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Rocks get better with age: HOW and WHY we date them · PlanetGeo: The Geology Podcast

• 0:03
  SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:12
  SPEAKER_01: Chris, how you doing today?
• 0:14
  SPEAKER_01: I'm doing great.
• 0:14
  SPEAKER_01: How are you doing, Jesse?
• 0:16
  SPEAKER_01: Oh man, I'm doing really well.
• 0:17
  SPEAKER_01: I'm excited for today's episode, to be honest with you.
• 0:19
  SPEAKER_01: But before we get to that, let's do some brief introductions.
• 0:22
  SPEAKER_01: You are Chris Bullheis, a nationally recognized Earth Science teacher from the great state of Michigan.
• 0:27
  SPEAKER_02: And you are Jesse Remink, one of my former students, now a professor of geoscience at Penn State.
• 0:33
  SPEAKER_01: And this is Planet Geo, a podcast where we talk about amazing aspects of our planet and why it matters to our everyday lives.
• 0:40
  SPEAKER_02: All right, Jesse, let's get going today.
• 0:42
  SPEAKER_02: Today we're going to talk about some geochronology.
• 0:45
  SPEAKER_02: What the heck is geochronology, Jesse?
• 0:48
  SPEAKER_01: Geochronology.
• 0:49
  SPEAKER_01: I mean, let's break it down, right?
• 0:50
  SPEAKER_01: Geo, rocks, earth, chronology, time, the study of time.
• 0:54
  SPEAKER_01: So this is Earth time.
• 0:55
  SPEAKER_01: We're studying Earth time right now.
• 0:56
  SPEAKER_01: Right.
• 0:57
  SPEAKER_01: And this is a huge field.
• 0:59
  SPEAKER_01: It would take decades to get through all of the details of geochronology and how we date rocks.
• 1:04
  SPEAKER_01: But really, that's the question, right, Chris?
• 1:06
  SPEAKER_01: How do we date rock?
• 1:07
  SPEAKER_02: Right, right.
• 1:08
  SPEAKER_02: So let's begin though by giving a brief overview of what we're going to do today.
• 1:11
  SPEAKER_02: Okay.
• 1:11
  SPEAKER_02: So we're going to start out by talking about dating of rocks and how this is done in two different ways.
• 1:17
  SPEAKER_02: Okay.
• 1:17
  SPEAKER_02: That's going to be kind of the first half of what we're doing today.
• 1:20
  SPEAKER_02: And then after this, because this is really your thing, and this is this is what you do.
• 1:25
  SPEAKER_02: This is your research.
• 1:26
  SPEAKER_02: You've been doing this for years.
• 1:27
  SPEAKER_00: Yep.
• 1:28
  SPEAKER_02: You're probably going on close to 10 years now that you've been doing this kind of thing.
• 1:32
  SPEAKER_02: And so we're going to talk about really specifically what you do and like how to set up a lab that does this kind of geochronology thing.
• 1:40
  SPEAKER_02: So that's going to be the second half of where we're going.
• 1:41
  SPEAKER_01: And hopefully we won't dissuade people from trying to set up a lab because it's a it's a bit of a pain in the ass to try and set up a lab.
• 1:47
  SPEAKER_01: But, anyways, yeah, that's where we're going.
• 1:48
  SPEAKER_01: I mean, I'm super pumped.
• 1:49
  SPEAKER_01: This is a really, as you said, I mean, it's a topic that's really close to close to home for me, close to my heart, and you know, occupies a lot of my mental time during the time.
• 1:58
  SPEAKER_01: Right.
• 1:58
  SPEAKER_02: So, unfortunately for the listener, this is going to be heavy into Jesse today.
• 2:02
  SPEAKER_02: And I apologize in advance.
• 2:04
  SPEAKER_01: Totally apologize for that.
• 2:05
  SPEAKER_01: Uh, unfortunately, I'm going to be talking all that.
• 2:07
  SPEAKER_02: Okay.
• 2:08
  SPEAKER_01: Okay, so I mean, one thing we have to kind of address really quickly, right up front, is we have to kind of get on board with how big geologic time is.
• 2:15
  SPEAKER_01: And Chris, you know, we talked about this with Jackie Fardy about astronomy and the distances in astronomy and space-time and all these things that are just super hard to understand.
• 2:25
  SPEAKER_01: And I I personally find geologic time the same.
• 2:28
  SPEAKER_02: I do.
• 2:28
  SPEAKER_02: We can't even really wrap our minds around what a million of something looks like.
• 2:33
  SPEAKER_02: But it's one of the things that I actually love, though.
• 2:35
  SPEAKER_02: It hurts your head, but it hurts it in a good way.
• 2:38
  SPEAKER_02: You know, it makes you feel like kind of unsettled when you think about things like this.
• 2:42
  SPEAKER_02: And every once in a while your mind is able to kind of like just maybe begin to get around this issue, you know, to comprehend it a little bit, and then it's gone.
• 2:51
  SPEAKER_02: It's like a fleeting moment, you know?
• 2:52
  SPEAKER_01: It's one of those things for me, I agree.
• 2:54
  SPEAKER_01: It kind of feels like this is a very human experience to be able to like just touch on thinking about these topics.
• 3:01
  SPEAKER_01: Like me, I remember, you know, during my PhD, I was going up in the Northwest Territories and we were collecting and sampling four billion-year-old rocks and standing on those rocks and thinking, wow, four billion years.
• 3:13
  SPEAKER_01: You know, you'd sit there eating lunch trying to figure out how big four billion years is and what that means.
• 3:19
  SPEAKER_01: And it's terrifying, it's a slightly emotional or spiritual like experience to try and sit there and figure this out.
• 3:25
  SPEAKER_01: I mean, this is a really difficult, really, really hard thing to grasp, but and you you've got a pretty good analogy.
• 3:30
  SPEAKER_01: And I think you use this in class if I remember correctly.
• 3:32
  SPEAKER_01: But let's let's let's try and break it down.
• 3:34
  SPEAKER_01: Let's try and distill it to something that we can kind of try to comprehend, right?
• 3:38
  SPEAKER_02: Okay.
• 3:38
  SPEAKER_02: The age of the earth is 4.54 billion years old.
• 3:42
  SPEAKER_02: To try to conceptualize that, think about it as let's scrunch this down to one year, from January one to January 1.
• 3:50
  SPEAKER_01: So 4.5 billion years in one year.
• 3:53
  SPEAKER_01: Right.
• 3:54
  SPEAKER_02: Yeah.
• 3:54
  SPEAKER_02: So, you know, 4.54 billion years old ago was January 1.
• 3:59
  SPEAKER_02: And, you know, so you think about all right, the age of the dinosaurs was from December 17 to December 28.
• 4:06
  SPEAKER_01: It's most of the year has gone by.
• 4:09
  SPEAKER_02: It is December.
• 4:11
  SPEAKER_02: You know, I bypassed a lot of things because we have to do this.
• 4:14
  SPEAKER_02: There's a lot of really cool landmark things that you can put into this kind of one-year thing, right?
