Dear friends and colleagues of Dr. Timothy J. Lee. By now you are aware of his recent and unexpected passing. We interviewed Tim some time ago and were looking forward to posting it in the Scientist of the Month series on the Code ST website once the final review and edits had been accomplished and the final version approved. Upon hearing of his passing, we reached out to his family through Chris Dateo and obtained permission to post the interview, which follows below.
At the end of the interview is notice of a virtual memorial gathering and ceremony for Tim, hosted by his colleagues, on January 21, 2023, at 11:00 am PST/2:00 pm EST/7:00 pm GMT via Zoom, per the invitation and link provided.
Scientist of the Month Interview
with Dr. Timothy J. Lee of the Planetary Systems Branch
We generally start by asking about your childhood, where you are from, something about growing up, your family, and in particular if there was anything about your young years that might have directed you along the path that resulted in where you are today.
I grew up in Colorado, in a suburb on the outskirts of Denver. I had two brothers, one a year and a half older and the other a year and ¾ younger. I was the middle boy. Now, after having had three boys myself, not that close together, I think my parents must have been insane (laughs) having three boys so close together! I grew up in an area that I guess you’d call blue collar; none of the parents in the neighborhood had gone to college. My parents may have taken a community college class but nothing more than that. And at a time when most women didn’t work, my mother did work, so I had babysitters from the time I was about 2 or 3, up until my teen years. My mother died when I was in high school due to medical incompetence and that was quite a difficult time, but all us boys were really good, so we managed in spite of that to go to college and graduate. Eventually my father got remarried and things were better for all of us. My brothers and I were the first in our family, at least in our line of the family, to go to college. We had an uncle who was a lawyer on my mom’s side and she had a cousin who was a professor at Harvard, that I got to know a little bit. I guess to finish up my young life, one of the babysitters we had, their family was really into sports and they had one boy who was the same age as my younger brother and they got all of us into sports, so from early on we all played sports. We played everything and anything: football, baseball, basketball, pick up sports, tennis, bowling, even putt golf during the summer, anything that didn’t cost too much money. We did regular golf at a par three golf course. That is how we stayed out of trouble, I guess.
And then I went to college, to the Colorado School of Mines. My brothers and I were relatively smart and did pretty well in school, although I can assure you, given where my children have gone to school, and where I went to school, that the schools around here are a lot more competitive than the ones I went to. It was a blue-collar area with a lot of engineers’ children there, but we did well, and between working and scholarships, I paid for college. And I should say, I’ve had some sort of job ever since I was eight, so I have worked most of my life.
So you went to an engineering school. And what guided your interest toward chemistry?
It was before that. I had high school chemistry teacher who was really good, really a nice person, and I decided I would study chemistry. That’s what really motivated me to become a chemist. Then at the School of Mines, I found I was really good at math as well, so I took some extracurricular classes in physics and realized that although I was getting a degree in chemistry, I really liked math and physics too. At some point, talking with the professors there, I decided that I wanted to go off and do a PhD and I realized that they actually pay you. You don’t have to pay to go to school, and I thought, “Well, I can do that”. So I applied to various places, to some really good ones, and to some not as great, and during the time after I applied but before they made decisions, I went out to visit a few of them. I was accepted into most of the second-tier places, but not the top rated ones.
I spent the summer between my junior and senior years doing a Lando Summer Research Fellowship. NSF has these programs where universities can apply and are provided money to have summer interns in a particular discipline. I had gotten to know some people from all over the world; one of them a fellow from San Francisco and another a girl from North Dakota. The three of us had become friends and we decided that the girl from North Dakota and I would meet up with the guy in San Francisco and together visit Stanford and Berkeley. When I called up Berkeley, they said fine, and they scheduled a whole day with interviews and everything. I met with one of the professors there who was an organic chemist but who was also doing what he called “molecular orbital theory”, which was really applied quantum chemistry. I am a quantum chemist, that’s what I ended up doing my PhD on, and I think the only reason I got accepted to Berkeley was because of him. I showed interest and had taken some more advanced math and physics classes, and he could see that. I had also taken an advanced organic chemistry class and I think he thought I would be an ideal student for him. When I arrived at Berkeley, they told me “You’re in the organic section”, and I said “I don’t want to be in the organic section, I want to be in the physical”. And they said “OK, you’re in the physical section!” So, I was in the physical chemistry section and that was when I met the professor who was the theoretical chemist, the electronic structure theory person, and that’s what I had my PhD in. He was a really nice guy, I really liked him, and he had room in his group, so that’s the group I ended up joining.
