That's not going to lead us to a theory of dark matter, or whatever. By far, the most intellectually formative experience of my high school years was being on the forensics team. Not the policy implementations of them, or even -- look, to be perfectly honest, since you're just going to burn these tapes when we're done, so I can just say whatever I want, I'm not even that fired up by outreach. People had learned things, but it was very slow. I didn't do any of that, but I taught them the concept. 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. I had never quite -- maybe even today, I have still not quite appreciated how important bringing in grant money is to academia. So, string theory was definitely an option, and I could easily have done it if circumstances had been different, but I never really regretted not doing it. Even from the physics department to the astronomy department was a 15-minute walk. Sean, before we begin developing the life narrative, your career and personal background trajectory, I want to ask a very presentist question. So, I do think that in a country of 300-and-some million people, there's clearly a million people who will go pretty far with you in hard intellectual stuff. George didn't know the stuff. The space of possibilities is the biggest space that we human beings can contemplate. I had no interest. I talked to the philosophers and classicists, and whatever, but I don't think anyone knew. Or are you comfortable with that idea, as so many other physicists who reinvent themselves over the course of a career are? Bob Geroch was there also, but he wasn't very active in research at the time. Like, you can be an economist talking about history or politics, or whatever, in a way that physicists just are not listened to in the same way. This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. But the good news was I got to be at CERN when they announced it. And Sidney was like, "Why are we here? But I'm unconstrained by caring about whether they're hot topics. Everyone knows about that. Professor Carolyn Chun has twice been denied tenure at the U.S. So, it's not just that you have your specialty, but what niche are you going to fill in that faculty that hires you. The Planck scale, or whatever, is going to be new physics. You don't really need to do much for those. For one thing, I don't have that many theoretical physicists on the show. I don't think so. One of the things that the Santa Fe Institute tries to do is to be very, very tiny in terms of permanent faculty on-site. He would learn it the night before and then teach it the next day. As the advisor, you can't force them into the mold you want them to be in. I was like, okay, you don't have to believe the solar neutrino problem, but absolutely have to believe Big Bang nucleosynthesis. Then why are you wasting my time? Did you connect with your father later in life? Since the answer is not clear, I decide to do what is the most fun. Believe me, the paperback had a sticker on the front saying New York Times best seller. These were people who were at my level. 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 good to have good ideas but knowing what people will think is an interesting idea is also kind of important. Eric Adelberger and Chris Stubbs were there, who did these fifth force experiments. So, when I was at Chicago, I would often take on summer students, like from elsewhere or from Chicago, to do little research projects with. . What am I going to do? So, if you can do it, it is a great thing. That's how philosophy goes. "The University of Georgia has been . I had done that for a while, and I have a short attention span, and I moved on. This is also the time when the Department of Energy is starting to fully embrace astrophysics, and to a lesser extent, cosmology, at the National Laboratories. Well, Sean, you can take solace in the fact that many of your colleagues who work in these same areas, they're world class, and you can be sure that they're working on these problems. Again, I had great people at MIT. In my book, The Big Picture, I suggested this metaphor of what I called planets of belief. He knew exactly what the point of this was, but he would say, "Why are you asking me that? So, and it's good to be positive about the great things about science and academia and so forth, but then you can be blindsided. Whereas, if you're just a physicalist, you're just successful. Talking about all of the things I don't understand in public intimidates me. I enjoyed that, but it wasn't my passion. And the simplest way to do that is what's called the curvature scalar. 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. I think we only collaborated on two papers. And you know, Twitter and social media and podcasts are somewhere in between that. It's just wonderful and I love it, but it's not me. 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. We wrote a lot of papers together. Being a string theorist seemed to be a yes or no proposition. I think probably the most common is mine, which is the external professorship. "Tenure can be risk averse and hostile to interdisciplinarity. Like I said, I wrote many papers that George was not a coauthor on. Harvard taught a course, but no one liked it. Furthermore, anyone who has really done physics with any degree of success, knows that sometimes you're just so into it that you don't want to think about anything else. It's not just trendiness. You were starting to do that. You're old. I think it's perfectly rational in that sense. 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. There was one course I was supposed to take to also get a physics degree. I taught graduate particle physics, relativity. Stephen Morrow is his name. So, I said, well, maybe there's one theory that does both, that gets rid of dark matter and dark energy by modifying gravity, and the criterion would be gravity gets modified when a certain numerical parameter is less than the Hubble constant. They actually have gotten some great results. Bless their hearts for coming all the way to someone's office. What I wanted to do was to let them know how maybe they could improve the procedure going forward. If you take a calculus class, you learned all these techniques, like the product rule, and what to do with polynomials. I might do that in an academic setting if the opportunity comes along, and I might just go freelance and do that. You had already dipped your toe into this kind of work. Perhaps you'll continue to do this even after the vaccine is completed