popularmechanics | Is NASA really working on . . . a warp drive? An internal feasibility report
suggests the agency might be, or at least that the idea of traveling
through folded space is part of the NASA interstellar spaceflight menu.
The Alcubierre drive works like a physics version
of a classic party trick. The spaceship sits in spacetime while science
pulls the fabric from in front of it to behind it, like a tablecloth
pulled out from under a full spread of dishes. White explains:
“The concept of operations as described by Alcubierre is that the spacecraft would depart the point of origin (e.g. earth) using some conventional propulsion system and travel a distance d, then bring the craft to a stop relative to the departure point. The field would be turned on and the craft would zip off to its stellar destination, never locally breaking the speed of light, but covering the distance in an arbitrarily short period of time just the same.”
Alcubierre’s
theory dates to 1994, and physicists have used it as a jumping-off
point for further discussion ever since. By creating a kind of pocket
world where a spaceship can operate seemingly outside of physics, the laws of physics can be sidestepped—or so the theory goes.
What’s
the paradox? White describes it this way: “When the energy density is
initiated, the choice in direction of the +x-axis is mathematically
arbitrary, so how does the spacecraft ‘know’ which direction to go?”
Sci-fi has solved this paradox by inventing a “stable wormhole,” but
White can’t fly a deus ex machina to Alpha Centauri.
