Piet Martens

Behrman:

All right, it is March 2nd of 2020. My name is Joanna Behrman, and I’m here in Piet Martens’s office in Atlanta, Georgia to do an oral history about his work in heliophysics, and his life in general. So perhaps let’s go chronologically and start with your childhood. Could you tell me a bit about your life growing up?

Martens:

Oh, my god. [laugh]

Behrman:

[laugh]

Martens:

I was born in a medium-sized town in the Netherlands called Den Bosch in December of 1953. Went to elementary school and high school in a small town next to it, a Dutch gymnasium for high school. We moved to an even smaller town outside [laugh] Den Bosch when I was 6 years old. My parents divorced when I was 12 or so, but I spent a lot of time with my grandparents, which was very positive.

I went to Utrecht to study when I finished gymnasium. Studied astronomy, and spent a lot of time doing other stuff [laugh] the first couple of years. I was a head of the student organization called Unitas, and I partied a lot, and then, at some point, [laugh] I decided to become serious. So I never took—went to any classes as an undergrad. Just read the book and took the test and passed, not with great grades, but passed. And then—

Behrman:

Do you—

Martens:

Say again?

Behrman:

Do you have any siblings?

Martens:

Yes, OK, yeah, I have a younger brother, and two younger sisters. And I have an older half-sister that I only found out [laugh] about 10 years ago. So, yeah, I was the only one in my family, the first and the only to get a university degree. My father and my grandfather were business people, and so that set me quite apart [laugh] from the rest of the family.

Behrman:

Did you become interested in science when you were a child?

Martens:

I was interested—I was totally fascinated by the race to the moon. I wanted to become an astronaut [laugh] and go to the United States and work in the space project, which I’ve done, actually. [laugh] I didn’t become an astronaut but so—and that actually happened. [laugh] I was really good at math and physics in high school, so I wanted to study something like that, and astronomy was the logical thing to do.

The university in Utrecht, the astronomy department there had connections with NASA. They were—they ran—built and operated instruments on the Solar Maximum Mission in the ‘80s. So there was that link, which I found interesting. So after my undergrad, I got serious about studying, and studied in—I finished in fairly record time, my PhD, with cum laude even, which they have in Holland. They don’t do that here. And got an offer to come to the United States to be a postdoc at NASA Goddard.

Behrman:

Were there professors in your time at Utrecht who particularly influenced you?

Martens:

Oh, yeah, definitely. So there’s Kees de Jager who’s world-famous. He was PI on one of the instruments on the Solar Maximum Mission. He was the one most related to space research. And there was Kees Zwaan who was a very well-known solar ground-based observer who also spent quite a bit of time in the U.S. at Sac Peak, Sacramento Peak.

And there was Henk van Bueren who was my thesis adviser. But he became—like two months after I started [laugh], he became the head of the, well, what you call the Dutch Academy of Sciences, the equivalent of our Academy of Sciences. So I didn’t see him very often, but he gave me good advice, and was very helpful. But I didn’t do research with him.

Behrman:

But you took classes from Kees de Jager and Kees Zwaan?

Martens:

Yep, and Max Kuperus, who did plasma physics and MHD, which what interested me most. Tony Hearn was a British professor there, stellar winds, and Kees de Jager, stellar evolution, so. And then I took a lot of theoretical physics and mathematical physics, which Utrecht has a very good institute in that. There’s a Nobel Prize winner even now, which—so things like general relativity and electromagnetism and non-linear waves and all that stuff.

Behrman:

Yeah, Gerard ‘t Hooft was the—

Martens:

Yeah, yeah.

Behrman:

Did you work at all with him or—?

Martens:

No, he was still very young. [laugh]

Behrman:

Yeah. [laugh]

Martens:

No, I took classes in mathematical physics with Niek van Kampen who wrote several books, and was—he was a strange teacher [laugh] but his courses were really good. He would always look out the window, never give you eye contact [laugh] and look out the window while he was writing on the blackboard, and doing his things. But his syllabi were really good, so it was—actually, I really enjoyed taking those classes.

Behrman:

So it sounds like you didn’t get involved much in research in undergraduate school—

Martens:

Right.

Behrman:

—but only when you got to graduate school.

Martens:

That’s correct. Although, yeah, I did write a paper as an undergraduate. [laugh]

Behrman:

[laugh]

Martens:

Because I just happened to find something wrong in a paper of one of my professors. And so I wrote a paper on it, correcting it [laugh] with his help, actually. He was very generous about it. [laugh]

Behrman:

What was that on?

Martens:

It was with Tony Hearn, and it was on the amplification of sound waves in stellar wind driven by the radiative field of the stars. So mostly hot, young type stars, O and B. And he just made a mistake in his math. So he found that those waves will be damped but they were actually amplified [laugh] and it is an interesting physical mechanism.

So I described a physical mechanism, and then showed how the equation should be solved correctly. It was a third order quadratic. No. What’s the next thing? Cubic equation [laugh], and which are directly analytical solutions for those.

Behrman:

When did you first hear about the field of heliophysics? Because it sounds like you were already thinking about stars and their mechanisms and effects on the—

Martens:

Right. Well, Utrecht had a strong focus on solar physics among Dutch universities. Leiden was more focused on extragalactic stuff. Utrecht was doing solar, so they ran solar—they helped run solar observatories in the Canaries, and built this instrument on the Solar Maximum Mission. So it was kind of a logical thing to get into.

And I found the sun interesting because you can actually see something. [laugh] If you’re looking at a star, it’s a point, right. [laugh] You get a spectrum, and there’s very little to be known. And since I’m interested in plasma physics, I’d like to look at things you can see, like coronal mass ejections and loops and—yeah.

Behrman:

Right. How did you come by your dissertation topic?

Martens:

It was a suggestion from my thesis adviser. It was non-linear—applications of non-linear math that’s in astrophysics, so very general. And mine happened to be mostly on the sun.

Behrman:

When did you think you might become a physicist or an astrophysicist as a career?

Martens:

In high school.

Behrman:

In high school? [laugh]

Martens:

Yeah. [laugh]

Behrman:

So your interest in NASA and in the moon and everything was already getting you thinking about a scientific career?

Martens:

Absolutely, yeah.

Behrman:

Were your parents or, I guess, your grandparents encouraging you in this?

Martens:

Yeah, definitely. [laugh] Yeah, definitely my grandfather, because he was a very intelligent man, but he—well, he was born in 1900, so he grew up during World War I. And even in Holland, there wasn’t any public education. I mean, it wasn’t free to go to universities as it is now. So he never could do that, and became a businessman and a millionaire. So he always recommended to get your degrees and do that as something he couldn’t do. [laugh]

Behrman:

So perhaps then moving on to your work after graduate school.

Martens:

Right.

Behrman:

You start off with a postdoc at NASA actually. Correct?

Martens:

NASA Goddard, yeah.

Behrman:

How did you find out about the postdoc?

Martens:

One of my teachers, Max Kuperus, worked very closely with Jim Ionson, who was a civil servant at NASA at Goddard then, and who was working on coronal loops. And he managed [laugh] to be very controversial, but he was a very fierce debater, which was kind of fun. So through Max.I was introduced when Jim visited Utrecht, and he was happy to take me on as a postdoc.

Behrman:

When did you find out about this—during your graduate school?

Martens:

Yeah, so like in the last half-year or so, yeah.

Behrman:

OK. What were you thinking when it came to moving away from the Netherlands and to the United States?

Martens:

Oh, it’s really—it’s something I really wanted to do. It was very exciting. But it did come at a high personal cost. I was married, and my wife eventually could not deal with coming here. So we divorced after we’d been here for a couple of months. We had no children.

Behrman:

What surprised you when you came to the United States?

Martens:

How conservative it was [laugh] compared to Holland, I think. And this was the beginning of the Reagan era when I came here, and I could not believe how these people all could think that Ronald Reagan was such a great [laugh] president or a great person at all. And one of the first months here was the 1984 election, and I just couldn’t believe that Reagan would win with such a—in such a landslide.

Behrman:

Right.

Martens:

Yeah, anyway, that has never changed [laugh], that feeling now.

Behrman:

[laugh]

Martens:

And the thing I like is the U.S., seen from Holland, is almost like a Mediterranean country. First of all, it’s warm [laugh], at least if you live in Washington, D.C. And, you know, life is for a good part outdoors, unlike Holland. And the other thing I liked, really, there’s a very high level of energy with people here, more so than in Europe.

People in Europe are less willing to take risks or relocate. Definitely not relocate to another country. They spend much more time with family, which is a good thing, but that limits them too.

Behrman:

Right. So did you find the work culture different along these lines?

Martens:

Yeah. It was much—there was much more accountability [laugh] basically. You know, you meet with your advisers weekly or so. And in Utrecht, you could just do want you want, which worked for me but it doesn’t work for everybody. [laugh]

Behrman:

Right. So what did you work on when you were at NASA Goddard?

