But those kind of big picture things, which there are little experiments here and there. They've tried to correct that since then, but it was a little weird. I can pinpoint the moment when I was writing a paper with a graduate student on a new model for dark matter that I had come up with the idea, and they worked it out. Absolutely brilliant course. But, you know, I did come to Caltech with a very explicit plan of both diversifying my research and diversifying my non-research activities, and I thought Caltech would be a great place to do that. So, no imaginable scenario, like you said before, your career track has zigged and zagged in all kinds of unexpected ways, but there's probably no scenario where you would have pursued an academic career where you were doing really important, really good, really fundamental work, but work that was generally not known to 99.99% of the population out there. I'm not someone who thinks there's a lone eccentric genius who's going to be idiosyncratic and overthrow the field. Okay, with all that clarified, its funny that you should say that, because literally two days ago, I finished writing a paper on exactly this issue. It's okay to recommit to your academic goals, or to try something completely different. A video of the debate can be seen here. What you would guess is the universe is expanding, and how fast it's expanding is related to that amount of density of the universe in a very particular way. Everyone could tell which courses were good at Harvard, and which courses were good at MIT. It was very long. Remember, the Higgs boson -- From Eternity to Here came out in 2010. People didn't take him seriously. And then I got an email from Mark Trodden, and he said, "Has anyone ever thought about adding one over R to the Lagrangian for gravity?" I think both grandfathers worked for U.S. Steel. His article "Does the Universe Need God?" I wonder, Sean, if there's the germinating idea that would inform your interests in outreach, and in doing public science and things like that, it was that inclination that was bounded in an academic context, that you would take eventually into the world of YouTube, and hundreds of thousands of lay people out there, who are learning quantum gravity as a result of you. It's an honor. I had an astronomy degree, and I'd hung out with cosmologists, so I knew the buzzwords and everything, but I hadn't read the latest papers. Honestly, I still think the really good book about the accelerating universe has yet to be written. Believe me, the paperback had a sticker on the front saying New York Times best seller. This could be great. I took almost all the physics classes. That's what supervenience means. Or are you comfortable with that idea, as so many other physicists who reinvent themselves over the course of a career are? In other words, you have for a long time been quite happy to throw your hat in the ring with regard to science and religion and things like that, but when the science itself gets this know-nothingness from all kinds of places in society, I wonder if that's had a particular intellectual impact on you. It had been founded by Chandrasekhar, so there was some momentum there going. So, my job was to talk about everything else, a task for which I was woefully unsuited, as a particle physics theorist, but someone who was young and naive and willing to take on new tasks. Yeah, there's no question the Higgs is not in the same tier as the accelerated universe. Because the thing that has not changed about me, what I'm really fired up by, are the fundamental big ideas. I didn't even get on any shortlists the next year. "One of the advantages of the blog is that I knew that a lot of people in my field read it and this was the best way to advertise that I'm on the market." Read more by . But honestly, no, I don't think that was ever a big thing. So, despite the fact that I connected all the different groups, none of them were really centrally interested in what I did for a living. So, we wrote a little bit about that, and he was always interested in that. I never had, as a high priority, staying near Lower Bucks County, Pennsylvania. I had it. But the only graduate schools I applied to were in physics because by then I figured out that what I really wanted to do was physics. So, that was my first glimpse at purposive, long term strategizing within theoretical physics. So, it's not quite true, but in some sense, my book is Wald for the common person. 4. I took a particle physics class from Eddie Farhi. The first super string revolution had happened around 1984. The polarization of light from the CMB might be rotated just a little bit as it travels through space. Everyone knew it was going to be exciting, but it was all brand new and shiny, and Ed would have these group meetings. But he does have a very long-lasting interest in magnetic fields. There was one formative experience, which was a couple of times while I was there, I sat in on Ed Bertschinger's meetings. It's good to have good ideas but knowing what people will think is an interesting idea is also kind of important. There are numerical variables and character variables. So, I was on the ground floor in terms of what the observational people. My mom got remarried, so I had a stepfather, but that didn't go very well, as it often doesn't, and then they got re-divorced, and so forth. Wilson wanted the Seahawks to trade for Payton's rights after his Saints exit last year, according to The Athletic. But there's an enormous influence put on your view of reality by all of these pre-existing propositions that you think are probably true. Even the teachers at my high school, who were great in many ways, couldn't really help me with that. The bad news is that I've been denied tenure at Chicago. I was less good of a fit there. But the astronomy department, again, there were not faculty members doing early