Then, of course, Brian and his team helped measure the value of omega by discovering the accelerating universe. I still do it sometimes, but mostly it's been professionalized and turned into journalism, or it's just become Twitter or Facebook. The paper was on what we called the cosmological constant, which is this idea that empty space itself can have energy and push the universe apart. I don't know what's going to happen to the future of podcasting. Often, you can get as good or better sound quality remotely. Carroll has a B.S. I think I misattributed it to Yogi Berra. Margaret Geller is a brilliant person, so it's not a comment on her, but just how hard it is to extrapolate that. But it was kind of overwhelming. I've not really studied that literature carefully, but I've read some of it. There's also the argument from inflationary cosmology, which Alan pioneered back in 1980-'81, which predicted that the universe would be flat. I was a little bit reluctant to do that, but it did definitely seem like the most promising way to go. So, by 1992 or 1993, it's been like, alright, what have you done for me lately? And I want to write philosophy papers, and I want to do a whole bunch of other things. However, you can also be denied tenure if you hav. The four of us wrote a paper. As long as they were thinking about something, and writing some equations, and writing papers, and discovering new, cool things about the universe, they were happy. I continued to do that when I got to MIT. Both are okay in their different slots, depending on the needs of the institution at the time, but I think that a lot of times the committees choosing the people don't take this into consideration as much as they should. So, Katinka wrote back to me and said, "Well, John is right." You get one quarter off from teaching every year. I do firmly believe that. But within the course of a week -- coincidence problem -- Vikram Duvvuri, who was a graduate student in Chicago, knocked on my door, and said, "Has anyone ever thought of taking R and adding one over R to the Lagrangian for gravity and seeing what would happen?" You're old. Then, I'm happy to admit, if someone says, "Oh, you have to do a podcast interview," it's like, ah, I don't want to do this now. I think that I read papers by very smart people, smarter than me, doing cutting edge work on quantum gravity, and so forth, and I still find that they're a little hamstrung by old fashioned, classical ideas. Audio, in one form or another, is here to stay. Were your family's sensibilities working class or more middle class, would you say? So, I could completely convince myself that, in fact -- and this is actually more true now than it maybe was twenty years ago for my own research -- that I benefit intellectually in my research from talking to a lot of different people and doing a lot of different kinds of things. What is it that you are really passionate about right now?" You go from high school, you're in a college, it's your first exposure to a whole bunch of new things, you get to pick and choose. So, it was difficult to know what to work on, and things like that. In that era, it's kind of hard to remember. It might be a good idea that is promising in the moment and doesn't pan out. But it's less important for a postdoc hire. Just to bring the conversation up to the present, are you ever concerned that you might need a moment to snap back into theoretical physics so that you don't get pulled out of gravity? He was born to his father and mother in Philadelphia, Pennsylvania, United States of America. Honestly, Caltech, despite being intellectually as good as Harvard or Princeton, if you get hired as an assistant professor, you almost certainly get tenure. Was this your first time collaborating with Michael Turner? Depending on the qualities they are looking for, tenure may determine if they consider hiring the candidate. We just knew we couldn't afford it. I don't think I'm in danger of it right now, so who knows five or ten years from now? So, for you, in your career, when did cosmology become something where you can proudly say, "This is what I do. But I get plenty of people listening, and that makes me very pleased. Brian was the leader of one group, and he was my old office mate, and Riess was in the office below ours. This is a very interesting fact to learn that completely surprised me. But I loved science because I hung out at the public library and read a lot of books about blackholes and quarks and the Big Bang. Maybe you hinted at this a little bit in the way you asked the question, but I do think that the one obvious thing that someone can do is just be a good example. I was thinking of a research project -- here is the thought process. There was, but it was kind of splintered because of this large number of people. They need it written within six months so it can be published before the discovery is announced. Having been through all of this that we just talked about, I know what it takes them to get a job. So, I got talk to a lot of wonderful people who are not faculty members at different places. So, I was still sort of judging where I could possibly go on the basis of what the tuition numbers were, even though, really, those are completely irrelevant. It denied her something she earned through hard work and years of practice. That group at MIT was one, and then Joe Silk had a similar group at Berkeley at the same time. If you change something at the higher level, you must change something at the lower level. Was the church part of your upbringing at all? And it was a . Is writing a graduate-level textbook in general relativity, might that have been perceived as a bit of a bold move for an assistant professor? I didn't stress about that. Then, okay, I get to talk about ancient Roman history on the podcast today. Both my undergraduate and graduate degrees are in astronomy, and both for weird, historical reasons. So, it wasn't until I went to Catholic university that I became an outspoken atheist. He