Martens:

That’s a good question. [laugh] Oh, I was asked to write an invited review, which is basically a repeat of my thesis on non-linear methods in solar physics. And then I started working on solar flares because I thought solar flares were interesting, because nobody figured out how to predict them. But they really pose a risk to astronauts, that was even known then, and to infrastructure, which we didn’t really know in the ‘80s. But I thought that was an interesting subject because it had some practical applications.

Behrman:

So who did you work with at NASA Goddard? Jim Ionson and—?

Martens:

Well, Jim Ionson left after two months. That’s kind of the story [laugh] of my life. So I basically worked on my own. I shared a room with Joe Davila. We definitely talked about science. And Gordon Holman was there. So there was a small solar group there that I, you know, talked science with. [laugh]

Behrman:

Right. [laugh]

Martens:

And a good friend of mine, Paul Kuin, who also got a PhD in Utrecht a couple of months before me, I think, yeah, he had a postdoc in Oxford, England first, and then also came to Goddard on the same kind of fellowship. And we worked together a lot.

Behrman:

Was it when you were living in Washington, D.C. that you met your wife, Kathleen?

Martens:

Yes [laugh], a couple of years later, and she was a teacher. She teaches in—or was teaching in inner city D.C. And her parents are diplomats. Her father was a diplomat. So she’d lived in Europe and in Africa and in the United States, which was—we had a lot in common [laugh] we found in that respect. And, yeah, so we [laugh] met, and her family liked me [laugh] and so—and we got married after—a couple of years after my divorce.

Behrman:

How did you come to live and work in Cambridge?

Martens:

Mass.?

Behrman:

Yes, Cambridge, Massachusetts. [laugh]

Martens:

Oh [laugh], well, my fellowship in Utrecht—at Goddard ended, so I had to look for another job. And I was actually—I don’t know who contacted whom. But Leon Golub, who was in charge of a group there, he knew about me, and invited me to apply. And I applied, and got the job [laugh], which was basic—well, it was a staff position but it was soft money, so, which is pretty hard. [laugh]

Behrman:

Were you able to work on research, or was it more of a bureaucratic staff position?

Martens:

Oh, no, staff, I mean, a research scientist.

Behrman:

Ah, OK.

Martens:

Yeah, I wasn’t a postdoc anymore, yeah. No, it was research, pure research, yeah, in that group.

Behrman:

Could you tell me a little bit about your research projects while you were there?

Martens:

What did I do there? [laugh] Well, I continued working on flares, and particle acceleration in flares. Yeah, I wrote this paper on proton acceleration in solar flares that still gets cited a lot, still. That was in ‘88. And then in ‘89, I finished the paper with Paul Kuin, which got—oh, which gets lots of citations, again, on solar flare eruptions.

And then at CFA, I had Aad van Ballegooijen, who’s also Dutch, and who also graduated like two months, you know, before or after me [laugh] I forget. And he also had the same position as I had there at Center for Astrophysics, and we worked together, and wrote this paper on the formation of filaments, formation and eruption of filaments, which gets cited a lot still. And I think that it’s basically the right model for understanding the formation and prominences of filaments.

Behrman:

Could you describe the model a little bit to me?

Martens:

Well [laugh]—

Behrman:

[laugh]

Martens:

—it has to do with motions on the surface of the sun. And in this case, a neutral line or a polarity inversion line—in the photosphere there is a line where the magnetic field changes sign. The line of sight component of the magnetic field changes sign. And in between those is a line with zero magnetic field. If it goes from plus to minus, it has to go through zero, right. And on those lines, filaments always sort of hang in the corona above those lines.

And the model that we made to explain that is that there’s converging motions towards that polarity inversion line that drive the field lines together. They reconnect at the point where they come together. And that sort of stitches them together into a flux loop. And this was really based on observations of Sara Martin, who is a famous—probably the best filament observer [laugh] in the world. She’s still active. So we both read those papers and said, “Hey, I’ve figured this one out.” [laugh]

Behrman:

[laugh]

Martens:

And then we decided to work together on it, yeah.

Behrman:

So you independently had the idea, and you said, well…

Martens:

Yes, we both had the idea. We were talking over coffee. And we decided, well, rather than compete, why don’t we write [laugh] a paper together?

Behrman:

[laugh] That’s very nice.

Martens:

Yeah.

Behrman:

While you were in Cambridge, Massachusetts, you also attended the Harvard University Extension School.

Martens:

Oh, that’s right, yeah. You’ve seen my CV. [laugh]

Behrman:

[laugh] Why did you decide to go to the Extension School?

Martens:

I’m interested in management, or in setting up my own business. And it was free. [laugh] and so I thought, oh, Harvard’s not the worst school [laugh] so I could learn some things here.

Behrman:

[laugh]

Martens:

And we didn’t have kids yet. My wife was going to school there too. And so why not? [laugh]

Behrman:

Is this something that’s happened at other times in your life, taking outside classes and doing these sorts of things?

Martens:

I haven’t had much opportunity [laugh] for that since. When I was in Utrecht, when I was at the university, I spent a summer in Spain learning Spanish in that language course, which was very useful. So before that, I did that. [laugh] Afterwards, got too busy. [laugh]

Behrman:

Right, of course. [laugh]

Martens:

Yeah. [laugh]

Behrman:

And after Cambridge, is that when you immediately moved to Montana to work there?

Martens:

What did I do after Cambridge? No, I got a—and this is 1990. I got a job offer by Lockheed Martin on staff at Stanford campus, and they were running the Soft X-ray Telescope on the Yohkoh Mission.

Behrman:

Ah, right.

Martens:

Right. And that really interested me. So both Loren Acton, who’s the PI on the Soft X-ray Telescope, and Alan Title, who was the PI on what was then called—I forget what’s—soup, this thing, I think, flew on the shuttle. And they really wanted me to come there, so we moved to Palo Alto. And I wanted to be involved with real space missions, so that helped.

So while I was there, I spent quite a bit of time in Japan—that was part of the deal—to operate a Yohkoh SXT. And my wife was teaching in Palo Alto. She got a degree from Lesley College in Cambridge. So that was really interesting. [laugh] And I might’ve stayed there forever.

I enjoyed the work. But my wife hated it [laugh]; she hated California [laugh] and she hated sort of the techie atmosphere that you have there. And I can see that now [laugh] very clearly. You know, if you’ve seen the series, what is it? Silicon Valley. [laugh]

Behrman:

[laugh] Yes, yes.

Martens:

That’s what she hated. [laugh] So a job came up with European Space Agency to do something similar for the SoHO mission to guide operations. And my wife would love to live in Europe again. I didn’t, [laugh] but I said, “OK, I’ll apply for the job.” And actually what they asked me, you come to Holland, but then when the mission is on, you have to go back to Washington, D.C., because it’s operated from NASA Goddard.

But she loves Washington, and so do I. So I got the job. We moved to Holland for a year and a half or so. And then operation started, so we had to move back to D.C. That was for the European Space Agency.

Behrman:

You’ve worked in a number of different types of environments, business environments—

Martens:

Right, yeah, well, it’s all science. [laugh]

Behrman:

—scientific organizations [laugh] and universities as well. What have you found you’ve liked or disliked about each of these different sorts of places?

Martens:

Well, I think I did not like working for the European Space Agency. [laugh]

Behrman:

[laugh]

Martens:

I mean, the work was great. SOHO is a fantastic mission. But it was a very hierarchical bureaucratic organization. And basically they work a quota. So you have different countries that put in so much money, and they have to get jobs at higher level at pro-rated with their—the money they put in.

So I was pretty—I had no chance of any advancement as a Dutch person [laugh] because the Dutch are already heavily overrepresented. [laugh] And so it was they were looking for German people and French people and so on. I couldn’t deal with that. [laugh]

Behrman:

Right.

Martens:

But the SOHO was a great mission. We really enjoyed it, and I had good people to work with, and interesting people. You know, there were teams from England and from France, and they were all spending time at Goddard, some permanent, and so it was a very international thing. And I was chairing most of the meetings. And I guess that was possible because I knew the Americans quite well [laugh] and I could get along with the Europeans too. [laugh]

So that worked. I enjoyed that aspect of the work. But then I realized I was never going to go anywhere in that organization. So I left [laugh] after five years. Or was it—yeah. When did I go there? ‘93, I left ‘98, yeah.

Behrman:

So how did you make your next transition? [laugh]

Martens:

Well [laugh], the PI of Yohkoh SXT was Loren Acton. I’m sure you’ve heard [laugh] about him.

Behrman:

[laugh]

Martens:

I got along great with him in Palo Alto, and he retired from Lockheed. They were shrinking, and so they gave good opportunities to get out, and he’d been there for more than 20 years. And he went back to Montana, where he’s from, and started the solar physics group in Bozeman, Montana.

And I happened to be—there was a conference there, and I went there, and I just loved the place [laugh]. I love Montana. And so I sent him an email. “Loren, do you have a job?” And he answered with a yes. [laugh]

Behrman:

[laugh]

Martens:

So I got hired there as associate professor but a research professor, so on soft money still. I had left two permanent jobs [laugh] in the meantime to go back to soft money [laugh] but what the hell, you only live once.

