It's fascinated scientists and moviegoers alike for decades. People still wake up at night in cold sweat thinking about it. But what exactly is it that makes John Travolta's hair so eye-catching? Is it the silky smooth hyper-conditioned sheen that radiates from it? Or perhaps the fact that it varies so much to reflect his inner mental state?

As John's scalp rears its balding head in From Paris with Love, let's a take a stroll through Travolta's tong-curling hirsute history...

Grease - 1978

Travolta's hair started off with a bang, some oil and a massive quiff. Sure, we can look back and laugh at it (and frequently we do) but Grease proved that such gravity-defying greatness had enough power to seduce Olivia Newton John. If that's what you want to do with your life.

Mental State: I like singing. And hair. Preferably together.

Pulp Fiction - 1994

Tarantino's gore-splattered movie proved a comeback was still possible for Johnny, which he dutifully honoured with a daring comb-back. Sporting it with some slight chin-hair and a sharp black suit, Travolta's hair here has inspired many a fancy dress costume over the years. Perhaps even more so than his Grease-d up self. Blood-stained accessorising is optional.

Mental State: Mmm, hamburgers. Yay, guns. Ooo, suitcase.

Primary Colors - 1998

This was, in many ways, the boldest of all The Travolta's hair-raising moves. Not for style or height, but for colour: here he went as grey as a fox to portray his Clinton-esque President. And boy could he pull it off. Look at those eyebrows. No wonder Emma Thompson looks so jealous.

Mental State: I spilled talcum powder over my head. But I'll still sleep with your wife.

Battlefield Earth - 1999

Never has a haircut so summed up the three most important things in life: science fiction, scientology, and John Travolta. These incredible dreadlocks are either a. the worst wig in the history of mankind, or b. a message to all Thetans that we must follow in his follicle's footsteps. It's clearly b.

Mental State: Scientology rocks.

Swordfish - 2001

How do you follow on from the worst wig of all time? Why, with another wig, of course! Here, Travolta played a Euro-banking, financial wizard with a taste for espresso. So naturally he combined his bleached plugs/brown locks with a mini landing strip, which made everyone think of crap dribbling down his face every time they watched Swordfish. Which was quite an appropriate reaction really.

Mental State: European.

Hairspray - 2007

John Travolta as a woman? This could've been a huge mistake. Instead, it just about worked. Partly because Hairspray's music was catchy enough to pull you along with it. And partly because his bouncy period wig had enough product to pull in nearby planets with its gravitational force. Let's not forget that it was enough to turn on Christopher Walken. And that guy has a serious thing for cowbells - no, his cowbell fever isn't particularly relevant to this topic.

Mental State: I like singing. And hair. And dressing as a woman.

The Taking of Pelham 123 - 2009

Cross-dressing scientologists may seem unbalanced, but they ain't nothing compared to this chap's barnet. Shaved closed to the scalp with one hell of a facial growth, Travolta here was simply mental. Crazy enough to hijack a train, insane enough to shave off his head, and dumb enough to work with Tony Scott.

Mental State: I've made a terrible mistake.

From Paris with Love - 2010

Travolta has his own brand of crazy folks under his belt (see Broken Arrow and Face/Off - in which he opts for a Nicolas Cage-style haircut/face combo for most of the movie). But alongside Johnny Rhys Meyers, Charlie Wax's hairless head is a sight to behold. Yes, Travolta has finally gone bald. Just like Bruce Willis. If Bruce Willis spent his time shooting up French people and swearing. Check out the trailer and an exclusive clip over here.