Season 4 - Episode 409
What do dust bunnies and plasmas have to do with outer space? Dr. Lorin Matthews explains on this Baylor Connections. Matthews, professor of physics and associate director of Baylor’s Center for Astrophysics, Space Physics and Engineering Research (CASPER), is a leading researcher into processes that form planets and continue to shape our galaxy, and she explains the impact of these events while taking listeners inside Baylor space research.
Derek Smith:Hello and welcome to Baylor Connections, a conversation series with the people shaping our future. Each week, we go in depth with Baylor leaders, professors, and more, discussing important topics in higher education, research, and student life. I'm Derek Smith, and our guest today is Dr. Lorin Matthews. Dr. Matthews serves as Professor of Physics at Baylor and Associate Director of Baylor's Center for Astrophysics, Space Physics, and Engineering Research, better known as CASPER. She received both her bachelor's degree and PhD at Baylor, returned to her alma mater to teach and research with distinction, earning a prestigious NSF career award and over $2.6 million in grant funding. Last year, she was awarded an Outstanding Undergraduate Mentor award from Baylor's Undergraduate Research and Scholarly Achievement. Her research focuses on dusty plasmas in space, and we'll learn more about those and their importance ahead on the program. Dr. Lorin Matthews, we appreciate your time today. Thanks so much for joining us.
Lorin Matthews:Well, thank you for inviting me, Derek. I'm really happy to be here.
Derek Smith:Curious, as we start out, was space something that always fascinated you from a young age? Where did that begin?
Lorin Matthews:I think that I've always found space very interesting. Actually, it was my older sister who was more interested in space when we were younger. She was the one who had a telescope and had the subscription to Odyssey magazine, which was all about space. Interestingly, she went into biochemistry and I was the one who ended up doing space research.
Derek Smith:What led you into space research more specifically?
Lorin Matthews:As an undergraduate, I was looking for a summer research project. So I went around talking to all of the professors in the physics department about the research they were working on. And one of those professors was Dr. Truell Hyde, and his area of research was dusty plasma research, which is related to the formation of planets. And I thought that was really interesting. So I began that project and it became my honors research project when I was an undergraduate at Baylor.
Derek Smith:So you visited with Dr. Hyde and became interested in this, and let's zoom back out a minute, because obviously now you are a colleague of Dr. Hyde's and many people might not know just how highly regarded Baylor is in space research. What does that look like at Baylor? And how has that grown over the years?
Lorin Matthews:Yes. So Dr. Hyde came to Baylor in the eighties and was working with Merle Alexander, and they were developing dust detector systems to fly on space probes. So the Craft mission was supposed to be a sister mission to Cassini, which did go to Saturn and collected lots of great data. Unfortunately, Congress slashed the budget and the Craft mission went away. So Baylor has this long history of building dust detectors. And more recently, what that has looked like is we have built diagnostic devices to fly on nanosatellites, which are small satellites, just the size of a breadbox, which then are able to collect data and send it back to earth. So not only do we have collaborations with the University of Stuttgart, who develop shielding devices for planetary atmospheres for re-entry, but we have collaborations with people all around the world, in Russia, in Hungary, in Germany, at universities all around the United States. And we're all looking at various aspects of plasmas in space, where we have dust.
Derek Smith:We're going to define some of these things, or have you define some of these things, as we talk about plasmas and dust, and planet formation, and things of that nature. But I want to ask you a little bit further on that before we move into that. Another thing we might need to define a bit is CASPER, as it relates to Baylor space research, a very highly regarded research center, a number of research groups. If you are talking to a colleague from another department and they said, "What is CASPER?" What would you tell them about what it is and what makes it a special place for you to do your research?
Lorin Matthews:Right. So CASPER was started in late 1999, early 2000. And it is a center, which means that it's outside of a specific department at Baylor. So we have members of the center from the department of physics, from the math department, from the department of engineering, and even the education department, because we do have a large education and outreach component. And in addition to that, we also have adjunct members that are at universities around the world, as well as research directors that are very highly regarded in their own areas. So our research directors are Dr. Oleg Petrov, who is the president of the Russian Academy of Sciences, and Dr. Vladimir Nosenko, who has been working at the German Space Agency, DLR, as well as Dr. Peter Hartmann, who is at the Wigner Research Institute in Hungary.
Derek Smith:So we've defined CASPER, and know a little more about that. And great ends, we talked about at the top of the show. They've done a lot of fantastic research that has been highly funded by organizations like the Department of Defense, the National Science Foundation and others, and your work has been a big part of that. But one of the fun things about your work, because I think it's something that I and a lot of people just know very little about. So we've got the chance here, to kind of give us a bit of a dusty plasmas 101, a look into your research focus. And then help us understand not only what they are, but how they impact space, and why they matter to you and to others in these organizations that we've talked about.