Behrman:

Right. [laugh]

Martens:

[laugh] So there is—our oldest daughter had been born already, and my son too. My daughter’s from ‘91, Thomas from ‘96, we moved there in ‘98. So our kids grew up there basically. And my wife was very reluctant because she said, “I’m a big city girl.” [laugh] “I like it here but I like the east coast.”

But once we were there, she actually loved it. And she did [laugh] sacrifice to go there, but, once she was there, she made good friends, and got a job and everything. So that’s where we raised our kids, and that’s the place I really love. And we still have a house there. Probably we’ll retire there.

So I took up skiing. Well, I had skied in Europe. But we used to go skiing with my—oh, our five kids every weekend. [laugh] And it was a like military operation: left glove, right glove [laugh], ski boot left [laugh]. Because, otherwise, then when you get there, “Oh, I forgot my hat.” [laugh] So we did that.

In the summer, it’s just a lot of hiking. And summer’s absolutely beautiful there. It never gets too warm but it’s dry and sunny. So, yeah, that’s where we raised our kids. I really enjoyed that. And working with Loren, who I get along with very well, I consider him as a mentor; just like Leon Golub.

Behrman:

You have worked on a number of different projects while you were at Montana.

Martens:

Oh, lots of stuff, yeah. [laugh]

Behrman:

[laugh] Yeah. Perhaps we could start maybe with the Solar Dynamic Observatory.

Martens:

Oh, yeah. So that was a mission out of Lockheed again, or the proposal came out of Lockheed. They asked me to be part of it to help to write the proposal, which I did, served as Co-I on SDO. And prepped for it. And the research I did was again mostly on flares, loops, and things in the corona, basically. [laugh] But I wasn’t done yet.

At some point in 2007 or so, my wife said, “I want to [laugh] I want to move again.” So she wanted to go back to the east coast. So I contacted Leon Golub, whom I’d worked with before at the Center for Astrophysics, and he said, “Yeah, we’ll be happy to have you.” [laugh]

Behrman:

[laugh]

Martens:

So we moved to Boston for two years.

Behrman:

Ah, right. [laugh]

Martens:

Then we realized that even with two jobs—we had five kids by then. We adopted three more kids after the first two who are biological. We just couldn’t afford to live there [laugh] with five children. And nobody else that I know in the Boston area has five children. [laugh] And the houses aren’t even built for that. [laugh]

Behrman:

[laugh] Right.

Martens:

So, anyway, after two years, we went back, my wife hated her job in Boston. And so I asked Loren, “Can I come back?” He said, “Yep.” [laugh] And so we went back to Montana—we hadn’t sold our house yet, thank god. [laugh]

Behrman:

[laugh] Yeah.

Martens:

Because this was in the middle of the financial crisis, so we couldn’t sell our house. [laugh]

Behrman:

Right, 2008, yeah. [laugh]

Martens:

Which was a disaster, until we go back. [laugh] So, and then we—that’s how after that, I became involved with the SDO.

Behrman:

Ah, I see.

Martens:

Yeah. I did a little bit more work for Yohkoh as well until it died. No, it died earlier. When was it? No, 2010 or so. I forget. [laugh] Anyway, so, yeah, the plan was to stay there basically.

But then I found it getting harder to bring in enough money to support myself and my students and other people who worked for me. And it was all soft money full-time. And Montana State made it quite clear: “If you’re a research professor, we’re not going to offer you a permanent position.” [laugh] Although I definitely would qualify for a new one because positions became available.

So then I decided, OK, I’ll go apply somewhere else. If they give me an offer, I can turn around [laugh] and show them that. And I applied to Georgia State here. And to my great surprise, I did get an offer. [laugh]

And I decided I really liked this university actually, because it’s very diverse. My family’s diverse. I have adopted two African-American children, and one girl from Russia. And my wife was born in Africa. She’s white but—and she went back to teach in Africa later on, just before we married. So we definitely have a multicultural affinity [laugh] and background.

So I liked this job. I did turn around, because my wife didn’t want to move, and asked them for a counter-offer. But they didn’t give one. So the VP for research was really upset that they didn’t. But so be it. It actually turned out great.

Except my wife didn’t want to move. [laugh] So she stayed in Bozeman, and helped our younger—youngest kids get through high school there. And now she’s moved here, just a couple of months ago. [laugh] But I used to—so I’d go home for Christmas for a month, and in the summer for four months, because I don’t have to teach, and then spend the rest of the time here.

And my son lived with me for a year first, and then my oldest daughter lived with me for a year and a half until we drove each other crazy. [laugh] And she’s married now, and she lives in—and she bought a house in Atlanta. And then in last September, my youngest daughter came with me, and she’s here now in school.

Behrman:

[laugh] This might then be a good segue to talk briefly about something you mentioned in a TEDx talk you gave five years ago, which was that it’s—you said it’s your experiences outside science which have really shaped you, including your experiences with interracial adoption.

Martens:

Right.

Behrman:

Would you like to talk about that for a bit?

Martens:

Oh, yeah, absolutely. So my wife—we lost a baby, and the doctor told us—or the—what is it—the gene doctor—I forget [laugh] what the term is—that we’re too similar genetically [laugh], which is strange coming from different continents. [laugh] We shouldn’t have any more babies. So—and my wife definitely wanted more children, and me too.

So we decided to adopt. And then we find out if you want to adopt a healthy white baby, there’s a seven-year waiting list. So what do you want? She said—she goes, “Are you open to interracial adoption?” [laugh] “Yeah, of course.” [laugh] I grew up in the ‘60s. [laugh]

So that’s what we did. And then there’s no waiting list. It’s like, “Come and pick them up,” basically. [laugh] And so we did an open adoption in Dallas—Dallas, Texas, Fort Worth. I forget the name of the agency now. So, yeah, we actually—with our first adoption, we met our—the mother, who was a high school—a woman in high school, had gotten pregnant.

She was a top student, top athlete, and so she gave us the baby, basically. She picked us, and that was how it works. So we had my wife—Kathleen was actually there when Gabriel was born. It was very sweet. We organized a sort of ceremony in the park where she handed over the baby.

So, yeah, Gabe is a really handsome and tall guy, and a great student [laugh], very pleasant, very easy to deal with. After that, we adopted Elizabeth, who’s also African-American. And she was born in Louisiana, and was in a foster home for a couple of months just right after birth. The mom picked us out but we never met her. And I went to pick her up in Dallas, Texas, again. So that was Ellie. [laugh]

So they were both babies basically when we got them. And it really doesn’t make any difference. Certainly for the husband [laugh], it doesn’t make much of a difference because I don’t carry the child. And then we adopted two girls from Russia, and that was—they were older, and that really was—we underestimated the troubles that came with adopting older children. They’re sisters. So we got them from an orphanage.

They’d spent a summer with us through a religious organization who organized adoptions from Russia. I don’t share their religion but the adoption was a good thing. They came for a summer, and then we went back in November to go pick them up. And that didn’t work out very well, definitely with the oldest one. So we had her re-adopted by another family, and the youngest one stayed with us. She now has found a partner, a woman, and they live in Washington State in a small town, and they seem to be happy. We’re in touch, don’t see each other very often, but definitely email and text and all that. So, I mean, she went through it. We got her when she was six, and we don’t know much about her early childhood, but I’m sure that left scars with her. So bonding—that’s a well-known issue with—when you adopt older children. Bonding is much harder than when you adopt a baby. So that’s been for us the issue. But I think she can lead a productive and healthy life.

Behrman:

In the TEDx talk, you said that your experiences with interracial adoption with having a multiracial family have taught you a lot about white privilege.

Martens:

Oh, absolutely. [laugh]

Behrman:

[laugh]

Martens:

Yeah, you realize—well, I have my son, Gabe, and I’m just scared for him because I know that, you know, young Black men get beaten up and sometimes even killed by the police—it’s not a rare phenomenon [laugh]—for nothing. And I know Gabe, he can have a pretty bad temper so [laugh] when he gets challenged. And, you know, if he’s in a stressful situation, he may also do something that gets him in trouble. He’s never done that.

And Gabe is very smart. He said, “I’m staying in Bozeman for the rest of my life.” [laugh] He’s one of the few Black people there, everybody knows him, and he’s very popular [laugh] in fact, so why should—and he has good friends. “So why should I come to Atlanta or go to a big city where I’m anonymous, basically?” So I can see that. And, besides, he loves skiing. [laugh] He’s really good at it.

Behrman:

Have your views on white privilege affected how you see your work in science?

Martens:

Yeah, that’s why I love working at Georgia State so much. Most of the students I teach are Black here, definitely the undergraduates. And for the first time now, I have my four graduate students, two of them are Black, which is quite unique in solar physics. And I just see that as an opportunity just to make a little bit of change [laugh] in the world.

Behrman:

How do you see yourself being able to be a mentor for students of color as an adviser?

Martens:

I’m not sure I’m so good at it [laugh], but I try, and they seem to like me [laugh]. So, for a good part, you have to do the same things. You have to support them, and try to teach them how to do research, and have discipline while doing it. That’s not different, right? [laugh]

Behrman:

Right.

