Earth on the Rocks

Shelby: 00:06

Hi, folks. Welcome to Earth on the Rocks, the show where we get to know the person behind the science over drinks. I'm your host, Shelby Rader, and joining us today is doctor Arndt Schimmelmann. Arndt, thanks for coming on the show.

Arndt: 00:17

Thanks for letting me talk.

Shelby: 00:18

Arndt, as we get to know you over drinks, what would be your drink of choice for today?

Arndt: 00:22

Well, my choice, actually, I found out last year. My wife and I went to Mexico, to Oaxaca, and there, they have the most delicious freshly squeezed orange juice ever. I mean, I could never have this either in The US or in Europe, but there, they they have their own orchards apparently, and they squeeze it almost in front of your eyes. And it is so sweet. And they have these big jugs full of it for almost nothing.

Arndt: 00:48

That's dirt cheap and so delicious. That's my favorite drink.

Shelby: 00:51

Do you make plans to try to go back when you can just to to have the orange juice experience?

Arndt: 00:56

We went there twice already, and we go again this winter.

Shelby: 01:00

Hey, perfect timing to go too. That's a nice time to escape Indiana. So you're also part of this sort of diverse Earth and Atmospheric Sciences department. And so if someone were to ask you, what sort of scientist are you, how would you answer that?

Arndt: 01:14

Well, my grandkids say I'm a crazy scientist. Probably they're right. I'm a geoscientist in the widest sense of the world with an emphasis on organics, but not exclusively so. So I was I was actually a chemist before I became anything else, and, chemistry became too dangerous for me. I hated organic chemistry because I almost got killed a couple of times while I was in university.

Arndt: 01:41

At one time, they gave me a substance to analyze as a test. Right? It was in a real class and it was a practical part. So I always had ask the instructor, can I do this test? And so I was very careful.

Arndt: 01:58

They said, yeah, go ahead. Go ahead. So I asked, can I nitrate this material?

Shelby: 02:03

And can you tell listeners what you mean by can I nitrate this?

Arndt: 02:06

Okay. Nitration is something that you add oxygen to a compound and that makes it very dangerous potentially because organic compounds with oxygen can burn very, very strongly or even explode. That's why I always ask people first, can I nitrate this? So he said yes, and I went ahead and I did that stuff. And I asked, can I distill the product?

Arndt: 02:33

Sure. Go ahead. So I distilled it, and I determined the boiling point precisely. And after that, I went to test for elemental abundances and can I add a little bit of this with sultiment test for reaction? Yes.

Arndt: 02:50

And I used only a small amount of my product and it blew up in my face and it destroyed my glasses. Turned out, I had nitrided methanol. I made rocket fuel, really. And I had, like, produced 50 mils of that. If that would have blown up and I was distilling it, I would be killed.

Arndt: 03:10

So at that time, I I thought, no. This is not for me. I'm going to do something more benign. I go into something geologically oriented, geochemistry. There was only one person in my university who did something like that and he worked on natural gas.

Arndt: 03:26

And so I did my master's thesis on nitrogen isotopes in natural gas, which was fine. It was not dangerous. I blew up a few things in his lab anyway, but it was okay. And that was really a nice experience. And after that, I decided, okay.

Arndt: 03:41

Let's continue this. And I applied to a number of universities in Canada and in The US. Canadians had a mail strike, so my application never reached the university. And the only reply I got was from UCLA, and they accepted me. So that was the end of that, I was very happy, actually, and I never regret that.

Shelby: 04:01

And so these experiences you were just describing, these are while you're an undergraduate?

Arndt: 04:06

In Germany, undergraduate towards a master degree.

Shelby: 04:09

Yes. Okay. And then from there, you were applying for graduate programs and ended up at UCLA.

Arndt: 04:15

And I was so lucky to get in. And later, I found out the professor who was an assistant professor, brand new, he needed a graduate student to bring that student to the PhD level before he could get promotion. Yeah. I was the one to get him promoted and so we had a symbiosis. I didn't know that, but it was wonderful.

Shelby: 04:39

And it seems like some of these stories you're describing, maybe you have a tendency to blow things up. Did you blow things up in his lab too while you were a graduate student?

Arndt: 04:47

Yes, I did a number of times, of course, and it also destroyed my glasses. But that wasn't really my fault. At that time, we had to heat substances in sealed quartz ampoules.

Shelby: 05:01

And an ampoule, can you describe

Arndt: 05:03

Okay. And a piece of glass tubing where both ends are sealed shut. So you have a little bomb, basically, a bomb made out of glass. And, the substances to react were sealed in that little ampoule type thing. And then we put these things into a muffled furnace where it's red hot.

