"Sweet is the melody, so hard to come by.
It’s so hard to make every note bend just right.
You lay down the hours, and leave not one trace
But a tune for the dancing is there in its place."
This is a slightly edited transcript of what I told the students in my alumni seminar series course when I took an open spot on our schedule this past spring. It's a set of lessons illustrated with stories from my past. Among other things, I attempt to expose some of what is usually unseen by students looking at a successful academic scientist. There's a bit of Q & A at the end.
Lying to a Nobel laureate
When I started in graduate school, I definitely wanted to do theory. Laboratory courses as an undergraduate, really, I hated them. In looking back, we had so little time. There was not enough time to sit back and think about what you’re doing, maybe change something, improve it. At the University of Chicago, where I was in graduate school, there was a very rigorous laboratory course requirement that all the theory students hated. I put it off as long as I could because I had heard my friends complaining about how they weren’t able to get any of their real work done during the lab course, so I just decided I’m going to avoid all that stress. I’m not going to try to get any work done. I’m just going to take the lab course. It was taught by Jim Cronin and Ed Blucher. All my time was available for doing these experiments, looking at the data, and trying to figure out what happened, and trying to make things work. Actually having the time to do that, I found I really enjoyed it. It was an extraordinarily different experience from when I was an undergraduate. Jim Cronin was on a mission to convert would-be theorists into experimentalists. I actually considered it. The problem was, I was in my fourth year of graduate school and I had a lot of other stuff to learn if I was going to be on the beginning of a successful career as an experimentalist rather than a very short one. I looked into it. I spent a couple months down in Palestine, Texas working on a balloon-borne microwave telescope, but I was convinced to stay in theory, and that actually I could kind of work at this interface that could be the best of both worlds for me, and I wouldn’t have to learn all the stuff I don’t know about how to do experiments. That’s the path I went. I did a postdoc at the Canadian Institute for Theoretical Astrophysics and while I was there, Jim Cronin came to the University of Toronto and, he has a Nobel award in particle physics for discovering some particle. He came to the University of Toronto and did a colloquium there and afterwards I came down to say hello, and he said, “You look very familiar. You’re in experimental physics now, aren’t you?” Here I am in the Canadian Institute for Theoretical Astrophysics and, the truth is a little bit of a story, he’s a busy guy, and he’s so happy that he’s recruited me to experimental physics so I just say, “yes!” Then, a couple years later, I’m giving a talk at the University of Chicago and I notice as I’m about to get up and start speaking, Jim Cronin’s in the front row. There’s no hiding what kind of work I do. I started off the talk telling this story, and that’s how he found out that I lied to him. He just smiled and laughed!
That’s a little bit about my path toward being here, and I want to give you some of the wisdom I’ve gained over a couple decades, and one of the things is I want to also expose some of my inner experience in doing so, things we don’t often talk about, but I think are useful to know about. Before I tell you about my weaknesses and frailties, I also want to establish my credentials so you know something about who’s talking.
After joining the faculty at UC Davis I was put up for early tenure; two years after getting here, I had tenure. A couple years later, I was selected as a Chancellor’s Fellow. Five associate professors are awarded this each year, and I was one of them in 2004. I’m a Fellow of the America Physical Society, and the citation reads, “For motivating major observations (WMAP and Planck), developing widely-using data analysis tools, providing insightful interpretations of data, and calculating the impact of astrophysical processes on the microwave sky.” Just selecting my papers with one to a handful of authors: I have 18 papers with over 100 citations each. If we look at large collaborations I’m in, there’s 20 more papers with over 100 citations. Papers with over 100 citations are technically considered "famous." I have many more invitations to speak and visit than I can accept.
So there you have it. I have some degree of accomplishment. I'd say there are those in my generation who have had more distinguished careers to date, but I'm no slouch.
My title today is, "Sweet is the Melody." This is from a song I love by a country singer named Iris DeMent. The chorus is here on the board (and at the top of this article). Does anybody care to say what it means to them?
Student 1: Possibly that we do these things that are so very creative, meaningful, possibly very impactful, but they sometimes just drift off into the air.
Me: (Laughing) I hadn’t thought of that one. That’s definitely true, though. Any others? I promise not to laugh at you!
Student 2: Putting a lot of work into something, and sometimes the excruciating amount of effort that it takes to produce something good. I don’t quite get what the “leave not one trace” part means.