• 4:21
  SPEAKER_01: Right.
• 4:22
  SPEAKER_02: The ice age, which I just put a number on it like 20,000 years ago, the end of the last ice age, that was on a one-year scale, December 31st at 11 58 p.m., two minutes before the new year.
• 4:34
  SPEAKER_01: Oh my god.
• 4:34
  SPEAKER_01: So you've spent the whole year, you've lived your life, and now you got a glass of champagne, you're getting ready to kiss Jenny.
• 4:40
  SPEAKER_01: Happy New Year, right?
• 4:41
  SPEAKER_01: You're watching the ball drop, and and that's the ice age.
• 4:44
  SPEAKER_01: That's 20,000 years ago.
• 4:45
  SPEAKER_01: That's incredible.
• 4:46
  SPEAKER_02: So the birth of Christ, roughly 2,000 years ago, December 31, 1159, and 46 seconds.
• 4:54
  SPEAKER_02: You have 14 seconds before the new year hits.
• 4:56
  SPEAKER_02: All right, all right.
• 4:57
  SPEAKER_01: 2,000 years ago.
• 4:58
  SPEAKER_01: I mean, it's amazing.
• 4:59
  SPEAKER_01: One more American independence.
• 5:00
  SPEAKER_01: When was that?
• 5:01
  SPEAKER_01: 1776?
• 5:02
  SPEAKER_01: When would that be on our scale?
• 5:04
  SPEAKER_02: That is 1159 and 58 seconds.
• 5:08
  SPEAKER_01: That's crazy.
• 5:09
  SPEAKER_01: You know, two seconds less.
• 5:10
  SPEAKER_01: I mean, sorry.
• 5:11
  SPEAKER_02: It's really hard, isn't it?
• 5:12
  SPEAKER_01: We need we need to apologize to all of our international listeners who don't really give a damn about when American independence was.
• 5:17
  SPEAKER_01: But for all of us Americans, it's a very American thing to do, but it's good.
• 5:20
  SPEAKER_01: Two seconds before then.
• 5:22
  SPEAKER_02: That's a good point.
• 5:23
  SPEAKER_02: I don't know.
• 5:24
  SPEAKER_02: It it kind of puts it in perspective, though, about how deep this is and how hard it is to wrap your mind around things.
• 5:30
  SPEAKER_02: Right.
• 5:31
  SPEAKER_02: Yeah, for sure.
• 5:32
  SPEAKER_02: It's appropriate.
• 5:33
  SPEAKER_02: The kids like it.
• 5:34
  SPEAKER_02: I like it.
• 5:34
  SPEAKER_02: Makes you think.
• 5:36
  SPEAKER_01: So when we're thinking about how to date rocks, and this is something that you, I know you get this question a lot.
• 5:41
  SPEAKER_01: I get this question a lot.
• 5:42
  SPEAKER_01: I get this from my father.
• 5:44
  SPEAKER_01: He's as geoscience fluent as they come for somebody who doesn't have a geoscience degree.
• 5:48
  SPEAKER_01: He still is like, well, how do you know?
• 5:49
  SPEAKER_01: How do you know how old these rocks are?
• 5:51
  SPEAKER_01: And really we can break it down.
• 5:53
  SPEAKER_01: There's two different ways.
• 5:54
  SPEAKER_01: There's one that's called relative dating and one that's called absolute dating.
• 5:58
  SPEAKER_01: And one, absolute dating is putting an actual number on an age of a rock or a mineral grain or a series of rocks.
• 6:07
  SPEAKER_01: And relative dating is putting them in order.
• 6:10
  SPEAKER_01: So no real numbers, just putting them in order.
• 6:13
  SPEAKER_01: So let's get into those a little bit, Chris.
• 6:14
  SPEAKER_01: Let's tackle relative dating first.
• 6:16
  SPEAKER_01: So what is relative dating?
• 6:18
  SPEAKER_02: Like you said, you just said it.
• 6:20
  SPEAKER_02: Relative dating is putting the rocks that you have in front of you, putting them in order.
• 6:26
  SPEAKER_02: What happened first, second, third, and fourth.
• 6:29
  SPEAKER_02: So not only just rocks, but you're also putting events in there.
• 6:32
  SPEAKER_02: Events such as like folding or faulting or some sort of mountain building event that happened.
• 6:38
  SPEAKER_02: You're putting things in there such as erosion.
• 6:40
  SPEAKER_01: So when rocks are bent or broken, uh, or when tectonic plates collide together, yeah, we're we're we're kind of putting these things in order.
• 6:49
  SPEAKER_01: So, I mean, how do we do that?
• 6:50
  SPEAKER_01: Like functionally, how do we do that as geoscientists?
• 6:54
  SPEAKER_02: Uh, we use certain principles that have been around in geology for a long time.
• 6:58
  SPEAKER_02: I'll give you just some terminology, but you know, we use the principle of original horizontality, for instance.
• 7:04
  SPEAKER_02: Rocks are laid down.
• 7:05
  SPEAKER_02: So let's say sedimentary rocks, right?
• 7:07
  SPEAKER_02: They're laid down by rivers, oceans, sometimes wind, and so on.
• 7:10
  SPEAKER_02: But the most common way that sedimentary rocks are deposited are by oceans or by rivers that enter the oceans, you know, and they're laid down flat.
• 7:18
  SPEAKER_02: So when you see rocks that are squished and contorted and tortured, like you, you know, squeezing an accordion, that tectonic event happened after the rocks were deposited.
• 7:30
  SPEAKER_02: And so that puts things in order, right?
• 7:32
  SPEAKER_02: You had the deposition of sedimentary rocks, and then sometime later you had folding and faulting that may have taken place.
• 7:40
  SPEAKER_02: Now, we're not concerned with like how long ago something happened here.
• 7:44
  SPEAKER_02: We're just concerned with putting things in sequence.
• 7:47
  SPEAKER_02: So we use that.
• 7:48
  SPEAKER_02: There's another one, the principle or the law of superposition, which is basically sedimentary rocks, the oldest is on bottom and the youngest is on top.
• 7:56
  SPEAKER_02: Now that's an easy thing to understand, unless they've been like overturned by some tectonic event.
• 8:02
  SPEAKER_02: That principle applies.
• 8:03
  SPEAKER_01: If they're being laid down on top of one another, then the oldest is on the bottom.
• 8:07
  SPEAKER_01: And even if they're tilted a little bit or folded a little bit, that oldest will still be on the bottom as long as they're not completely flipped over, right?
• 8:14
  SPEAKER_01: Right.
• 8:14
  SPEAKER_02: Yeah.
• 8:14
  SPEAKER_02: And then Jesse, what is so I'm I'm gonna quiz you here.
• 8:18
  SPEAKER_01: Uh-oh.
• 8:18
  SPEAKER_01: Hopefully I don't get it wrong.
• 8:19
  SPEAKER_01: Hopefully it's not a pumice fiasco here.
• 8:21
  SPEAKER_01: What's what is the principle of cross-cutting relations?
