The Men Who Stare at Goats, a rollicking film based on Jon Ronson’s book, is out now.

Clooney and MacGregor in The Men Who Stare At Goats Clooney and MacGregor in The Men Who Stare At Goats

When Jon Ronson finally saw the film Hollywood made of his book The Men Who Stare At Goats, he loved its “battiness” and likened it to “Little Miss Sunshine goes to Iraq”.

Speaking from London via satellite last night, at Popcorn Taxi’s preview of the film, Ronson said he was able to watch the film like any other member of the audience because he felt quite disconnected from the film.

“There's a tendency for those making Hollywood films not to want the author around, making them feel guilty… and I didn’t want to hover,” Ronson joked, though he had spent time with the film makers and actors early in production.

Ronson’s book on the US military’s interrogation practices and research into psychic and paranormal techniques in the 70s was rich in bleak comedy, but the film takes it to a whole new level of screwball.

Ewan MacGregor plays Bob, a cuckolded Michigan journalist who decides to go to Iraq to prove himself. There he meets Lyn Cassady (George Clooney), who claims to be a former member of the U.S. military’s New Earth Army, a unit that employs paranormal powers in their missions. Among the self-proclaimed Jedi soldiers’ tactics: “remote viewing” and the ability to stop a goat’s heart just by staring at it.

Some of the film’s best scenes are flashbacks to the New Earth Army’s creation by Bill Django (Jeff Bridges, in full Dude mode). Django is based on a real man, Jim Shannon, who was brought in as a consultant right from the start. According to Ronson, Shannon not only became firm friends with Bridges, but designed the New Earth Army’s uniforms and painted psychedelic murals on set.

It's a beautifully shot film – from hot-tubbing hippies to sweeping panoramas of the Iraqi desert so sculptured they barely seem real. The soundtrack is cheeky; Clooney’s character admits he finds it easiest to tap into his Jedi powers through “drinking, and soft rock. Boston, I like Boston.”

Perhaps the funniest thing about the film is an ironic twist of MacGregor’s casting. Considering he played Obi Wan Kenobi in the Star Wars movies, it must have been hard for him to keep a straight face as the naive journalist asking what a Jedi is.

Given the subject matter of some of Ronson’s other books and documentaries – extremists, psychopaths and conspiracy theories - the Q&A session didn’t take long to veer into even stranger territory.

Ronson recounted the beginning of his unconventional friendship with pop star Robbie Williams, who contacted Ronson as a fan and asked him to take him to a haunted house. Ronson found himself writing to dozens of little old ladies with manor houses, asking if Robbie Williams could sleep over with their spectres.

“And every one of them wrote back immediately. They were throwing their ghosts at Robbie like they were their debutante daughters!”

So does Ronson believe it's possible to stop a goat's heart simply by staring at it? Or even a hamster?

“I guess if you stare at any animal long enough, it'll die.”

The Men Who Stare at Goats is in cinemas now.