I lived in Berkeley from 1982 until the end of 1986.
This is great, you’ve basically ripped through the first three questions, about your young years and education, and your path, but then something at that point must have gotten you interested in either space related physical chemistry or the space program and NASA Ames?
Well, NASA Ames had a computational chemistry branch. You’ve been here a long time but I don’t know if you have ever run into or heard about it?
I have heard of it.
Some of the early people in it, who really made its reputation, were Charlie Bauschlicher, who is still here, and Steve Langhoff, subsequently Stephanie Langhoff, and Harry Partridge. These are all names you know. The people who started the branch were Jim Arnold, Dave Cooper, and another guy, I can’t remember his name, they started the Computational Chemistry Branch.
Yes, when I started in Code S, we had four divisions and Jim was Chief of the Space Technology division.
I remember that. That was a very short period of time, I was in one of the branches in his division. Dave Morrison was the Director of Code S. I remember because it was during that time that I won the Dirac Medal. The Dirac Medal was in electronic structure theory, but it’s a little broader than that. It also includes the dynamics as well. In theoretical chemistry they have two major awards for people under 40. One is a medal given by the International Academy of Quantum Electrosciences and the other is the Dirac Medal, given by what is now called the World Association of Theoretical and Computational Chemists. Their acronym is WOTOC, because it was originally the World Organization for Theoretical Organic Chemists. They kept the same acronym but they changed the name. I was awarded the first Dirac Medal which is interesting because it was the only one that never had any restrictions. Now you can’t have two people from the same country win it back to back and you can’t have anyone who has won the medal from the International Academy of Quantum Electrosciences win the Dirac medal, so that was the only time it had no restrictions on it.
OK, so you found out that Ames had a computational chemistry group. Did you seek it out?
Charlie Bauschlicher was also a student with my advisor at Berkeley, and my advisor at Berkeley and a colleague of his were the first professors in the US, in the world actually, to have their own, what they called then a super-minicomputer. They had proposed to the NSF to get money to buy a machine that was probably not as powerful as these phones are now, and they were successful. This was at the time when people were finally beginning to use computing a lot. Theoretical chemists had been using computers since they first existed. The first theoretical chemists who did calculations in the 1930’s used the hand cranks. And as computing power developed over the years, theoretical chemists were always among the first on these systems wherever they were, in Cambridge or wherever. So, my advisor and his colleague around 1979 got funding for their first super-mini and when I joined the group they had already upgraded it once and were getting ready to upgrade it again. But they made a bad decision: they chose a competing company that had hardware that was pretty fast but it didn’t work. The operating system didn’t work very well and that meant that your codes ran into a lot of problems. And in those days if you were a theoretical chemist you couldn’t just do calculations because you’d be taking 20 years to do your PhD. You had to do development of methods, too, otherwise you just weren’t going to get done in a reasonable amount of time. I worked a lot on the development of methods, transporting codes from one computer to another, and writing new codes and things like that, which was in Fortran of course, which is not what people generally use today. And during that time we got to know, because of the difficulties we were having, my advisor was reaching out to some of his friends and colleagues who had computing facilities, that we could collaborate with, so that we could: 1) get some calculations done; and 2) also do some development work with these people. During that period I got to know some of the people in these groups, both at NASA Ames and at IBM Almaden, the IBM Research Center. My advisor knew them both very well. My advisor was a real bigwig in the field. He was approaching 2,000 publications and had won all kinds of awards, so he had friends all over the place. I got to know the computational chemistry branch pretty well during that time and then when I was finishing up, I met my wife. Well, she would become my wife, she was doing a PhD in theoretical chemistry at the University of Cambridge and her advisor