Arndt: 05:22

Okay? And once in a while, we have to open that thing to take a sample out and then when they blew up. Yeah. That was not nice. But he paid for the glasses.

Arndt: 05:32

Yeah.

Shelby: 05:33

Are these like prescription glasses?

Arndt: 05:35

It was. Yes.

Shelby: 05:36

How many pairs of glasses do you feel like you've gone through from lab related things?

Arndt: 05:41

Certainly a couple. Other explosions were not so severe, but those two, yeah, they destroyed my glasses.

Shelby: 05:49

Yeah. So, Arndt, you're really, I'd say, a very accomplished geochemist in a range of fields. And so can you talk to us a little bit about you're now sort of established here at IU as this geochemist. What are some of the research types of questions that you're interested in? You mentioned you're sort of a geochemist in the broadest sense.

Shelby: 06:08

So what sorts of things are you interested in?

Arndt: 06:10

I like fieldwork and also lab work, but mostly fieldwork. So when I go out in the field, when I even travel, I look for projects. So my wife and I, we traveled to Vietnam One time about fifteen years ago. My wife is from Vietnam, so we get along very easily. And we came across all these caves, cave entrances.

Arndt: 06:32

And I thought, well, this is something I could do research with. Let's talk about some collaboration. So my wife called the university in Hanoi, not knowing anybody there, of course. And but she speaks Vietnamese, so she had no problem getting reconnected. And we talked to a guy who works on caves.

Arndt: 06:52

And we had this collaboration where we actually went back to Vietnam then and measured the atmosphere in caves and I had a detector for methane. Methane is a very potent greenhouse gas and it's naturally occurring in the atmosphere, and so we walked into these caves and as you go further into caves, methane drops to essentially zero in many caves unless it's very well ventilated. And the reason why they go to zero often is because there are microbes living on the on the rocks in the cave. And these microbes in the dark, they don't rely on sunshine to live, but they have to eat something and it's the methane in the air. It's fantastic.

Arndt: 07:34

So we did a lot of that research and published that and as a byproduct, my detector could also measure radon. So we measured this like free and got publications out of that. And so one thing follows another one. Chance encounters with some people. We have a project and then we find something unexpected and then another project pops up.

Arndt: 07:58

And one of those Vietnamese collaborators, he asked me, what else can we do? And so I said, well, I always wanted to to measure lake sediments. I never did that, but we could do that. Do you have any good lake here? And he found these fantastic maars.

Arndt: 08:14

A maar is an old volcanic crater that over many, many thousands of years to millions of years accumulate sediment, and eventually they fill up, of course. But we he had this one crater that was still with water and below the water, sediment. And so we started coring that stuff, and it was so interesting. So and by now, he got a Fulbright, came to my lab, and and now he's an established scientist. He just finished coring some 60 meters into the sediment there, which is like a world record for his equipment that he built by himself.

Arndt: 08:53

So this is a fantastic example how you can sponsor, how you can kind of help a young scientist to get an idea and run with it. And so he was invited to have a crash course in sediment coring here in The US in a very special lab. He came to me as a Fulbright scholar, and now he's very established and he's doing great. This the most rewarding encounter in my entire career, that this young person learned just the basics for me, and then he ran with it. And he's so good.

Shelby: 09:29

Well, and I I think that really highlights what I think is an interesting and fun part of of the science that we all get to do that have been on the show is, you know, we really just get to be curious, and we get to find interesting questions that come up through these conversations and collaborations, and then start to ask ourselves, you know, what can we do with this? What sorts of things can we explore? And so you've mentioned these really interesting sort of field applications. And so I want to talk in more detail about a couple of those. So with these cave projects, you say you're going in and you're measuring things like methane and radon.

Shelby: 10:04

Mhmm. And so first, I wanna sort of ask you about radon because I think that that's something that a lot of people aren't necessarily familiar with, but probably would would benefit from being a little more familiar with. So can you tell us, what is radon? Why do we care about it? Why should sort of the average person be aware of this idea of So

Arndt: 10:21

radon is recognized by the EPA as one of the leading causes of lung cancer globally. It depends on where you live and what house you live and the construction of your house. Radon typically is emitted from the ground and it can go into your basement.

Shelby: 10:42

It's very heavy.

Arndt: 10:43

Well, that isn't really important. Yes, it is very heavy, but it's a single little atoms and they kind of float around easily. So the heaviness is not the deciding factor. But it is the radioactivity of this gas. It has several isotopes, by the way.

Arndt: 10:58

The most common that we talk about is the radon isotope that has a half life of three and a half days. So every three and a half days, half of this decays. Before that, it's harmless gas. It's actually a noble gas. It doesn't react with anything.

