And in order for the vessel to travel through time it's got to find a portal, or in this case a wormhole...
8 seconds sound clip from the Donnie Darko movie soundboard.
You can hear this line at 01:12:56 in the Blu-ray version of the movie.
Quote context
[...]
- Each vessel travels along a vector through space-time, along its center of gravity.
- Like a spear that comes out of your chest.
- Well, could these portals... Could these portals just appear anywhere, anytime?
- I think that's highly unlikely. No, I think what you're talking about is, um, an act of God.
- If God controls time, then all time is pre-decided.
[...]