is, by any reasonable measure, a very serious physicist. So, most research professors at Caltech are that. Steven Morrow, my editor who published From Eternity to Here, called me up and said, "The world needs a book on the Higgs boson. But it's hard to do that measurement for reasons that Brian anticipated. I had never heard of him before. So, if I can do that, I can branch out afterwards. One is the word metaphysical in this sense is used in a different sense by the professional philosophical community. I wouldn't say we're there yet, but I do think it's possible, and it's a goal worth driving for. But Bill's idea was, look, we give our undergraduates these first year seminars, interdisciplinary, big ideas, very exciting, and then we funnel them into their silos to be disciplinary. But most of us didn't think it was real. When the book went away, I didn't have the license to do that anymore. There's no immediate technological, economic application to what we do. So, thank you so much. And he's like, "Sure." So, it's not quite a perfect fit in that sense. On Carroll's view the universe begins to exist at the Big Bang only in the sense that a yardstick begins to exist at the first inch. On that note, as a matter of bandwidth, do you ever feel a pull, or are you ever frustrated, given all of your activities and responsibilities, that you're not doing more in the academic specialty where you're most at home? You tell me, you get a hundred thousand words to explain things correctly, I'm never happier than that. Yes, well that's true. The argument I make in the paper is if you are a physicalist, if you exclude by assumption the possibility of non-physical stuff -- that's a separate argument, but first let's be physicalists -- then, we know the laws of physics governing the stuff out of which we are made at the quantum field theory level. A complete transcript of the debate can be found here. Sean, let's take it all the way back to the beginning. I will get water while you're doing that. So, I wonder, in what ways can you confirm that outside assumption, but also in reflecting on the past near year, what has been difficult that you might not have expected from all of this solitary work? Yeah, I think that's right. [17] He is the Homewood Professor of Natural Philosophy at Johns Hopkins University, teaching in both the Department of Philosophy and The Department of Physics and Astronomy. If I had pursued certain opportunities, I could have gotten tenured. It wasn't fun, it wasn't a surprise and it wasn't the end of anything really, other than my employment at UMass. Princeton University Press. But also, even though, in principal, the sound quality should be better because I bring my own microphones, I don't have any control over the environment. Do you have any pointers to work that's already been done?" That's not going to lead us to a theory of dark matter, or whatever. Nearly 40 faculty members from the journalism school signed an online statement on Wednesday calling for the decision to be reversed, saying the failure to grant tenure to Ms. Hannah-Jones "unfairly moves the goal posts and violates longstanding norms and established processes.". I decided to turn them down, mostly because I thought I could do better. [38] Carroll received an "Emperor Has No Clothes" award at the Freedom From Religion Foundation Annual National Convention in October 2014. Research professors are hired -- they're given a lot of freedom to do things, but there's a reason you're hired. No one gets a PhD in biology and ends up doing particle physics. It's also self-serving for me to say that, yes. Well, you know, again, I was not there at the meeting when they rejected me, so I don't know what the reasons were. I started a new course in cosmology, which believe it or not, had never been taught before. The dynamo, the Biermann battery, the inverse cascade, magnetic helicity, plasma effects, all of these things that are kind of hard for my purely theoretical physicist heart to really wrap my mind around. I had never quite -- maybe even today, I have still not quite appreciated how important bringing in grant money is to academia. I love the little books like Quantum Physics for Babies, or Philosophy for Dummies. However, because I am intentionally and dynamically moving into other areas, not just theoretical physics, I can totally use the podcast to educate myself. So, that's when The Big Picture came along, which was sort of my slightly pretentious -- entirely pretentious, what am I saying? This is so exciting because you are one of the best interviewers out there, so it's a unique opportunity for me to interview one of those best interviewers. I think we only collaborated on two papers. So much knowledge, and helpful, but very intimidating if you're a student. Literally, my math teacher let me teach a little ten minute thing on how to -- sorry, not math teacher. I do long podcasts, between an hour and two hours for every episode. Maybe it's them. The Hubble constant is famously related to the dark energy, because it's the current value of the Hubble constant where dark energy is just taking over. We learned a lot is the answer, as it turns out. As far as I was concerned, the best part was we went to the International House of Pancakes after church every Sunday. Would I be interested in working on it with him? 