For much of the 20th century, scientists believed that the slower one's metabolism, the longer one's life. This is called the rate of living theory, and although it is not actually true for humans, it feels increasingly accurate of our machines. The faster our computers get, the faster they seem to break, burn out or become obsolete. The average life span of an American cellphone is 18 months. No wonder the members of my superconnected demographic - young, urban, educated, "creative," often described as "millennials" - are all afraid we're shooting to obscurity. "When a young artist today gets hot, he has 48 months to stay hot," a Scandinavian gallerist said at the recent edition of Art Basel in Miami Beach. Then that's it. Unless he becomes super-super-famous, he's done. Only a few months earlier, DIS magazine, the arts research initiative 89plus and the Serpentine Gallery had given out the DIScrit 89plus awards for "visionaries" who are "younger than Rihanna." On the cover of that week's Bloomberg BusinessWeek were photos of ancient artifacts alongside a familiar smartphone, tagged 2010 A.D. The headline read, "How Blackberry Became a Relic." Elsewhere in Miami, the artist Daniel Arsham had an exhibition of "90s cordless phones cast in decomposing plaster called "Future Relic." "With these objects," explained the artist, who, at 33, is a fringe member of my demographic, "I'm taking things from the recent past and jumping over the present into the future, so that they feel like they've been uncovered on some future archaeological dig. It's really ... a dislocation of time. It's not nostalgic. "A dislocation of time" also describes "Her," the new, much-lauded Spike Jonze film with Joaquin Phoenix and Scarlett Johansson. It takes place in an alternative Los Angeles, one described by the gallerist Jeffrey Deitch - in conversation with Jonze after a screening of the film in Miami - as "looking like Japanamerica." Theodore (Phoenix) is a semifailed writer and very lonely divorcé who's into phone sex but lacks a sense of kink - a Blackberry in an iPhone world. When he buys an intelligent operating system with a name (Samantha), a hot voice (Johansson's) and a fetish for making him feel good, he falls in love. So does she. It's sweet, until Theodore goes from satisfied user to dissatisfactory boyfriend. After all, Samantha has an impossibly high rate of living, and eventually, like an overachieving grad student who dates her older professor, she finds her intelligence out-evolving his. If the film is partly about the love affairs we have with our gadgets, the twist is that we're never quite sure whether Theodore or Samantha is the tool. Lately, the fear of death - the wrong button pushed; a wire crossed - seems almost quaint. Jonze's film, like Arsham's objects, touch on our newer fear of rapid obsolescence. We worry that our still-young bodies will stay here while our brains fall out of date. So we rush to preserve our old machines not for nostalgia's sake, but for our own. The other day on Tumblr I saw a photo of a chunky, early-"00s cellphone buried in sidewalk cement. It was captioned "fossil." It was strangely like seeing a human bone.