and my advisor were good friends. She had come out to visit our group to do some development work and I had gone back to Cambridge to do some development work during our PhD’s, and then she came out to postdoc with my advisor, because in the UK they typically take three years to do their PhD and in my group you took four years so she was done a year before me. She was a postdoc in the group I was in for a year and then we both went back to Cambridge and postdoc’d there. While we were back there for about a year and three quarters, we got married. And then we needed to go somewhere, and we had a two-body problem at that point, and to be honest I would have preferred to be in academia, that was my preference, but my wife really didn’t want to be in academia. And the opportunity came up for her to go to IBM for another post doc, so she was going to go have her third post doc, and I came to Ames to work in the computational chemistry branch as a contractor. They were building the program and within five months I was hired as a civil servant. That was in February, 1989. A few months later she was hired as a permanent research staff member at IBM.
Great! What an interesting story of your life before you got here, that probably very few people know about. Tell us a little bit about the interesting work you’ve done in your field here at Ames, including what you’re currently working on, and how that work is relevant to NASA’s research interests and why it’s important to the taxpayers who are paying for it.
When I got to Ames in the computational chemistry branch, I was still doing development work, but I needed an application area that I found interesting. Sometime in the early 90’s I decided to start working in atmospheric chemistry and that was really the first area, the first application area, where I started to become passionate. But I should take a step back. I had always been interested in spectroscopy, so I had always been doing, as a graduate student and as a postdoc and then in my early days at Ames, I was always doing aspects of vibrational spectroscopy and ro-vibrational spectroscopy. I would apply it into different areas but in the early ‘90s I started to get into atmospheric chemistry and I applied for spectroscopy there but I also looked at a lot of other aspects, ozone depletion chemistry, for example. That was really what I focused on in the early ‘90s because there was a lot of interest and understanding of what kind of molecules are in the stratosphere, in the troposphere and tropopause, and they were still trying to explain how ozone holes occurred and opened up and things like that.
Is there any difference between vibrational spectroscopy and the standard kind? Are they the same?
Oh, there’s all kinds of spectroscopy. Vibrational is like the molecules will vibrate. In the ground state it’ll be like that (wiggles his fingers back and forth), and in the excited state it might be going like that (wiggles his fingers much faster), you’re looking at transitions from one state to another. And ro-vibrational just means that it’s higher resolution so you’re taking into account rotation, rotational transitions within the vibrational manifold as well. I had done some of that as a postdoc because, really where I started to make a name for myself and probably one of the reasons for the Dirac medal, is . . . there was another postdoc in Cambridge who had also done his PhD in the same group as me, and then postdoc’d in Cambridge, who developed this vibrational second order perturbation three program to compute the ro-vibrational spectroscopic constants of small molecules, like water, methane, ammonia, things like that. During that time, starting from the late ‘80s through the ‘90s, that was sort of a hot area for development. In a lot of fields, you have a period of time where everybody starts to jump on the same bandwagon and they make a lot of progress in some area and that’s when people started to make a lot of progress on ro-vibrational spectroscopic constants for small molecules. And one of the things I had done was to develop – again I was an electronic structure theorist – in late ‘89 a particular electronic structure method had been developed and I was one of the first people to implement it in a really good program. This method was called “singles and doubles couple cluster with perturbational estimate of triples”. As it turned out, that is now considered the gold standard in electronic structure theory, and that’s because we could compute a force field for a molecule and then use the vibrational second order perturbation theory to compute the ro-vibrational spectroscopic constants and could get very close to experiment, very close to high-resolution experiment.