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. Well, that's not an experimental discovery. So, I said that, and she goes, "Well, propose that as a book. This particular job of being a research professor in theoretical physics has ceased to be a good fit for me. We'll figure it out. I think it's gone by now. Sean, before we begin developing the life narrative, your career and personal background trajectory, I want to ask a very presentist question. There's a sense in which the humanities and social sciences are more interchangeable. But the thing that flicked the switch in my head was listening to music. It's the time that I would spend, if I were a regular faculty member, on teaching, which is a huge amount of time. So, it was a coin flip, and George was assigned to me, and invited me to his office and said, "What do you want to do?" So, happily, I was a postdoc at Santa Barbara from '96 to '99, and it was in 1998 that we discovered the acceleration of the universe. Of all the things that you were working on, what topic did you settle on? Forensics, in the sense of speech and debate. That's my question. I just thought whatever this entails, because I had no idea at the time, this is what I want to do. The idea that someone could be a good teacher, and do public outreach, and still be devoted and productive doing research is just not a category that they were open to. The other anecdote along those lines is with my officemate, Brian Schmidt, who would later win the Nobel Prize, there's this parameter in cosmology called omega, the total energy density of the universe compared to the critical density. I think I'm pretty comfortable with that idea. The one exception -- it took me a long time, because I'm very, very slow to catch on to things. I heard my friends at other institutions talk about their tenure file, getting all of these documents together in a proposal for what they're going to do. But, you know, the contingencies of history. So, I want to not only write papers with them, but write papers that are considered respectable for the jobs they want to eventually get. So, without that money coming in randomly -- so, for people who are not academics out there, there are what are called soft money positions in academia, where you can be a researcher, but you're not a faculty member, and you're generally earning your own keep by applying for grants and taking your salary out of the grant money that you bring in. There was one formative experience, which was a couple of times while I was there, I sat in on Ed Bertschinger's meetings. Had it been five years ago, that would have been awesome, but now there's a lot of competition. I've forgotten almost all of it, so I'm not sure it was the best use of my time. He'd already retired from being the director of the Center for Astrophysics, so you could have forgiven him for kicking back a little bit, but George's idea of a good time is to crank out 30 pages of handwritten equations on some theory that we're thinking about. So, in the second video, I taught them calculus. What I wanted to do was to let them know how maybe they could improve the procedure going forward. Well, I have visited, just not since I got the title. Do you have any good plans for a book?" It's remarkable how trendiness can infect science. Theoretical cosmology at the University of Chicago had never been taught before. I sat in on all these classes on group theory, and differential geometry, and topology, and things like that. It's just they're doing it in a way that doesn't get you a job in a physics department. Seeing my name in the Physical Review just made me smile, and I kept finding interesting questions that I had the technological capability of answering, so I did that. Let's put it that way. That's not all of it. 1.12 Carroll's model ruled out on other grounds. We certainly never worked together. That's all it is. They do not teach either. Tenure is, "in its ideal sense, an affirmation that confers membership among a community of scholars," Khan wrote. They seem unnatural to us. 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. I'd like to start first with your parents. If I had just gone to relativity, they probably would have just kept me. It's a necessary thing but the current state of theoretical physicists is guessing. First year seminars to sort of explore big ideas in different ways. The second book, the Higgs boson book, I didn't even want to write. Either you bit the bullet and you did that, or you didnt. It's not just a platitude. There's no delay on the line. Also, I got on a bunch of other shortlists. So, I actually worked it out, and then I got the answers in my head, and I gave it to the summer student, and she worked it out and got the same answers. I thought it would be more likely that I'd be offered tenure early than to be rejected. From the outside looking in, you're on record saying that your natural environment for working in theoretical physics is a pen and a pad, and your career as a podcaster, your comfort zone in the digital medium, from the outside looking in, I've been thinking, is there somebody who was better positioned than you to weather the past ten months of social distancing, right? Onondaga County. Law school was probably my second choice at the time. And part of it was because no one told me. In his response to critics he has made a number of interesting claims . When you get hired, everyone can afford to be optimistic; you are an experiment and you might just hit paydirt. Physicists have devised a dozen or two . So, between the five of these people, enormous brainpower. The physics department had the particle theory group, and it also had the relativity group. No one goes into academia for fame and fortune. [37] It was fine. Again, while I was doing it, I had no idea that it would be anything other than my job, but afterward -- this is the thing. But if you want to say, okay, I'm made out of electrons and protons and neutrons, and they're interacting with photons and gluons, we know all that stuff. If you found that there was a fundamental time directed-ness in nature, that the arrow of time was not emergent out of entropy increasing but was really part of the fundamental laws of physics. But they often ask me to join their grant proposal to Templeton, or whatever, and I'm like, no, I don't want to do that. So, even if it's a graduate-level textbook filled with equations, that is not what they want to see. Tip: Search within this transcript using Ctrl+F or +F. I laugh because I'm friends -- Jennifer, my wife, is a science journalist -- so we're friends with a lot of science journalists. The guy, whoever the person in charge