• 8:24
  SPEAKER_01: Yeah, the principle of cross-cutting relations is basically, you know, the thing that is cutting across something came later.
• 8:29
  SPEAKER_01: You know, you can put this in a real world analogy.
• 8:31
  SPEAKER_01: If you have like a plaster ceiling or a drywall ceiling or something that slumps and breaks a little bit, the break has to come after the drywall was there, right?
• 8:41
  SPEAKER_01: Something was there that was broken, something was there that was cut across.
• 8:44
  SPEAKER_01: So when you see rocks that have another rock cutting across it, the one that is cutting across the thing is second or is last.
• 8:52
  SPEAKER_02: Right.
• 8:52
  SPEAKER_02: So putting things again, it's it's uh folds and faults, things like that, happened after the rocks were deposited.
• 8:59
  SPEAKER_02: So it's putting events in sequential order.
• 9:01
  SPEAKER_02: You know, there's also another one.
• 9:03
  SPEAKER_02: Here's here here go, Jesse.
• 9:04
  SPEAKER_02: What is the law of inclusions?
• 9:06
  SPEAKER_01: The law of inclusions, I love this one.
• 9:08
  SPEAKER_01: When I was teaching the intro class this year, I used the analogy of a chocolate chip cookie.
• 9:12
  SPEAKER_01: The law of inclusion says that whatever is included in the other thing is older.
• 9:16
  SPEAKER_01: So this means that when you're making a chocolate chip cookie, you've got chocolate chips in your cookie, right?
• 9:20
  SPEAKER_01: But the chocolate chips got put in the cookie.
• 9:23
  SPEAKER_01: So the chocolate chips are older than the cookie.
• 9:26
  SPEAKER_01: The cookie was made after the chocolate chips.
• 9:28
  SPEAKER_01: And that makes it's it's a pretty obvious thing once it's pointed out to you.
• 9:33
  SPEAKER_01: And I remember I learned all these laws sitting in your class in ninth grade or in 11th grade.
• 9:38
  SPEAKER_01: I mean 11th grade, yeah.
• 9:39
  SPEAKER_01: You kind of in 11th grade it was, yeah.
• 9:41
  SPEAKER_01: Yeah, 11th grade.
• 9:42
  SPEAKER_01: We kind of I remember sitting there thinking, wow, I mean, these are really basic things.
• 9:47
  SPEAKER_01: Like logically, they're not hard, but I'd never thought of them before, right?
• 9:52
  SPEAKER_01: So they're things you just never really thought about, but they're dead obvious once you think about them and realize them.
• 9:57
  SPEAKER_01: And you realize you can go out into the world and look at the rocks and apply these principles and figure out what came first, what came second, what came fifth, what came sixth, all the way through uh a series of outcrops or a whole region just based on using these really simple processes.
• 10:12
  SPEAKER_01: Chris, let me ask you, what is the best example of relative dating that you've ever seen with your own two eyes, like seen in real life?
• 10:19
  SPEAKER_01: IRL?
• 10:20
  SPEAKER_02: Okay.
• 10:20
  SPEAKER_02: Yeah.
• 10:21
  SPEAKER_02: That's I think that's easy for me.
• 10:23
  SPEAKER_02: I don't know, six or seven years ago on one of our family trips in the summer, we always take three weeks, and we just do just dedicated to our family.
• 10:32
  SPEAKER_02: And we went and uh we started in the Grand Canyon and we backpacked down to the bottom of the Grand Canyon.
• 10:37
  SPEAKER_02: We spent four days down there, and one of the things that we did is you know, get down there, you set up camp.
• 10:42
  SPEAKER_02: The next day, uh, we got up early, like I don't know, 4 a.m.
• 10:46
  SPEAKER_02: Because you wanted to get all your hiking in before the sun comes up and it starts cooking, right?
• 10:50
  SPEAKER_02: You want to get to your destination before it gets super hot.
• 10:53
  SPEAKER_02: So we're hiking and the sun starts to to come up, it starts to lighten, and uh we're alongside the river, and I see the great unconformity.
• 11:04
  SPEAKER_01: And this is a this is a this is capital G, capital U, great unconformity.
• 11:09
  SPEAKER_01: This is this is literally a a proper noun in geology, the great unconformity.
• 11:14
  SPEAKER_02: So you have this this metamorphic rock called the Vishnu schist there, and on top of that, metamorphic rock is unaltered, unmetamorphosed, uncooked, unevything sedimentary rock.
• 11:29
  SPEAKER_02: And between it, it's a n it's what we call in geology a knife-like contact.
• 11:33
  SPEAKER_02: I mean, it's there's no transition between the schist, which is very metamorphosed, right?
• 11:38
  SPEAKER_02: Lots of heat, lots of pressure, and then you have this just sedimentary rock sitting right on top of it.
• 11:44
  SPEAKER_02: There's over a billion years of missing time between those two rock layers.
• 11:49
  SPEAKER_02: And so I'm with my kids, I'm with my wife, and I'm like, Oh my gosh, guys, here it is, right?
• 11:54
  SPEAKER_01: And Jenny goes, Oh my gosh, not again.
• 11:58
  SPEAKER_01: We gotta listen to a lecture.
• 11:59
  SPEAKER_02: This is one of the times when Jenny was on my side.
• 12:02
  SPEAKER_02: She's like, What?
• 12:03
  SPEAKER_02: What is that?
• 12:04
  SPEAKER_02: I told her, right?
• 12:05
  SPEAKER_02: And she's like, Oh, that is really, really cool.
• 12:08
  SPEAKER_02: So I'm like, kids, my kids, you know, Lincoln and Annabelle, hey, get over here.
• 12:13
  SPEAKER_02: Uh so we have this stupid, cheesy picture with the three of us touching, we put our palms on the knife-like contact, you know.
• 12:22
  SPEAKER_02: So our palms were straddling a billion years of missing rock record, missing time, gone.
• 12:28
  SPEAKER_01: Yeah, and it's amazing.
• 12:29
  SPEAKER_01: You put that in the context of our one-year analogy.
• 12:31
  SPEAKER_01: I mean, it's like two and a half months, right?
• 12:33
  SPEAKER_01: Of missing year.
• 12:34
  SPEAKER_01: You know, you're in a coma for two and a half months or something, and and you're missing this time.
• 12:38
  SPEAKER_01: It's unbelievable.
• 12:39
  SPEAKER_01: That's so cool.
• 12:40
  SPEAKER_02: Whenever I see those kinds of things, Jesse, I get chills.
• 12:43
  SPEAKER_02: I mean, and it does.
• 12:45
  SPEAKER_02: I get emotional when I look at that and I think about what that is and what that represents.
• 12:49
  SPEAKER_01: So, you out there listening to us right now, next time you walk across some rocks, try and figure out what order they came in.
• 12:55
  SPEAKER_01: Use those first principles of relative dating.
• 12:57
  SPEAKER_01: Try and figure out what order they came in.
• 12:58
  SPEAKER_01: Right.
• 12:59
  SPEAKER_01: Report back to us.
• 13:00
  SPEAKER_01: We'd love to hear it.
