The Accidental Time Machine

Author’s Note

Back in 1971, when I started writing The Forever War, I needed a way to get soldiers from star to star within a human lifetime, without doing too much violence to special and general relativity. I waved my arms around really hard and came up with the “collapsar jump”—at the time, collapsar was an alternate term for “black hole,” though I was unaware of the latter term. (Scientists now use “collapsar” in referring to a specific kind of massive rotating black hole.)

Years later, working from actual science rather than a novel’s plot requirements, physicist Kip Thorne came up with his “wormhole” theory that did the same thing, to my delight. I never thought it could happen again, but with this novel it did.

Casting about for some reasonably scientific mumbo jumbo to use for a time machine, I settled on gravitons and string theory. Nobody has ever seen a graviton, so I was pretty much home free on that, and normal people can’t understand string theory, so that was fair game, too.

When I was about halfway through the novel, though, an article in New Scientist pointed me to a paper by Heinrich Päs and Sandip Pakvasa of the University of Hawaii, and Vanderbilt’s Thomas Weiler, “Closed Timelike Curves in Asymmetrically Warped Brane Universes,” which indeed uses gravitons and string theory to describe a time machine. My jaw dropped.

It’s a truism of science fiction that if you predict enough things, a few of them are going to come true. But this particular phenomenon seems to be of a different order. It’s not that I have any special scientific credentials, just an old B.S. in physics and astronomy. What I think it actually demonstrates is that if you wave your arms around hard enough, sometimes you can fly.