Ziggy Stardust reaches for his slippers Bizarrely, given the conspicuous absence of the man himself, the pop-cultural landscape is a furious blur of Bowie-related activity. Earlier this year, the 40th anniversary of his magnum opus, The Rise and Fall of Ziggy Stardust and the Spiders from Mars, was celebrated with a lavish re-release, and reverent acknowledgement of the album's importance in shifting pop from its four-square, macho roots into a realm of sexual ambivalence and peacock theatricality. Last month, the Institute of Contemporary Arts paid tribute to Bowie the actor, with a showing of his films including Labyrinth and The Man Who Fell to Earth. The V&A's exhibition carries the season of homage to a fitting conclusion. But where is Bowie? Never easy to pin down, the singer has been almost invisible since suffering a major heart attack during a jinxed 2004 tour. The problems began with a "friendly fire" incident in Norway when a fan threw a lollipop that hit Bowie in the eye, causing him to storm off stage. A few days later, he cut short another performance, believing he had pinched a nerve in his shoulder. What he didn't know was that the muscle pain was due to a clogged coronary artery. At his next gig, in Scheeßel, Germany, he delivered a final encore of Ziggy, went backstage and collapsed. Today he lives mostly in New York, in a large, Lower Manhattan apartment with his ex-model wife Iman and their 11-year-old daughter, Lexi. He avoids public events, and has reportedly instructed his agent to bin all offers of work. Yet the view that he has sunk thankfully into retirement does not go unchallenged. "He has consciously dropped out of sight," argues Paul Trynka, author of a well-received Bowie biography, Starman, published last year. For someone so consistently vain and self-obsessed, the heart attack - the realisation of his mortality - came as a massive psychological blow. But he is someone who has always had an understanding of how to manipulate the media and he saw the dramatic potential of a disappearance in a very Hollywood way. It became a kind of Houdini disappearing act. The fact that it has gone unstated [Bowie has made no formal announcement of retirement] makes it even more mysterious. Logically, the advent of illness should come as anything but a shock to a man who lived for a decade on cocaine and cheese triangles, but Bowie's other-worldly persona is something more than an act. People who have worked with him talk of a "normal" David and a "strange" David, with the two constantly vying for moments of supremacy. The actress, Scarlett Johansson, whom Bowie helped record an album of Tom Waits songs, recalls: "His management had said that he would only fly in a blue helicopter - blue on the inside - and we managed to find one. When it arrived, I said: 'Look at the inside of this helicopter. He looked at me as though I was mad. He didn't give a s--- what colour it was. Yet Bowie has been changing the colours of his life since he emerged from a lower middle-class, suburban south London childhood to hear Little Richard singing Tutti-Frutti on the radio. "I believed," he said later, "that I had heard God." At the age of 15, David Jones, as he was then, had formed his first band, The Konrads, and the re-inventions have never ceased, bringing forth Ziggy the space oddity, the artily schizoid Aladdin Sane, Major Tom, the ghostly Thin White Duke and the crypto-Brechtian Berlin subversive. Now, perhaps, we have the most outlandish Bowie incarnation of all - the doting late-life dad, who, having largely missed out on the upbringing of his film-maker son Duncan, prefers to help out with his daughter's homework, and fills his spare time browsing in bookshops. Not that it will necessarily be the last one. "When he takes on a character, he takes it on 110 per cent," says Ken Scott, an old friend and the producer of four Bowie albums. Right now he's in the character of the family man. Maybe one day he'll drop that and become a rock star again. And when he does, he'll take that on 110 per cent as well. The V&A exhibition may tell us what Bowie looked like. But perhaps not who he was.