Zero point energy exist in a vacuum at a temperature of zero degrees. Particles and waves of power that spontaneously appear out of nowhere. The zpe generates thrust from essentially nothing. you know when you turn a car hard right and feel pushed to the left. That's called inertia. It was discovered back in 94 that zero point energy fluctuations are the cause of inertia. by opening a zero point zone no bigger than an ipod and shape an exit gate for the energy, you get your self a big kick back that doesn't stop. Zero point energy is free and limitless. in addition this would create an intresting side effect artificial gravity.