in the paper.
• 22:37
  SPEAKER_02: It's a bend in the rock.
• 22:39
  SPEAKER_02: That's what it looks like.
• 22:40
  SPEAKER_02: It doesn't look like a creased fold.
• 22:42
  SPEAKER_00: That's not that's a good point.
• 22:44
  SPEAKER_00: That's a good point.
• 22:45
  SPEAKER_02: So, but whenever they see that, they are universally blown away.
• 22:50
  SPEAKER_02: Like that is amazing.
• 22:53
  SPEAKER_00: As they should be.
• 22:54
  SPEAKER_00: I mean, I agree.
• 22:55
  SPEAKER_00: That's that's a very cool thing.
• 22:56
  SPEAKER_00: So, you know, when we've used the phrase in our previous episodes that a tectonic plate is if you bend it, it will break.
• 23:03
  SPEAKER_00: But that's not quite accurate because tectonic plates can bend and they do bend and they get folded, but sometimes they do break, and at a large scale they break.
• 23:12
  SPEAKER_00: But you know, deformation in the crust creates a lot of folds.
• 23:16
  SPEAKER_02: Yeah, so I don't like I don't know if they don't realize that, but then when they see the first one, they're impressed.
• 23:25
  SPEAKER_02: Everyone's impressed, you know.
• 23:27
  SPEAKER_02: So, but I don't know if that arises from a misconception or not.
• 23:30
  SPEAKER_02: So I don't know if you answer the question.
• 23:31
  SPEAKER_00: So that's probably a good one to end on.
• 23:33
  SPEAKER_00: So we'll put a link to this article.
• 23:36
  SPEAKER_00: If you have things that you think might be misconceptions, if you think, oh, I know that this is true about the earth, but then maybe on second thought you're thinking, oh, that might be a misconception, hit us up, will you?
• 23:49
  SPEAKER_00: Send us an email at planetgeocast at gmail.com or hit us up on Twitter or Instagram or Facebook.
• 23:55
  SPEAKER_00: We are at Planetgeocast.
• 23:58
  SPEAKER_00: We'd love to hear that.
• 23:58
  SPEAKER_00: And we could make a whole nother episode about listeners' potential misconceptions.
• 24:03
  SPEAKER_02: Or or we could do an episode on the things that Dr.
• 24:05
  SPEAKER_02: Remick doesn't know.
• 24:08
  SPEAKER_02: That'd be a pretty easy category.
• 24:14
  SPEAKER_01: Okay, all right, all right.
• 24:15
  SPEAKER_00: Well, okay.
• 24:16
  SPEAKER_00: All right.
• 24:17
  SPEAKER_00: Well, that's uh a little brief foray into misconceptions.
• 24:20
  SPEAKER_00: That was fun, Chris.
• 24:21
  SPEAKER_00: That was.
• 24:22
  SPEAKER_00: Thanks for thanks for putting up with it.
• 24:23
  SPEAKER_00: You got it.
• 24:24
  SPEAKER_02: See you next week, everybody.
• 24:26
  SPEAKER_00: Peace.