Christopher Nolan (CN) on the appeal of the project…

My interest in it was a few key things. I’m a father myself and found it very powerful.

I grew up in an era that was a golden age of blockbusters, Close Encounters. It addressed [aliens] from a family perspective and I really liked the idea.

(American theoretical physicist) Kip Thorne’s long held dream was to do a sci fi film based on the possibilities afforded by real science. It was really about what real world science can offer us.

And the things he offered were far more exotic and surprising than anything I could have come up with.

There are so many influences on the film – 2001 is a huge inspiration.

There are a lot of different things rattling around in there. The film is optimistic. It’s saying that mankind exists separately from its situation. The film is fiction and feeds off certain of our worries but really it’s saying what mankind’s place in the universe? 

Maybe because my eldest child is a girl (he has four children with wife, Emma Thomas, who also produces all of his films) I decided to change Murph to a girl. You bring the actors in to flesh out the characters. I like working with the same actors.

The success of Alfonso’s (Cuaron) movie (Gravity) is very encouraging from the point of view of working in science fiction. The thing you hope for in doing an original story is that if it succeeds it will encourage that kind of filmmaking. But we’ll wait and see.

Anne Hathaway (AH) on working with Matthew McConaughey (MM)…

It’s a real pleasure to work with someone who takes their job seriously but also has a light touch. He’s full of amazing stories. I loved hearing tales about how he got to where he is now. If I got tense, he was wonderful at putting me at ease. He’s a kind man.

The cast, on working with Christopher Nolan…

MM: Even though it went on for five months, when you’re acting in a Christopher Nolan film, it feels just as intimate. It’s very raw and natural so I never felt overwhelmed by the scope or the set pieces. He was always on top of it.

Jessica Chastain (JC): I don’t normally do big movies and I’d always been afraid that you’d lose the relationships in favour of special effects. But [in Interstellar], there’s no greenscreen, they were chucking dust in my face, there was real corn that they grew.

It was so incredible, he let me get it out of my system and then with a very delicate hand come over to me and say one sentence. That exquisite note would open up my performance in a way that I’d never imagined. I admire the scientific discovery that [her character Murph] makes but I also admire a person who is able to overcome their anger to become a more loving person.

Michael Caine (MC): I’ve done six pictures with Christopher and every one was a hit. So every time he says do you want to make a movie, I say yes. And he says do you want to read the script and I say no [laughter].

I’m a very good amateur gardener so I see quite a few wormholes. I didn’t understand it until I saw this movie. I know a lot more about wormholes now. We know what’s on the other side – special effects.

AH: When I first read the script I didn’t totally understand my character. Then all of a sudden she made sense to me as someone who goes through a journey.

I loved my spacesuit from the moment I put it on. It felt like Halloween instantly. It was challenging, which was part of what I loved about it. I had to work out hard just to be able to stand up in it all day. The suit became like its own character – I always felt like it raised the hermetic states.

MM on fatherhood (he has three children with wife Camilla Alves) 

Fatherhood has restored a certain sense of wonder. They have reminded me as we get older that we take things for granted. Give things the justice of seeing them again as you saw them the first time.

CN on possibly working in TV …

I like movies. I think movies are great. For me the great thing about movies is the large screen, large audience experience.

I saw my first IMAX film when I was 15 and I immediately wanted to make films in that medium. It has been a long held dream of mine.

CN on the future of film...

It certainly has been swamped by technology but it has to have a future even from an archival perspective. It’s very important to preserve its place in the filmmaking process. I don’t see any reason why it can’t find the right level, the right place.

MC: If you’ve got digital, it goes on forever. I like film - nice short takes.

Who are your favourite sic-fi characters?

CN: Darth Vader.

MM: Chewbacca and Murph.

AH: R2D2, Ripley, Starbuck.

MC: Sandra Bullock in Gravity.

JC: Princess Leia and Hal.

Interstellar is in cinemas now.