Lorin Matthews:Yes. So one of the things that I look at is the formation of cosmic dust bunnies, which is dust bunnies in space. So, you know how you collect dust bunnies here on earth, and they kind of pile up under your sofa or under your bed? In space, there's not a corner for them to pile up, but you have the whole dust cloud that you create stars from. So when you create a star, what happens is you have this huge cloud of gas and dust that, for some reason, starts to collapse. And as the star forms in the middle, all of the rest of the material is collapsing towards the star. And then just like a figure skater that is bringing in their arms and rotates faster and faster, as the cloud collapses, it starts to spin faster and faster. And what that does is that it causes the cloud to actually collapse to a disk, just like when you're throwing pizza crust in the air and it's spinning. It spreads out into a flat disk. So that material in the flat disk is what we call a protoplanetary disk. And the planets are then formed from the gas and the dust that is in that protoplanetary disk. So one of the things I look at is, how do you actually stick the dust together to form larger structures? And the very first stage in that is the formation of dust bunnies, where you're just sticking these tiny little dust screens together, and they form these fluffy structures.
Derek Smith:When we picture space dust, how big is this space dust, and how big can the bunnies become?
Lorin Matthews:So when we talk about dust, we're talking about things that are micron-sized, which means that it's one billionth the size of a meter, which is rather hard to picture. But if you think about a human hair, it has a diameter of 100 microns. So the dust that we're usually talking about is one to 10 microns in diameter. And some of that dust can be smaller than a micron in size, but the average is about one micron. So you can see it, if it is say eliminated by, in the lab, we use a laser beam. You know how dust sparkles in the sunlight, it'll do the same thing in a laser beam. So you can actually see it with your unaided eyes, if you're looking at it in the lab.
Lorin Matthews:So the dust bunnies, how big do they get? So when they start to stick together, they can actually form quite large structures. When I say large, I mean up to a couple of millimeters or possibly even up to a centimeter in size.
Derek Smith:So obviously, these can be the building blocks, as you said, for planetary formation. But as they're floating around in space, gathering dust, collecting size, what are some of the impacts that they can have? What intrigues you, as you picture a dust bunny floating in space? What are some of the questions that you have that you want to answer?
Lorin Matthews:So one of the outstanding problems is, how do you get larger than say a few centimeters in size? Because we know eventually planets can be as large as Jupiter or even bigger. And there is a stage in planet formation where you have something called planetesimals, which are some sort of a fraction of the size of the earth, that then can interact through gravity and actually stick together through gravity. So with these small centimeter-sized dust structures, gravity doesn't work very well. But since they're charged, they do interact with electromagnetic fields, which means that any magnetic fields in the protoplanetary disk, or since they're charged, they're going to repel and attract each other. And that affects their growth. And it affects how fluffy the dust bunnies are. And that's important because we want to know how fragile they are. And so as you start sticking them together and they're colliding at higher velocities, do they actually survive or do they fragment and fall apart? We know they have to survive at some point because planets exist, but we haven't come up with a model that can actually build things from the micron-sized up to the planetesimal size. All of our models show that at some point, everything should disintegrate.
Derek Smith:This is Baylor Connections. We are visiting with Dr. Lorin Matthews, Professor of Physics at Baylor and Associate Director of CASPER, Baylor's Center for Astrophysics, Space Physics, and Engineering Research. And Dr. Matthews, as you talk about planet formation, how should we envision what that looks like in the current day? I think most of us, we studied the planets at some level through elementary and high school, and to whatever extent people took science courses in college. We know about Saturn, we know about Jupiter and Mars. But what does space, excuse me, planet formation look like now long after most of us probably stopped thinking about the basics, the fundamentals?
Lorin Matthews:The telescopes that we use today have evolved so far. And the very first planets were actually discovered in 1995, when I was a graduate student, just starting to study this. So that was the first time that we were actually able to see protoplanetary disks in our telescopes. That was the Hubble Space Telescope pictures. And so that was exciting to see, that the theories that people had come up with about planet formation were actually true. And now we have telescopes that are so good that we can actually image planets around other stars. And we can see the things that we've predicted, such as the gaps in the protoplanetary disk. If you have a planet that is actually gathering material, it should empty out a lane in the protoplanetary disks, so that you have these grooves, like records, in the disk. And we can see those with the telescopes now.
Derek Smith:In a lot of ways, are we talking about, in what you're involved in, still a relatively new area of study?
Lorin Matthews:That is true. So not only is it the development of the telescopes, but it's also the development of the computers that we have to actually study these. So I do numerical modeling, which means that I write computer programs that contain the physics of how these charged dust particles interact, and how they actually collect the plasma particles and then interact with the plasma. And so the computers are getting powerful enough now that we can model the hundreds of thousands of particles, or really we need millions of particles, to actually start seeing what goes on when we have these complicated interactions occurring.
Derek Smith:What kind of things excite you, as you look at, as you create these computer programs that model behaviors? What are the things that, as you complete a specific program, you're most excited to look at or excited to see?
