Stephen Hawking is famous for his research in general relativity and quantum gravity, but also well known because of his near-total paralysis from ALS. Before taking on the role of the acclaimed scientist, that's what actor Eddie Redmayne knew about Hawking: "I knew he was a physicist, but I didn't know about astronomy, cosmology, and astrophysics. But when I read this script, I just couldn't believe how much there was behind the icon." Based on Jane Hawking's memoir, "Traveling to Infinity: My Life With Stephen," "The Theory of Everything" delivers a more complete picture of Hawking as a husband and father. Eddie Redmayne talked to me about what he learned playing Hawking, developing chemistry with co-star Felicity Jones, and his favorite apps.

Eddie Redmayne
Eddie Redmayne plays Stephen Hawking in <i>The Theory of Everything</i>. (Credit: Focus Features)

Prior to getting involved with this film, what did you know about ALS, and what did you know about Stephen Hawking?
I knew embarrassingly little about both. I don't think I even knew that ALS was degenerative. I had been at Cambridge and had seen Stephen Hawking from a distance. I knew his voice. I knew he was an icon. I knew he had done certain things with black hole theory. I knew he was a physicist, but I didn't know about astronomy, cosmology, and astrophysics. But when I read this script, I just couldn't believe how much there was behind the icon, really. I find it so inspiring that I fought quite hard to get the opportunity to play him.

How did you prepare for the role?
I got cast five months before we started filming, and I had all that time to prepare, and I started collecting documentaries and photographs. I gave it all to the production team and said, "Can I get something that I can put it all on?" And they gave me an iPad. So I had all this footage, and I'd go to the ALS clinic and meet the specialists there and meet some of the patients and film them and hear them. I had this iPad with everything on it. And you can do all that research, but it gets to the point where you have to start trying. And I did a lot of the physical stuff working with a choreographer, who would go through all that with me. When it came to the facial thing, it literally came down to me holding the iPad up to the mirror, playing a documentary of Stephen Hawking from the '80s and watching it. I literally had to replicate it. That experience became riveting, because you always hear about muscles not working, but it's also about some of them becoming rigid. So it's about holding muscles in places and learning to isolate new muscles, and it was an interesting experience to use things you've never used before.

When you play a character, do you have to identify with them?
I've played some pretty screwed-up characters in my time, so I have to be careful about what I say here. I don't think you have to identify, but you have to find the humanity in it. You're the vessel of these characters, so there will always be aspects of your personality that come in. But I couldn't understand cosmology. You can do all the research and homework you can, but eventually you just have to throw yourself at it.

Could you relate to his personal journey?
The moments of intimacy, you try to find a version of it in you, so whether it's heartbreak or camaraderie with his pal, Brian...that was lovely for me, because Harry Lloyd, who played him, was a mate of mine from when we were 15 years old. So it meant we could play our version of that. Even Charlie Cox -- who plays Jonathan -- is an old, old mate, so even though they're love rivals, there was a friendship there, and that was fun to play.

What was it like to sit in a wheelchair for hours on end?
One of the realities of that was as simple as what you see. You see the world from a different perspective. So that was an interesting thing. But above and beyond that, staying in a certain physicality, you realize how frustrating that feels, even with the knowledge that at the end of the day you can get up. So I can't imagine how frustrating it must be when you don't have that option.

How did you and Felicity Jones develop the necessary chemistry to play husband and wife?
I had known Felicity for eight, nine years. We started out together at the Donmar Warehouse. We had this friendship, and I had always admired her from a distance. So when she was cast we had a bit of a shorthand and, more importantly, an absolute trust in each other. When she arrived a week or two prior to shooting, we learned that Jane Hawking was almost an extension of Stephen Hawking, so it was about us learning to dance together. But the most important thing was that we trusted each other a lot.

Eddie Redmayne, Felicity Jones
With so much history and trust between them, it was easy for Eddie Redmayne and Felicity Jones to slip into playing Stephen and Jane Hawking. (Credit: Focus Features)

When I interviewed Jared Leto last year for "Dallas Buyers Club," I predicted his Oscar win. Now I ask you, are you already devising your acceptance speech?
Oh God. If I could be totally honest, when I read the script and thought it was the most extraordinary story, I fought pretty hard for it. Then when I got the part, there was a moment of serious excitement, and then it was a feeling verging on crippling anxiety. That was because you're playing an icon who's living, and I knew he'd see the film. And this is before I met Stephen Hawking. I knew Jane would see the film. I knew Stephen and Jane's children would see the film. It felt to me that that was the group of critics we had to step up our game for. Throughout our process, they were so generous at giving up their time. To me that almost raised the stakes higher, because what if we didn't do them proud? So when they enjoyed the film, that was the greatest compliment.

So are you nervous about the prospect of winning, or are you just not driven by awards?
I try not to think about that. I really don't. When you're doing work, it's more important to me how the audience receives it. So in this case, what they thought was the most important, and the fact that they approved was gift enough.

What do you want audiences to take away from this film?
I would love audiences to take away what I've taken away: that this gentleman was dealt the most extreme hand of cards and refused to see that as a limitation or obstacle and exploited every minute of his life. He lived it to the fullest and lived forward rather than back, and for me that's been the most inspiring thing. So finding that humor and optimism, but also his passionate agenda about those extraordinary things he's interested in and brilliant at, and refusing to take no for an answer.

What are your top mobile apps?
1. Jedi Lightsaber, because you get to record a sound with your own voice and move the phone around like a lightsaber.
2. My Talking Pet. You take a photo of your pet and then record what it's saying. Then you play it.
3. Fandango.
4. Jamie Oliver's Recipes. My brother's girlfriend works for his foundation, and I love his recipes. So that's great for my attempts at cooking.
5. I look at Instagram a lot, because it's a good way to keep up with my brother, who lives in Hong Kong, and see my niece and nephew growing up.
6. WhatsApp.
7. Shazam.

The Theory of Everything
<i>The Theory of Everything</i> opens Friday. (Credit: Focus Features)

Joshua Rotter is a copy editor for and covers iOS.