universe cosmology at Harvard, in either physics or astronomy. You can skip that one, but the audience is still there. So, on the one hand, I got that done, and it was very popular. So, I'm doing a little bit out of chronological order, I guess, because the point is that Brian and Saul and Adam and all their friends discovered that the universe is not decelerating. At Chicago, you hand over your CV, and you suggest some names for them to ask for letters from. But we don't know yet, and it's absolutely worth trying. I'm not quite sure I can tell the difference, but working class is probably more accurate. The book talks about wide range of topics such as submicroscopic components of the universe, whether human existence can have meaning without Godand everything between the two. We could discover that dark energy is not a cosmological constant, but some quintessence-like thing. No, tenure is not given or denied simply on the basis of how many papers you write. George and Terry team-taught a course on early universe cosmology using the new book by Kolb and [Michael] Turner that had just come out, because Terry was Rocky Kolb's graduate student at Chicago. I do have feelings about different people who have been chosen as directors of institutes and department chairs. But part of the utopia that we don't live in, that I would like to live in, would be people who are trying to make intellectual contributions [should] be judged on the contributions and less on the format in which they were presented. You can be a physicalist and still do metaphysics for your living. As long as it's about interesting ideas, I'm happy to talk about it. No, I cannot in good conscience do that. But I'd be very open minded about the actual format changing by a lot. Carroll endorses Everett's Many Worlds Interpretation and denies the existence of God. That's just not my thing. Do the same thing for a cluster of galaxies. In many ways, I could do better now if I rewrote it from scratch, but that always happens. Measure all the matter in the universe. So, I read all the latest papers in many different areas, and I actually learned something. Absolutely. Not only did I not collaborate with any of the faculty at Santa Barbara, but I also didnt even collaborate with any of the postdocs in Santa Barbara. Wildly enthusiastic reception. Naval Academy, and she believes the reason is bias. Almost none of my friends have this qualm. So, it was difficult to know what to work on, and things like that. I guess, one way of putting it is, you hear of such a thing as an East Coast physics and a West Coast physics. Caltech has this weird system where they don't really look for slots. He was the one who set me up on interviews for postdocs and told me I need to get my hands dirty a little bit, and do this, and do that. Being a string theorist seemed to be a yes or no proposition. So, there's three quarters in an academic year. As ever, he argues that we do have free will, but it's a compatibilist form of free will. Whereas, if I'm a consultant on [the movie] The Avengers, and I can just have like one or two lines of dialogue in there, the impact that those one or two lines of dialogue have is way, way smaller than the impact you have from reading a book, but the number of people it reaches is way, way larger. Metaphysics to a philosopher just means studying the fundamental nature of reality. I might add, also, that besides your brick and mortar affiliations, you might also add your digital affiliations, which are absolutely institutional in quality and nature as well. Part of that was a shift of the center of gravity from Europe to America. It never occurred to me that it was impressive, and I realized that you do need to be something. [3][4] He has been a contributor to the physics blog Cosmic Variance, and has published in scientific journals such as Nature as well as other publications, including The New York Times, Sky & Telescope and New Scientist. So, when Brian, Adam, Saul, and their friends announced in 1998 that there was a cosmological constant, everyone was like, oh, yeah, okay. So, I made the point that he should judge me not on my absolute amount of knowledge, but by how far I had come since the days he taught me quantum field theory. Do you go to the economics department or the history department? So, I gave a lot of thought to that question. It was -- I don't know. But, you know, my standard is what is it that excites me at the moment? It also has as one of its goals promoting a positive relationship between science and religion. Was that something that you or a guidance counselor or your mom thought was worth even considering at that time? I thought and think -- I think it's true that they and I had a similar picture of who I would be namely bringing those groups together, serving as a bridge between all those groups. It moved away. They assert that the universe is "statistically time-symmetric", insofar as it contains equal progressions of time "both forward and backward". They actually have gotten some great results. Bill was the only one who was a little bit of a strategist in terms of academia. Even back then, there was part of me that said, okay, you only have so many eggs. The topic of debate was "The Existence of God in Light of Contemporary Cosmology". There's a sense in which the humanities and social sciences are more interchangeable. And I knew that. I just did the next step that I was supposed to do. Even if it were half theoretical physicists and half other things, that's a weird crazy balance. But in 2004, I had written that Arrow of Time paper, and that's what really was fascinating to me. Yeah, absolutely. Tenure denial, seven years later. [55], In 2018, Carroll and Roger Penrose held a symposium on the subject of The Big Bang and Creation Myths. The benefits you get from being around people who have all this implicit knowledge are