- The point of being a scientist is that you are now the explorer of the tribe of humanity. You are now out there to explore on behalf of your tribe, but then your job is also to come back and tell the story after the exploration. What have you seen out there that we don't know? Now you go back, you go out and see the world. Now for what I do, I see the universe, and then I come back and tell everyone, "This is what the universe is like." - [Voiceover] You're listening to "Further Together, the ORAU Podcast." Join Michael Holtz and his guests for conversations about all things ORAU. They'll talk about ORAU's storied history, our impact on an ever-changing world, our innovative scientific and technical solutions for our customers, and our commitment to the communities where we do business. Welcome to "Further Together, the ORAU Podcast." - Welcome to "Further Together, the ORAU Podcast." Recently I had that opportunity to speak with several NASA National Post-doctoral Program Research Fellows about the amazing work that they're doing. And I gotta tell you, I think you'll agree with me, their work is amazing and it's very interesting. If you're a space junkie like I am, you're gonna nerd out on these conversations, enjoy. Dr. Aaron Yung, if you would, talk to me about who you are, your current role as a NASA NPP Fellow, and then just a little bit about your background. How did you get to where you are? - Right, so I am an NPP Fellow at NASA at Goddard Space Flight Center, and I'm hired directly to work with the JWST team. So JWST, it need not further introduction, is pretty much the mission of this entry, is the most expensive, but also most powerful space telescope that was built, and now in space doing science. So I am a theorist, I've been making predictions for this telescope since five years ago. - Okay. - So when I was a grad student I created these galaxy models, and we create predictions that the observers can use to forecast what the observations will see. And to justify their science and to get telescope time. So, right when I graduated, the NPP program took me in, and gave me this opportunity to continue this theory-work here at Goddard Space Flight Center. So in the past couple of years I have been working with JWST teams. You know, we anticipate future observations, but now the telescope is actually in space and doing science, so I'm involved in a lot of these projects that go after the most distant galaxies in the universe. - How do you, Aaron, from a layman's perspective, how do you model what you don't know? I mean, I know that may sound like a dumb question, but how do you model what we don't know, we haven't observed? - Not dumb at all actually. So we do know something, largely thanks to the last generation of telescopes, like Hubble, like Spitzers. So by observing the nearby universe we already are able to learn the incredible amount of physical processes that drives galaxy information. We also combine this with other types of simulation. For example, there are cosmological hydrodynamic simulations that allowed us to simulate physical processes in a way that we cannot normally observe, 'cause they take a long time. So by combining this we can put together a self-consistent model, and we ask the question, with this physics that we know, do we reproduce the galaxies in the earlier stages of the universe that we are about to see? - Awesome, and have you been able to determine if your early modeling lines up with what you're seeing? Or is that still to be determined? Since I know that JWST is still pretty new, but... - It is, so it is been doing science for the past, just nearly four months actually. And there are already an incredible amount of observations and it already started the process of rewriting textbook. So what we found, or what the observers found, is that there are incredible amount of very bright, massive galaxies, forming within the first couple hundred million years of the universe's history. So the universe itself is 13.8 billion years old. So within the first couple hundred millions, meaning that it's just the first few percent of the universe's history. And there are these incredibly massive galaxies that form at that time, that we don't understand how they gained their mass so quickly, within so short period of time after the universe was born, when the universe was so hot. And, you know, conventionally, we think that it requires, it takes time for gas to cool before stars can form in the galaxy. So there are physics, definitely, we don't fully understand now, and some people are even coming out and say, "Hey, this is breaking our current understanding of cosmology." There's the standard model of cosmology, called Lambda-CDM, which consists of the cold, dark meta and dark energy, which predicts how the universe was formed and evolved over time. But this seems to be raising some tension, maybe the universe is older than we thought, we don't know. - That has to be exciting though, to sort of be on the cutting-edge of that scientific inquiry, but also changing what we thought we knew. - Yes, so I kept telling people about, this is how science is being done