How real-world science sets The Expanse apart from other sci-fi shows

On 13 December, Amazon Prime will air the fourth season of The Expanse, a hardboiled space drama renowned for its working-class characters and real-world space physics. Showrunner Naren Shankar is part of the reason the science checks out. The veteran writer and producer for programs such as Star Trek: The Next GenerationFarscape, and the police procedural CSI: Crime Scene Investigation, has a doctorate in applied physics and electrical engineering.

Shankar chatted with Science about why he feels it’s important to have a realistic sci-fi show, and how television work is like the scientific peer-review process.

This interview has been edited for clarity and length.

Q: How did you end up making sci-fi shows?

A: I actually started at Cornell [University] as an arts student. But I always loved science and math. In my second year, I transferred into the college of engineering. Usually, people transfer out of the college of engineering! I stayed all the way through to get my Ph.D. And somewhere along the line I just kind of decided I didn’t want to be an engineer anymore. The field rewards incredible specialization, and I saw myself becoming more and more of an expert over a smaller and smaller corner of the universe. I had a couple of friends out in Los Angeles that I had just done creative writing with when I was in school. They said, “Hey, come out, be a screenwriter.” And I thought, great.

Q: What did your science education bring to your television work?

A: One of the most valuable things I took away from school is peer review. You write a paper, sit down with your colleagues, and then you pare it down. That is really the process of the writing, when you’re writing a script. Everybody sits down and reads it and then you take it apart.

Naren Shankar, showrunner for The Expanse


I did a lot of science fiction in the early stage of my career, and then I did a lot of cop shows and crime shows. CSI: I ran that show for many years. It had a lot of scientific method in it. Investigating, the idea of the logical path to do a criminal investigation, evaluating evidence: All of that sort of really did play to the training.

Q: The Expanse tries to incorporate real-world science. Does that fire up the physicist in you?

A: It does, and it’s actually one of the things that attracted me to the project. When I got the script for the The Expanse, the pilot, I was, like, “Wow, this is a very different kind of a show.” Because they embraced all of the things that most science fiction shows run away from: the fact that you don’t have weight unless your ship is accelerating, the fact that communication in space is not instantaneous. We use that for drama. At the end of one episode, a bunch of missiles are heading off to basically hit Mars. In the very next episode, people on Earth are realizing that that has happened, like, 25 minutes ago.

Q: What about the physics of your spaceships?

A: They fly with realistic physics. You see conservation of momentum, conservation of angular momentum: all of the things that would actually occur in space. You don’t see control surfaces and aerodynamic flight, because they’re all moving in a vacuum. You see realistic objects changing orientation with thrusters. Personally, I’m quite tired of seeing spaceships fly around like fighter planes in the Pacific in World War II.

In the pilot, the series opener, the big action sequence was the ship making a turn. This crappy old ship has to suddenly divert off of its course to go investigate a distress call. The only way a ship can change course is “flip and burn,” which is to flip around and fire the rocket. But they decelerate much harder than they should have. “This could break the ship apart!” That was the tension of it.

Q: In season four we see an exoplanet, Ilus, that’s rich in lithium—a rare mineral that’s valuable in the future. Ilus is like Earth but a bit wrong. You see different continents from space. Animals on its surface are different. There’s sort of an uncanny valley experience.

James Holden (played by Steven Strait) suffers the physical consequences of acceleration in The Expanse.


A: That’s a really good way to describe it. It appears to be Earth-like, because you can breathe the air. “Oh, things are fine.” Well, biology is much more complicated than that. There are things that happen when you have interacting biomes. Imagine the first Europeans coming to Australia. All the biology that was there was stuff that they were not used to. There were things that were poisonous, that they didn’t understand. Many of them died. It’s a little different with Ilus because we’ve got humans coming to an alien planet with a different biome than human genetics. So that causes some interesting interactions.

Q: How is Ilus different than a Star Trek “planet of the week” planet for you?

A: Star Trek is a wonderful show, but it’s not really, in any true sense, a hard science fiction show. The kind of stories it chooses to tell are largely allegorical in nature. Star Trek went to planets with monolithic cultures and dealt with certain sociological problems. Ilus is uninhabited. It’s just a place that’s got a lot of lithium. The only people there are a bunch of refugees saying, “You can’t have our mine.”

Q: Is that maybe a couple of steps from happening, right now? Maybe somebody will claim an asteroid and become a trillionaire.

A: Absolutely. It’s amazing when you’re getting into these stories that are set hundreds of years in the future and then you look at the present: You know, maybe it’s not going to be that long. Because that stuff is out there, for sure.

Q: Do you think you’re raising the game for everybody, as far as how to make a science fiction show?

A: I hope we’re raising the game. I do get the impression, though, that people are a little intimidated by trying to pull it off. It does require you to pay attention to things that people aren’t really told to pay attention to. That requires a different kind of appreciation of the reality of what’s going on. And so it’s a fairly high bar, I think. But it’s certainly not inaccessible.