truly incalculable, which I know because I wasn't around them. Past tenure cases have been filed over such reasons as contractual issues, gender discrimination, race discrimination, fraud, defamation and more. At the end of the interview, Carroll shares that he will move on from Caltech in two years and that he is open to working on new challenges both as a physicist and as a public intellectual. Talking about all of the things I don't understand in public intimidates me. They're a little bit less intimidated. This philosophical question is vitally important to the debate over the causal premiss. I will confess the error of my ways. In many ways, it was a great book. This is the advice I tell my students. Then, when my grandmother, my mother's mother, passed away when I was about ten, we stopped going. I was in on the ground floor, because I had also worked on theoretical models of it. What sparked that interest in you? My stepfather had gone to college, and he was an occupational therapist, so he made a little bit more money. So, I realized right from the start, I would not be able to do it at all if I assume that the audience didn't understand anything about equations, if I was not allowed to use equations. I've gotten good at it. I think it was like $800 million. I do remember, you're given some feedback after that midterm evaluation, and the director of the Enrico Fermi Institute said, "You've really got to not just write review papers, but high impact original research papers." Bill Wimsatt, who is a philosopher at Chicago had this wonderful idea, because Chicago, in many ways, is the MIT of the humanities. (2013) Brave Genius: A Scientist, a Philosopher, and Their Daring Adventures from the French Resistance to the . Let's go back to the happier place of science. Having all these interests is a wonderful thing, but it's not necessarily most efficacious for pursuing a traditional academic track. As much as, if you sat around at lunch with a bunch of random people at Caltech physics department, chances are none of them are deeply religions. Be prolific and reliable. Then, the other big one was, again, I think the constant lesson as I'm saying all these words out loud is how bad my judgment has been about guiding my own academic career. We did briefly flirt with the idea that I could skip a grade when I was in high school, or that I could even go to a local private school. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. And the other thing was honestly just the fact that I showed interest in things other than writing physics research papers. Carroll conveys the various push and pull factors that keep him busy in both the worlds of academic theoretical physics and public discourse. First year seminars to sort of explore big ideas in different ways. Again, I just worked with other postdocs. He was another postdoc that was at MIT with me. The second book, the Higgs boson book, I didn't even want to write. No one expects that small curvatures of space time, anything interesting should happen at all. Even if you're not completely dogmatic -- even if you think they're likely true but you're not sure, you filter in what information you think is relevant and important, what you discount, both in terms of information, but also in terms of perspective theories. That's what I am. Sean Carroll on free will. Brian was the leader of one group, and he was my old office mate, and Riess was in the office below ours. And that's the only thing you do. We talked about discovering the Higgs boson. Some people say that's bad, and people don't want that. This is what's known as the coincidence problem. He received his Ph.D. from Harvard in 1993. Do you want to put them all in the same basket? We discovered the -- oh, that was the other cosmology story I wanted to tell. But I did overcome that, and I think that I would not necessarily have overcome it if I hadn't gone through it, like forced myself to being on that team and trying to get better at it. Get on with your life. Sean, thank you so much for spending this time with me. I have no problems with that. So, I went to an astronomy department because the physics department didn't let me in, and other physics departments that I applied to elsewhere would have been happy to have me, but I didn't go there. I became much less successful so far in actually publishing in that area, but I hope -- until the pandemic hit, I was hopeful my Santa Fe connection would help with that. One of my good friends is Don Page at the University of Alberta, who is a very top-flight theoretical cosmologist, and a born-again Evangelical Christian. But I have a conviction that understanding the answer to those questions, or at least appreciating that they are questions, will play a role -- again, could very easily play a role, because who knows, but could very easily play a role in understanding what we jokingly call the theory of everything, the fundamental nature of all the forces and the nature of space time itself. It was a huge success. I'm trying to finish a paper right now. Now that you're sort of outside of the tenure clock, and even if you're really bad at impressing the right people, you were still generally aware that they were the right people to impress. I think that it's important to do different things, but for a purpose. I made that choice consciously. Our senior year in high school, there was a calculus class. So, how did you square that circle, or what kinds of advice did you get when you were on the wrong side of these trends about having that broader perspective that is necessary for a long-term academic career? But to shut off everything else I cared about was not worth it to me. There are very few ways in which what we do directly affects people's lives, except we can tell them that God doesn't exist. I worked a lot with Mark Trodden. But anyway, I never really seriously tried to change