Arndt: 11:11

You can breathe radon in and out. No harm done. However, if a radon atom decays, it produces a very strong alpha radiation. And if this radon is in your lung at the time, it can cause lung tissue problem. And even worse, it decays to another isotope, a metal isotope, which is also radioactive.

Arndt: 11:35

And this metal isotope loves to adhere to your lung tissue. So now there is a little metal isotope on your lung tissue, poof, and another alpha emitter. And then it produces another isotope. It's also metal that will also decay. So it's like this series of metal isotopes that decay until eventually it becomes a lead atom.

Arndt: 11:58

So that is the danger. You have stuff in your lung, adhere to lung tissue, and a whole sequence of events that can cause lung cancer. To avoid that is, you want to reduce the abundance of radon in the air that you breathe. And there are various ways of doing that. You can, for example, suck the air from under your slab of your house.

Arndt: 12:22

That's what I do actually. I I I did that at my home. That's one way you can reduce the amount of radon that seeps into the air in your basement. Another way is you can actually ventilate the room air in your house, but then you have the big fan and probably noisy, lots of energy. Some people do that.

Arndt: 12:41

Some people don't have to worry about this at all because if you happen to have your house built on substrate which is low in uranium, which is a source of radon, probably you're okay. You just have to measure it. And there are cheap ways to do that. You can actually order a kit. You place the kit into your basement for a certain time, send it in for measurement, and they tell you.

Arndt: 13:07

So please try to do that in your basement for the sake of your own health and also your kids and grandkids.

Shelby: 13:14

Yeah, so radon is one of those things, like I said, I don't think people think about often at all and is pretty dangerous if you have high levels of that in your Absolutely. I bought a home here in Bloomington a few years ago and as part of that purchase, there was a home inspection, and I opted for a radon test and had elevated levels. So I also had a radon mitigation system installed, similar to what you described, where they basically drill a hole in your foundation, and then they put in a pump. And so it's continually pulling air out from below your home to sort of evacuate that radon before it becomes dangerous. But you're right, it is one of the leading causes, depending on where you are In The US, I think it's the second leading cause of lung cancer.

Shelby: 13:59

And it's one of those things you don't think about. When you're interacting, if you're in a home with high levels of radon, you don't even know it. It's odorless. You're not going to smell it. You don't see it.

Shelby: 14:10

So I do think this is sort of like a PSA for folks to, yeah, to think about getting some of these at home tests, which, like you mentioned, are fairly inexpensive and really accessible and easy to deploy and get measured.

Arndt: 14:24

There's another isotope, thoron, which is also called radon, but it's a different isotope. And that is produced by thorium in minerals. Okay? And what people don't realize that although the half of it is only three and a half seconds, it can also be dangerous if you live in a mud house. That's why we went in Vietnam and did a study about that.

Arndt: 14:46

Many people in rural Vietnam, where the minorities live in mountainous areas, they're very poor. And they build traditional houses made out of compacted mud that then dries to adobe like structures. And this is a very porous clay rich material. And if you have enough thorium in these minerals, the thoron that comes out of that wall can be a rather high concentration and decays very fast. If you sleep at night right next to that wall, the same effect like the regular rhythm I talked about earlier.

Arndt: 15:20

Now, here in The US, we don't have that problem. We don't live in mud houses. Right? But many people, many many countries, poorer countries, people have this problem, which is widely unrecognized. And we we try to publish some of that.

Arndt: 15:35

And, I talked to other people who have, studied this and they they say, yeah, this is an ignored problem. And, when that person in Germany, he was an expert, he tried to publish this in a journal of architecture using natural materials. They wouldn't even accept this publication because they would offend the building industry. So they are strong, industrial organizations that put pressure on, publications to be suppressed.

Shelby: 16:07

So going back to sort of these cave systems in in Vietnam, when you all are are doing this fieldwork in these caves and you're measuring these different gases, what does that fieldwork look like? You're exploring these caves. Deep underground are you? Are you underground at all? What are you using to measure these sorts of things?

Arndt: 16:28

Well, in in case of Vietnam, you have to have people on the ground there who know the caves and who get the permits. And I was lucky that my colleagues there at University of Hanoi, they were very, very good collaborators. They still are. And they did all our fieldwork, the planning from A to Z. Hired the bus and hotels and the driver and permits and so forth.

Arndt: 16:54

There's one story. We had this one study near the Chinese Vietnamese border, just like a kilometer away from the border. And they thought we have a permit, but when we got there, turns out they had misspelled the name of the village. So our permit was invalid. And, they talked to all kinds of officials, and we finally with an escort of border police, we were allowed to go to that village.