Martens:

So those things I can definitely teach. And I can have more empathy for their background because my own children are African-American, some of them. [laugh]

Behrman:

Yeah. Do you think there’s more, and if so, maybe what do you think other scientists or scientific society should do to address white privilege in science?

Martens:

Oh, that’s a good question. [laugh] Well, first of all, be aware of it, and then try to be open-minded when people from a different cultural background come. This is what I really find strongly in astrophysics, in astronomy. That the students we get are typically white, middle-class, kind of nerdy [laugh], right? Hard-working, disciplined.

They love what they do, and they’re all sort of the same. And nothing against them. A fair amount is women now. So that at least [laugh] we’ve got there, and made some progress there. But they’re still—culturally, they’re very similar, all of them. And I don’t think all –most professors are not really used to students that are different.

So, say, returning students [laugh]. Before I had my first African-American student, my first student was basically a redneck from Alabama [laugh], who didn’t—you know, didn’t fit the stereotype either, and he’s done great in his life after getting his PhD. [laugh]

Another one also was an older student. He had worked in a mental hospital, and he said he didn’t want to be a nurse, [laugh] so he wanted to get a degree. And I told him, “It’s not that much different here [laugh] from a mental hospital,” but [laugh] he said he realized that.

So I think professors should try to be aware and tolerant of different cultural backgrounds. And it’s not just for minorities. It’s also for, say, blue-collar people, or rednecks [laugh], for that matter. Yeah. And we’re not just trained that way, and we don’t live in an environment that prepares [laugh] us for that at most universities.

So everybody will pay lip service, right. [laugh] We have long declarations about, you know, every—equal access for everybody, no sexual harassment, and so forth. But that doesn’t mean [laugh] that much to me, what you write down on a piece of paper. It’s really about—you really have to challenge yourself or be challenged. And that’s not comfortable for a lot of people.

And certainly among scientists, we’re not—you know, they’re the people who look at their shoes [laugh] when they have a conversation. They’re not the best equipped for that either. So I don’t know how to solve that, but I know there is an issue. [laugh] And if, as a country, apart from the fairness issue, I mean, everybody should get equal opportunity. I mean, that’s what we claim we pride ourselves in this country.

But we’ve gone a long way from that, in fact. There’s several other countries where it’s much easier to get from the bottom to the top. So, in order to fulfill that promise—and the other thing is for the country itself, if you only have white middle-class people doing highly demanding scientific jobs, then you’re looking at only half of the potential pool of brilliant people, right?

Behrman:

Right.

Martens:

So we miss a lot, and we’ll miss out in competition if we don’t manage to get other groups involved. So it’s self-interest as well to try to diversify. And I know NASA tries very hard, and I certainly appreciate that. But I don’t think it’s easy. [laugh]

Behrman:

No, certainly not. Well, would you like to talk a little bit more about some of the various research projects you’ve been involved in? We only touched briefly on the Solar Dynamic Observatory.

Martens:

Right. Well, when I was in Bozeman, just a year or two after I started there, there’s a young assistant professor in computer science, Rafal Angryk, came to me. And he does big data, so basically machine learning, and big data. And he really got me interested in that. And he sort of sought my collaboration because we have a lot of data [laugh] in heliophysics.

Behrman:

Right. [laugh]

Martens:

And so we’ve been working together for 15 years now. And that has been my main interest in the last 15 years. So I was one of the co-founders of the Virtual Solar Observatory, which was about—that’s about access to data. That’s step 1. Because I remember in the ‘80s, getting data was a bloody nightmare [laugh], you know. It had to be mail tapes and that kind of stuff.

So I’m advocating that we do a different kind of approach to solar physics as well. Much of the solar physics, certainly for flares, was, OK, people study one event, and get observations on that, describe it, and there you have a paper. Well, you can do that ad infinitum [laugh], and still not get big data. Still not see big trends. So that’s what we’re trying to do, and everybody agrees about that now. [laugh] That’s not an issue anymore.

Behrman:

Is this part of your Feature Recognition Project?

Martens:

Yes. Oh, the Feature Recognition…yeah. So that was step number 2. [laugh] Step number 1 is access to big data -- VSO. Then for SDO, NASA had foreseen that very well. We get so much data, so much images, you can’t just say, “OK, here I have 60 observations of, say, filaments. Give it to your grad student, and say, ‘Study those, and come up with something.’” [laugh] Right.

Now we have 60,000 observations [laugh] of filaments. How’re you going to analyze those? So, first of all, we have to know when and where filaments are. So that’s what Feature Recognition does. I won that grant while I was at CFA, in the brief time I went back.

There’s an international team, and the idea was to look at the SDO data, the imagery, and train computers to recognize the different features that you see on the sun, like sunspots, filaments, flares, and what have you. And that’s widely used now. So I didn’t write all that software. In fact, I didn’t write [laugh] any software at all. I just was in charge of the team to put all these things together, all that software together.

Behrman:

This was the first sort of large-scale data project you were working on with Rafal Angryk?

Martens:

On data project, yeah, definitely.

Behrman:

Did this work on—with the large-scale data analysis and Feature Recognition inspire the later AstroInformatics Nexus?

Martens:

Oh, absolutely, yeah. [laugh] Because, yeah, my—the guy I worked with, Rafal Angryk that I mentioned, he was hired here a year before I came. [laugh] Because he wanted to get—he didn’t like the computer department at Montana State very much. He didn’t think they were very enterprising.

So he was looking for new jobs. He got a job here, and then he pushed for me [laugh] to come, and that worked out. So we continued working together. And this is great because we’re in the same building.

The computer science department’s one floor up from here. So we actually have a lot of face-to-face contact, which makes things a lot easier. So we have this joint group, we meet once a week with all the grad students and the faculty, discuss joint projects that are interesting to both sides, and then, as a result of the weekly meetings, groups will split off—a couple of grad students and maybe one professor from the different departments—and work on the problem.

Behrman:

What’s it like collaborating across the computer science and, you know, astrophysics?

Martens:

Oh, it’s amazingly difficult [laugh] because we speak a very different language. I’ve been actually keeping up a sort of dictionary between terms in solar physics and in computer science. And it can be really confusing because, for example, if you talk about features, when we talk about features, solar physicists, we think of things in the sun, like filaments and so Feature Recognition, right.

Behrman:

Right.

Martens:

For a computer scientist, it’s a totally different thing. It’s basically a label you put on the data. So if you have an observation of, say, a filament, one feature could be its location on the sun. So you can get very confused during talks. [laugh]

Behrman:

[laugh]

Martens:

The one term I really like is what we call a truth table in solar physics. It’s called a confusion matrix in computer science. [laugh]

Behrman:

[laugh]

Martens:

So you’re sitting there in a seminar, and people start talking about a confusion matrix, and what the hell are you talking about? [laugh] And the first time you hear that…

Behrman:

So the Georgia AstroInformatics Nexus, have you found it interesting having multiple audiences as well for your research that you’ve worked on?

Martens:

Oh, yeah. You learn to express things [laugh] in different ways for different groups.

Behrman:

Do you each, you and Rafal, have a role in talking to different audiences? Or have you also had—?

Martens:

Well, we don’t give seminars together.

Behrman:

[laugh]

Martens:

We say we write proposals, and, yeah, then it’s clear I talk about the data and the solar background, and the why, and what it’s needed for. And he talks about the methods for analyzing the data, and getting them, and storing them, and accessing them. So that’s what he does, yeah.

Behrman:

How have you built support for this group?

Martens:

Well, Georgia State is a very forward-looking university. [laugh] They’ve done—you’ve probably heard about they’ve done very well in undergraduate education, in particular. And they decided that they wanted to get their—expand their research base as well. That’s one reason I was hired here. And so focus on really becoming a top-level research university.

And one of the things they really understand and stimulate from that is interdisciplinary work, which is really a difficult thing to do in reality. I mean, everybody will pay lip service to it like racial equality. [laugh] But, in practice, different departments will fight over resources, even silly things like office space, let alone positions, right.

Behrman:

Right.

Martens:

So it’s not easy to get them to work together and, say, sacrifice something for the common good. That can only happen if you have strong support from one level up. And so that’s what’s happening here. And Montana State was not aware of that at all. That was just beyond their horizon. It wasn’t going to happen any time soon.

Behrman:

You’ve also done a lot of outreach with GAIN, including going to the White House and—

Martens:

Oh, that wasn’t outreach. [laugh]

Behrman:

[laugh]

Martens:

Yeah, that was fun. They—well, there’s this National Space Weather Policy, right, that they came up with. And basically people in Boulder invited a bunch of scientists to be there at the official unveiling [laugh] of the National Space Weather Policy. And so when I got the invitation, I said, “Rafal, we got to go here [laugh] because this will be great PR for GSU.”

Hey, it wasn’t really important. I was just sitting there listening to people [laugh] announcing the Space Weather Policy. I didn’t have any role in doing that. But it did work for the visibility of our group. So it was interesting, yeah.

Behrman:

Was that similar to when you met with the Dalai Lama?