Lorin Matthews:So my numerical models actually result in movies. And so it's always really interesting to watch the movie of how your model has evolved. And sometimes you'll see a model and things that happen, you'll go, "That could never happen. There must be a mistake." You'll see things flying off in strange directions. And other times I will see behavior and say, "This doesn't really make sense. I must have some bugs somewhere in my computer program." But then I show it to my colleagues that do the experimental research in the lab and they'll say, "Oh, no, we have actually seen that happening in the lab. We thought it was strange, but that's what it actually does." So that's how we do our research. We have the numerical models, and we try to make it match what's going on in the lab. And in the lab, we see behavior, but we don't know why it's occurring. In the computer model, we know exactly which forces we have turned on. And so we're able to see the unseen. So in my computer models, I can say, look at exactly what the ions in the plasma are doing, which we can't see when we're looking at the gas in the lab.
Derek Smith:Very exciting. And obviously that work that you're doing, the interest in, as we talked about the program, a lot of interest from organizations that have funded your work, like the Department of Energy, National Science Foundation, and others. And in fact, in particular, you've recently received grants from the NSF and from the Department of Energy. Can you just take us a little bit inside those projects and what they'll have you working on in the years ahead?
Lorin Matthews:Yes. So one of the really interesting things about the dusty plasma systems is that they are able to self-organize. So we talked about building the dust bunnies, which are kind of fractal in nature. They're fluffy, irregular structures. But in the lab, when we just put a few dust screens into the plasma and they charge up and interact with each other. They actually form regular structures. So we can form dust crystals, or we can form dust strings. And the interesting thing about the strings is if we form more than one string, they'll actually form helical structures. And sometimes we can form balls of dust that actually have shells, and each shell has a certain crystalline structure to it. So one of the things we're looking at on the fundamental level is, how does structure evolve, and how does the plasma interaction with the dust screen stabilize these structures? And this becomes important, say for the Department of Energy, where they're looking at fusion and trying to confine the plasma with magnetic fields. And at the same time, the plasma will eat away at the walls of the container. And it will form dust, which is bad if you're trying to have fusion. And so we're looking at, how does the plasma interact with the dust? Where's the dust going to go when it's in this electromagnetic field, and how will that affect the ability to create power in the future?
Derek Smith:Well, Dr. Matthews, another example of research growth and opportunities is some news that's very exciting, especially for you and your colleagues, that Baylor was one of five institutions recently selected to study dusty plasmas on the International Space Station, by NASA and the NSF. How was Baylor selected in that process and what opportunities will that open up?
Lorin Matthews:Yes. So the dusty plasma research has a long history on the International Space Station. It was actually one of the very first scientific experiments to be performed on the space station. And this experiment was developed by ESA, the European Space Agency, and the Russian Space Agency, Roscosmos, and they have been the ones that have selected all of their research and run this project since its inception. And about three or four years ago, they partnered with NASA to actually have a call for research proposals that would be from American universities and American scientists to propose research. So Truell Hyde and I wrote a research proposal for that, essentially a competition. And we were able to leverage all of our partnerships at other universities and around the world to write a very competitive research proposal. And so we were one of the six selected in the United States. And since that time, we have also worked with the other universities in the United States who were selected for these research projects, so that we've collaborated on the kinds of projects and experiments to be run on the space station. So we'll all get together and say, "If we run this experiment, each of us will look at a different part of the experiment and bring our own expertise in how to analyze the results." So that has been very fruitful. And one of the fun things about that is at Baylor, in the lab, Truell Hyde built a mock-up of the experiment that's on the space station. So this is an exact replica of the experiment, but this is the only one in the world where we can switch the diagnostics in and out. And so we can look at what's going on in the experiment, different ways than anyone else in the world can, and test different things that we'd like to try before they're actually implemented on the space station.
Derek Smith:Well, Dr. Matthews, as we head into the final couple of moments of the program, I want to shift gears just a little bit, because we mentioned at the top of the program that you earned an outstanding Undergraduate Mentor Award from Baylor's URSA, Undergraduate Research Scholarly Achievement. And you mentioned at the top of the show, how it was a conversation with a professor, Dr. Truell Hyde, that really shaped your career path. And I'm curious, for you, what role students play in your research and what your philosophy is on mentoring students and what it means to get to pour into them through your work?
Lorin Matthews:Yes, so much of my research would not be possible, were it not for the contribution of the students who have worked on it over the years. So I've been very fortunate to work with many talented students. And for the numerical modeling side, a lot of these students are writing components of the computer code. And if they set up a part of the computer code that works well, we'll use it for the next 15 or 20 years. So a lot of what I do is provide guidance. They'll get stuck on something and I can help them try different things until they get unstuck. And every single student has a different personality. So some of them need to be given instruction along the way, and others I can say, "Here's the main goal. Now go off and do your thing." So it's kind of getting to know each student and their personality and their work style and helping them then work towards the goals that they want to achieve.
Derek Smith:Dr. Matthews, appreciate your time today, coming on Baylor Connections. Thanks so much for joining us today to share.
Lorin Matthews:You're so very welcome. I've enjoyed it.
Derek Smith:Dr. Lorin Matthews, Professor of Physics and Associate Director of CASPER, our guest today on Baylor Connections. I'm Derek Smith. A reminder, you can hear this and other programs online at baylor.edu/connections, and you can subscribe to the program on iTunes. Thanks for joining us here on Baylor Connections.