Arndt: 17:22

So you need to have the right people and the right communication channels to get fieldwork done in other countries. Here in The US, it's less problematic. But otherwise, don't do it alone. You have to have locals.

Shelby: 17:36

And then when you all are going in these caves

Arndt: 17:38

Yeah.

Shelby: 17:39

What are these caves like? Maybe people who are listening to this in The US are familiar with places like Mammoth Cave, which has parts of it that are very much commercialized so that people can come and go very freely. So are these very confined cave systems? Are you going very deep within them? Are you having to sort of crawl in any points?

Shelby: 17:59

Yes.

Arndt: 18:00

And yes to all questions. Okay. So there's a wide variety of caves in Vietnam, for example, but many other countries. Very few are actually developed as tourist caves. Some are practically unexplored.

Arndt: 18:14

And I'm always very careful. I don't really want to be a cave explorer. So especially with my instruments, they are very fragile. I didn't want to risk that. I let the other guys crawl in there.

Arndt: 18:23

And in that case, I gave them plastic bags. So they they have these big plastic bags. They're called drumliners. They're very sturdy plastic, not the regular plastic from Kroger. So they go in there with these drumliners and they hold like 50 gallons.

Arndt: 18:39

Right? So in the cave, they kind of shake them around in a certain way that they fill the big plastic bag with cave air and then they tie them shut. And if they do that right, they can carry this plastic bag out of the cave to me, or at least to the cave entrance where my instrument is sitting. And so it takes only like ten minutes. During that time, that air in that bag does not exchange with the outside air, so we can measure methane, we can measure the long lived radon, but not the three and a half minutes Anyway, so we were able to measure cave gases even in caves where I didn't want to, I could not crawl in.

Arndt: 19:18

Some of caves were really scary. It was this one cave. It was locked because it was a municipal water supply. So the villages nearby relied on water from that cave and but we had permission to open the lock and go inside. And then a bunch of kids followed us because it was the only chance they would ever go into that cave.

Arndt: 19:41

We were really, like, the sensation of of the neighborhood.

Shelby: 19:44

Yeah. And when you bring these big bags of gas out of the or big bags of air out of the cave, what's the process of then getting it into whatever instrument you're using to measure

Arndt: 19:57

Ah, my instrument has a little pump inside, and it's operated. So it sucks the air out of whatever into its internal measurement chamber and then measures radioactivity and methane and CO2 , by the way, also. So all I have to do is have a little plastic hose that comes from my instrument and attach this to the opening of the plastic bag. And the the flow rate is maybe a liter a minute. So it it takes a long time to empty that bag.

Arndt: 20:27

I have plenty of time to measure that gas. No problem.

Shelby: 20:30

Yeah. Yeah. Yeah. I think so I grew up in Eastern Kentucky and then did undergrad in Western Kentucky. There's a lot of caves in Western Kentucky.

Shelby: 20:40

And then when I was in Arizona for grad school, not the same thing as caves, but was involved in going to lots of underground mines. And so the idea of caving and being underground is sort of strange for a lot of people and is sort of scary because some of them can be a little, you know, you're not sure what you're getting into. So you definitely need to know what you're doing or be with somebody who knows what they're doing if you're going into a newer cave. But this sort of going into these natural systems and going to places where you're collecting this air from deep portions of the cave, which is pretty stagnant

Arndt: 21:16

Yeah.

Shelby: 21:16

Is sort of a really interesting approach and application of of geochemistry to understand what's happening in these sort of macro environments.

Arndt: 21:24

Yeah. We went to many commercial caves in The US and you have to be very careful. They they may not even want you in there if you ever mentioned the word radon. Yeah. So they didn't know that I measure radon at the same time with methane.

Arndt: 21:37

And some of these caves are pretty high in radon, actually too high. And they were commercial caves. And, okay, if the visitor goes in there once, they don't die from this. But the cave guides, okay, they do this every day, season after season. And, oh my goodness.

Arndt: 21:54

I mean, I told them they got concerned.

Shelby: 21:57

Yeah. I wonder if they're if they're like implementing any sort of testing now or Yes.

Arndt: 22:02

Supposed to, but some just skirted. Okay? Yeah. There's one cave where we measured high radon. They said, no.

Arndt: 22:09

Don't publish our results at all. Be quiet about it. It's in Indiana, by the way.