Martens:

Oh, no, that’s totally different. [laugh]

Behrman:

OK. [laugh]

Martens:

Well, I didn’t actually get to meet the Dalai Lama. But the—let’s see. Well, Emory University here has a project where they work with the Dalai Lama to teach basic physics and also psychology and philosophy to Buddhist monks in India. So they’re refugees from Tibet, and built their own communities there.

And the Dalai Lama thinks it’s important that science and Buddhism get integrated, basically. He doesn’t want a Galileo situation to develop, I guess. [laugh] He hasn’t said that. [laugh] That’s my interpretation.

So Emory set this—the Emory-Tibet Science Initiative—actually set up this program, and they need volunteers to go and teach there. And I just heard about that through an email, and I jumped on it. [laugh] So that would be so interesting to do that. And so I volunteered, I was accepted, and I spent— two years, I went for a couple of weeks to live with the monks in their monastery near Bangalore, and teach physics, in my case.

So you get to live there. You eat the—there’s no alcohol. You eat vegetarian. There are no women in the cloister [laugh] or whatever there. So there are no diversions, and you—we spend a lot of time—well, the days are long teaching.

But then, in the evening, we would sit outside and drink tea together, and just talk politics a lot of the time—it’s really interesting—with the monks that are your students. So, yeah, I really enjoyed doing that.

Behrman:

So you’ve put a lot of effort into making Georgia State a center for, you know, heliophysics study and research. Where would you say are some of the other centers for heliophysics?

Martens:

Oh, well, there’s Boulder, of course, [laugh] which has everything. [laugh]

Behrman:

[laugh]

Martens:

There’s CU, there’s SwRI, there’s HAO and LASP. Actually, I think it’s too much concentrated in Boulder. [laugh] They may not like hearing that but what the hell. [laugh] There’s NASA Goddard. There’s a strong solar physics program, together with George Mason.

And then there’s Cambridge, the solar physics group there, although it’s not growing, but they’ve always been very prominent. Berkeley used to have a strong group that’s sort of gone down a little bit now, although it’s still there. Then the University of Minnesota just started with Lindsay Glesener, started a solar group.

Oh, Marshall Space Flight Center, which actually we work with because it’s only a couple of hours’ drive from here in Huntsville, Alabama. They have a prominent solar physics group. That’s the U.S. Oh, Hawaii [laugh] Jeff Kuhn.

Behrman:

Right.

Martens:

And then there’re the people in Los Angeles who do mostly—well the helio part of [laugh] heliophysics, right, the interplanetary space.

Behrman:

Do you think the growing awareness of space weather has helped grow the field of heliophysics?

Martens:

Oh, absolutely, yeah. [laugh] That was—I guess at the time, it was sort of a rescue action [laugh] because solar physics was close to disappearing, and then they—but it’s real. I mean, [laugh] the influence of space weather on so many things, definitely technology, is tremendous, and you have to find ways to protect yourself.

So good warnings are one good thing, and so that’s what we work on. But then you can also take protective measures. I think under Obama, they started hardening our power grids to deal with happenings like the big coronal mass ejections.

Behrman:

You mentioned that it was part of the motivation for you to work in solar physics because of your interest in, you know, astronauts and going into space and everything. Has it continued to be a motivation for you in the years since?

Martens:

Oh, yeah, absolutely. [laugh]

Behrman:

[laugh]

Martens:

We’re involved now actually with the NASA Houston, the Space Radiation Analysis Group. We got a contract from them to try to build the best possible prediction mechanism for solar energetic particle events. And so together with flares and CMEs, you get this ejection of really high-energy electrons and protons, which travel a fraction of the speed of light—not a small fraction.

And they can really hurt astronauts. They can cause cancer. In the worst case, they could die from overexposure. And they also, well, can hurt the spacecraft itself, so offset the computers. Any high-voltage equipment could get damaged. So you want to have warnings for that.

And we’re trying to do the best model that can be achieved using machine learning for SEPs. So we look at the sun, get the magnetic fields and all that, and get the X-rays from GOES, and try to predict when it’s coming. And the astronauts need to know that because if they have an extravehicular activity, or if they’re on the surface of the moon or Mars, they’re unprotected.

So when an SEP comes, you want to go inside. Inside the spacecraft, you have a factor 10 better protection. So the risks are much lower. So you don’t plan EVAs when you know big solar flares are coming.

And, for that, you need a warning system, just like you need a warning system for hurricanes. So that’s what we’re trying to do [laugh] to build the best possible system. We’re really—everybody’s really excited [laugh] that we’re doing that.

Behrman:

What are you using as the training and testing sets for the machine learning?

Martens:

Oh, for the machine learning, well, there’s the vector magnetograms from HMI. Those are the most. Then you get filaments, and we’re starting to look at AIA data in general. And then for the short-term warning, we use what’s already used in UMASEP, which is the X-ray fluctuations that you see with GOES.

So if a flare is coming, the X-rays go up, and that’s a warning that there may be solar energetic particles coming. That depends on a lot of other things. But this is a good way to see it. And then you see locally—in the GOES satellite, you see the proton flux going up. And from the way it rises, you can sort of predict how large it’s going to be, and how long it will take to get there, which is a warning. So, you know, when the wind starts blowing a little bit harder, you know that a [laugh]—

Behrman:

Right. [laugh]

Martens:

You know that a rainstorm may be coming. And this is sort of the same idea.

Behrman:

Right. Have you encountered much pushback from other scientists who are involved in space [laugh] weather prediction for doing—using machine learning?

Martens:

[laugh] Yeah. Rafal and I have for years now written a whole bunch of proposals to do applied machine learning to flare forecasting. And the first couple…this is four or five years ago. It was, “Oh, this is not science, right [laugh], because it’s not pure science. So it doesn’t fall under this program.”

And then afterwards when NASA made it an official goal with the National Space Weather Policy, [laugh] you cannot just ignore that. [laugh] So, yeah, there’s quite a bit of pushback, and the pushback doesn’t come from higher up, again. And NASA management is well aware [laugh] of what needs to be done, and what methods you should use. The pushback comes from your colleagues who just want to keep on doing what they’ve been doing forever [laugh], which is a different way of approaching things.

Behrman:

Right. Have you found that having this collaboration in computer science has helped you at least gain support in the field of computer science, if not among other heliophysicists?

Martens:

Yeah, I get the impression. I mean, I’ve been to meetings where there were quite a few computer scientists, and they’re really enthused about what they’re doing. Because, you see, what they—they’re starved for data. It sounds strange. But they’re looking for really good data sets that they can apply their algorithms to.

So you need cleaned up data. That’s a big thing. And we’ve been working on that for solar flares. So when they hear about that—and, besides, it’s practical, right. [laugh] This is different from, like, saying studying social media [laugh] to see who contacts who and then why [laugh] because who cares? But they do because there’s big money in it of course. But this just gives you a better feeling [laugh] than working on social media, I would think. [laugh]

Behrman:

So how do you convince your colleagues then that machine learning is a worthwhile approach to prediction?

Martens:

Well, I think by now it’s pretty obvious, yeah. [laugh] And I think NASA management and also the GSU management understands that quite well. And then we basically had the shortcut when I meet—I met those people from SRAG at a conference where I gave a talk on a paper that one of our computer scientists had done for flare—for SEP prediction. And he comes up to me after the meeting and said, “This is interesting. Can we talk?” So that’s how we got the contract from SRAG. Well, you don’t even have to write a proposal. [laugh] It’s a—

Behrman:

[laugh] That’s very handy.

Martens:

Yeah, and, well—and they want to have a really good system in place when people start going back to the moon. And that’s their assignment, right. So they don’t care about whether it’s science or not. And so then he tells us, “It doesn’t matter if you write papers [laugh], I want a good system.”

Behrman:

Right. What do you think are some of the challenges that remain with space weather prediction?

Martens:

Oh, it’s hard [laugh], yeah. You’re never going to get really, really perfect predictions. Well, it’s the same for weather, of course. So we basically predict space weather the way farmers would predict weather 100 years ago, right. [laugh] If it’s red in the sky, and when the sun comes up in the east, there will be rain later in the day. Right. [laugh]

Behrman:

[laugh] Right, yes.

Martens:

That’s what we do. We look at the data, and then try to predict what’s going to happen. Now, there’s another approach, which is just as hard, which is simulations, where you solve the MHD, and plasma equations, and try—start at the sun as a boundary condition and initial condition, and then let your simulation run. And that’s hard too.

That hasn’t, no, convinced a lot of people [laugh] either. But there will be progress made there, I’m sure. What I’m really interested in for the longer run is combining the two, making them work together. So you could use your machine learning actually to adjust your simulations while they’re running. So there’s basically one computer looking at the other computer that’s doing the hard work, say, “Oh, no, no, you’re going the wrong way.” [laugh]

Behrman:

[laugh] Oh, yes.

Martens:

Yeah. So we can’t do that. We’re not quick enough [laugh] to do that, right. So that’s one approach. And the other approach is building libraries of simulations, which are very time-consuming, say, for CMEs.

You solve for a whole lot of CME eruptions for different boundary conditions, different initial conditions, build up a library of them, and then when the thing—when actually something happens that’s very close to one of those things you build in your library, you don’t have to go through the simulation. Because the simulation sometimes goes slower than real time [laugh], so there’s nothing you can predict. But now you can just pull it out and do it.

