"Gravity goes all dreamy," Gordon-Levitt told MTV News.
It's an amazing spectacle to take in on the big screen — "The Matrix" on steroids — and not an easy one to have filmed in the real world. "One of the coolest things about it is that we kind of did it for real," Gordon-Levitt said. "We weren't in one of those zero-gravity machines, but we weren't in front of a green screen either. The mode, the fashion in Hollywood nowadays, is to do it all with computers later. But [director] Christopher Nolan likes things to feel real. If he had put me in front of a green screen and said, 'Pretend you're floating. Pretend you're off-balance,' I would have been like, 'Ah, I'm floating, I'm off-balance.'
"But instead, he put me in the middle of this set that spun around 360 degrees or he hung me on wires or put me on this seesaw contraption," he added. "All of those moments where it looks like I'm off-balance? That's because I was off-balance. I was doing my best to keep my balance and fight this guy when the floor was becoming the wall and the ceiling was becoming the floor."