The star of The Wind That Shakes the Barley and Sunshine talks about his upcoming projects in an interview excerpt exclusive to Premiere.com.

PREMIERE: I'm going to give my recorder to you because I'm concerned about the noise.

CILLIAN MURPHY: Okay. Sure. It's very noisy, yeah. Will I just leave it here?

In your armpit? [laughs]

[laughs] I don't particularly want to hold it. Okay, I won't leave it in my armpit.

You can leave it in your armpit.

Okay.

So tell me a little about the character you play in Sunshine, which reunites you with 28 Days Later… director Danny Boyle.

I had to try and play a physicist. It was very interesting just trying to get into the mind-set of these people. I went over to Geneva to where they're doing this particle accelerator, and they're going to find this stuff called [dark] matter, which they reckon is what caused the big bang. And I hung out with these guys, and they're burdened with an extraordinary intellect, and they're like very serious people. No, I shouldn't say that. I mean, we had fun with them, but they are very aware of the seriousness of their job, which is to discover the meaning of life, basically, through science. And with this character, I wanted him be very... not closed-up emotionally, but aware that there's a bigger thing at stake here, which is the survival of mankind.

Were you good at science in school?

I was good academically, but languages are what I enjoyed. I couldn't do math or physics or any of the sciences. I dropped them all very quickly.

I liked biology.

Did you? I couldn't do biology. Isn't there a left side and a right side of the brain or something?

Some people have both.

Yeah, and they're good at sports, too?

So not being much for science, what attracted you to the role?

I think what Alex Garland does as a writer is manages within genre pieces—for example, in 28 Days Later… and with Sunshine—to make a really compelling, engaging movie that also does have something to say. 28 Days Later… was very prescient at the time. We shot it, like, in September 2001, and then we watched the Twin Towers come down when we were shooting, and then SARS happened. Also, there was the whole rage thing, which is, I think, a modern condition now. Everyone's fucking raging against everything—you know, car rage and phone rage and fucking plane rage. But it's a good old zombie movie also.

Was there a lot of greenscreen involved in Sunshine?

No, actually, there was not that much. Most of the stuff was actually tangibly there. So I never had to act with a dot, which is brilliant. It's so hard to impress with effects now, you know.

Do you impress with stunts instead?

Yeah, there were wires and stuff. And that [space] suit was pretty challenging. They did this thing called a helmet cam, where Danny had a camera in the helmet. But, in effect, it was this ginormous rig that you have to carry around on your back. But he would operate it from far away.

So the audience can see through the helmet?

Yeah, but you're seeing my face also. It's a brilliant device, but it was very physically challenging to wear.

How do you choose your roles? You have a remarkable filmography—28 Days Later…, Batman Begins, Red Eye, and Breakfast on Pluto to name just a few.

My aspiration has always been to not have a film on my filmography that I don't want to talk about or that I'm not passionate about as a project. And so far I think I've achieved that. Obviously, I'm giving myself a total get-out clause that I can do shit down the line if I need to. But right at the moment, I want to pick very carefully.

What kinds of projects tend to appeal to you?

Well, it will always start with the script. Always. I suppose it's trying to challenge myself and trying not to repeat myself. And then there's the combination of the director. They would be the main principles that I would use.

But you didn't pick The Wind That Shakes the Barley on the basis of the script, because you didn't read the script before signing on, right?

That is the exception because of the way [director Ken Loach] works. I mean, if you had a big speech, he would give you these scenes maybe the night before or the morning of. And that was a tremendously revealing process for me as an actor to work like that, to make it all instinctual and not intellectual. Events would unfold on film. For example, at the beginning of the movie when the Black and Tans come into the house, we didn't know that was going to happen. And similarly, when I was given information about the traitor within the Flying Column, that happened onscreen. So that was a genuine, natural reaction to the information I was being given. Which was great because film acting can get very self-indulgent, and this is anti all of that.

Since you didn't read the script before signing on, and it deals with the history your own hometown of Cork, were you worried about whether it would be a film you could stand behind politically?

Yeah, I kind of abdicated responsibility there ... I tend to agree with Ken's politics anyway. So I knew that I would be in the right hands. I didn't even know it was going to be about the civil war. I just thought it was going to be the War of Independence. And then as we went along, it became clear that it was going to be about the split.

Do you think the IRA violence was necessary?

I think that when a nation or a country is repressed, they will rise up. Someone said, "Sovereignty can't be given. It has to be taken." I believe in that. But it was a lot simpler back then. There's a very fine line now between a freedom fighter and a terrorist, and it's very tricky.

The Troubles have been the topic of endless art—

I mean, again, it's part of our history. That conflict will always feed us, the Irish people, creatively, and there's nothing you can do about that. You have this nation of poets, in a way, and then this centuries-old struggle. So it's good combination for art, I guess, but not for the people that had to live through it.

Has it affected you or your family at all?

Yeah, I had, like, a cousin who was killed when he was 17, and my grandfather was shot at. That's part of who I am. And the two main political parties in Ireland trace their roots back to this split. And it's never really been dealt with, that specific time. I mean, Michael Collins is the closest, but that was more about the myth of the man, where this is just about real people.

How strongly do you relate to your identity as an Irishman?

Well, I'm not sentimental about it. I recognize it is who I am, and I'm from Cork all the way back. [laughs] It's been undiluted. And I love going home and I love Ireland, but I'm an actor first and foremost, and my extraction is secondary. And I don't think I will ever live in Ireland. It's very pretty and very small. I left there when I was 19, and I was quite happy to be out of there. You just know everybody. I like living in a world capital, because I like the anonymity that it offers, and I like the scope that it offers. I mean, I lived here [in London] before I ever did a film or anything like that. And I just loved it, being able to go and disappear and just go to galleries and walk.

Do you ever think about how your son is growing up in London as opposed to Ireland? Has he started talking with a London accent yet?

Well, he's talking, but it's—I know, yeah. I do think about that. It has given me pause. But his values and everything else come from his parents. He's going to be a Londoner, and I'm okay with that, I think. Listen, the Irish diaspora—it's just like everyone is Irish, almost. And it's just a question of how much or little you wish to be aware of those roots. And I think he'll be very aware. He can go back when he wants, and it'll be his choice.

How are the values different in London?

Well, it's trickier bringing up a kid in a big, big city, obviously. But I just think the values come from the parents. They don't come from the environment.

Would you ever live in L.A.?

Would I ever live there? No. I've worked there and lived there while I was working, but it doesn't really suit me, my temperament. And I'm European, you know. I need to live in Europe. And I love what [L.A.] has to offer in terms of the climate and food and everything else, but it's just too one-industry for me.