Shelby: 22:13

Yeah. We won't go into more detail on that here,

Arndt: 22:16

but

Shelby: 22:17

maybe we'll talk about it afterwards. In addition to these cave systems in Vietnam, you also said you've done lake coring. And so we've heard about coring on other episodes of the podcast in different sorts of contexts, so sediment coring, rock coring, geologic coring. Can you talk us through how do you core a lake, especially when you're going to 60 meters, which is a really big section to sort of punch through sediment below a lake and pull it back up? So are you like walking out into the lake?

Shelby: 22:49

Are you boating out? What is that process like?

Arndt: 22:51

My coring actually started in Santa Barbara Basin. It was marine coring when I was a postdoc at Scripps. So we caught in five and fifty meters of water depth. That was a different thing. We had a big research vessel and we used different coring devices.

Arndt: 23:03

That's gravity coring. You basically punch a hole with a hollow tube into the ground and hopefully by the time you pull it up, there's something left in the tube. And then we have like a piston coring. It's like a syringe really. So you lower a syringe type thing and then as you suck in into the bottom, acidity gets sucked in really.

Arndt: 23:24

We have all kinds of coring devices. In Vietnam, we didn't have any of that, of course. So there we had to improvise and we published one method actually. We started with short course like half a meter, one meter, building our own device. And then my collaborator there began to build his own piston coring which he now has perfected and probably is the best in the world.

Arndt: 23:51

So what it does, he lowers a sequence of interconnected plastic tubes, you know, like drainage pipe tubes. They're cheap. And you push them down slowly from a from a platform, a floating platform. So he has, like, empty oil barrels tied together with plywood and

Shelby: 24:16

That you you get on and sort of float out to a point in the lake

Arndt: 24:19

float out and you have long ropes. You tie it with trees so you don't get blown away. He did actually once or twice. That's another story. So you're more or less steady.

Arndt: 24:30

And you push this pipe down through a central hole in your platform. Now what he's doing, he has a little compressor and he also blows some air to the bottom of this. While he's pushing down, he lubricates the process by pushing air that helps the tube to slide into the mud. And now they were able to push down more than 60 meters into the mud, which is unheard of. Sometimes they encounter a sand layer.

Arndt: 25:04

Sand is hard to push through. Mhmm. It works sometimes. I'm really proud of that guy. So it's a platform, long pipes, and a lot of ingenuity.

Shelby: 25:15

And and how long is this process for for you to go through 60 meters of of sediment that's built on the bottom of the lake. How long does that take?

Arndt: 25:22

He has a whole team of graduate students and coworkers there. And he even got Peter Sauer down there last time. So Peter was in Vietnam. Peter is my colleague at IU. So he has good help.

Arndt: 25:35

And they do one coring in one day. They start probably before sunrise. And then they work their butt off. And by the time it gets dark, they have to have it done. Then the next day they try another one and so forth.

Arndt: 25:50

So, yeah, it's it's very labor intensive.

Shelby: 25:52

And so in one day, however deep they get, then they pull that

Arndt: 25:56

Yeah.

Shelby: 25:56

That sediment up for that day, and that's a core.

Arndt: 25:58

And the reason why you don't wanna leave it overnight, one time they had a heavy storm coming up at night or in the afternoon, but they were actually there, then the storm, and it blew the whole raft across the lake, and they would have lost their equipment. They lost some of it, actually. You don't want to risk that.

Shelby: 26:17

Yeah. Yeah. And then once this core comes up, what sorts of measurements are the team making on this?

Arndt: 26:23

Okay. They are getting these things up and then they disconnect segments and cap them on both ends and label them, of course, top and bottom in the numbers so don't get confused.

Shelby: 26:35

So that way you know sort of where you are, how deep in that sediment Yes.

Arndt: 26:41

Then they ship those cores to their lab in Hanoi. And the way they do this they have these long distance buses in Vietnam. And they are very cheap, actually, and they drive like crazy. And if you tell the bus in advance, I have half a ton of sediment cores. Can you take it?

Arndt: 26:58

That bus actually will do it. Unbelievable. At one time, we were there in the town near the lake, we had to transport equipment to the lake. We only had a small minibus. So what our guy did, he waited for a for a commercial truck to just pass by, flagged the drop down for the truck and said, hey.

Arndt: 27:20

I pay you. Can you can you carry this equipment to the lake? He said, sure. And he just drove to the lake. He got a hundred dollars or something.

Arndt: 27:30

It would be impossible in this country. Liability question. Here, we have all kinds of red tape in Vietnam. No. Money does everything.

Arndt: 27:40

Yeah. Yeah. Money and connections. You can get anything done.

Shelby: 27:44

And and once they have the sediment core back at their lab

Arndt: 27:48

Mhmm.