in real time. So there are things that has been written on textbook, which took years of science to distill, to get to a point that, you know, it goes into textbook. But before that happens, there are these cycle, that theory and observations works together. So the way I describe this is astronomers are like someone riding on a bike, or just humanity in general. And sometimes theorists put a foot down by making predictions, and so we go forward a little bit. But then observers go do observation, and they look at the universe, and tell us what the universe is actually like. So the observer put another foot down, and then the theorist now, scratch our head, and try to model these galaxies and explain how this works together. And then we put another foot down, and this whole field advancing our understanding of the universe. - I love that analogy, that makes perfect sense. Aaron, have you always been interested in science? Was it something that came to you as a kid? Did you get interested later in high school and college or, you know? - So this is, yes, and there's a little story behind this. So physics always have a special place in my heart. I'm always curious about how the world around me works. You know, go back to playing Lego blocks, you know, building stairs and pushing things over. You know, everything is, to me, it's about understanding how things behave in the world. - Right. - But then I was really bad at math in school, not joking. So I barely passed math all the way up to high school. And I graduated high school with, I think, Algebra II, in American terms. So, not a particular advanced math class. So then I went to college, and at first I majored in finance and I thought that would be it. But then I was encouraged by someone, an uncle of mine actually, to pursue something I really like, 'cause I only get one chance. I got four years, I can do whatever I want. So I did well in the first calculus class I took, I got an A, it gives me some confidence that I can actually do math. And then I also was bold enough to switch over to major in physics, hoping that I would at least pass out. - Right. - And not knowing that, I did graduate with a physics and math double major in 2014. And that was around the time I considered maybe I should pursue graduate study in astrophysics. So I was also given the chance to do astrophysics research as an undergrad, and that carried me forward. And I was in grad school for a few years, and I get to start working with the James Webb Space telescope, which at the time, no one knows when it will be launched. And then here I am now. - Amazing, what a great story. Aaron, so how long have you been a NASA Fellow? - I've been a Fellow since October, 2020, so this is the beginning of my third year. - Gotcha. It sounds like there's been a tremendous impact on your career being a NASA NPP Fellow. Talk a little bit more about that. I mean, I know you're working now with the telescope that really didn't exist when you started, right? It was a theory when you started working on the models, right? - Yes, being, well, of course, three decades of hard work. A lot of people put in their effort way before me, and I joined- - Sure. - sort of at the tail-end, so I survived. So the fun part is when I graduated from my PhD, it was back in 2020, I was looking for a PostDoc job, and no one hired me at that time. My work was okay, but no one hired me, because mostly no one knows when JWST will be launched. Again, it's the mission of the century, but also it's been notoriously delayed for few times. - Right, right. - So the NPP program offered a chance that I can apply and go work with NASA, which is the only organization, hopefully, probably at that time, that actually need people to work on JWST. And my advisor, Jon Gardner, we met a few times before we actually worked together. But he he gave me a lot of good advice for how to approach this application. And at the end, this was my chance to continue my career, continue to make more theory predictions for that two extra years, which is very much needed to keep my career going. But now I get to actually work with the telescope because of the program. - Right, very cool. Is there an element of science that, or of STEM, that you find most empowering? - What kinda elements are we talking about here? - I guess, is there something about being a scientist that you find either empowering in your work, in your life? - So, yes, I think I get a sense of that now. So I'll tell you, it's actually the storytelling part. So actually this was way back when I was in high school. It's an acquaintance, I have not started doing science yet, but a friend of mine, which was a scientist, he used to study reverse streams and stuff like that. So nothing to do with astrophysics, but he told me the point of being a scientist is that you are now the explorer of the tribe of humanity. You are now out there to explore on behalf of your tribe, but then your job is also to come back and tell the story after the exploration. What have you seen out there that we don't know? Now you go back, you go out and see the world. Now for what I do, I see the universe, and