And that’s basically a library of—this is the way your email works. I mean, you can sort by time or you can sort by who it’s from, and that’s not your computer program that does that while you push the button. It actually has done it beforehand. [laugh] It’s made a library, and you can look it up. Because if you have 7,000 emails in your inbox [laugh], right—

Behrman:

Right. [laugh]

Martens:

—it’s hard to sort them out, which a lot of us do. [laugh]

Behrman:

Yeah. So if you’re—you know, you have these sort of sets of items which you might know you want to sort by, oh, a flare, a filament, have you come across or had ideas for other types of features that might be indicative of interesting space weather events?

Martens:

Yeah, well, yeah. Basically, you put in as much data as you can, and then you let the algorithm decide which one are interesting, which one are really predictive for solar flares. So one of the things we looked at was the time variation—the second moment of the time variation of the magnetic current helicity. Who would’ve guessed that, right, [laugh]—

Behrman:

[laugh] I didn’t.

Martens:

—that it is a real good indicator for a flare’s going to happen? So it goes up and down quite a bit, finally, before the flare. That’s what our algorithm told us. Now, I don’t think a theorist would’ve come up with that. [laugh] Although, I’m sure they can explain it after the fact. [laugh]

But, yeah, and so that’s basically—you really get fun things with machine learning. One of the things they found out for supermarkets is—so supermarkets try to place their product together. So if you buy one thing, and the other thing you buy with it, it’s right there because it makes it easier for people, and it makes them sell more, of course.

Behrman:

Right. [laugh]

Martens:

So one thing that goes together very well is diapers and six-packs of beer. [laugh]

Behrman:

[laugh]

Martens:

Why would that be? Well, I can only think of desperate fathers making a midnight run [laugh] to the supermarket because they ran out of diapers. [laugh]

Behrman:

[laugh]

Martens:

I thought that was really hilarious.

Behrman:

That’s very funny, and certainly different from, you know, spaghetti sauce and Parmesan cheese. [laugh]

Martens:

Right, exactly, yeah, [laugh] that’s obvious things you think of.

Behrman:

[laugh] Yeah. You’ve also worked a lot with simulations and modeling, speaking of that, including looking at the dynamo.

Martens:

Oh, yeah, yeah.

Behrman:

So with the dynamo modeling, one of the major sort of papers that came out of it was looking at the solar cycle 23 minimum.

Martens:

Yeah, so when I was at Montana State, after I came back from the CFA again, they had a postdoc there, Dibyendu Nandi, who—his work is on dynamos. He’s a professor now at IISER in Kolkata. And he sort of sought out my collaboration, and we became actually really good friends. And then we had a REU student from Colombia, the country, Andrés Muñoz, he spent a summer at MSU. And we were so impressed, we offered him a graduate fellowship.

So the three of us started working on dynamos because that’s what Dibyendu does. [laugh] And I didn’t do any of the numerical simulations, so we set up Andrés to write his own program, and start doing the simulations. I gave my physical insight [laugh] and Dibyendu gives both a physical and his simulation experience, and we started working on dynamos, because it’s interesting. [laugh]

Behrman:

Yeah.

Martens:

Yeah. And, in the end, we did come out—or Dibyendu came out with one way you could get—reproduce the very dearth of sunspot observations. [phone rings]

Behrman:

All right, continuing with our discussion of dynamo modeling.

Martens:

Oh, dynamo modeling?

Behrman:

Yes, you were working with Dibyendu —

Martens:

Dibyendu?

Behrman:

—Dibyendu Nandi and Andrés Muñoz—

Martens:

Correct.

Behrman:

—on this. So one of the projects you were working on was the unusual minimum in sunspots—

Martens:

Correct.

Behrman:

—for in solar cycle 23. Was this a project that you were thinking of initially when you got into—

Martens:

No, not at all.

Behrman:

—modeling?

Martens:

No. We just noticed there was [laugh] a really deep solar minimum which hadn’t happened since 1913 or so, I believe. Then we said, “OK, can our model—we have the model. We have the simulation model now. Can we reproduce this?” So we started playing with the parameters until [laugh] you could do that, and I got that paper published. So it has to do with the Meridional circulation if it—I think it slows down. [laugh] I forget how it works [laugh] exactly.

Behrman:

[laugh]

Martens:

If you make it slow down, then you can get a deep minimum.

Behrman:

Yeah, this gets back to your interest in plasma physics though in the sun. Did you enjoy working on the modeling aspects more or less than other types of projects you’ve worked on with data analysis and machine learning?

Martens:

No, it’s all the same. [laugh] You’re curious, you want to figure out something, and you use the tools you need. That’s it, yeah.

Behrman:

And Andrés Muñoz, he’s one of the many graduate students you’ve had. What do you think goes into being a good graduate adviser?

Martens:

Oh, [laugh] I wish I knew. [laugh]

Behrman:

[laugh]

Martens:

Ah, well, you got to be honest with your student. So you have to tell them when they’re not doing well. You have to give them as much opportunity as you can think of, and so you send them to summer schools, conferences. You push them to write their paper because that first paper is [laugh] like giving birth. [laugh]

Behrman:

[laugh]

Martens:

You make sure that the research they’re doing is what they want to do, not just a project that you want to get finished, because you can’t make people do research that they’re really not interested in. It just doesn’t work. So you give them opportunities. It’s more giving opportunities than really very strictly guiding them along a given path. And then, in the end, it depends on them, not on you [laugh], if they really get into it.

Behrman:

Right.

Martens:

And when I interview grad students, potential grad students, I tend not to look at scores at all, frankly, or very little. Some are exceptional, of course. But GPAs and—what are the other test scores? I forget what they’re called. [laugh] But if you get a face-to-face…if you talk with them face-to-face, you get an impression of their sort of character. And I think that’s more important.

But, again, then you have to be very careful because then comes the white privilege thing [laugh] and you’re more comfortable with people who are like you, not people who are different. Yeah. So you have to keep that in mind as well.

Behrman:

Have you been involved with the graduate admissions at Georgia State?

Martens:

Yeah, every year we go through—yeah, I get 70 people applying. We make a sort of formal ranking, based on GPA scores. [laugh]

Behrman:

Do you mean GRE scores?

Martens:

GRE scores, that’s it, and GPAs—grad what is it?

Behrman:

Grade point average.

Martens:

Yeah, yeah [laugh], anyway, which I do not—try to not pay attention to. And then we sort out interviews. We do Skype interviews. And based on the Skype interviews, and the needs of different professors—because if I say I’m not taking on any students this year, then students can [laugh] apply but they won’t get in.

And then we set up interviews. And in the interviews, you get a real idea of the people, I think, and then we interview—we ask them for campus visits, but that’s after they’ve gotten an offer already. Then they can still say no, and they can, and they should if they’re not feeling comfortable. One of the things we’re dealing with, not so much for solar but extragalactic here, is that people apply to GSU as a backup option, but they’d rather go to Harvard or Princeton [laugh] of course.

And so we make offers to people who have incredible GPAs, [laugh] and very strong letters, and, well, they go somewhere else [laugh] because we’re not Ivy League.

Behrman:

Yes, so, graduate students, and advising and—how does Georgia State then try to compete with these big powerhouses, Harvard and Princeton and everything?

Martens:

Well, I don’t think we get the very best students, if they are they get offers for somewhere else. But there’re quite a few students I notice who really do their homework very well, they try to find a school that fits with them, and they know about individuals. So somebody may say, “I really want to work with Misty Bentz,” who is one of the professors here, or, “I want to really want to work with Stuart Jefferies,” who has an observatory on the South Pole. That’s kind of [laugh] sexy, right.

Behrman:

[laugh] Yeah.

Martens:

And you make—you have to—you may get to get a trip to the South Pole. So, yeah, they do that, and they said, “I really want to work with one of - with that person.” And so that’s what we’re finding now. And I noticed that both the number of applications and the average quality of the grad students has gone up in the five years that I’m here, so, I think because they’re hiring new people.

Behrman:

You’ve actually collaborated with Stuart Jefferies a bit, correct?

Martens:

Correct, yeah.

Behrman:

He’s part of GAIN, right?

Martens:

Yes, yeah.

Behrman:

What is your collaboration been like?

Martens:

Well, he’s delivered us data that we can work on, his South Pole data. And we make plans for both future missions or for future instruments or things that need to be studied, basically. [laugh] I mean, we have very different approaches. He builds instruments, basically, and then operates them. And we look at data, but we have enough overlap that it’s worthwhile collaborating.

Behrman:

You’ve done a bit of instrument design, though, correct, with the atmospheric—?

Martens:

AIA?

Behrman:

Yeah, the AIA, Atmospheric Imaging Assembly.

Martens:

Oh, yeah, I helped to write the proposal, yeah.

Behrman:

Oh, OK.

Martens:

That’s all.

Behrman:

You weren’t involved in the instrument design, yourself?

Martens:

I’ve never touched any hardware. [laugh] But before you build it, you have to design—come up with the—what do you want to build? Which wavelengths do you want to look at? What resolution do you want, which are scientific questions, right?

