Sean Carroll Versus the “Science Silo”

Photo: Bill Youngblood

Photo: Bill Youngblood

While science is a powerful tool for understanding our universe, it is not the only one, insists Caltech theoretical physicist Sean Carroll. On Mindscape, his podcast, Carroll hosts conversations with interesting thinkers on topics across the academic spectrum: from superstring theory to the fall of Rome and everything in between. 

Where did you get the idea for Mindscape?

It really came about because I had appeared on a lot of podcasts as a guest, and it seemed like fun. I'm very interested in all sorts of communication, so I wondered whether I should do a podcast. But then I thought, “What kind of podcast would it be?” The first obvious answer was that it would just be me talking, but I was humble enough to realize that I don't have that many interesting things to say on a regular basis! The next obvious thing was to talk to somebody else. I had recently written a book called The Particle at the End of the Universe about CERN and the Large Hadron Collider. For that book, I interviewed people and tried to get their funny stories. But being a journalist is a skill, and one I don't exactly have. So, interviewing other people didn't seem to be a good fit either.

But then I wrote another book called The Big Picture where I was again interviewing people, but this time I wasn't looking for funny stories or their personal life history; I was just trying to figure out what their ideas were. I was talking to biologists, Nobel Prize winners in a bunch of different fields. That was a lot of fun! I really enjoyed when I just got to talk to them about their ideas. It struck me that this was something I could successfully do as a podcast. Really, a podcast is just my excuse to talk to a bunch of interesting people. I realized afterward that I should have just called the podcast The Big Picture. I don't know why I didn't do that. [laughs]

How do you select guests for your podcast?

I generally have very broad interests, and I have a whole list of people who I would like to invite on the podcast. What is a little bit more work is trying to find a balance. I try to find different areas, different styles. When I'm choosing people, it's like being a chef preparing a meal, where I'm fitting all these different aspects together. I don't want to have two physicists in a row, for example. I don't even want to have two scientists in a row if I can avoid it. I don't want to have three movie critics in a row either. I really want to make it balanced and interesting so no one knows what's going to come next, and I'm keeping my own interest up. If I'm traveling somewhere, then I'm going to try to visit people while I'm there and talk to them. I kind of take the people at Caltech for granted because they'll always be here. [laughs] Nevertheless, I have talked to Mike Brown—the Planet Nine, Pluto-killer guy—and I talked to Kip Thorne after he won the Nobel Prize. 

Why do you think it is important to bring in thinkers on, well, everything?

First, the life of the mind can take many different forms, and science is just one of them, and, second, I want to break down the barriers between science and other intellectual pursuits. I want science to be a part of the conversation when we talk about what it means to be an educated, curious human being. There's an aspect of doing something like economics or law or philosophy that allows people to spread their thoughts a little bit more widely than someone who is a scientist and has a very narrow lane that they can go down. I want to establish that science should be part of this interconnected ecosystem rather than just a separate silo. 

I have been really impressed by how important and real philosophy can be, and how things that might seem relatively narrow like, say, bioethics, end up reflecting more broadly on what a democracy is and how we reconcile different values. What happens when certain people feel strongly that something should be forbidden while other people think it is good? Whether that comes from biology or anywhere else, we have this problem in society of reconciling competing values. I actually do think all of the various conversations I have with guests build up to something and interact with each other.  

Does being a physicist impact the way that you run these interviews? 

Yes, I can't help it. In most interviews, I end up saying, "Well, I'm a physicist. I think this." Physics, in particular, lends itself to having opinions about all sorts of things. When I talk to economists or even musicians, there's always an aspect of what they say that resembles or relates to what I do as a professional scientist. I always tell people I'm talking to that this is supposed to be a conversation; we can have give and take. But they don't always take me up on that, so it’s always a pleasant surprise when people start asking me questions. For instance, I was talking to the economist Tyler Cowen, and in the middle of it he wanted to ask me questions about the many-worlds interpretation of quantum mechanics!

Why is science communication important to you?

My primary interest is actually doing the science, or, more broadly, doing the intellectual work, working hard to understand the universe. So, when I write books or do the podcast, the communication aspect is part of a scholarly attempt to improve our understanding. Secretly, the science communication I do isn't really outreach. I'm not that interested in saying “let me teach you general relativity or cosmology or whatever.” I actually want to use my book writing, blogging, and podcasting to advance our understanding of the world. 

 What do you want listeners to get out of your podcast?

Something that is special about podcasts is that the listener gets a kind of intimate relationship with the host that you just don't get through text. They’re hearing your voice on a weekly basis, so you get this loyalty. I think I can take people who are listening to my podcast—maybe because they mostly want physics—and drag them along into things they might not normally have found. In my personal research, I find that philosophy is very useful, but a lot of my physics colleagues don't agree. If I have a really compelling interview with a philosopher, then that's very useful. 

But still, you don't need to be a scientist to listen to my podcast. You don't need to be an expert on anything, I hope, to listen along. Every conversation should be understandable to almost everybody. But while some of the episodes are just fun, you have to be willing to do a little work. Anyone who's willing to hear something new, be open to an idea, that's my audience. And while I feel like I have an obligation to keep doing new and interesting things for them, I also feel proud of them. I get to choose who to talk to, and they listen. So far, they've been willing to go along with me for the ride. 

New episodes of Mindscape are posted weekly and can be found on Carroll's website at and on most popular podcast apps including iTunes, Google Play, and Spotify.