From 1974 until his death in 1987, Andy Warhol filled more than 610 boxes with his life’s detritus — T-shirts, invitations, receipts, photographs, letters, anything. He called them Time Capsules, which meant that, unlike their mortal creator, they would travel into the future. They would preserve evidence of what it was like to be alive and famous for a heady 13 years in New York. The boxes are kept at the Warhol Museum in Pittsburgh, his home town. You will be able to view the contents of Capsule 92 at the Other Voices, Other Rooms exhibition at the Hayward Gallery in London in October. Only 172 capsules have so far been opened.

What are they all about? Matt Wrbican, archivist of the museum, points out that Warhol made up different versions of his life story for journalists. He did this so successfully that, even when he told them the truth, they ended up printing the lies. But the capsules do not lie. “They are,” says Wrbican, “evidence of the truth.” Warhol could fantasise as much as he liked, but daily he tossed the material truth into a 1.5 cubic ft box, knowing it would outlive him and testify to his flamboyant stay on this planet. Like art, the time capsule addresses eternity.

It is a strange and seductive idea. In one sense, it is the idea that defines civilisation. All our monuments and museums are time capsules: grand gestures against mortality. The tombs of the pharaohs were capsules, as are the carvings of peasants and masons on gothic cathedrals. Pompeii was an involuntary capsule. Humans cannot leave eternity alone.

In the strictly modern sense of a carefully chosen and sequestered selection of artefacts designed to define an age, however, they were born in 1936, in Atlanta, Georgia, when Thornwell Jacobs, teacher and cleric, proposed the Crypt of Civilisation. We had, he said, an “archeological duty” to preserve the present for the future. He had his way and, today, the Crypt lies buried beneath Oglethorpe University in Atlanta. It is not to be opened for more than 4,000 years. That long delay may be a good thing, as its contents — one Donald Duck, one package Masonite, one cover for milk bottle, one pair ladies’ stockings, among many other things — have yet to take on the exotic patina of the distant past.

Since Jacobs, time capsules have boomed. The International Time Capsule Society estimates 5,000 have been made in the past few years. And who among us can forget the Blue Peter capsules that were unearthed a mere 30 years after they were buried in 1971? Their somewhat self-regarding contents included a Blue Peter annual, decimal coins and photos of the presenters. Silly perhaps, but human, all too human. For time capsules embody hope. “They are a kind of ‘instant archeology’,” says Paul Hudson, a founder of the ITCS, “where people think they can bottle something up, ‘project forward’ and then expect that others will make sense of them 50 or 100 years from now. It seems that everybody loves a time capsule — that is, if they are naïve and positive about the future — and somehow they think they can make a difference.” Above all, times capsules say “I was (or we were) here”. They project our identities beyond the grave, easing the awful pain of the realisation that the future will happen without us.

So, to ease my pain and that of a few others I recruited for suggestions — Melvyn Bragg, the philosopher John Gray, historians Michael Burleigh and Dominic Sandbrook, the scientist James Lovelock, the artist Michael Craig-Martin and the writer Clive James — I have attempted to define our time with a list of carefully chosen artefacts to give the flavour of what it is like to be alive in 2008. Of course, one ends up giving the flavour of what it is like to be me and alive. Any such collection is going to be personal. But, as Warhol showed, after a time the most random collection can begin to tell a story, to become a kind of art.

One temptation is the simply archival. This is made possible by our new recording media: hard discs, flash memory, CDs, DVDs. Craig-Martin proposed storing 1m MySpace postings, while Bragg suggested putting BBC Radio 4 in our capsule: a recording of a year’s worth would probably take little more space than a paperback, and it would certainly be a convincing picture of Britain in 2008. The danger, of course, is that all these media decay. Furthermore, we can’t be sure future people would be able to play them. You try sticking a wax cylinder in your CD player and you’ll see what I mean. But if we can be sure, then Radio 4 it is.

Away from the archival, there is one glaringly obvious item to include: a photograph and perhaps technical specifications of the Large Hadron Collider (LHC). This gigantic machine in Geneva is about to go online, to prove — or disprove — our current theory of how matter is constructed. If we are right, the LHC will be looked upon by the future with the same awe with which we regard Galileo’s telescope. If we are wrong, it will be, as the Pyramids are to us, a failed but magnificent idea. Never mind the outcome; the enterprise itself would define an aspect of our age.

After that, my list becomes less obvious and increasingly personal. Don’t ask me why, but I feel a Pizza Express menu, with its LP-sleeve logo, its domesticated exotica and its multiple offers of consolation, captures much of the way we live now. Consumerism, globalism and, somehow, secularism lurk behind the pepperoni, the garlic bread and the salade niçoise. An AK-47 assault rifle has something of the same effect. Also global, also consumed, this is a killing machine that never seems to go out of style. It’s as sexy and vile in 2008 as it was when it first went into service in 1949. More than any other object, it seems to embody the anguish of Africa and the incorrigible original sinfulness of humanity.