• 13:01
  SPEAKER_02: Let us know.
• 13:01
  SPEAKER_01: Take a picture, hit us up on Instagram or Twitter or email, and uh let us know what you would what you thought about it.
• 13:07
  SPEAKER_01: We'd love that.
• 13:08
  SPEAKER_01: Right on.
• 13:09
  SPEAKER_02: Well, let's go ahead and pivot, Jesse, and let's talk about the other way that we date rocks, which is absolute dating.
• 13:16
  SPEAKER_01: Okay, yeah, that's right.
• 13:17
  SPEAKER_01: So absolute dating is really putting numbers onto the ages of rocks.
• 13:22
  SPEAKER_01: We can date many different types of events.
• 13:24
  SPEAKER_01: We can date when magmas crystallized, when they formed igneous rocks, we can date when sediments formed, we can date these tectonic events.
• 13:32
  SPEAKER_02: You can date metamorphic events too.
• 13:34
  SPEAKER_01: Yeah, we can date metamorphic events when things were heated up and the minerals changed their composition.
• 13:39
  SPEAKER_01: There's several different ways to do absolute dating.
• 13:43
  SPEAKER_01: The by far the most common and the most reliable is something called radiometric dating.
• 13:48
  SPEAKER_01: And this relies on radioactive decay of one isotope of an element to another isotope of an element.
• 13:55
  SPEAKER_01: For instance, uranium-lead geochronology or rubidium-strontium geochronology, where there's radioactive decay in there.
• 14:02
  SPEAKER_02: Okay, so just a minute, Jesse.
• 14:03
  SPEAKER_02: So that would be uranium decaying into lead.
• 14:07
  SPEAKER_02: And that would, there are different isotopes of uranium.
• 14:10
  SPEAKER_02: There's uranium-235, there's uranium-238.
• 14:13
  SPEAKER_02: Both of them decay to lead, but they decay to different isotopes of lead.
• 14:18
  SPEAKER_01: That's right.
• 14:19
  SPEAKER_01: So it's a kind of a hard concept to really get if we don't have a graph in front of us to explain, you know, exactly what's happening here.
• 14:26
  SPEAKER_01: But Chris, you have a good example of this.
• 14:29
  SPEAKER_01: I remember learning this in the geology class sitting in the back of your classroom.
• 14:32
  SPEAKER_01: So how can we think about this?
• 14:34
  SPEAKER_01: Radioactive decay.
• 14:36
  SPEAKER_02: Well, you can you first of all, we need to establish what's called a half-life.
• 14:40
  SPEAKER_02: And this is the time it takes for one half of the parent atoms, we call them parents, to decay into the daughter isotope or daughter atoms.
• 14:50
  SPEAKER_02: Okay.
• 14:50
  SPEAKER_02: So the parent decays into the daughter.
• 14:53
  SPEAKER_02: In other words, uranium decays into the daughter lead.
• 14:56
  SPEAKER_01: Yeah.
• 14:57
  SPEAKER_01: So can I interrupt you here?
• 14:58
  SPEAKER_01: Yes.
• 14:58
  SPEAKER_01: Can I interject and talk about what decay actually looks like?
• 15:01
  SPEAKER_01: So, you know, let's think back to basic chemistry.
• 15:03
  SPEAKER_01: If anybody has taken a chemistry class, you know that the nucleus, the atom has a nucleus in it where the protons and neutrons are.
• 15:09
  SPEAKER_01: We're talking about decay, meaning that nucleus is turning into something else.
• 15:13
  SPEAKER_01: We're losing mass from there.
• 15:14
  SPEAKER_01: We're losing either an electron or we're actually losing a helium atom from that.
• 15:18
  SPEAKER_01: That nucleus is breaking apart.
• 15:20
  SPEAKER_01: And the way to kind of think about this is to think of those protons and neutrons that are kind of bound together.
• 15:24
  SPEAKER_01: They're like attached by a bunch of springs.
• 15:26
  SPEAKER_01: And those springs are kind of vibrating around, and all of them are attached to all the other ones by these a whole bunch of springs.
• 15:32
  SPEAKER_01: And so you think of this thing as just a vibrating mass of little balls that are attached by a spring.
• 15:36
  SPEAKER_01: Every once in a while, uh half the balls are going to go in one direction, the other half are going to go in the other direction at the same time, and it might break apart because it's just random, random vibrations, and suddenly, randomly, they're all going to go in one direction at the same time, they're going to break off.
• 15:51
  SPEAKER_01: That's what we mean by the decay into a different thing.
• 15:54
  SPEAKER_01: Once those atoms leave, it becomes a different element.
• 15:56
  SPEAKER_02: Yes, and most of the elements on the periodic table are stable elements.
• 16:01
  SPEAKER_02: They don't do this.
• 16:02
  SPEAKER_02: The radioactive elements that exist on the periodic table, they are unstable.
• 16:07
  SPEAKER_02: And so they spontaneously decay into something that is more stable.
• 16:12
  SPEAKER_01: Exactly.
• 16:12
  SPEAKER_01: So how do we think about this in a sense of how do we use it to date rocks, Chris?
• 16:16
  SPEAKER_02: Okay, well, first of all, I gotta go back to the whole half-life thing, the time it takes for one half of the of what you have of the paranisotope to decay into the daughter.
• 16:24
  SPEAKER_02: And each radioactive element has its own half-life.
• 16:27
  SPEAKER_02: I mean, there there's a huge spectrum of half-lives, but this is very well established, the half-life of the elements.
• 16:38
  SPEAKER_02: Okay.
• 16:39
  SPEAKER_02: I mean, the half-life of uranium-238 is 4.5 billion years, the half-life of carbon-14 is 5,730 years.
• 16:48
  SPEAKER_02: These are well-established half-lives.
• 16:51
  SPEAKER_01: And they're and they're characteristic and they do not change.
• 16:54
  SPEAKER_01: They're based on quantum physics, right?
• 16:56
  SPEAKER_01: So don't ask me to explain quantum physics, but they're based on really basic first-order principles of physics that make sense and they do not change.
• 17:05
  SPEAKER_02: And extreme temperatures and pressures don't change the half-life.
• 17:08
  SPEAKER_02: Maybe an analogy for half-life, then, if we understand what half-life is, the time it takes for half of the elements to decay into the daughter isotope, is say, uh envision a shoebox full of pennies.
• 17:21
  SPEAKER_02: Okay.
• 17:21
  SPEAKER_02: You have a a hundred pennies in it, and you shake the shoebox up with the lid on, right?
• 17:26
  SPEAKER_02: You shake it up pretty good, you get you got it going.
• 17:29
  SPEAKER_02: And then you open up the lid and you take out all of the pennies that are tail side up.
• 17:35
  SPEAKER_02: That represents the decayed daughter isotope.
• 17:39
  SPEAKER_02: Okay.
• 17:39
  SPEAKER_02: Okay.
• 17:40
  SPEAKER_02: So if you have a hundred pennies in your shoebox, statistically you're going to take 50 of them out.
• 17:46
  SPEAKER_02: Okay.