Shelby: 27:49

They're, I'm assuming, taking portions of it Yes. And and sending it to different people or using it for different types of analysis

Arndt: 27:54

They a device to slice this long segment on two sides, and then they cut it in half and flip it over. Now you have two half cores. And we have one professor here at IU who is a microbiologist, Jay Lenin. And he's collaborating with them now to look at microbes in sediment layers that are up to 60,000 years old. That's like back several, a couple of ice ages.

Arndt: 28:25

Yeah. Incredible. So, yeah. So Jay just told them how to take samples in an uncontaminated way, in a clean way, and ship them to IU when they do the next coring.

Shelby: 28:38

Right. Yeah. It's like a very cool project, it's very interdisciplinary and collaborative, there's so many bits of information you can gather just from this core of a lake that stretches back in time, so you can also see changes over different years or seasons or things like that.

Arndt: 28:55

And there are very few records from near equatorial regions. Most sediment cores from lakes or even tree ring records and so forth are further north or further south where you have seasons. But near the Equator, don't have strong seasonality, so tree rings don't exist mostly. Tree grows continuously a whole year. So that kind of is hard to read.

Arndt: 29:21

But sediments of that length are hard to find. So in Vietnam, they really do exciting, groundbreaking work.

Shelby: 29:29

Yeah. So in addition to these research projects that you're involved in, you also run a standards program here through IU. And so for listeners, I say this term standards, they probably have no idea what that means. So can you first tell us a little bit about what we as geochemists mean when we say aren't as making standard reference materials?

Arndt: 29:51

Okay. So a lot of scientists use machines to measure stuff. But when you get the data from the machine, it's just numbers. And if another person in a somewhere else measures the same stuff, has a different machine, he gets different numbers maybe. So how do we make sure we talk about compatible numbers?

Arndt: 30:11

For that, you need a standard. You have to have a substance that anybody can measure anywhere in the world with any machine. And we know the result already. We know the real value. So they can then adjust their machine to get their measurements right.

Arndt: 30:29

And in my case, when I came to IU some thirty two years ago, I was very lucky that in the lab where I was working, they developed a new methodology to measure organic chemicals. And they needed new standards that didn't exist. And I had measured isotopes, which is a different thing. I don't want to compare that. So I had measured isotopes as a postdoc.

Arndt: 30:56

I had a track record. So I was asked, can you make standards for us for this new method? And I started doing that and it worked really well and I was asked by other people, can you give me some of your standards? Sure. So there was really a need and I saw the opportunity to make this like a little side business for you.

Arndt: 31:18

So over the next thirty two years, I developed more and more standards and I was also collaborating with international organizations, the IAEA and Vienna and the USGS and God knows who, lots of collaborators. So we make these ring tests where five or six or seven laboratories, we all measure the same pure substance. And then we compare our results and we get a best estimate of what the real value is with a very high confidence. And that is a new standard which is distributed worldwide. And it makes good money for IU and has been doing that for more than twenty years now.

Shelby: 32:03

And these standards are really critical to the geochemistry community too. So I use standards all the time. Everybody in the field does. And just like you mentioned, we need some way for labs in different areas and different parts of different countries, even different tops of different manufacturers of the same instrument to be able to communicate in sort of the same language. And there can be these really small variations from day to day, from place to place, depending on temperature or humidity. you name it because these instruments are really sensitive. And so having some way to standardize what we're comparing to is really, really critical. And so I think you do this great service for the community. Another thing that I think is important about standards is we try to have standards that are comparable to the things that we're measuring. So if we're going to measure a plant, we don't want a standard that's water.

Shelby: 32:57

We'd really like to have a standard that's another plant. That way they're sort of made up of the same sorts of things. And so you've now developed this really large catalog of these standard reference materials that people globally use. I think that you're pretty known globally across the geochemistry community.

Arndt: 33:17

Yeah. And because our prices are not too high, others are actually discouraged to make their own standards. Yeah.

Shelby: 33:23

So whenever you're going through making these standards, I know that it's going to be different for different types of standards, but can you give us sort of a broad overview of what that process is like? How do you make something that you're going to know with a high degree of confidence what the composition is and that you make enough of it that you can distribute it to people.

Arndt: 33:41

Yeah, we just make another 10 new standards and they are volatile organic aroma substances. For example, benzaldehyde is the stuff that almonds smell like, okay? Fresh almonds before roasting them. And other

Shelby: 33:58

Like almonds the nuts.

Arndt: 34:00

Almond nuts. Yeah, yeah,

Shelby: 34:01

Right. Okay.