Me: Thank you. To get at what I see in that chorus, let me give you another story. Richard Feynman, he would spend hours, days, weeks, hard work, trying to calculate something, trying to figure something out, and then once he finally figured it out, then he’d spend just as much time trying to find out the simplest possible way to understand it. And then all that was hidden, and he’d tell you, “Of course it has to be that way, because blah blah blah,” you know. There was no trace of the hard work! All you see is what looks like unfathomable genius. I think that often happens. We see performances and we think, “Wow, I could never do something like that.” You don’t see all the hours, the hard work, the doubts and the troubles. When you experience challenges yourself, and you didn’t see the other person go through that, it can lead to distorted conclusions about yourself.
So, we see the sweet melody, and if done really well, if it’s good physics, it should look beautiful, and there shouldn’t be any sign of all the struggle. It’s one of the great things about physics, is just how beautiful understanding can be, how great that can feel to achieve it. With the credentials I’ve mentioned, you’d never know that in 1991, after my first year of graduate school, I brutally failed my candidacy exam. Leo Kadanoff, a member of the exam committee, felt compelled to let me know that there were more remunerative careers than academic ones. That was a really tough thing to deal with. Clearly, I recovered from it. Then, in 1995, months out of my Ph.D., I was struggling with this calculation. I kept thinking I was on the verge of solving it, and two months went by, the clock’s ticking, I’ve got a three-year position, and in the first two years I’ve got to do stuff that’s impressive enough so that I can get another job. And, here I was, two months in, beating my head against this thing, getting nowhere, and I thought for sure I was headed for Wall Street. I don’t know why I thought somebody who couldn’t solve problems would be successful on Wall Street, but clearly I was pretty doubtful about making it in academia. Self doubt is not all in the distant past either. In 2011, just a few years ago, I gave a talk at Stanford I was really unhappy about. I was feeling horrible about it. I remember waking up in the morning the next day and instantly I had a diagnosis of what was wrong with me, and a prescription of how I would rectify it. And also, following that was, “I don’t want to live this way for the rest of my life. Forget it.” Many times, feeling like I’m deficient in some way, has motivated my hard work aimed at remedying the situation. My accomplishments are partly driven by fears of my deficiencies and not being good enough. It’s also out of the love of the work. It’s not a simple thing. I feel really privileged to have been able to participate in a time that we were/are finding out so much about the cosmos. It’s been fantastically amazing. I've been able to contribute to the growth of a body of knowledge that will be in textbooks for longer than there are textbooks! But, it hasn't always been a stroll in the park.
Discoveries are out there just waiting to be made, or how I slowed down the advancement of science
This is the story of how I set back an important discovery by a couple years. This was in 1994. Arthur Kosowsky and I were graduate students at the University of Chicago. He came to me one day, and he was doing his thesis on cosmic microwave background polarization. He said, “Hey, Lloyd, I noticed that scalar perturbations source Q but not U.” The Q and U Stokes parameters quantify the amount of linear polarization. Arthur was saying that scalar perturbations (density perturbations) source Q polarization, but tensor perturbations (gravitational waves), source both Q and U. He was really on to something because it turns out that there’s a signature in the polarization pattern that’s distinctive, that isn’t sourced by the density perturbations -- by exploiting this fact one has a much more sensitive means for detecting tensor perturbations. I said to Arthur, “Well that doesn’t mean anything, Q and U are coordinate system dependent quantities.” And it’s true: if you choose one coordinate system and measure Q, and then you choose a different coordinate system, that Q will be entirely U. Saying that something produces Q and something else produces Q and U didn’t make much sense to me because of that. Things would have turned out quite differently if I had also said, “and yet, in your calculations, this difference happens. What is that about?” If I had had that response instead, then Knox and Kosowsky would be a very famous paper and everyone would have been citing it with the recent claimed detection of this signal in the microwave background on March 17th of this year. But that didn’t happen. Instead, two different groups (one including Kosowsky, fortunately) published this important discovery in 1997.
