 The previous equation shows that when the dielectric material of a capacitor is cyclically charged then discharged while being accelerated, its mass density fluctuates, by around plus or minus its rest mass value.Therefore, a device can be made to oscillate either in a linear or orbital path, such that its mass density is higher while the mass is moving forward, and lower while moving backward, thus creating an acceleration of the device in the forward direction, i.e.a thrust.