• 17:46
  SPEAKER_02: So you put the that's one half-life.
• 17:49
  SPEAKER_02: One shake up, one half-life.
• 17:50
  SPEAKER_02: Okay.
• 17:51
  SPEAKER_02: You put the lid back on.
• 17:53
  SPEAKER_02: Now I have 50 pennies in there, ish, right?
• 17:56
  SPEAKER_02: And you put the lid back on, you shake it back up, and you open at the top, and there's going to be statistically 25 pennies that are tail side up.
• 18:04
  SPEAKER_02: 25 have decayed into the daughter.
• 18:06
  SPEAKER_02: You take the daughters out.
• 18:07
  SPEAKER_02: I have 25 left.
• 18:08
  SPEAKER_02: And you just keep doing this again and again.
• 18:10
  SPEAKER_01: I really like this analogy.
• 18:11
  SPEAKER_01: This is a great one.
• 18:12
  SPEAKER_01: I'm gonna I'm gonna steal this from you.
• 18:13
  SPEAKER_01: This is a really good one because if you don't shake it, then none of them are gonna flip over.
• 18:18
  SPEAKER_01: So you gotta have at least a couple good shakes in there.
• 18:20
  SPEAKER_01: You have to have enough quote unquote time in there to get them to decay, right?
• 18:25
  SPEAKER_01: So I I love this analogy.
• 18:26
  SPEAKER_01: This is great.
• 18:27
  SPEAKER_02: And you can do the same thing with sugar cubes, which changes the half-life, right?
• 18:31
  SPEAKER_02: If you take sugar cubes and you take a sharpie or something like that, and you put a dot on one of the sides of a sugar cube, a sugar cube has six faces on it, right?
• 18:39
  SPEAKER_02: Six sides.
• 18:41
  SPEAKER_02: If you put a dot on one of them, so one sixth of the sugar cube has a dot, and you put them in a shoebox, you take you got a hundred of them, and you shake it up, one sixth of that hundred then is gonna be dot side up, and you're gonna take those out.
• 18:57
  SPEAKER_02: Now, I haven't gotten through a half-life then.
• 19:00
  SPEAKER_02: I've only removed one sixth, so I put the lid back on, I gotta shake it back up, and I have to do it again and again to eventually where I get to 50 sugar cubes have been removed out of my original hundred.
• 19:13
  SPEAKER_01: The number of shakes and opens and shake and open and shake and open, it takes more of those to get half of the sugar cubes gone than it does for the pennies.
• 19:21
  SPEAKER_01: Correct.
• 19:22
  SPEAKER_02: And all I'm doing up with that is I'm not trying to be confusing or anything like that.
• 19:26
  SPEAKER_02: I'm just saying that every element, you got pennies and you got sugar cubes, they have their different half-lives.
• 19:30
  SPEAKER_01: Yeah, so this is 235 uranium and 238 uranium in our analogy that have different half-lives that decay at different rates.
• 19:37
  SPEAKER_01: That's a good one.
• 19:38
  SPEAKER_01: I really like that analogy.
• 19:39
  SPEAKER_01: That's a great one.
• 19:40
  SPEAKER_01: How do we figure out time by looking at the heads and the tails and how many are in the shoebox and how many are out of the shoebox?
• 19:46
  SPEAKER_02: You have to look at then if you have a rock and it has 50% of the parent isotope in it and 50% of the daughter isotope in it, it has gone through one half-life, right?
• 19:58
  SPEAKER_02: So if we know the half-life of that isotope, then we can begin to get some ideas to how old the rock is.
• 20:06
  SPEAKER_02: Now, this does bring up a very important point, Jesse, regarding the daughter isotope.
• 20:13
  SPEAKER_02: What is that point?
• 20:14
  SPEAKER_01: The point is that you could have some of the daughter there to start with.
• 20:19
  SPEAKER_01: So if we're doing this with your pennies in the shoebox analogy, if you got a hundred pennies in the shoebox and you got no pennies outside the shoebox, you shake it up, and 50 of them are going to be tail side up.
• 20:29
  SPEAKER_01: You take those 50 out, you put them on the table, and you'd say, Oh, we've got 50 inside, 50 outside.
• 20:35
  SPEAKER_01: We went through one half-life, right?
• 20:37
  SPEAKER_01: That would be one way to do geochronology or to do the dating of our pennies in the shoe box.
• 20:42
  SPEAKER_01: Now, what if we did the same thing and we put 100 pennies in the shoebox, except we had another 50 outside of the shoebox already on our table, and then we did the shakeup with the hundred pennies, and we took 50 of them out, put them on the table, and now we said, Oh, we have a hundred outside the box, we have 50 inside the box.
• 21:00
  SPEAKER_01: We must be more than one half-life long in our system here, in our pennies in the shoebox.
• 21:06
  SPEAKER_01: When actually you're only one half-life, so it matters that's really good.
• 21:10
  SPEAKER_02: That is a really good analogy, Jesse.
• 21:11
  SPEAKER_02: But for the listener, I just want to be clear that what we're saying, and I'm just gonna say it, is that we can't assume that there wasn't any of the daughter isotope present in the rock at the time the rock formed.
• 21:25
  SPEAKER_02: We can't assume that all the daughter got there from decay, and that's what you're saying with the 50 pennies outside, they were there at the time.
• 21:34
  SPEAKER_02: And so is that assumption made?
• 21:37
  SPEAKER_02: Because this is one of the most common misconceptions about radiometric dating.
• 21:41
  SPEAKER_01: Yeah, so let me be really explicit and really clear here that we are very, very good at accounting for that initial daughter isotope concentration or the amount of pennies outside the shoebox when we start.
• 21:56
  SPEAKER_01: We're very, very good at accounting for that.
• 21:59
  SPEAKER_01: And if Fact, many times we're actually interested in that data.
• 22:03
  SPEAKER_01: We don't really care about the age.
• 22:05
  SPEAKER_01: We want to know how many pennies were outside the shoebox to start with.
• 22:09
  SPEAKER_01: That's what we're interested in for scientific reasons.
• 22:12
  SPEAKER_01: So we're very good at accounting for this.
• 22:14
  SPEAKER_01: And uh we have many avenues around that, many ways to correct for that part of radiometric decay and radioactive uh dating.
• 22:22
  SPEAKER_02: All right.
• 22:23
  SPEAKER_02: Well, Jesse, then I think it's time to transition to how does this actually happen?
• 22:29
  SPEAKER_02: How do we date rocks?
• 22:30
  SPEAKER_02: And and what does your lab look like?
• 22:32
  SPEAKER_02: And how do you set up a lab?
• 22:34
  SPEAKER_02: I mean, this is what you've devoted your time to.
• 22:36
  SPEAKER_02: You're the expert in the field.
• 22:38
  SPEAKER_02: So this part of the podcast is going to be really me asking you questions because you're the expert in the room.
• 22:44
  SPEAKER_02: All right, let's do it.
• 22:45
  SPEAKER_01: And I want I want to make sure, hold on, let me make sure that's recorded properly because I want that on record that I'm the expert in the room.