Why was it not Knox and Kosowsky 1994? Why didn’t I ask that question? I’m not entirely sure, but one thing was that it felt good to have something definitive. I knew about these Q and U parameters, and it felt good to be in a knowing state. And yet there was this puzzle that I didn’t follow up on: why Arthur was getting this difference. Why? What’s going on there? It can be uncomfortable being in a situation where you don’t know. I don’t know if that played an important part. I know another important thing was that, when you’re studying physics in school, you learn Newton’s laws and you don’t typically study Newton thinking “I wonder what Newton missed.” You’re learning what you’re being handed as the truth. It’s a much more efficient way to learn things, assuming that it’s all been worked out, and there’s nothing new there, because for the most part, that’s the case. You go through this whole training of everything’s all been worked out, everything’s already been discovered, and then it’s hard to psychologically switch into thinking there are things out there just waiting to be discovered, there are things out there that nobody’s thought of before. For CMB polarization, the first development of the theory probably went almost three decades before Arthur was doing his thesis on it, but there was still something really interesting to be discovered. You never know when that’s going to be the case. Know that they’re out there, just waiting to be made, and exercise your curiosity, and try to understand things! And, if some idiot tells you your ideas are not interesting, don’t be so quick to abandon your potentially interesting idea; i.e., don't make the mistake Arthur did.
On the flip side of this: I did a second postdoc back at the University of Chicago, and one day I went to the printer, that a bunch of people used, to pick something up. There was some paper there that somebody else had printed out. I started looking at it, and it looked really interesting, and I actually ended up calling up the authors because I wanted to work with them on this, and we did, and we published a paper that’s one of those famous papers. Using those tools and some other tools I put together, and just exploring the implications of the current microwave background data, (with these tools I could rapidly look at different combinations of parameters, different things) and one of the things I looked at was the age of the universe today. I was looking at probability distributions for all kinds of things, and suddenly I had an age on the x axis, and the probability distribution was this big spike. I just stumbled across this. I said, “Huh, that’s interesting.” I latched onto this as something interesting and got an analytic understanding of it, and published a paper on a more precise determination of the age of the universe. Actually, that was one of the significant things in getting early tenure, because that’s a result that a dean (from a different field than physics) can understand. If I had been younger and a little less experienced, I might have seen this and not known it was something interesting. So, discoveries are out there just waiting to be made.
Get comfortable with feeling stupid
When I was in my second or third year of graduate school, my professor gave me some problem, and for this I was supposed to read this review article about inflationary perturbations, perturbations from inflations of the early evolution of the universe, and these fluctuations are the seeds of all structure. Right at the beginning of the article, was this statement about the most general types of perturbations you could have to the spacetime metric, and it was just asserted like it was obvious, and I had no idea why it was true, and I just stopped working on that and moved onto something else. That all went fine, but what stopped me here was that it was really scary for me to look at this thing that I didn’t understand, here at the beginning of this review article, and there was something being asserted that I just didn’t know, I just didn’t know why it was true, I didn’t even know how to start to figure it out. Since then, I’ve learned from students who come and ask me about what they don’t understand. It’s not that I never asked questions, I did, but there was something particularly scary about this one that, subconsciously, I let it mean something about me. I was afraid that I wasn’t good enough, and this struck me as evidence that I wasn’t, so I just avoided it. Watch out for that. Now I understand it, it’s not a big deal.
That was not following the advice, "get comfortable with feeling stupid." Here's a story where I followed the advice. I was preparing just a few years ago to give a talk called “We Are Amplified Quantum Fluctuations: The Story of the Creation of All Structure in the Universe.” One thing that’s great about teaching and public lectures is that you learn a lot putting stuff together. You realize where your holes are, one of the wonderful things about teaching, is the rigor that applies to sorting out your understanding. I came back to inflationary perturbations, trying to understand this process well enough to talk about it, and realized that I don’t understand quantum mechanics. I don’t understand quantum field theory, and that’s really important to understanding the quantum fluctuations in the whole calculation! I was blessed to have colleagues here who thought about this a lot. I went to Andy Albrecht and told him that, and he said, “Great! Come to my group meeting and let’s talk about quantum field theory.” I did, and it was a fantastic conversation in which I learned a lot, and it was really exciting. I could have easily been afraid to admit to my colleague that I don’t understand quantum field theory. A lot of fun flowed from not being too afraid to expose my ignorance.
Learning never stops
Well, I guess it could stop, but it’s much better if it doesn’t. You’re not going to finish your education and then apply your knowledge. Even if you leave academia, that’s not true (see the interview with Greg Spooner). I know much more about physics, I have a much deeper understanding of physics than I did when I graduated with a Ph.D. I don’t know if that’s obvious from where you are now.
Close doors, and watch out for your ego!
