Meditações - viajar no tempo através de buracos negros

Christopher Nolan’s 2014 blockbuster movie takes time dilation to a new level and adds some weird science of its own—and Matthew McConaughey. When our hero Coop (McConaughey) blasts off for the stars, he leaves behind his 10-year-old daughter, Murph (Mackenzie Foy). “Time will change for me,” he explains. “It’ll run more slowly. When I get back we’ll compare.” She is a budding scientist herself. “You say science is about admitting what we don’t know,” she remarks wisely. By the time Cooper returns from his near-light-speed and black-hole travels, having aged hardly at all, Murph will have grown up to be Jessica Chastain, and then, at the end of the film, an even older Ellen Burstyn.

Interstellar deploys its own kinds of mumbo-jumbo—some ghosts from a hypothetical fifth dimension, for example—but it’s full to the brim with real science. They’ve got cryo-beds for deep sleep (speculative, but maybe possible); they’ve got counter-orbital slingshots for fancy gravitational dynamics; and, best of all, they’ve found what seems to be one end of a wormhole, which is a disturbance of spacetime.

Are wormholes real? Yes and no. The great theorist John Archibald Wheeler, who also named black holes, invented the word to describe a possible shortcut through the warped fabric of spacetime—a “handle of multiply connected space” that can be visualized as a tube or a tunnel. Later theorists, like Kip Thorne of Caltech, who won the Nobel Prize in physics this year, have speculated that a “traversable” wormhole could be used as a sort of time machine: If one end (“mouth”) of a wormhole could be accelerated by hypothetical “advanced beings” to near light speed, a hypothetical spaceship entering that mouth and exiting the other could be hurled backward to the past.

Thorne himself signed on to the movie as a producer and scientific advisor and worked hard to make everything theoretically plausible—up to a point. After all: How do you illustrate an event horizon? The script featured factual descriptions that likely challenged the special-effects team:

Just as the wormhole was a spherical hole, THESE SPHERES ARE HOLES WITHIN HOLES … we are dropping through A FOUR-DIMENSIONAL RABBIT HOLE – LIGHT/DARK/LIGHT/DARK/LIGHT/DARK with BLINDING RAPIDITY

… Cooper PLUNGES INTO THE WORLD SPHERE … As he falls his SINGLE WORLD LINE stretches behind him – the INFINITE FUTURES OF HIS WORLD LINE splitting ahead to all the different possibilities in spacetime.

Already sucked in by plausible physics, we may be too distracted to notice when the science gives way to plain old magic. To make the plot work out, for example, Coop needs to get a message back from the future to young Murph. He accomplishes this by reaching across time and flicking the second hand of an old wristwatch with the help of some hypothetical, invisible, presumably benign beings who live in the fifth dimension. Science!

James Gleick in Quartz, sobre Interstellar