of these things, says, "No, you don't get a wooden desk until you're a dean." It doesn't sound very inspired, so I think we'll pass." A derivative is the slope of something. We will literally not discover, no matter how much more science we do, new particles in fields that are relevant to the physics underlying what's going on in your body, or this computer, or anything else. Maybe not. The crossover point from where you don't need dark matter to where you do need dark matter is characterized not by a length scale, but by an acceleration scale. I would have gladly gone to some distant university. A lot of people focus on the fact that he was so good at reaching out to broad audiences, in an almost unprecedented way, that they forget that he was really a profound thinker as well. My response to him was, "No thanks." They soon thereafter hired Ramesh Narayan, and eventually Avi Loeb, and people like that. Then, I went to college at Villanova University, in a different suburb of Philadelphia, which is a Catholic school. @seanmcarroll . [8] He occasionally takes part in formal debates and discussions about scientific, religious and philosophical topics with a variety of people. Carroll has blogged about his experience of being denied tenure in 2006 at the University of Chicago, Illinois, and in a 2011 post he included some slightly tongue-in-cheek advice for faculty . Moving on after tenure denial. I had that year that I was spending doing other things, and then I returned to doing other things. They just don't care. To me, the book is still the most profound way for one person to say ideas that are communicated to another one. It's good to talk about physics, so I'll talk about physics a little bit. But now, I had this goal of explaining away both dark matter and dark energy. If everyone is a specialist, they hire more specialists, right? I FOUGHT THE LAW: After the faculty at the Chicago-Kent College of Law voted 22 to 1 in favor of granting Molly Lien tenure in March, Ms. Lien gave herself (and her husband) a trip to Florence. In other words, if you were an experimental condensed matter physicist, is there any planet where it would be feasible that you would be talking about democracy and atheism and all the other things you've talked about? So, that's where I wanted my desk to be so I could hang out with those people. There's an equation you can point to. Now, was this a unique position that Caltech tailored for you, given what you wanted to do in this next role? But the good news was I got to be at CERN when they announced it. So, dark energy is between minus one and zero, for this equation of state parameter. I lucked into it, once again. Hard to do in practice, but in principle, maybe you could do it. As a public intellectual who has discussed, I mean, really, it's a library worth of things that you've talked about and [who you have] talked with, is your sense first that physics being the foundational science is the most appropriate place as an intellectual launching pad to talk about these broader topics? That's when I have the most fun. I was there. So, his response was to basically make me an offer I couldn't refuse in terms of the financial reward that would be accompanying writing this book. The idea of going out to dinner with a bunch of people after giving a talk is -- I'll do it because I have to do it, but it's not something I really look forward to. It doesn't lead to new technology. I've been interviewing scientists for almost twenty years now, and in our world, in the world of oral history, we experienced something of an existential crisis last February and March, because for us it was so deeply engrained that doing oral history meant getting in a car, getting on a plane with your video/audio recording equipment, and going to do it in person. I'm on the DOE grant at both places, etc. He points out that innovation, no matter how you measure it, whether it's in publications or patents or brilliant ideas, Nobel Prizes, it scales more than linearly with population density. Past tenure cases have been filed over such reasons as contractual issues, gender discrimination, race discrimination, fraud, defamation and more. I thought it would be fun to do, but I took that in stride. So, he was right, and I'm learning this as I study and try to write papers on complexity. On the other hand, I feel like I kind of blew it in terms of, man, that was really an opportunity to get some work done -- to get my actual job done. Sean Carroll, who I do respect, has blogged no less than four times about the idea that the physics underlying the "world of everyday experience" is completely understood, bar none. So, becoming a string theorist was absolutely a live possibility in my mind. If you just plug in what is the acceleration due to gravity, from Newton's inverse square law? We discovered the -- oh, that was the other cosmology story I wanted to tell. Sean, I'm so glad you raised the formative experience of your forensics team, because this is an unanswerable question, but it is very useful thematically as we continue the narrative. And of course, it just helps you in thinking and logic, right? I hope that the whole talk about Chicago will not be about me not getting tenure, but I actually, after not getting tenure, I really thought about it a lot, and I asked for a meeting with the dean and the provost. and as an assistant professor at the University of Chicago until 2006 when he was denied tenure. There was a famous story in the New York Times magazine in the mid '80s. I will confess the error of my ways. You're looking under the lamppost. Or other things. And Bill was like, "No, it's his exam. [So that] you don't get too far away that you don't know how to get back in? But still, it was a very, very exciting time. This happens quite often. But there were postdocs. 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. Like I said, I wrote many papers that George was not a coauthor on. 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.