Arndt: 34:02

So, when I start with that, I buy the purest substance I can commercially obtain. And they are quite expensive sometimes. So that is an initial investment. It costs thousands of dollars to buy the initial stock of very pure material and in this case, this stuff is volatile, so it even oxidizes like in this case the almond aroma would oxidize pretty fast and make benzoic acid. Anyway, so once I get this bottle, I immediately after opening, I transfer aliquots into other glass containers, suck the air out or replace the air with argon, which is a noble gas, and flame seal them shut.

Shelby: 34:46

And by aliquot, you just mean you're taking some portion of this larger amounts.

Arndt: 34:50

Okay. So now from the big bottle, I have a lot of small amounts, but they're all perfectly sealed in glass. There's no more exchange, no more loss of substance, no oxidation. And those go to the refrigerator even. So now I have time, right?

Arndt: 35:05

And I take one of these ampoules or so and I measured in my lab. Another ampoule is sent to another lab, actually I have five or six labs, they all get these little ampulles and they measure it in their lab. And then we compare the values and get the best common estimate of what should be the best value. Some labs do a bad job, the value goes all over the place, but then they do it again maybe and, oh, now it is a good agreement and they know what they did wrong in the first place. Anyway, so when we come to the final agreement, we write a paper about this.

Arndt: 35:41

We introduce this as a new reference material. And then I use one of the bigger flasks and I seal smaller aliquots into small ampoules under argon and store those in the refrigerator for global distribution for years to come. And if my initial stock of small ampoules is exhausted, well, I open another big one and

Shelby: 36:04

Do the same thing.

Arndt: 36:04

And separate the stuff. That is my strategy and it has worked for decades now. And the stockpile, I only keep part at IU. Most of it goes to the USGS in Virginia, and they have more refrigeration available there. So they keep most of it.

Arndt: 36:22

And it's also they they call this a USGS standard. So the stuff that this ring test is now producing will be a USGS standard with a certificate issued by the USGS. And both IU and the USGS have the authority to sell the stuff and we agree on a price, so we have no competition.

Shelby: 36:41

And with these sorts of standards, you mentioned this sort of almond standard that's this aromatic standard, what sort of the breadth of types of standards that you have made? So these aromatic standards, what other sorts of things have you made standards

Arndt: 36:54

We have food stuff like flowers, honey even, because lots of counterfeit honey in the world. So labs want to test, is this honey authentic or is it like counterfeit? So, yeah, that's we have honey standards. We have oil standards, oil components, would say, components, pure hydrocarbons, liquid, waxy or even gas. We have a methane standard, Methane I mentioned earlier, we have a standard for that.

Arndt: 37:21

Water standards, the USGS has that. I help them sometimes. We have a lot of different standards from water to rock to gas, you name it.

Shelby: 37:32

With this sort of laundry list of standards, this might be asking people do they have a favorite child, do you have a favorite standard that you've worked on that has stood out to you for some reason?

Arndt: 37:43

I think it's caffeine. Yeah. Caffeine standards. That was a special one because caffeine well, you know, it's in coffee. Right?

Arndt: 37:53

But you can buy it very pure. But we had to start with a lot. And I had a hard time getting that. So until I went to Bremen in Germany and they had this humongous factory like outfit where before they roast the coffee, they decaffeinated. And they gave me a tour and they sold me their caffeine product.

Arndt: 38:17

In fact, their caffeine is sold to Coca Cola and Pepsi and all these energy drinks.

Shelby: 38:22

So it's like a waste product for them.

Arndt: 38:24

Well, it's expensive to buy it from them. It's it's a product. They they buy the decaf coffee and the caffeine separately.

Shelby: 38:30

Right. Right.

Arndt: 38:31

And nothing goes to waste. Anyway, so they gave me this caffeine and then we developed this into a variety of standards. Yeah. I like that. It it was fun and I always think I have lots of caffeine leftovers, by the way.

Arndt: 38:46

I have, like, kilograms in my lab. And and one could actually make caffeine cookies. I had this idea. You could bake cookies with a certain caffeine content and sell these during exam time for the students.

Shelby: 38:58

Yeah. Energy cookies. Exactly.

Arndt: 38:59

The only danger is you can't give it to kids. Yeah. So that's why I don't do it. Yeah. Yeah.

Arndt: 39:05

But I think that is you could guarantee it's only for students, that would be a good hit.

Shelby: 39:10

Yeah, especially during finals week. That would be very popular. Sp you have done lots of these different components in geochemistry and so if someone thinks they're interested in that field, what advice would you have for them? Or what would be something that you might tell yourself, your younger self, when you're sort of thinking about pursuing this as a field?

Arndt: 39:32

I'm happy I did what I did. I have no regrets. It's a wonderful profession. I love my job. And whatever I would want to advise my grandkids, for example, do something that you can be proud of that helps the world in the long run.

