Capturing Dark Energy
The physics behind the warp drive is, as you'd expect, complex. However, it is hoped that in the future mankind will learn how to harness 'dark energy', an energy that is theorized to permeate through the entire universe. Cosmologists are particularly interested in dark energy as it is most commonly associated with the observed expansion of the universe.
Immediately after the Big Bang, some 13.73 billion years ago, the universe expanded faster than the speed of light, an event called universal inflation. Dark energy (which still has experts baffled as to what it actually is) is theorized to have driven this expansion, and it continues to this day. Much like the 2-dimensional surface of a balloon stretching when being inflated, 3-dimensional space is stretching, propelling the galaxies away from one another.
If an advanced technology could harness this dark energy, a warpship could possibly manipulate the spacetime surrounding it. According to Dr. Obousy, the extra dimensions as predicted by superstring theory could be shrunk and expanded by the warp drive through manipulation of local dark energy. At the front of the warpship spacetime would be compressed, and it would expand behind.
"You can apply the analogy of a surfer riding a 'wave' of spacetime," Dr. Obousy told Discovery Space. This 'wave' would facilitate faster-than-light-speed propulsion without breaking any laws of physics.