And that’s important to NASA because?
Because, for example, right now we are using these types of techniques to help identify molecules that are being observed by Naseem (Rangwala) and her co-workers on SOFIA (Stratospheric Observatory for Infrared Astronomy) using the EXES (Echelon-Cross-Echelle Spectrograph) instrument. A lot has happened since then so we are also using variational methods to solve the nuclear equations for what we call “line lists”, which allow people like Mark Marley to use them to help characterize exoplanet atmospheres and things like that.
Is it related to the search for life?
We can do this kind of thing for molecules that would be considered a bio signature and then help to identify whether a particular atmosphere or planet might be habitable or inhabited or something like that, so yeah.
That’s something the taxpayers love to support, the search for life, because everyone wants to answer the big question.
Right. It’s still early days for trying to do that and not just in the work we’re doing but especially in the telescopes that will be able to do those observations.
Your career is not by any means finished now. . .
But it’s getting closer to the end than to the beginning! (smiles)
Have there been major findings, or interesting discoveries or things that you’ve been involved with?
A: Well, to sort of finish up what I was saying, in the ‘90’s we were the first ones to really show that the main problem with computing these ro-vibrational spectroscopic constants was the electronic structure method. We didn’t have a good enough electronic structure method, but the second order perturbation theory was pretty good at computing the spectroscopic constants. We needed the better potential, because we had developed a method to do that. And then we had this program from my colleague, who was also a postdoc at Cambridge, and we were able to use it and show that the spectroscopic constants were close to experiment. And that was a surprise to the community. We got a lot of good press out of that. I’ve been involved with a lot of things where we’ve had really useful results, where we were able to explain things where before nobody had been able to do it. But they tend to be sort of technical, too. One thing that we’ve worked on recently, if you were to talk to somebody like Xander Tielens, he would tell you from about the 1980’s onward one of the holy grails of PAH (Polycyclic Aromatic Hydrocarbons) is to compute the anharmonic spectra of PAHs, and then be able to actually simulate the emission spectra that astronomers actually observe from PAH’s in the mid-infrared. About six years ago, Xander had a lot of research funding and he wanted to try and do this so he was talking to me about it. He was working with somebody else at the time and I said “Why are you working with somebody else? I’m one of the world’s experts on this, on vibrational second order perturbation theory, why don’t you work with me?” He said “OK”, and then he advertised for a student and a student applied who had a really good background for this, and he accepted him, and he came in to do his PhD at Leiden. We spent four years meeting on skype every week whenever we could, whenever we were all in town. And he came out here a few times to work with us, again this was a code that my colleague at Cambridge had developed. He had developed it from molecules like water and methane and ammonia but now we wanted to use it for polycyclic aromatic hydrocarbons, PAH’s. These are much bigger systems and the code was not developed for that although we had made some improvements to the code in the ‘90’s that were absolutely necessary to do this PAH work. Anyway, we had to make again some modifications to the code to use it for these really large systems and the student that Xander had was really good, his name is Cameron Mackey. Over the four-year period he worked out how to compute these anharmonic vibrational spectra of PAH’s and from there he worked out how to do temperature dependent vibrational spectra of PAH’s taking into account resonances, which change as you move up the vibrational progression. He figured out how to do that. And once he had this library of temperature dependent spectra, he could take that and simulate the emissions spectra that astronomers actually observe. So for the first time we could actually simulate the spectra that astronomers actually observe, and that was just his one PhD. In four years, he managed to do that! Just to give you an idea of how impressed the community was, in the last few years we’ve had the astrochemistry subdivision of the physical chemistry division of the American Chemical Society established and also the Laboratory Astrophysics Division of the American Astronomical Society. Farid (Salama) had a lot to do with that one and I had a lot to do with the first one. Both of those organizations give out dissertation awards and so Xander and I nominated Cameron for both of them, because they were both due about the same time, and he ended up winning both of them the same week! He won not only from the more astronomy-based organization but also the more chemistry-based organization!