then I come back and tell everyone, "This is what the universe is like." You know, when I was a kid I was curious, but I did not know there are people that study the universe. - Right. - I didn't have that resources, didn't know that these books existed, but then now I know this. So I also do a lot of outreach, I go tell kids, "Hey, do we have a telescope? This is what we will see." And then from there we can understand the universe's history, how does that work? Well, this is how it works, we have a time machine. - Right, right, oh my gosh, that's amazing. I was just talking to one of your colleagues about the early pictures that came back from the JWST team. What was that like for you to see, you know, firsthand, those first pictures that, you know, of course they were published and put in the public contents. But as a scientist, who's been around this project for as long as you have, how did that feel? - It's actually more sentimental than I first anticipated. - Okay. - So I was actually at Stockholm at that time for a conference. So when the US dropped those photos, at I think something like 5:00 or 7:00 PM, it was almost midnight in Stockholm. - Okay. - And a bunch of us, the astronomers, are gathering in, at first a bar, the bar closed, so they kick us out to the hotel lobby. And then we still have the two bottles of champagne, but we're all waiting for the web's first deep-field image. But that that was obviously really sentimental, but there are also several other moments that really touches me. For example, my personally, the moment that makes me feel real is when NASA released that image of JWST fully folded up. Actually, it dates back to November, when JWST is fully assembled and folded up. We have never seen JWST in that shape before, it was only the first frame of, the first free-frame of the animated sequence, how it unfolds. But seeing the real JWST in folded up position means that we're done, we're ready to go. After so many years, we're ready to actually launch it. It's not just a projected launch date, it's an actual, you know, we are ready to go. And they're also the 30 days of "terror," some people might call that, I call it 30 days of good news. While JWST is in the sky, unfolding on its way to the orbit. It's, we follow every step of it, I get hourly update on it. And it is so exciting to see that everything is working. And in March, it sends back the first set of engineering image. And that actually gave us the actual first glimpse of its performance, and how it compared to a past telescope. And that absolutely is blowing me away. - Right. - So yeah, there are so many moments of these that really touches my heart and really keeps me going, because there are days that I would just write code. That's what I do, as an actual day job. - And I love the image of you and your astrophysics colleagues, you know, in Stockholm, in a hotel lobby celebrating- - Yes. - you know, together, even though it's midnight. But celebrating together because you've all been living for that kind of moment. I can see how that would be completely sentimental, absolutely. - Yeah, it's been so long. We had Jennifer Wiseman, who's the project scientist of Hubble, who was with there with us, but also have Dan Cole from Space Telescope, who is involved in the reduction, the actual creation of those first images of JWST. - Okay. - So we get a personal tour of what is in there and what to look after, all the details. So it was a little of a privilege to be able to hang out with these people when the image dropped. But also all of us were just excited, no matter how long we have been with the project. - Sure, absolutely. Aaron, I know that, and you've talked about this a little bit, you know, science is a collaborative process. You're working with scientists of various disciplines. You're also in a mentored Fellowship as well. Talk about those things together, if you would, One, the collaborative process, but also the importance of mentorship. - Yeah, so I am a junior scientist myself. So I have been both a mentee, and starting to transition over to do some mentoring work. - Awesome. - So, it turns out doing science is never meant to be a lone process, you don't do it on your own. It's really learning everything, not just the knowledge, but also the work style, the skills they pass on from a person to the next person, when you work with someone, or from a group to another group. And the culture also pass on. So we sometimes we talk about inclusivity and things like that. It really comes from a, you know, a good working environment, which builds me, so that I will take it with me to the next place. So as a theorist who work with a telescope, I am required to collaborate a lot. I work with many observing teams. So there are lot of things that I learned from the process. For example, when I talk to an observer who needs to create mock images, there are things that, as theorists, take for granted, which the observers would have never thought of. So there is a general disconnection between these theory and observation community, which I see myself as the bridge for that. So my functional work