• 22:51
  SPEAKER_01: Okay, good.
• 22:51
  SPEAKER_01: Yeah, we got it.
• 22:52
  SPEAKER_01: We're good.
• 22:52
  SPEAKER_01: We're good.
• 22:52
  SPEAKER_01: We got it.
• 22:53
  SPEAKER_02: This won't happen again, by the way.
• 22:54
  SPEAKER_01: That was a mistake on my part.
• 22:56
  SPEAKER_02: Yeah.
• 22:57
  SPEAKER_02: Can you talk a little bit about Jesse, then how the lab is set up?
• 23:02
  SPEAKER_01: Yeah, there's many ways to do this radiometric dating.
• 23:05
  SPEAKER_01: I mean, there's many different methods, many different isotopes that decay to other isotopes.
• 23:10
  SPEAKER_01: What we're going to be kind of specialists in is uranium-led geochronology.
• 23:14
  SPEAKER_01: And this is uranium-238 decays to lead 206, and uranium-235, the one that is used in atomic weapons, that decays to lead 207.
• 23:23
  SPEAKER_01: And we're going to be.
• 23:23
  SPEAKER_02: Can you give the half-lives of those real quick?
• 23:25
  SPEAKER_01: Yeah, 238 uranium decays to 206 lead with a half-life of around about 4.5 billion years.
• 23:32
  SPEAKER_01: 235 uranium decays to 207 lead with a half-life around about 750 million years or so.
• 23:38
  SPEAKER_01: So we use the the two isotopes uranium decay to the two isotopes of lead, and we kind of focus on minerals that do not take in lead initially.
• 23:49
  SPEAKER_01: So it gets around this initial daughter problem by focusing on minerals that don't really like lead.
• 23:56
  SPEAKER_01: They like uranium, so they take uranium in and they kick out lead.
• 23:59
  SPEAKER_02: Let me let me so an analogy, right?
• 24:02
  SPEAKER_02: Is that the way these minerals grow is kind of like building a brick wall.
• 24:06
  SPEAKER_02: And in order to put a block in the wall or a brick in the wall, the brick has to fit.
• 24:11
  SPEAKER_01: Yeah.
• 24:11
  SPEAKER_02: And so what we're talking about, probably, right, and you can correct me if I'm wrong because this is your field, but the lead is the wrong shape, it's the wrong size, it doesn't fit exactly in the crystal structure.
• 24:21
  SPEAKER_01: Totally.
• 24:22
  SPEAKER_01: Totally.
• 24:23
  SPEAKER_01: So the mineral grows, doesn't like lead, kicks it out, it likes uranium, uranium fits in nicely, and then uranium decays to lead, and then we can measure the ratio of uranium and lead.
• 24:32
  SPEAKER_01: So the way that we do this is all very it sounds very fun and fancy and is a pain in the ass to set up, but we use a laser.
• 24:40
  SPEAKER_01: So we take a pretty high-powered laser and we blast the mineral grain.
• 24:45
  SPEAKER_01: We hit the laser on the mineral grain, and that mineral, the constituent elements of that mineral, it's sitting in this sort of crystal structure of the mineral.
• 24:53
  SPEAKER_01: Those elements get vaporized, and and so it's now in a gas.
• 24:57
  SPEAKER_02: Hold on.
• 24:58
  SPEAKER_02: We're talking about blasting a mineral that is the width of a human hair.
• 25:02
  SPEAKER_02: Yeah, okay.
• 25:02
  SPEAKER_01: So yes, they're tiny.
• 25:03
  SPEAKER_01: They're tiny.
• 25:04
  SPEAKER_01: That's important.
• 25:05
  SPEAKER_01: I it's it's very yeah, it's important.
• 25:07
  SPEAKER_01: It's sophisticated.
• 25:08
  SPEAKER_01: So a typical human hair, you know, if you have thin hair or fine hair, your hair is probably like 50 microns thick.
• 25:16
  SPEAKER_01: If you have really coarse hair, your hair is probably like 200 microns thick or something.
• 25:20
  SPEAKER_01: We're talking about mineral grains that are about 200 microns big.
• 25:23
  SPEAKER_01: So they're like grains of sand or the the width of your human hair.
• 25:27
  SPEAKER_01: We're gonna aim a laser at very specific portions of that grain.
• 25:30
  SPEAKER_01: We're not gonna hit the whole grain, we're gonna hit very small parts of that grain.
• 25:34
  SPEAKER_01: So we we have this laser unit, and the elements in that mineral grain are evaporated, and they are transported into what is called a mass spectrometer.
• 25:45
  SPEAKER_01: And the mass spectrometer is measuring uranium and lead.
• 25:48
  SPEAKER_01: And we need to use a mass spectrometer to measure uranium and lead because we need to separate uranium from lead in order to count, you know, the proportions of each.
• 25:57
  SPEAKER_01: And uranium weighs more than lead weighs, and so we separate them out by their weight or by their mass, and so we use a mass spectrometer to create a mass spectrum, which is the amount of uranium versus lead in that particular part of that particular grain which came from a particular rock.
• 26:15
  SPEAKER_01: So this is kind of how we're doing it.
• 26:17
  SPEAKER_01: Are you wearing a white lab coat when you do this?
• 26:19
  SPEAKER_01: Yeah, the in this part it's not it's not super clean necessarily.
• 26:22
  SPEAKER_01: This part of the city.
• 26:23
  SPEAKER_01: What do you look like when you do this?
• 26:24
  SPEAKER_02: What do you what do you look like?
• 26:25
  SPEAKER_01: I need to just just giddy, just so excited, you know, it's so happy.
• 26:30
  SPEAKER_02: Okay, you got do you have your man bun?
• 26:32
  SPEAKER_02: Are you sporting your man bun?
• 26:33
  SPEAKER_01: Yeah, yeah, super, yeah.
• 26:33
  SPEAKER_01: You gotta have a man bun come in.
• 26:35
  SPEAKER_01: You gotta when you drink your coffee, you gotta have your pinky in the air because we're very pretentious about it.
• 26:39
  SPEAKER_02: Do you have the white lab coat on, or are you just wearing your grungy flannel and not in here?
• 26:43
  SPEAKER_01: We we we you can come in with your outdoor shoes on and stuff.
• 26:47
  SPEAKER_01: It's not super clean because we're putting our little mineral grains, we're mounting them in an epoxy grain mount.
• 26:53
  SPEAKER_01: And so dust, you know, we want to keep dust down, but it's not an ultra clean lab.
• 26:57
  SPEAKER_01: All right.
• 26:58
  SPEAKER_01: So we we have you know, those sticky mats.
• 27:00
  SPEAKER_01: If you watch the college basketball or NBA, they always step on the sticky mat before they go on the court.
• 27:04
  SPEAKER_01: We have those sticky mats in the entryway to the lab to kind of keep dust down.
• 27:08
  SPEAKER_02: I'm glad I don't have to envision you in a white lab.
• 27:11
  SPEAKER_01: No, no, no.
• 27:12
  SPEAKER_01: That's for another time.