Behrman:

Another project I wanted to ask you about was your interest in the faint young Sun paradox.

Martens:

Oh, yeah.

Behrman:

It’s all so fascinating.

Martens:

It is, yeah. [laugh]

Behrman:

Could you tell me a bit about that?

Martens:

I just have—I go to the AGU meeting in San Francisco in December usually because it’s a nice place to go to anyway. But it’s—I like—it’s a humongous meeting. It’s not very good if you want to focus on just solar physics. But what I do, I go to lectures that are a little bit outside my field, invited lectures, and sort of, you know, catch up that way. And there was this fantastic lecture on the faint young Sun, but I forget the presenter's name now. I’ve corresponded with him just recently.

It sounds like a really interesting problem. I’ve never heard [laugh] of this. So the faint young Sun is that stellar evolution calculations tell you that the sun had a brightness of 70% of what it is now, when it entered the main sequence, so when the Earth was young. And, yet, we know life developed almost instantly. And from all we can see from geological evidence, the temperature was even higher than it is now.

So that’s contradictory because if you run climate models with 70% brightness of the sun, the whole Earth’s frozen over. And then we found out even more that Mars had oceans for the first one or two billion years, and the faint young Sun problem’s even worse for Mars because it’s further out. It gets even less sunlight. [laugh]

Behrman:

Right. [laugh]

Martens:

So how could that be? [laugh] Now what convinced me to—it must have something to do with the faint sun was that there was a problem for Mars. If you think of the Earth alone, you can—there’s many possible solutions you can think of. An enhanced greenhouse effect, you can think of more volcanic activity. So a lot of heat comes from the inside of the Earth to warm up the atmosphere.

There’s still a few percent of the heat of the atmosphere comes from volcanoes and vents and Yellowstone and so on. And that definitely was more in the past. Anyway, that doesn’t work either. So I decided if it’s both Mars and the Earth, it must be the sun. That’s the simplest solution, right. [laugh]

So the sun wasn’t faint. So running stellar evolution models now with a sun that was slightly heavier when it was born, so about 5% heavier, and somehow that works out to 30% increase in brightness. And then it—well, but it’s solar mass now, so you have to lose those 5% over the five billion years, right.

Behrman:

Right.

Martens:

So the sun must’ve had way larger amounts of mass loss than it has now in the past. At some point, that stopped obviously because we know what the mass loss is now. So I’m trying to—with a student, I’m trying to run numerical simulations to see if you can work that out, and then I’m trying to figure out is there a way that—is there any we can observe this kind of mass loss if it happened in the past? What would the indications that we have now?

And when I started looking at it, actually it turns out if you take the current mass loss of the sun, and you look at the slowing down of the sun’s rotations, most stars like the sun when they are young have a rotation period of five, six days. And the rotation period of the sun now is like 28 days. It depends where you look. [laugh] It’s faster at the equator than at the poles.

So it slowed down a lot, lost most of its rotational energy, and angular momentum. Now how do you do that? Well, the solution is magnetic breaking. So mass flows out of the sun along the magnetic field, is held in place, and then it’s let go at some point where the outflow velocity is the Alfvén velocity. And that’s where the momentum is, the angular momentum is lost.

So you—it’s like a—you know, these rotating sprinklers you have in the yard? [laugh] They rotate because of the angular moment from the water flow. Then I said if you look at the current mass loss, and you would try to slow down the sun like that. That doesn’t work at all. You need to have an Alfvén radius, an arm where your momentum all the way beyond the orbit of Venus. And there’s absolutely no indication that’s the case.

So maybe but when the mass loss is higher, then you could slow down the sun easier, you lose more angular momentum. So maybe that’s an indication that maybe it works. [laugh] And that’s what we’re trying to do now.

So in order—so to lose angular momentum, you use a torque, right, like when you turn a screwdriver or a wrench. So you know the longer the arm, the easier it is, right.

Behrman:

Right.

Martens:

So it’s the same with the sun. You need a very long arm with very little mass loss to slow down the sun, or you have a much shorter arm, which sounds more reasonable, given modeling, with a high mass loss. And it turns out if you put in a reasonable length for that arm, then the mass loss comes out, the very high number I needed. [laugh]

Behrman:

[laugh]

Martens:

So I’m excited by that. And now we’re going to actually simulate that. Put the—add the mass loss to the stellar evolution calculation, and the magnetic breaking, and then see if we can make it work.

Behrman:

Who is the “we” in this?

Martens:

Oh, my newest grad student [laugh], KhaDeem Coumarbatch.

Behrman:

Why do you think the idea of a large mass loss of the type you’ve described hasn’t received as much support as other ideas?

Martens:

I have no idea. [laugh]

Behrman:

[laugh]

Martens:

But, well, people tend to find a solution in their own field. So there’s a lot of atmospheric scientists working on the faint young Sun. What they come up with is greenhouse [laugh], of course.

Behrman:

[laugh] Right.

Martens:

Because that’s what they know. [laugh] And then when a volcanologist starts working on it, he’ll come up or she will come up [laugh] with there’s a lot of heat from inside the Earth that passes through to the upper layer, and kept the atmosphere warm. And I’ve seen an abstract by a—what do you call that—an extragalactic person—cosmologist, who came up well, “If you change g—capital G [laugh] in the gravity law, make that change with time, you can explain that as well.”

Because if gravity changes in force—in amount as the solar system evolves, you’d still maintain angular momentum, but you have—the planets will move out slowly. So this Earth would have been closer in [laugh] to make up for the fainter sun. So that’s an option too. But no cosmologist has ever told me that that’s a reasonable option. [laugh] They tell me the whole universe would fall apart if you start [laugh] tinkering with G. [laugh]

Behrman:

Right. [laugh] So you mentioned you go to the AGU meetings pretty regularly. What other societies or meetings are you involved in on?

Martens:

SPD, solar physics division of the AAS. I go—and now I go to space weather meetings quite often. There’s an annual meeting in Boulder in April on space weather that I like to attend. And then depending on what’s interesting or what I get invited for. [laugh]

Behrman:

[laugh] Could you tell me a bit about SCOSTEP, the Scientific Committee on Solar-Terrestrial Physics?

Martens:

Yeah. So that’s an international organization that, in this case, works on space weather, and heliophysics in general as well. And I—just before I left MSU, I got a role in that to look at the faint young Sun problem. But, in reality, once I got here, my schedule got so full [laugh] that I really haven’t done as well with that as I should have.

You know, still—the program is over now, and I know other groups did way more work than we ever did at organizing meetings. I couldn’t even go to all the meetings because, it just happens, one crisis in my family after the other one [laugh] when the meetings happened.

Behrman:

[laugh]

Martens:

For example, my mother-in-law died in June, which was the final symposium.

Behrman:

Oh, I’m sorry.

Martens:

And I couldn’t go, of course. [laugh] I had to go the funeral. And—I’m sorry, I must have…

Behrman:

Right. So, then, perhaps we could transition to talking about some of the work you’ve done in the various committees and in your kind of work outside research. Last year, you were appointed to the Astronomy and Astrophysics Advisory Committee as well.

Martens:

Right, oh, yeah.

Behrman:

What are your duties in this role?

Martens:

Well, it’s a committee that formally advises Congress and the Administration or Department of Energy, and NSF and NASA on—basically on the budget. And although it’s under the NSF Astronomy Division, the DKIST, for example, gets funded by them. So they need all this assistance.

Well, basically, you try to give [laugh] wise advice to the Government on that. You know, it’s not my favorite thing to do, but you got to do it [laugh] for a couple of years. And it rotates. You only stay on it for three years. That’s a good thing.

Behrman:

Right. What are your priorities on the committee, or what do you think the Government should be looking for in terms of funding?

Martens:

Well, I think—actually, I think NASA and NSF are doing a pretty good job. And so we’re not telling them to totally change their funding profile. But we try to—basically what we convey is that the community supports—maybe except for a couple of small items—supports what NASA and NSF are doing.

And then put some marginal notes on this and that, and this could be different, no, that could be different. But, in general, there’s pretty good agreement. But I guess Congress wants to know that, you know, NASA comes with a budget. Well, what’s the support in the community for that? And that makes sense.

Behrman:

You’ve also worked in various capacities with scientific journals. You’re associate editor of The Astrophysical Journal Letters, and guest editor for Astronomy and Computing on an issue, et cetera, et cetera. How did you get involved in scientific publishing or in your work there?

Martens:

God, I don’t remember. [laugh] I think—well, I edited two books for conferences around 2000. And then with ApJ, I think I even—I applied to be ApJ Letters editor, and didn’t get it. But Chris Sneden, who became the editor, then approached me, and asked me, “Do you want to be associate editor for solar physics?” Because he’s not a solar physicist.

So and actually it was a kind of nice job because you don’t have all—do the drudgery work, you know, going through every paper that comes in, and then find a referee. But when there was any issues with the solar physics papers, he would contact me, and say, “Can you explain this to me [laugh] because I have no idea what’s going on here?” Usually when a referee and an author get into—lock horns, and can’t resolve their conflict, and then I, you know, read the papers, and give him advice and then—that wasn’t a very hard job but—and it was interesting. [laugh]

Behrman:

How have you seen scientific publishing change since you started doing research work many decades ago?