is, yes, I work with these observing teams, I am collaborating with them. But also, my work and myself now facilitate as the the bridge between the community, between the observing community and the theory community. So this is actually a thing that should have been done for a long time, but hasn't been done much. So as a result, now we actually have more theory comparison, or theory mentioned in observation papers. - Okay. - So the observers, when they write a paper, they can ask themselves, or we ask ourselves, "Does these observation make sense, how do they stack up with current theory? And is the current theory sufficient to explain what we see?" Or we just don't understand it at all, so, yeah. - Wow, okay, that's great. What would you tell an up-and-coming scientist, someone who might be following your footsteps, what would you tell them? - Yeah, so I always recommend... When a high school student or more junior person approach me, I always tell them, "Do something that you are truly excited about." And don't just follow where the money goes. A lot of people do, when there's a big project happening, people always want to jump into it, and hopefully, you know, ride on the hype and become part of something bigger. But these projects come and go. And it's important to know that it's hard to jump in, because there are people investing a decade of the effort into making this project. But as long as I'm doing something I really like, for example, I fall in love with galaxy early on in graduate school. So I just love galaxy, an I can do galaxy with any telescope. And just give me a computer, I can also do galaxy without a telescope. - Right. - But it's important to explore enough in grad school, you can take advantage of being a grad student. Try as many things as you like without delaying graduation. Gotta say that safely. But just try something new and figure out what might be your true love, and then go spearhead and follow through that. - Love it, so figure out what it is that you love and follow that. - Yeah. - That's awesome, why would you recommend a NASA NPP Fellowship to others? - Well, NASA is a very special place for the thing I do, or that might be analogous to your interest, a student's interest. So unlike a traditional university, we have access to people actually building hardware, building a space telescope, building a balloon-born telescope, building a telescope that fly on a plane. So being able to directly talk to these people, just meet them, you'll see how the hardware side of things connect with the astrophysics, you know, with the things that we use this hardware to do. So there are some rare occasions that we get to influence the choice, the design choice of an instrument. For example, when the Roman Space Telescope has an extra future slot open up, they just solicit for, you know, simulations and reasoning, "Why should we add this feature?" And we were able to quickly do some simulations and tell them, "Hey, with these future choices, this will be the science outcome," which is something they can consider. So these are things that a traditional university will not be able to offer. - Awesome, and you have, as we've talked a little bit, you get to explore your ideas. You get to talk about, you know, this might work a little bit differently, or this might, you know, help us down the road. So you have a lot of input in the work that you're doing with the overall project. Last question for you, Aaron, is what brings you joy? - So there are days, of course, I was locked up, especially when I was a grad student, in the basement. Now we've been locked up and code all day, which does not bring me joy necessarily. - Sure. - But there are times, like when we receive the first image of JWST, when we look at the full resolution image, which is 300-something megabytes in a JPEG file. And we just zoom in and look at the glorious detail, you know, it's almost like doing your own sightseeing in the deep universe. And look at those cute spiral galaxies, look at the string of galaxies, almost like PacMan eating a string of beans. - Yeah, yeah. - Look at all those things, and it's all worth it. The late night crunching, everything. Now we get to actually see what the universe is like, and ask ourselves, "Do we understand what is going on in there?" Or there's more for us to discover, "Is there more galaxies than we thought?" Because physics is not exactly what we think it is. - Right. - So being able to understand and see the universe firsthand really brings me joy. - Awesome, Aaron, thank you so much for spending this time with me, I really appreciate it. - Well, thank you so much. - It's been great talking to you and getting to know more about your work. - [Voiceover] Thank you for listening to "Further Together, the ORAU Podcast." To learn more about any of the topics discussed by our experts, visit www.orau.org. You can also find us on Facebook, Twitter, and LinkedIn @ORAU, and on Instagram @ORAUtogether. If you like "Further Together, the ORAU Podcast," we would appreciate you giving us a review on your favorite podcast platform. Your reviews will help more people find the podcast.