That’s impressive! So, what is a typical day like for you in your work here at Ames and what do you like best and least about your job?
I like best now that I get to spend most of my time doing research. And the aspect that is probably least favorable right now is having to write so many proposals. But then if you win you don’t have to write so many! (laughs)
That’s a good attitude!
And I’ve been doing pretty well so far this year, we are two for two!
So, you have come along this track and you’ve gotten to where you are, a luminary if you will, in your field, but if you weren’t doing this have you ever thought about what your dream job might be?
I’ve always liked doing research. The grass always looks greener on the other side, of course, but as I said earlier, I would have always preferred to be in a university, and I still have a lot of academic colleagues. On the other hand, at times they have all had to deal with things in their jobs that were not so great either, so I don’t know. I am looking more towards the retirement aspect at this point, than what my dream job would be. I can tell you in retirement what would be nice is to set it up so that I could come in and do the research I wanted to, work with young people, and not have to deal with a lot of the bureaucratic things.
What advice would you give to a young person who would like to have the kind of career that you are having?
Actually I gave a talk on that at a university, I believe it was the University of Buffalo, about a year and a half ago. They invited me specifically to give that kind of a talk and to give advice on what their students should do, and one of the things I said was that you have to persevere. I tried to tell them you have to put your name out there and keep trying. One of the reasons I probably received the DIRAC medal is that I kept applying for academic jobs, so my name was out there. And as the only non-academic ever to win the medal, I think that tells you something. I had done really well as a grad student and when I came here as a contractor, I expected to apply for academic jobs. Julie was at IBM but when NASA offered me the job, I said, “Well I would be stupid not to take it, it doesn’t mean I can’t still apply for academic jobs”. I interviewed for the SST branch chief’s job and when Michael (Bicay) got promoted and Yvonne (Pendleton) became the division chief, she hired me, initially on a detail from Code T, as the branch chief. And then Yvonne went to HQ and she encouraged me to consider the division chief’s job, and when Michael asked me, I accepted. So, I think the lesson here is you should persevere.
Is there anything else you want to share about your family, like kids, pets, trips, anything like that?
We have 3 boys and one dog now, she’s 2 ½ years old, a Labradoodle, because my family has allergies, asthma and allergies. Our boys are all pretty smart, not surprisingly because their mother has a degree in theoretical chemistry, as I do. Our oldest son is finishing up a PhD at Cal Tech in theoretical chemistry, not because we told him to do it but because it’s something he wanted to do. Our middle son has already graduated from Berkeley in computer science, with a minor in physics, and is now working at Google and living at home. And I’m sure a lot of people who knew me during the time he was in high school would be just shocked to know that he and I are getting along just great, because he could really push my buttons when he was in high school (laughs). But he’s turned into a wonderful human being.
It takes a while for kids to learn that their parents aren’t quite as dumb as they thought they were!
Yeah, well there’s this famous Mark Twain quote, have you heard it? He said: “When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much he had learned in seven years.” (laughs). And that’s sort of how that worked out.
And our youngest son just started at the University of Washington. He’s like that a little bit, and I’m waiting for him to learn that as well.
How about talents, hobbies, and the question we like to ask the most: what do you do for fun?
Well, let me talk a little bit about what I did in the past, because I played a lot of sports when I was growing up. I wanted my boys to do something like that, and I love baseball, so I coached baseball. I coached them all in baseball. I coached baseball for fourteen years straight. Six of those years I coached two teams, so about twenty different teams in all, and that’s not counting several All-Star teams. By the end of that I was so happy that it was done. But I enjoyed it, in the beginning especially, although I also knew at the end of it that it was getting to be harder for me to do things. The last couple of years I couldn’t even throw the ball as hard as the boys could, and these were 13-14 years old boys, and I thought that was ridiculous. I remember in high school, throwing the ball was one of the things I did well. Once I was playing catch when I was on the varsity team, one of the kids standing next to the guy I was playing catch with said “The ball’s whistling. It’s whistling!” I was throwing the ball hard enough that it whistled, which must have been 85-90 miles per hour. So, when I got to the point where I couldn’t throw it as hard as 13-14-year-old boys, I thought, “It’s time” (laughs). Now I think my wife and I would like to travel. We haven’t done that too much recently. We also like to eat out. So, it’s getting to be more like “old fogie” stuff. (laughs)
Who or what inspires you?