Martens:

Decades ago, yeah. [laugh] That’s a good question. [laugh] Well, one thing that really changed is there’s way more attention now for outreach than there was 30 years ago. A little bit too much, actually [laugh], for—in my opinion. There’s more accountability. You can’t just say, “I’m a theorist and, you know, society should pay me for doing my [laugh] very lofty work.” It has to have some purpose, right.

Behrman:

Right.

Martens:

That doesn’t mean there shouldn’t be people who do pure theoretical research, say, number theory mathematics. It turns out that has a great application too [laugh] in cryptography. So you never know that’s why you want to do pure research. But, yeah, I do think it’s good, this accountability.

I think—I remember proposal writing was just as bad [laugh] in the ‘80s as it is now. It takes up a lot of your time. But then you had hard copies, which you actually had to deliver. And now it’s a lot easier, electronically, quicker at least.

Behrman:

How did you get involved in the AAS-IOP e-books collaboration?

Martens:

Oh, they asked me. After I was done with ApJ Letters, they were basically looking for a person to represent solar physics. Again, given that I had a lot of experience, they asked me do I want to join? And I thought it was a real nice project.

Because the e-books are different from regular books in that you basically subscribe to them from a library, like you would do to ApJ. When they put ApJ on the shelves, then everybody can read it. Well, with books, it’s usually you have to buy a book, right. So now when I have a textbook, for example, and it’s in our library, I can share it with my students, and they don’t all have to buy the $120 textbook—

Behrman:

Right. [laugh]

Martens:

—that [laugh] they’ll only be able to use for once in their life. So I think that’s progress. It’s much cheaper. It’s more like the journal idea than the book idea. And, in fact, they only print a very limited amount of hard copies of the books that we publish. So I like that. That was fun. And my job is to look for authors in solar physics, because I know pretty much everybody, and see if they can—I can’t convince them to write a book on their specialty, on what they’re good at.

Behrman:

Have you ever thought about writing a book yourself?

Martens:

Yes, yeah. [laugh]

Behrman:

[laugh]

Martens:

I’m going to write a book on the course I teach here, plasma physics and MHD. I want to do it differently from the standard textbooks there are now, and publish it with IOP as an e-book, so you can use it in class easily.

Behrman:

What is this different approach you’re thinking of taking?

Martens:

Well, the MHD books we have now are very theory-oriented. It’s a lot of math, derivations. There’s actually surprisingly little information about the actual phenomena you’re studying. [laugh] So, say, you’re talking about loops, or, well, they put the obligatory picture of a loop in there.

But you should say more of the observation, and put in movies instead of loops—instead of images, because it’s not a printed book anymore. And that’s true for most data. And all the things you address, for example, when you derive the wave equations, you get gravity waves, which is different from gravitational waves. [laugh]

Behrman:

Right. [laugh]

Martens:

And the gravity waves, you can see when, you know, air passes over a mountain range, for example, and you see clouds forming in the wake of the mountains. Well, they never show that. And that’s really fascinating. When you see it, you understand it right away. So that’s the kind of thing I want to do. I’m going to put results of simulations in there as movies, not as images, and make it so the students can play with it, yes.

Behrman:

Sounds quite interesting, really. [laugh]

Martens:

[laugh] Yeah. Yeah, I teach that—I started teaching that course here, and the students are very reluctant. So I really enjoy doing that. And it doesn’t mean you don’t have to do the math, right. It’s not show and tell, but [laugh] this actually—this is what your equations show you, and this is what nature shows you. Look how similar it is.

Behrman:

What are, I guess, some other directions that you think you might see e-books and e-publishing going in the next couple of years?

Martens:

Well, I think for teaching, the printed book is pretty much going to disappear. And it’s something I actually really feel strongly about. I treat undergrad introduction to astronomy. And they make those poor students, most of them who are from a blue-collar, not rich background, buy this $120 book, which is a racket, if you ask me. [laugh] And they come with a new edition every two years, where they change a couple of words here and there.

So they can’t—they tell you you can’t sell the book to your [laugh]—once you’re done, right, and get $80 back of your $120. No, you have to have the new edition. I think that’s scandalous. And I think all these books should be e-books, and you just download them, and the university pays a standard fee, and save the students a lot of money.

And we know, from experience here at GSU, that money, especially for the kids who are not middle-class, is a real hurdle in getting their degrees. So we have this system of mini loans here, which is part of the way the minority students and blue-collar background students are helped. And one—so often they find out that a student drops out because they couldn’t pay the extra $500 for whatever, you know, for the books they need or whatever it is. So the university actually gives them loans for small amounts, and they pay back after they graduate.

Now, this is a way to [laugh] save money too, that way. You don’t have the expense in the first place. So I hope to get that done. I’ve told my colleagues, “Why don’t we write our own textbook for undergraduate astronomy? Because we have all these different disciplines represented here. [laugh] I’ll write a chapter on the sun, no problem.” [laugh]

Behrman:

[laugh]

Martens:

But they haven’t wanted to do that. But I know the administration really wants it. They see the issue here. So it’s going to change eventually. There are a couple of textbooks now that are actually online for free, and written by good people in the field. So I think we should use them.

Behrman:

What sorts of textbooks are you thinking of?

Martens:

Well, this is undergraduate introduction to astronomy. There are two parts. I teach usually the part on the solar system. So I know that one exists. So it’s about the planets, asteroids, planet Earth, atmospheres, formation of the solar system, all that stuff.

Behrman:

Were there any textbooks that you were particularly fond of when you were going through your undergraduate or graduate training?

Martens:

Well, [laugh] yeah, no. [laugh]

Behrman:

[laugh]

Martens:

I just read the book, and then took the class, and took the test. [laugh] That’s—I like a good book, yeah. Now we had this good thing as a result of the revolution in the ‘60s. Every professor was mandated in Utrecht—this is early ‘70s—to make a syllabus. Because before that time, [laugh] they just had the book often.

Behrman:

Really?

Martens:

They didn’t even have the syllabus. And now they were required to produce a syllabus with all the content of the material they would test on. So you get a syllabus like that. [Holds up fingers to show a thickness.] I still have them [laugh] in some cases.

Behrman:

How thick is that?

Martens:

Yeah, about this thick—

Behrman:

Maybe half an inch or so?

Martens:

Yeah. You study that, and you’re done. [laugh] So, in some cases, you didn’t even have to get the book. And it was really very helpful. And I know there was a lot of grinding of teeth, and this is 50 years ago [laugh], right. And so this—that the—you know, that such an exalted person as a professor had [laugh] to do such a lowly job. And in those days, it was actually quite a bit of work because somebody had to type out all these equations. [laugh]

Behrman:

Right. [laugh]

Martens:

Yeah, and then if you make a mistake, you have to start all over. [laugh] It’s not like now.

Behrman:

Yeah.

Martens:

So that was very helpful.

Behrman:

Did you have a study group you worked with as an undergraduate?

Martens:

No. [laugh]

Behrman:

It was all by yourself?

Martens:

[laugh] Yeah.

Behrman:

Did you ever get into study groups, or was this not something then?

Martens:

No, we had these laboratory exercises, and you work with a partner. And I worked with that partner quite a bit on them, all the lab work, basically. You’d write a report together.

Behrman:

Did you have recitation sessions or only a lecture?

Martens:

What is that? [laugh]

Behrman:

Problem sessions?

Martens:

Oh, yeah. I did show up for those, yeah, especially for math. [laugh]

Behrman:

[laugh] Well, is there anything else that we haven’t covered that you would like to talk about?

Martens:

Mm, [laugh] I don’t know. Let me think a little bit. [pause] Well, I am concern…I’m really enthused about going back to the moon [laugh] and going to Mars. They’ve finally decided to do that, and I think it’s important to do that. I’m a bit concerned about space tourism. I don’t like the idea that people spend millions of dollars for—you know, to cross off another thing on their [laugh] bucket list—

Behrman:

[laugh]

Martens:

—while that money could be spent in much better ways. And I’m a little bit concerned about commercialization of access of space. I mean, what they do is a great thing. Basically the cost of access to space, say, per pound has gone down by an order of magnitude, thanks to SpaceX and Blue Origin. So that’s good. But now they’re launching satellites all over, and it’s already so polluted up there [laugh], there’s going to be a major disaster coming. At some point, the Space Station will get hit by a considerable piece of junk, and people will die, and then that’s when they probably start doing something, right. But we could be more proactive, and just try to figure out ways to bring satellites down when they’re used up. We should be doing that, but it’s not being done.

Behrman:

Yeah. If the—speaking of satellites up there, if there were any other piece of equipment—say you had infinite money, infinite resources that you could put up around the Earth or the sun—what would you do?

Martens:

Oh, my god. [laugh] I have no idea. [laugh]

Behrman:

Well, that’s all the questions I have with me.

Martens:

OK.

Behrman:

So thank you so much for your time.

Martens:

No, thank you, [laugh] really.