Arndt: 39:50

And what cannot be computerized, what cannot be done by robots in the future, do something that takes a human brain to accomplish. So don't go into accounting or code writing or secretarial jobs or even financial industry. I think those are dead end jobs that will be automated. But environmental research or basic science, lab work, STEM research, that cannot be done by computers or robots. At least, I don't think it will ever be possible.

Arndt: 40:34

So, if people have a chance to go into that field and if they like it, that's a safe job to have. And my son does that now. So my son is an environmental engineer and I'm proud of that.

Shelby: 40:44

Yeah. Yeah, when I think what you said about doing something that you feel like has a positive impact is important too and something that your work very much has. Just from these standards alone, but then also the things you mentioned before about sort of working in these collaborative projects with various people, various faculty members at different levels and sort of building that community I think is also important for what we do. So Arndt that brings us to our last segment of the show which is the yes please segment where we each get a minute to talk passionately about something we're excited by in the moment. I always give folks the option to either go first or go second.

Shelby: 41:20

So I'll leave that up to you.

Arndt: 41:22

Do you want to go first? I can go first.

Shelby: 41:24

Okay. Let me get my timer ready.

Arndt: 41:25

Sure. Okay.

Shelby: 41:26

And I'll give you sort of a notification at thirty, fifteen, and five seconds. Yeah. So if you're ready

Arndt: 41:33

I'm ready.

Shelby: 41:33

This is Arndt Schimmelmann's. Yes, please.

Arndt: 41:36

In the sixties and seventies, there was a major campaign by the tobacco industry to refute scientific consensus that tobacco and nicotine is harmful to your health. The industry spent millions discrediting real good science, buying scientists to give false testimony, giving basically bad advice to the public just to make a buck, just to keep their profits alive.

Shelby: 42:04

30.

Arndt: 42:05

Today, we have the same thing with the fossil fuel industry. They buy scientists. They give fake websites. They provide misleading information that what we're doing to the world is not human caused. Global change is not caused by people.

Shelby: 42:23

15.

Arndt: 42:23

That is BS. Don't fall for this nonsense. Trust scientists. They are always bad apples in every profession. Some scientists are bad, but the overwhelming majority agrees that we are the problem.

Shelby: 42:36

That was perfect timing, and I feel like such a timely timely message with the way that that science is viewed, you know, depending on where you are globally. It's really important to recognize that, yes, there will always be, you know, voices that that go against sort of the consensus, but here the science is very sound and is overwhelming, And those are the things that I hope people people hear and focus on whenever we talk about some of these really important issues like climate change. Alright. I'll be up next. This will be my yes, please segment.

Shelby: 43:11

So yes, please. I wanna give a shout out to my favorite band, one of my favorite bands, Haim, h a I m. It's a sister group who have, I don't know, been releasing music for well over the last decade. They have three albums that are out with a fourth album that's just about to come out. I don't actually know the official release date.

Shelby: 43:30

It might come out sometime close to when this episode airs. But leading up to that, they have released two singles so far, which have been great. I love hearing them. I love seeing them. I've seen them in person two or three times now.

Shelby: 43:44

They put on a great show, and so I want to sort of give a shout out to them and also sort of recognize upcoming music drops. You know, I think one of our our previous episodes has talked about things that people really in enjoy in sort of pop culture. Music is one of those for me, and so I think we should give support to new album releases as much as we can. Arndt, do you have any any favorite bands that you would, you know, sort of be a big proponent of whenever they have a new album releasing?

Arndt: 44:15

No. I like the music from at the time when I was a teenager. Yeah. And the '20 and I was in my twenties.

Shelby: 44:21

Genre of music?

Arndt: 44:26

Very wide. I don't really have a narrow genre. So I listened to my old tapes actually. I I digitized all of my old tapes and when I'm in my lab, I just listened to those recordings.

Shelby: 44:36

Yeah. I talked on a previous episode about how I've listened recently to old CDs that I had that I had made and and like that's really nostalgic. And so I think it's a good idea to digitize some of those things and to have copies of those. Yeah. Alright, Arndt.

Shelby: 44:51

Thank you so much for coming on. This has been a really great conversation, and and we're happy to have had you.

Arndt: 44:57

Thank you so much.

Shelby: 44:58

And for listeners, we'll see you next week for what will be our season finale with a special surprise. So I hope that you all join in. Earth on the rocks is produced by Cari Metz with artwork provided by Connor Leimgruber, with technical recording managed by Kate Crum and Betsy Leija. Funding for this podcast was provided by the National Science Foundation grant EAR dash two four two two eight two four.