There are only so many things you can choose to do, and some things you just need to let go of, but it can be hard to do so. Instead of going on this prescribed work regimen to recover from my troubled Stanford talk, what I realized was, fundamentally, I didn’t care enough about the subject. I wasn’t interested in it enough. I had done some work early on making predictions for the cosmic infrared background, and it was fun. That was fun to make some predictions that no one had worked out sufficiently well before because the right time had not yet come. There was some interesting stuff to come out of it, and I saw that the data we were going to have on this was going to be really rich, and it was going to enable us to learn a lot about the complete history of star formation in the universe. So I saw this opportunity to develop that phenomenology so we could really make use of the data. But fundamentally, I didn’t care about star formation. Figuring out the whole history of star formation in the universe didn’t excite me. But, I was in this position to kind of be a pioneer in this area. It was hard for my ego to let go of it. The opportunity to be a leader in this area was seductive. I could write grant proposals, and bring in money, hire people, speak at conferences,.... So it was hard to let go. I didn’t know what was going to come up when I did let it go, but I did. Then I got curious about the impact of neutrinos on the cosmic microwave background, and we did some work trying to understand that, and got really excited for a while that maybe we were seeing evidence of some extra species of neutrinos. That eventually led to me giving a series of talks called “Neutrino Fever and How I Recovered.” It was a lot of fun, and never would have happened if I had never given up on the infrared background. Have some courage to close doors and trust that something else is going to come along. It’ll make you glad you did.
Know something about the benefits and risks of work
Having a job is one thing, not only for income, but having something to engage in productively is really important emotionally, to how you feel about yourself. It’s extraordinarily valuable. There are huge benefits, especially if you’re doing something you love to do. Now, doing something you love is not something I put on my list of prescriptions for you today because you have heard it a number of times. I am just taking that as a given.
But work comes with risks. The pull of feeling valuable and the push to avoid feeling like an idiot, working really hard on stuff because I’ve got a presentation to give and I don’t want to look like an idiot, and also the pull of “I’m really eager to figure this thing out and get this discovery.” Both of those, especially the fears there, certainly for me, impacted the rest of my life. There were things in my personal life that were difficult for me to deal with, difficult to face, and work was a great refuge from that. It allowed me to avoid a lot of problems that I eventually did have to face. Fortunately, a crisis occurred that shook me up and led me to wrestle with the things I wasn’t facing. It didn’t feel fortunate at the time, but it certainly was.
And then, finally, pay attention. This lesson is perhaps strewn throughout my presentation today. Pay attention to how you are judging yourself. Judgments just pop up, automatically. Neither give them too much credence, nor just shove them away. Ask yourself, what if this thing I’m afraid of is true? What would that mean? Be curious about it. “Why am I having this feeling?” Get at least one person who you trust, who you can talk to about these things, and know that other people are wrestling with similar things, whether they know it or not.
That’s what I’ve prepared. Let me stop there and answer any questions.
Q: How do you deal with the competitiveness of academia?
One, by really being very competitive myself. You know, a lot of the times, I started working on something because it was an idea that I thought was interesting, and I’d develop it. How would I actually get it into a finished and publishable piece of work? It’s a lot of work, finishing up a project and getting it out the door. A lot of the impetus for that came from two things. One, being afraid that someone else was going to beat me to it, and then secondly, I really became interested in something else that I wanted to pursue, and I had the discipline to not do it until I finished this other thing. I’m very competitive by nature, so I dealt with competition by rolling up my sleeves and doing the work.
Q: Do you think it’s required, to be extremely competitive?
I was just talking to a friend of mine recently, an academic, very successful, who, for the first time in his career, was feeling stressed out. I worked with him on something once and it was really his main project, and I was frustrated. I was like, “Why are you not cracking a whip on yourself and getting this done?” But, he wasn’t like that, and he’s done fine. Do you want to comment on that, Steve?
Professor Steve Carlip: My impression in Physics is that culture differs tremendously from tiny subfield to tiny subfield, and that there are some things in which the culture is very competitive. You could go into high energy experiments, that’s the way things work. If you go into quantum gravity, which is my field, everybody gets along, and there isn’t a lot of competition, but that’s because we all know that it’s hopeless. Well, maybe not quite, but we all know that this is a huge problem and there are only a few of us working on it, and there are very few competitive people, outside of String Theory, in quantum gravity. I don’t know how you find out before you go into a field.
Me: I’ve been really happy with my field and I love going to meetings and seeing friends that I’ve known now for decades, and even people that used to really aggravate me when I was in a more precarious position, when you’re competing for jobs. I’ve learned to really enjoy, and even work with them sometimes. As far as relations with other people doing the same thing, I’m really happy with my field. It’s been a really nice aspect of it. Now, there are times, especially working in a large collaboration, when I’ve also been surprised at the degree to which human problems can get in the way, things getting done, and the degree to which having an understanding of people can be really helpful.
