Time Travel. A History

Every death is an obliteration of memory. To counter, the online world promises a collective, connected memory and thus offers an ersatz immortality. In cyberspace, the present moment churns and past moments aggregate. @SamuelPepys, tweeting his diary day by day, is one of “ten dead people” the Telegraph (London) recommends we follow, because “Twitter isn’t solely the preserve of living beings.” Facebook announced procedures for continuing or “memorializing” the accounts of its deceased customers. A startup called Eter9 offered to “externalize” (and “eternalize”) customers in the persons of artificial agents. Evidently corporeal death is no reason to stop posting and commenting: “The Counterpart is your Virtual Self that will stay in the system and interact with the world just like you would if you were present.” No wonder science-fiction writers despair of inventing the future. Eternity isn’t what it used to be. Heaven was better in the good old days. Peering toward the afterlife, we can look forward and we can look back.

“When I look back all is flux,” writes John Banville, “without beginning and flowing towards no end, or none that I shall experience, except as a final full stop.”

What comes next? After the final full stop, nothing. After the modern—the postmodern, of course. The avant-garde. Futurism. You can read about all these epochs in the history books of the prewired world. Ah, the good old days.

When the future vanishes into the past so quickly, what remains is a kind of atemporality, a present tense in which temporal order feels as arbitrary as alphabetical order. We say that the present is real—yet it flows through our fingers like quicksilver. It slips away: now— no, now— wait, now…Psychologists try to measure the length of now as felt in, or perceived by, the brain. It’s hard to know just what to measure. Two sounds as close together as a millisecond tend to be perceived as one. Two flashes of light seem simultaneous even when they are one-hundredth of a second apart. Even when we recognize separate stimuli, we can’t reliably say which came first until they are close to a tenth of a second apart. Psychologists suggest that what we call now is a rolling period of two or three seconds. William James’s term was the “specious present”: this illusion, he said, “varying in length from a few seconds to probably not more than a minute…is the original intuition of time.” Borges had his own intuitions: “They tell me that the present, the ‘specious present’ of the psychologists, lasts between several seconds and the smallest fraction of a second, which is also how long the history of the universe lasts. Or better, there is no such thing as ‘the life of a man,’ nor even ‘one night in his life.’ Each moment we live exists, not the imaginary combination of these moments.” Immediate sensation dissolves into short-term memory.

In the wired world, creating the present becomes a communal process. Everyone’s mosaic is crowd-sourced, a photomontage with multiple perspectives. Images of the past, fantasies of the future, live videocams, all shuffled and blended. All time and no time. The path back through history is cluttered, the path forward cloudy. “Fare forward, travellers!” Eliot said, “not escaping from the past / Into different lives, or into any future.” Without the past for background and frame, the present is only a blur. “Where is it, this present?” asked James. “It has melted in our grasp, fled ere we could touch it, gone in the instant of becoming.” The brain has to assemble its putative present from a hodgepodge of sensory data, continually compared and contrasted with a succession of previous instants. It might be fair to say that all we perceive is change—that any sense of stasis is a constructed illusion. Every moment alters what came before. We reach across layers of time for the memories of our memories.

“Live in the now,” certain sages advise. They mean: focus; immerse yourself in your sensory experience; bask in the incoming sunshine, without the shadows of regret or expectation. But why should we toss away our hard-won insight into time’s possibilities and paradoxes? We lose ourselves that way. “What more terrifying revelation can there be than that it is the present moment?” wrote Virginia Woolf. “That we survive the shock at all is only possible because the past shelters us on one side, the future on another.” Our entry into the past and the future, fitful and fleeting though it may be, makes us human.

So we share the present with ghosts. An Englishman builds a machine in guttering lamplight, a Yankee engineer awakens in medieval fields, a jaded Pennsylvania weatherman relives a single February day, a little cake summons lost time, a magic amulet transports schoolchildren to golden Babylon, torn wallpaper reveals a timely message, a boy in a DeLorean seeks his parents, a woman on a pier awaits her lover—all these, our muses, our guides, in the unending now.