advisors from having George Field as my advisor. It became a big deal, and they generalized it from R plus one over R to f(R), any function of R. There's a whole industry out there now looking at f(R) gravity. Well, how would you know? Marc Kamionkowski proposed the Moore Center for Cosmology and Theoretical Physics. [37] Let's put it that way. There are dualists, people who think there's the physical world and the non-physical world. It was July 4th. Another follow up paper, which we cleverly titled, Could you be tricked into thinking that w is less than minus one? by modifying gravity, or whatever. And then, both Alan Guth and Eddie Farhi from MIT trundled up. I took courses with Raoul Bott at Harvard, who was one of the world's great topologists. Absolutely. Sean Carroll is a tenured research physics professor at Caltech with thousands of citations. Formerly a research professor in the Walter Burke Institute for Theoretical Physics in the California Institute of Technology (Caltech) Department of Physics,[1] he is currently an External Professor at the Santa Fe Institute,[2] and the Homewood Professor of Natural Philosophy at Johns Hopkins University. Recently he started focusing on issues at the foundations of cosmology, statistical mechanics, quantum mechanics and complexity. There's no other input that you have. The whole thing was all stapled together, and that was my thesis. I was very good at Fortran, and he asked me to do a little exposition to the class about character variables. We had people from England who had gone to Oxford, and we had people who had gone to Princeton and Harvard also. [29], Carroll is married to Jennifer Ouellette, a science writer and the former director of the Science & Entertainment Exchange.[30]. Harvard is not the most bookish place in the world. But the thing that flicked the switch in my head was listening to music. So, you didn't even know, as a prospective grad student, whether he was someone you would want to pick as an advisor, because who knows how long he'd be there. Not just that there are different approaches. So, there was the physics department, and the astronomy department, and there was also what's called the Enrico Fermi Institute, which was a research institute, but it was like half of the physics department and half of the astronomy department was in it. Because I know, if you're working with Mark Wise, my colleague, and you're a graduate student, it's just like me working with George Field. So, literally, Brian's group named themselves the High Redshift Supernova Project: Measuring the Deceleration of the Universe. I had this email from a woman who said, literally, when she was 12 years old, she was at some event, and she was there with her parents, and they happened to sit next to me at a table, and we talked about particle physics, and she wrote just after she got accepted to the PhD program at Oxford in particle physics, and she said it all started with that conversation. Again, I was wrong over and over again. There's a strong theory group at Los Alamos, for example. Rather than telling other people they're stupid, be friendly, be likable, be openminded. It's just they're doing it in a way that doesn't get you a job in a physics department. I mean, The Biggest Ideas in the Universe video series is the exception to this, because there I'm really talking about well-established things. There's always some institutional resistance. We were expecting it to be in November, and my book would have been out. It was not a very strict Catholic school. Frank Merritt, who was the department chair at the time, he crossed his arms and said, "No, I think Sean's right. You can see their facial expressions, and things like that. I had never heard of him before. During this migration, the following fields associated with interviews may be incomplete: Institutions, Additional Persons, and Subjects. So, I got really, really strong letters of recommendation. Literally, my office mate, while I was in graduate school, won the Nobel Prize for discovering the accelerating universe -- not while he was in graduate school, but later. Did you get any question like that? But the idea is that given the interdisciplinary nature of the institute, they can benefit, and they do benefit from having not just people from different areas, but people from different areas with some sort of official connection to the institute. What about minus 1.1? The thing that people are looking for, the experimental effort these days, and for very good reason, is aimed at things that we think are plausibly true. So, we wrote one paper with my first graduate student at Chicago -- this is kind of a funny story that illustrates how physics gets done. Whereas there are multiple stories of people with PhDs in physics doing wonderful work in biology. The one exception -- it took me a long time, because I'm very, very slow to catch on to things. You've got to find the intersection. So, that combination of freedom to do what I want and being surrounded by the best people convinced me that a research professorship at Caltech was better than a tenure professorship somewhere else. I think that responsibility is located in the field, not on individuals. So, I intentionally tried to drive home the fact that universities, as I put it, hired on promise and fired on fear. So, becoming a string theorist was absolutely a live possibility in my mind. He is the Homewood Professor of Natural Philosophy at Johns Hopkins University, teaching in both the . We should move into that era." So, they weren't looking for the signs for that. I thought it would be more likely that I'd be offered tenure early than to be rejected. Sorry, I forgot the specific question I'm supposed to be answering here. And she had put her finger on it quite accurately, because already, by then, by 2006, I had grown kind of tired of the whole dark energy thing.