Russia, birthplace of the AK-47, takes the 2008 gold medal for most annoying and troublesome nation. A few swaggering shots of Putin, born-again KGB, should be included, perhaps the shirtless ones. And I’d chuck in the recent edition of The Economist with Solzhenitsyn on the cover. This is because, first, Solzhenitsyn will live on, and second, The Economist is itself a testament to the mood of our age, with its suave faith in our reason and competence. Putting the two together is poignant: they agree, to a rough approximation, about nothing. For the Russian collection, Gray comes up with the subtle suggestion of a small Fabergé egg. The last tsar used to get them all the time; Putin, the new tsar, should get one, too.

The banks, of course, take the medal for incompetence, so I would include a balance sheet — post-subprime, post-credit crunch — of, say, Royal Bank of Scotland, as a warning to future generations that when people wear ties, bad suits and pretend to be clever and nice, you should politely tell them to go and boil their head. The same principle applies to my inclusion of documentary details from Foxtons, once the most swaggering of estate agents, now prime candidates for a spot of head-boiling. Contemporary British property folly and greed will provide hours of fun for our descendants.

Looming over all this financial and economic nonsense will be a large bottle of gleaming black Saudi sweet crude, the ultimate source of our ultimate woes. The future will look back in amazement at our destructive obsession with this stuff — assuming, of course, that we stop burning it in time to permit future humans to exist.

Technology is tricky. Little will survive as anything other than curiosities, like those sad gramophones with their felt-topped turntables you see in almost every antique shop. But I think Michael Phelps’s bodysuit should be in there. There’s a kind of maddening pointlessness and crazed cultishness about sporting technology — try reading a golf magazine: I just did and went mad. The suit captures all of this, as well as, of course, the whole absurd, bloated festival of the Olympics. It also foreshadows the man-machine that will ensue from our ever-increasing desire to “fix” the human body.

Apple’s iPhone also has to be included (Sandbrook chose it, too; Craig-Martin wanted 10 current mobiles). The second version is far outselling the first, and the touch-screen technology is the start of a new computer wave. But it also enshrines our mania for connectivity and distraction. Few machines more gracefully seduce you into the virtual world. And with Apple this year having become bigger than Google, it symbolises the cultural ascendancy and commercial power of Silicon Valley.

Politics would be covered by the inclusion of the presidential-bid video Paris Hilton Responds to McCain Ad. Wearing heels and a cutaway swimsuit, reclining on a plastic lounger and reading an airhead mag, she says: “I’m just hot,” and then comes up with a remarkably lucid energy policy. That’s it: sex, celebrity and geopolitics — 2008 in a nutshell.

Yet art, great art, is really what matters. Only the highest works of our imagination are likely to impress the future. There is one current work that qualifies as both art and document, the television series The Wire, preferably the fourth series, which achieves the spectacular feat of turning the Baltimore education system into the stuff of high, harrowing drama. The Wire is about the increasing impossibility of that ancient form of human organisation, the city. It portrays, accurately, the bottom end of the consumer society, the drug users and dealers, and it shows how the serpentine coils of urban connection lie far beyond our ability to improve. Its storytelling and character creation are the finest of our time. The future will be appalled and thrilled.

Other contributors to my list have often been less focused on the immediate present. James, for example, came up with Michelangelo’s head of Brutus, a P-51D Mustang (a small plane, gentle reader) and a tin of Maxim’s de Paris petits fours. He also tossed in the Sydney Harbour Bridge, which would make it so much more of an event but so much less of a capsule. Burleigh agonised on the conflict between the era — in which case, the Bible and Beethoven — or “a record of the brief time you and I are here, or something personal to me”. I catch him in anguished mode, so although he is drawn to the idea of a Harley-Davidson, he also wants to include a bottle of human tears — he adds, “of joy as well as pain” — a few bullets and a piece of rusty barbed wire.

In his most recent book, Lovelock, the environmentalist who created the Gaia hypothesis, floated the beautiful idea that we should now be putting together a bible of our age, primarily as a way of saving our primarily scientific wisdom from the destruction of our civilisation by global warming. It would be a time capsule, except that we could all consult it at any time we liked.

When I ask him about my capsule list, he first insists on using the finest paper and ink — they would survive and would need no special technology to be read in the future. On these would be written some fairly basic science. Daily observations of climatic conditions would be most valuable. These are the things that are most easily lost and forgotten. Leaving the future just to dig up a library or government archives would be futile, as they would be full of errors and completely lacking in the basic facts of the world. “What the future needs most from us,” says Lovelock, “is the truth.”

From Warhol’s boxes to Lovelock’s papers, the time capsule keeps coming back to the idea of truth, that most precious and fugitive of our age’s relics.

www.bryanappleyard.com