Well, at various times in my youth I wanted to be a policeman because I was inspired by the father of one of my friends, who happened to be the police officer assigned to the bank where my mother worked, so I wanted to be like him. Then later on, I wanted to be like my uncle, who was a lawyer, so I wanted to be a lawyer. And then after that, I wanted to be a chemist, because I had a really good chemistry teacher, and then eventually a scientist. I was inspired by my thesis advisor and my postdoctoral advisor, who were both . . . they were different people, but they were both really good scientists and decent human beings.
Did you ever get a chemistry set when you were little and work with that, or did you just go into the kitchen and do crazy stuff?
No, the chemistry I do is on a computer. My lab is a computer. I do remember though, when I was doing the Lando Summer Fellowship, the Colorado School of Mines has what they call a summer field session. Everybody has to do a summer field session and it’s usually between your junior and senior year. And in chemistry, at least at that time, I’m sure it’s different now, we looked through this book (a large tome: Cotton and Wilkinson, “Inorganic Chemistry”). We had 1½ hours of class every morning and the rest of the day was a lab. And in the lab, we had to make inorganic compounds, which can be a little smelly. And when I got to Minnesota, I still had to write up all my labs, so I spent some time in the library at Minnesota writing up my labs, and one time a couple of other Lando Summer Fellowship researchers came through and they were the type of guys you’re talking about, who liked to blow things up, and they were asking me “We’re trying to figure out how to make nitrogen triiodide”. And I said, “Oh. I remember we read about that; I know how to do that”. I told them how to make nitrogen triiodide. And maybe I shouldn’t have. It’s really simple to make it, you just have to bubble ammonia through an iodine solution. They did and it’s fine until it dries. It dries in a crystalline form but nitrogen triiodide very readily becomes nitrogen gas and iodine gas and so it explodes. They said they did a little under the hood and it was quite a bit more explosive than they expected. They took the rest of it, while it was in liquid form, and they threw it down on the banks of the Mississippi. And I thought that’s probably not very smart, because when it dries . . . (laughs). And another thing that they did that summer is that they got a piece of sodium or lithium or potassium, I don’t remember which. Do you know much about any of those metals?
No.
They react with water very readily. And so, when they ship things like that, they have to ship it in oil, for obvious reasons. Anyway, they got this piece of it and they told some people about it and then walked over the river, our dorm was on one side and our lab was on the other side, and halfway across they just dropped it. That was the first time that I’d ever seen fire underwater! It was pretty interesting! (laughs). I’m sure they were doing things they shouldn’t have been doing.
OK. We always ask if there is a particular image that is meaningful to you that may be related to your career or not that you would like to have posted with this and you can actually think about that and get back to us and maybe a favorite quote that you would like to share, that exemplifies your perspective or your approach to life or something like that. Thank you for taking time to sit down with us for this interview.
Thank you. (End of Interview)
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December 24, 2022:
Dear Colleagues,
As you almost certainly know, we lost Tim on November 3, 2022. Ryan Fortenberry, Xinchuan Huang, and myself are hosting an online memorial ceremony for him. This will be held on Saturday, January 21, 2023 at 11 am PST/2 pm EST/7pm GMT via Zoom. This ceremony is expected to last 1 to 1.5 hours. Please join us in this online ceremony to memorialize our esteemed colleague, friend and mentor Dr. Timothy J. Lee. Thank you.
Best regards
Partha, Ryan, and Xinchuan