Q: About discoveries being out there, and questioning the things that are given to us as truths, how early do you think it becomes important to ask someone? Can discoveries be made so early on using that method?
Earlier on, the chances are less. But, I think if you attack things with the idea that I’m not really relaxing until this all makes sense to me, that’s good training. Then you’ll start achieving a high standard for what it means to really understand something, and you’ll learn more. Now, there are only so many hours in the day and you’ve got other classes, and you got the next thing, and it’s all a matter of balancing. If there’s something about a particular thing that’s bothering you, making you think that there’s something you don’t understand, you can go talk to your professor or somebody else, and do it.
Q: I was hoping to get your take on scientists, physicists going out into industry.
It’s just a fact that that’s where most people go. Secondly, people go on to do a lot of interesting things and lead satisfying lives. Most of them, if you ask them if they would rather be doing what they’re doing or have an academic position, I think they’d probably say, “Oh God no, I don’t want an academic position. This is so much better.” I’m guessing that a majority of people would actually say that, and they’d mean it. That’s how they feel. I think it’s really important to expose our students to that. I think it would have been really helpful to me to know earlier on about the diversity of options that were there. It would have calmed down some of my anxiety. I’ve been delighted to hear from our alumni about the value they feel their Physics training gives them. Obviously I’m delighted about that because we’re part of that training process. Sometimes I wonder. I’m studying Cosmology. I’m not doing anything useful, right? There is no practical benefit to my work, and it’s nice to hear that I have some students who think there is some practical benefit to the education we provide.
I once did some consulting work outside of academia, and I loved it. I may do it again sometime. Right now I’m too excited about my academic work.
Q: Have you had some specific instances of self doubt, like that talk you gave at Stanford, but months or maybe longer. How long was that amount of time?
That time in 1995 when I thought I was all washed up, that was at least a couple months. It’s hard. I never did solve that problem I was working on. I moved on to a different one and it turned out much better. So, remember: failure is an option. If had stuck with it, thinking I’ve got to solve this problem or my worth as an individual is over, if I had been that existentially attached to it, I probably would have solved it, but my career would be over because it would have taken me so long. Or maybe I would have solved it the day after I actually gave up, I don’t know.
It was at the very beginning of my job. I knew I had more time there, and I moved on to the next thing and it ended up going well.
Q: You talked about your grad school experience. How was your undergrad experience?
I was at the University of Virginia, and my first year of physics there, I was in a class that was a real range of abilities, and the distribution of scores on the first exam was flat from 14 to 100. I had 100 so it was not the best environment for me to be stimulated. At the same time I was at university, and I was exposed to all these other things, and talking with people, for the first time immersed with a population of students who had intellectual interests, unlike the distribution in high school. It was really exciting, all this new stuff, and I decided I was going to major in international relations. I talked to my father after my first year and he said, “Well, you’ve been interested in science for a long time. Why don’t you give it one more semester?” I did, and then I loved it. It was electrodynamics and special relativity. The relativity just blew me away. It was awesome.
Q: Did you do research?
I did. I have a thesis titled, “Electroexcitation of 6- States in Silicon-30.” This was nuclear physics. We were scattering electrons off of silicon-30, and looking at the nuclear transitions that occur. I really didn’t know what I was doing. But, I learned some programming and it was an important part of the application to graduate school. If I hadn’t done that, I wouldn’t have gotten into graduate school at the University of Chicago. I remember taking the GREs. I came out of the GREs thinking, “Gosh, I’m not going to grad school anywhere I want to go.” It ended up okay. That’s some of my undergraduate experience.
If you want to go to graduate school, getting involved in some research is a really, really important thing to do. If you don’t like research, it’s a really good thing to find out. Of course, it could be that you just don’t like that research -- it can be hard to know what lesson to draw from experience!
Speaking of different paths, and how important it is to get A as opposed to B, there’s a really good TED talk, actually, about cognitive biases that I think is worth watching. Then, there’s a talk by BrenéBrown at TEDx Houston which is about vulnerability, and really this is a very touchy-feely thing, but I believe the vulnerability she talks about here plays an important role in how you approach your academic work life. Venturing into the unknown makes us vulnerable. I also have a TEDx talk which may have some overlap with what I have given you here.