• 27:12
  SPEAKER_01: That's for another time.
• 27:14
  SPEAKER_01: So, no, we're sitting at the at the computer, you know, amongst these machines, between the laser and the mass spectrometer.
• 27:19
  SPEAKER_01: And uh, and so you know, the mass spectrometer, it's another kind of cool thing.
• 27:24
  SPEAKER_01: The way that we separate these things by mass requires them to be ionized or have an electron stripped off them.
• 27:30
  SPEAKER_01: So we inject this material into a plasma, a really high temperature plasma that's like 8,000 degrees.
• 27:38
  SPEAKER_01: So we inject this stream of particles into that plasma, and then it gets we can measure the uranium and lead from that part of the mineral grain.
• 27:47
  SPEAKER_02: You know, so I want to say this right now.
• 27:49
  SPEAKER_02: You explain this process to my students, you know.
• 27:52
  SPEAKER_02: We alluded to this earlier uh in another episode about you know, you Skype or you zoom in with my class every year and you talk about this.
• 28:02
  SPEAKER_02: It oh my gosh, you talk about this, and and I learn as you talk.
• 28:06
  SPEAKER_02: Every year I learn something new.
• 28:08
  SPEAKER_02: This part of it is so cool how you bend these ions through like a 90-degree bend, right?
• 28:16
  SPEAKER_02: And and the degree to which they bend is directly related to their mass, and you count them on the other side, and it is that is such a cool process.
• 28:28
  SPEAKER_01: I mean, it's it's like kind of you know, swinging, you know, like a uh if you swing a really heavy object around you, it kind of pulls you out more.
• 28:35
  SPEAKER_01: If you swing a really light object around you, it doesn't pull you as much.
• 28:38
  SPEAKER_01: And so we buy these ions around a magnetic field, and the heavy ones bend less, the light ones bend more.
• 28:44
  SPEAKER_01: So you can separate things by weight that way.
• 28:47
  SPEAKER_01: And so cool.
• 28:48
  SPEAKER_01: We can count 206 lead, we can count 207 lead, we can count 235 uranium, we can count 238 uranium.
• 28:54
  SPEAKER_02: That is the precision there.
• 28:56
  SPEAKER_02: You you just said that we can discern between a lead 206 and lead 207, which is not a big difference in mass.
• 29:03
  SPEAKER_02: It's one atomic mass unit, and this equipment can pick that up.
• 29:07
  SPEAKER_02: All right, Jesse, let's go.
• 29:08
  SPEAKER_02: We got to get to the to the heart of this.
• 29:10
  SPEAKER_02: Um, how does this how does this help us date rocks?
• 29:13
  SPEAKER_02: You got two minutes.
• 29:14
  SPEAKER_02: Let's go.
• 29:15
  SPEAKER_01: Yeah, all right.
• 29:15
  SPEAKER_01: So, what we do is we if we're collecting a rock in the field, we're gonna take the rock, crush it up, separate out the mineral grains that we're interested in, things like zircon or monozyte or apatite.
• 29:24
  SPEAKER_01: Those are things that you don't need to know the intro the names of, but these are minerals that don't like lead, and so they take uranium in, don't really take in lead.
• 29:32
  SPEAKER_01: So we're gonna take those mineral grains, we're gonna put them in epoxy, put a bunch of mineral grains on some sticky tape, pour epoxy in there, and then polish that down so that we can see into the mineral grains.
• 29:43
  SPEAKER_01: We're gonna put them in our laser system, the laser hits them, the elements that are ablated from the laser go into the mass spectrometer.
• 29:49
  SPEAKER_01: We count the uranium lead.
• 29:50
  SPEAKER_01: And as a little aside, this is like the most rewarding measurement you can do, maybe even in science, certainly in geoscience, is you can see the laser drilling down into the mineral grain.
• 30:01
  SPEAKER_01: We can't we have a little microscope that watches this happen.
• 30:04
  SPEAKER_01: You can see the uranium lead ratio on the mass spectrometer, and you can basically just calculate an age right away.
• 30:10
  SPEAKER_01: I mean, it's so immediate.
• 30:11
  SPEAKER_01: The reward on this is immediate.
• 30:14
  SPEAKER_01: So, in order to convert a rock to an age, you know, that whole process of sample preparation and analysis might take like a day or two for one sample, but we can we can measure 400 laser spots in a day pretty easily.
• 30:30
  SPEAKER_01: So there's a fair amount of sample throughput there.
• 30:33
  SPEAKER_01: So, yeah, that that's kind of what we're doing.
• 30:35
  SPEAKER_01: Uh, but we've just had these instruments installed in the last like two weeks.
• 30:39
  SPEAKER_01: Uh, and so it's super exciting.
• 30:41
  SPEAKER_01: We're like just getting the lab dialed up.
• 30:43
  SPEAKER_01: It it's really fun and really exciting for me because it's been two years and two and a half years in the preparation stages to actually get these things here at Penn State fired up.
• 30:52
  SPEAKER_02: All right, I just woke up.
• 30:54
  SPEAKER_02: Um okay.
• 30:56
  SPEAKER_02: All right, well, come on, Chris.
• 30:58
  SPEAKER_02: What the hell was that?
• 30:59
  SPEAKER_02: Oh my gosh, Jesse.
• 31:01
  SPEAKER_02: I I said you had two minutes, and you know what you started, you started to talk faster, you idiot.
• 31:05
  SPEAKER_02: You are yeah, no, it talked fast because you only got two minutes.
• 31:08
  SPEAKER_02: You gotta fit more in.
• 31:10
  SPEAKER_02: All right.
• 31:10
  SPEAKER_02: I have a couple questions for you.
• 31:12
  SPEAKER_02: First of all, I want to know you've told me this before.
• 31:15
  SPEAKER_02: I want to talk about it real quick.
• 31:17
  SPEAKER_02: That zircons, the mineral that you use a lot, right?
• 31:20
  SPEAKER_02: Okay, you've talked about this.
• 31:23
  SPEAKER_02: That we use this in like magma chambers to date how the magma has cooled off.
• 31:30
  SPEAKER_02: Can you real quick?
• 31:31
  SPEAKER_02: Now, I mean like don't talk fast, but just talk.
• 31:36
  SPEAKER_01: So go.
• 31:37
  SPEAKER_01: Yeah, it goes back to our our answers to the listener questions about what is a magma chamber and the fact that magma chambers take a long time to cool down, and the minerals in them are growing much like tree rings are growing.
• 31:51
  SPEAKER_01: They take time to grow new outer layers to the to the mineral grain.
• 31:56
  SPEAKER_01: And so these mineral grains in magma chambers can have a really big age difference between the core when they started growing and the rim when they ended growing, and that can be like a hundred thousand years, two hundred thousand years age difference between the core and the rim of a single mineral grain that's the width of a human hair.
• 32:17
  SPEAKER_02: Okay, now that's to me, that is so impressive because then that speaks to you can extrapolate that out to how long it takes a magma chamber to cool off.
• 32:28
  SPEAKER_01: Exactly.
