Marvel’s hotly anticipated film Doctor Strange has the same core problem all superhero franchises rooted in science fiction do: It must walk the balance between scientifically feasibility and fantasy. After all, what good is sci-fi if we can’t have a little fun with science fiction?

Nevertheless, the film’s producers aren’t looking to just break the laws of physics willy nilly for a special effects bonanza; they’re also looking to adhere to natural laws in a way that combines imagination with realism. That’s why many movies enlist the help of scientific experts as consultants during production.

This is particularly fitting for Doctor Strange: the titular protagonist — Stephen Strange (played by Benedict Cumberbatch) — is a former neurosurgeon turned magical sorcerer, trained in the mystical arts to protect the earth from supernatural threats. As such, the audience is essentially put in the same position as Strange: They must leave a life of total empiricism and walk into one in which everything they know no longer applies.

Adam Frank, a professor of physics and astronomy at the University of Rochester, served as the film’s scientific consultant. Because Doctor Strange is so fixated on the nature of reality and consciousness, Frank’s role was to advise the movie on illustrating changes in the human experience of space and time.

Inverse spoke with Frank for a short Q&A. His answers are presented below (edited for clarity and brevity).

What kinds of physics and space-time concepts did Marvel need of guidance on?

Let’s talk in general about the Marvel Universe and science. One of the things that’s really awesome about what those guys have done across the Marvel Universe movies is that there’s — as much as you can have in a superhero movie — a respect for science. In particular, they’ve built a consistent set of rules, and they’ve obeyed them throughout most of the movies. Compared to [the DC movies], they’ve imagined there’s a science at work. You know, Tony Stark and what he can do with the devices he builds and the idea that Thor, the inhabitants of Asgard, are actually aliens, magic … a number of times they’ve used that Arthur C. Clarke quote: “Any advance of technology looks like magic to other people.”

The dilemma with Doctor Strange, to me, was to find a way to embrace that vision and that respect for science for a character who — in the comic books at least — is a magician, an occult master. And so how do you get that into the Marvel Universe? [The film’s producers] wanted to respect everything that they’ve been slowly and carefully building.

So the question is how do you fit Doctor Strange into this? There’s a lot of different ways. You could have imagined that it was all about neurological forces — the neurochemistry of the brain or something. I think that would have been an interesting way to go, but for me the biggest thing was the idea of consciousness. And so we spent a lot of time talking about the scientific and philosophical conundrums around the idea of consciousness.

When it comes to the laws of physics, we’ve pretty much got those nailed down and you can take those all the way to the frontiers of physics. In the Thor movies, there’s the Einstein-Rosen Bridge, so the rainbow way or whatever it’s called is actually a wormhole. In Ant-Man, they brought in quantum mechanics. And the great thing about Marvel is they use those devices — they’re good enough about their science — as twists in the story to be able to make the story move along.

Consciousness is not like that. We don’t really have a handle on what consciousness is. We don’t have a scientific, materialist, reductionist account for consciousness yet. Maybe we will have one, but it’s also entirely possible that we will not have one and we will need to add other things to have a proper science of consciousness.

A noted philosopher, David Chalmers, came up with the idea of the “hard problem” in the 1990s. He was trying to explain how neuroscience has made interesting progress on things like vision — how does vision actually work, how do you represent something from visual input, which part of the brain is active. For him, the hard problem was how to account for the personal vividness of experience. Even if I wrote an equation down for it — if I wrote an equation down for you eating an apple — that would be very different from your experience of eating the apple.

So your work was more along the lines of playing around with individual perception and consciousness, and playing around with what those effects have on someone’s perception of space-time as they see it?

It’s more than that. I think you can go much further and say, where does consciousness really live? It’s not just the mechanics of perception, it’s what is consciousness tapping into? What is consciousness part of? The typical materialist account of consciousness is you’re just your neurons. That’s it, end of story. You’re just the equivalent of a bunch of little springs and balls in your brain moving back and forth, or gears. For many years, people imagined that you could think of consciousness as just being the effect of the clockwork in your head. But people have always been pointing out the problems with that idea.

One way of playing with Doctor Strange is this idea that there’s a lot more going on there than just your neurons. The neurons are [just] one way of describing what’s happening with consciousness, but that’s not all of it: There are other, so to speak, universes that can be opened through what we don’t understand about consciousness.

Can you tell me a bit more about how the movie navigates through alternate universes and multiverse theory?

The multiverse is such a rich idea. I don’t think it’s true, but that doesn’t matter. It certainly is discussed by physicists, it’s received a lot of attention by physicists, and it’s a really potent and rich thing to bring to your fictional universe.

The scientific account of the multiverse is that after the Big Bang, you didn’t get one universe, you got lots of different universes. And each universe was separate from the others and had different physical laws.

That’s the idea that sort of comes from cosmology, but physicists have been playing around with lots of different ideas of multiverses. For example, in quantum mechanics (and trying to understand the weirdnesses of quantum mechanics), people have proposed that every time a quantum event occurs, the universe splits off into a bunch of parallel dimensions, each with a different quantum result, and then each of those individual universes goes on and evolves on its own. And then, of course, there’ll be more quantum events and then there’ll be more splittings until you have an infinite number of parallel universes. So what you could do in a movie is imagine that you’re getting access between all of these universes, like the universe that we’re living in is one universe out of an infinite number of universes in the multiverse. So the multiverse is all the possible universes, and all these different universes have utterly different kinds of laws, different behavior, so you can use that idea in a story to allow your characters — especially as they’re using consciousness, using this openness of consciousness in the story — to be able to have access and move between these different universes.

In the Doctor Strange comics, he’s always going to these different dimensions. And that was very 1960s, totally groove-orific, trippy. So a way of bringing that into modern physics parlance is [thinking about how the] different dimensions become the different universes in the multiverse.

A lot of times, different kinds of science fiction works will use dimensions and universes as a synonym, which is obviously not the way physicists talk about these things. Does Doctor Strange make that distinction between different dimensions and universes, or does it use those terms interchangeably?

In the multiverse (depending on which version of the multiverse you’re dealing with) they can be the same thing. In the quantum mechanical version of the multiverse, you have an infinite dimensional space, with each dimension representing a different universe. The number of spatial dimensions in the universe will be different — they can all be three-dimensional universes — but they all exist in this higher, in this more abstract, infinite dimensional space where each dimension represents a different universe. Physicists will think about dimensions in more than just the physical, spatial dimensions. So you don’t have to make that distinction.

Is there an example that you might be able to provide about how the movie runs with a scientific concept and the role you played in making sure that it was grounded in a factual basis?

Without getting into specifics, we had a long discussion about what that dialogue would look like between the Ancient One [Strange’s teacher] and Strange. What would it look like between a materialist, rationalist, reductionist; and someone who had this enlarged perspective. Because I’m a physicist, I know exactly what those materialist arguments look like; I’ve also written on science and human spirituality. I’m not a reductionist. I’m an atheist, but I’m not a reductionist. So that was one of the things we sort of went back and forth with.

And that was fun, just talking about, “What would somebody who just believes that there was nothing to consciousness except your neurons — how would he argue with someone who was saying, ‘No, there’s actually more’? What would that look like?” That was fun for me, that part was super awesome for me. I’m looking forward to seeing the final project, but what I’ve seen so far I’ve been really excited about.

Photos via Marvel

Neel is a science and tech journalist from New York City, reporting on everything from brain-eating amoebas to space lasers used to zap debris out of orbit, for places like Popular Science and WIRED. He's addicted to black coffee, old pinball machines, and terrible dive bars.