and the pandemic is over. We learned a lot is the answer, as it turns out. We don't know the theory of everything. So, on the one hand, I got that done, and it was very popular. I'm definitely not going to be at Caltech, even two years from now. And honestly, in both cases, I could at least see a path to the answers involving the foundations of quantum mechanics, and how space time emerges from them. I started a new course in cosmology, which believe it or not, had never been taught before. Different people are asking different questions: what do you do? I had great professors at Villanova, but most of the students weren't that into the life of the mind. It's just they're doing it in a way that doesn't get you a job in a physics department. Like I aspire to do, he was actually doing. Now, in reality, maybe once every six months meant once a year, but at least three times before my thesis defense, my committee had met. So, then, the decision was, well -- so, to answer your question, yes -- well, sorry, I didn't quite technically get tenured offers, if I'm being very, very honest, but it was clear I was going to. There was Cumrun Vafa, who had been recently hired as a young assistant professor. It gets you a job in a philosophy department. So, that was with other graduate students. Very, very important. Also, they were all really busy and tired. Right. In late 1997, again, by this time, the microwave background was in full gear in terms of both theorizing it and proposing new satellites and new telescopes to look at it. So, that's why it's exciting to see what happens. My hair gets worse, because there are no haircuts, so I had to cut my own hair. You're looking under the lamppost. Bill was the only one who was a little bit of a strategist in terms of academia. Carroll lives in Los Angeles with . 1.2 Quantum Gravity era began to exist. So, Sean, what were your initial impressions when you got to Chicago? What was he working on when you first met him? What they meant was, like, what department, or what subfield, or whatever. This particular job of being a research professor in theoretical physics has ceased to be a good fit for me. Refereed versus non-refereed, etc., but I wish I lived in a world where the boundaries were not as clear, and you could just do interesting work, and the work would count whatever format it happened in. Even though academia has a love for self-scrutiny, we overlook the consequences of tenure denial. I was a credentialed physicist, but I was also writing a book. So, the string theorists judged her like they would be judging Cumrun Vafa, or Ed Witten. I got on one and then got rejected the year after that because I was not doing what people were interested in. 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. His research focuses on issues in cosmology, field theory, and gravitation. They met every six months while you were a graduate student, after you had passed your second-year exam. You couldn't pay me to stick around if they didn't want me there. I think it was like $800 million. We all knew that eventually we'd discover CMB anisotropies if you go back even farther than that. The first super string revolution had happened around 1984. As a result, I think I wrote either zero or one papers that year. But the High-z supernova team strategy was the whole thing would be alphabetical, except the most important author, the one who really did the work on the paper, would be first. I just did the next step that I was supposed to do. And of course, it just helps you in thinking and logic, right? Neta Bahcall, in particular, made a plot that turned over. This is really what made Cosmos, for example, very, very special at the time. Let's put it that way. Also in 2014, Carroll partook in a debate held by Intelligence Squared, the title of the debate was "Death is Not Final". But they're going to give me money, and who cares? But the anecdote was, because you asked about becoming a cosmologist, one of the first time I felt like I was on the inside in physics at all, was again from Bill Press, I heard the rumor that COBE had discovered the anisotropies of the microwave background, and it was a secret. Evolutionary biology also gives you that. Then, of course, Brian and his team helped measure the value of omega by discovering the accelerating universe. Do the same thing for a cluster of galaxies. And in the meantime, Robert Caldwell, Marc Kamionkowski, and others, came up with this idea of phantom energy, which had w less than minus one. This is December 1997. I was hired to do something, and for better or for worse, I do take what I'm hired to do kind of seriously. He was reaching out and doing a public outreach thing, but also really investigating ideas. Having said all that, my goal is never to convert people into physicists. And I didn't. So, the fact that we're anywhere near flat, which we are, right? So many ideas I want to get on paper. Carroll, S.B. I taught both undergraduate and graduate students. Intellectual cultures, after all, are just as capable of errors associated with moral and political inertia as administrative cultures are. That was, I think, a very, very typical large public school system curriculum where there were different tracks. Carroll claimed that quantum eternity theorem (QET) was better than BGV theorem. Either then, or retrospectively, do you see any through lines that connected all of these different papers in terms of the broader questions you were most interested in? So, it was a very -- it was a big book. So, I audited way more classes, and in particular, math classes. Because you've been at it long enough now, what have been some of the most efficacious strategies that you've found to join those two difficulties? Thank goodness. This morning Wilson responded to a report in the Athletic that said he asked the organization to fire both head coach Pete Carroll and general manager John Schneider last offseason. So, it made it easy, and I asked both Alan and Eddie. I thought that given what I knew and what I was an expert in, the obvious thing to write a popular book about would be the accelerating universe. Once you do that, people will knock on your door and say, "Please publish this as a textbook." It was fine. Also, I got on a bunch of other shortlists. I don't want them to use their built in laptop microphone, so I send them a microphone. There's a lot of inertia. Like, that's a huge thing. And number two, I did a lot of organizing of a big international conference, Cosmo '02, that I was the main organizer of.