Sean M. Carroll has invented time travel. How do we know? The theoretical physicist somehow manages to teach at the California Institute of Technology, write for Discover Magazine’s Cosmic Variance, contribute his physics knowledge to TV (Fringe) and film (Thor, Tron:Legacy, The Avengers), and more than we have the energy to type out. Time travel is the logical explanation, but Carroll’s enthusiasm for communicating science is also a possible answer. Recently, Carroll took some time to chat with us about how he became involved in The Exchange, what questions he has been asked during consults, and what misperceptions each community has about the other.

Tell us about your background. What sparked your interest in physics?

I got interested in physics very early on, while I was still in elementary school. I'm not sure exactly what sparked it, but I started haunting our local public library, reading all the books in the low 500s of the Dewey Decimal System (math, astronomy, and physics). I loved reading about the Big Bang, black holes, and elementary particles, and became convinced that I wanted to “do” that for a living. At the time I had no idea what it meant to be a scientist, but it worked out eventually.

Quite a number of our consultants were inspired to explore science through Star Wars or Star Trek. Did you watch any science-fiction programming as a kid? Did it have any impact on your interest in science?

I watched some Star Trek, and loved Star Wars, but I wouldn't say they were crucial to my interest in science. I read a lot of science fiction, especially Robert Heinlein, Isaac Asimov, and Roger Zelazny.

But at the time I didn't consciously relate it to my interest in science. Of course, unconsciously all of these interests were driven by a common fascination with science and the future, and I wouldn't be surprised if they reinforced each other below the surface.

How did you become involved with The Exchange? What projects have you worked on (that you can tell us about)?

Being a scientist living in L.A., especially one who is interested in outreach, it is inevitable that you will intersect with Hollywood at some point or another. In fact, I consulted a bit for the TV show Bones and the film Angels and Demons, even before The Exchange came along.

But once The Exchange did come along, I had a major in -- I am married to Jennifer Ouellette, the founding director. She actually tried not to lean on me too much, but I was always available as an emergency back-up scientist in a pinch.

My first major consult was for Tron: Legacy. A small group of scientists, including myself, met with the director and writers and producers, tossing around ideas. Other notable projects include Thor and the TV show Fringe. But most of the consulting I've done has been for movie projects that are still deep in development, with directors like Michael Mann and Ridley Scott.

Can you give us examples of the questions you've been asked during consults? Has any particular question stood out from the rest?

There are roughly two types of questions. One is very specific and down-to-Earth: “I want to do this, how can we make it scientifically respectable?” The other one, more fun, is the open-ender: “How could we do something cool here?” People always want to know how to travel faster than light or backward in time. But the best questions are about building new worlds. “How can we make magic work in a way that is compatible with modern technology?”

Some questions are more about scientists than about science. When we were discussing Natalie Portman’s scientist character in Thor, the producers wanted to know what her lifestyle would be like -- what music or books she would be associated with, what kinds of posters might be on her walls.

What misperceptions do scientists, in general, have about the entertainment industry, and what misperceptions does the entertainment industry have about scientists?

Scientists tend to underestimate the passion and intelligence of filmmakers, who are generally very dedicated to getting things right as long as it's feasible and doesn't get in the way of the story. But in order to get things right, scientists have to offer constructive advice on how to reconcile the demands of the story with the laws of nature. If we can do that, the storytellers are usually more than happy to go along.

On the entertainment side, the stereotype is that scientists are scolds who ruin movies and shows by insisting on perfect realism. There's an element of truth there, but they are often surprised to learn that scientists can actually be good sources of new and interesting ideas.

You have quite the following on Twitter. Is there a science community on Twitter?

There’s some science community, but there's a bigger science-communication community (perhaps for obvious reasons). Scientists as a rule haven't flocked to social media, although there are a growing number of exceptions.

Thinking of the next generation of filmmakers and scientists – what message would you like to share with them?

I’d like to see filmmakers and scientists start talking to each other at a very early stage, before plans are set in stone. Scientists are dismayed by questions along the lines of “We’re doing this, give us some vocabulary that will make it sound respectable.” But they can give very useful input if they are asked “How can we achieve these particular ideas?” Likewise, filmmakers are dismayed when they are told “You can't do that.” But they love hearing “Here’s a much better way of doing that.”

Anything else you would like to share?

The most important point I like to share is that “getting it right” is not opposed to good storytelling -- it makes the story better, when properly applied. Audiences can tell when the science is hokey or the scientists are portrayed as caricatures, even if they can't explicitly put their finger on it. Being in touch with how the universe works is an important part of telling a riveting story.