• 32:28
  SPEAKER_01: So you can calculate the the sort of thermal evolution or the heat loss rate of a magma chamber.
• 32:34
  SPEAKER_01: It's so cool.
• 32:35
  SPEAKER_01: It's totally cool.
• 32:36
  SPEAKER_02: That is really cool.
• 32:37
  SPEAKER_02: All right, Jesse.
• 32:38
  SPEAKER_02: So we have to kind of wrap this up a little bit.
• 32:40
  SPEAKER_02: And I want to just end with what is the cost in setting up a lab like what you have going on?
• 32:48
  SPEAKER_02: And then what's the point?
• 32:50
  SPEAKER_01: Yeah, good question.
• 32:52
  SPEAKER_01: The the cost is a lot.
• 32:54
  SPEAKER_01: We're on the order of many hundreds of thousands of dollars by the time we factor in lasers and mass spectrometers and all the HVAC and all the lab renovations that it takes to fit these things in there.
• 33:07
  SPEAKER_01: So, yeah, we're we're we're pushing into the many hundreds of thousands of dollars range.
• 33:11
  SPEAKER_02: What does one ballpark one mass spec cost?
• 33:16
  SPEAKER_01: The one we bought is uh instrument that's around$450,000.
• 33:22
  SPEAKER_01: Our laser unit is$250,000 or something like that, and then you know, factor in all the renovations to the to the lab space.
• 33:30
  SPEAKER_01: So you're in the millions, probably.
• 33:32
  SPEAKER_01: Yeah, that's a term that don't like to throw around, but yeah.
• 33:34
  SPEAKER_01: Yeah, I know you didn't.
• 33:35
  SPEAKER_02: Yeah, but we call we call spades spades here on the stove.
• 33:39
  SPEAKER_01: So that's right.
• 33:39
  SPEAKER_01: So yeah, yeah, we're we're talking over a million dollars.
• 33:42
  SPEAKER_02: All right, so it cost a million dollars to set up your lab to do this.
• 33:47
  SPEAKER_02: What's the point?
• 33:48
  SPEAKER_02: What why are we doing this?
• 33:49
  SPEAKER_01: Yeah, great question.
• 33:50
  SPEAKER_01: The point is that we're gonna do analyses that allow us to really interrogate what's going on in these individual mineral growth layers.
• 34:01
  SPEAKER_01: So we're gonna look at things like how long does it take for a magma chamber to cool down?
• 34:06
  SPEAKER_01: Because that really controls how certain mineral deposits form.
• 34:11
  SPEAKER_01: It controls how igneous rocks are formed on Earth, what's going on in subduction zones.
• 34:16
  SPEAKER_01: We're gonna look at things like when you smash two continents together and you form a mountain range, how long does it take for that mountain range to cool off?
• 34:24
  SPEAKER_01: Because that's taught speaking to like the relaxation of these continents and the moving apart of these continents.
• 34:30
  SPEAKER_01: We're gonna look at things like dating fluid flow in mineral deposits or fluid flow through sediments that are related to hydrocarbons and oil and gas moving through the sediments.
• 34:41
  SPEAKER_01: So we're gonna really look at a wide variety of things, and it's it kind of goes back to what Diana Roman was talking about in our interview with her about how research is kind of entrepreneurial in a sense, that Penn State has given us this money as quote-unquote startup money to establish a lab with the hope and expectation that we will start to get research grants, we'll start to work with companies and develop research initiatives using this material that is beneficial to Penn State in the long run.
• 35:11
  SPEAKER_02: And I want to be real clear, too, that when I asked that question, um, that isn't really coming from my heart.
• 35:16
  SPEAKER_02: That's coming from just what I anticipate some people to think of.
• 35:21
  SPEAKER_02: Totally.
• 35:21
  SPEAKER_01: And I think listen, I I think that is a totally valid question.
• 35:24
  SPEAKER_01: And I think any anybody who's doing research or taking federal tax dollars or taking anybody's money to do research, they should have an answer to that question.
• 35:33
  SPEAKER_01: If you don't have an answer to that question, you need to fix that problem.
• 35:36
  SPEAKER_01: That's a problem you need to fix it.
• 35:38
  SPEAKER_02: You know, and I think I think that goes with anyone that teaches anything in the geosciences has to have an answer to this question because why are we studying rocks?
• 35:46
  SPEAKER_02: Why are we doing this?
• 35:47
  SPEAKER_02: Why are we studying what we're studying, right?
• 35:49
  SPEAKER_02: You need to have an answer to that question because we don't have there is no planet B.
• 35:54
  SPEAKER_02: I've said that before.
• 35:56
  SPEAKER_02: You know, we've just got this one and we need to learn as much about this planet as we possibly can just for the sake of knowing.
• 36:06
  SPEAKER_02: It is it's ours.
• 36:08
  SPEAKER_02: We gotta take care of it.
• 36:10
  SPEAKER_02: We can't take care of it if we don't know it.
• 36:12
  SPEAKER_02: This is something that absolutely needs to be like a comfortable conversation with somebody that that works in the geosciences.
• 36:21
  SPEAKER_02: Why are you doing what you're doing?
• 36:22
  SPEAKER_02: What's important about this?
• 36:23
  SPEAKER_02: Well, what's more important?
• 36:25
  SPEAKER_01: Yep, I agree.
• 36:26
  SPEAKER_01: And I think it's a valid question that people should be asking, and you you better have an answer to it, and you better have a good answer to it.
• 36:33
  SPEAKER_01: Because there are, as you said, a many, many, many good answers to that question of why are the geosciences important.
• 36:39
  SPEAKER_01: You just got to make sure you know why they are, and that's kind of the point of this podcast, right?
• 36:43
  SPEAKER_01: I mean, to help emphasize that.
• 36:45
  SPEAKER_02: So good answer, Jesse.
• 36:46
  SPEAKER_02: Well done.
• 36:47
  SPEAKER_02: All right, yes, you win.
• 36:49
  SPEAKER_01: All right, all right, I like it.
• 36:50
  SPEAKER_01: Well, I mean, you know, this is a topic that we could go on and on and on.
• 36:54
  SPEAKER_01: I mean, you and I could sit around for hours talking about this, but we're gonna wrap it up there.
• 36:58
  SPEAKER_01: And, you know, if you have questions about how we date rocks or details about the techniques or anything like that, hit us up, let us know.
• 37:06
  SPEAKER_01: We're happy to answer questions.
• 37:08
  SPEAKER_01: And, you know, it's a really interesting feel that is uh you know is near and dear to both our hearts for sure, right?
• 37:14
  SPEAKER_02: And please, if you got something out of this or you know somebody or think of somebody that might enjoy this kind of stuff, this kind of talk, this kind of discussion, pass it on.
• 37:24
  SPEAKER_02: Share our podcast.
• 37:26
  SPEAKER_02: With that, we'll wrap it up.
• 37:27
  SPEAKER_01: Chris, good chat, man.
• 37:28
  SPEAKER_01: I love it.
• 37:29
  SPEAKER_01: Yeah, see you next week.