The Bias Drive is probably the most far-fetched form of space drive. Sometimes classified as a form of Pitch Drive, it involves the vehicle altering the properties of spacetime locally, usually the gravitational contant, G, to have a localized asymetric bias. By altering the gravitational constant directly in front of and behind the vehicle, a local gradient is created that propels the vehicle.

Besides the difficulty of altering the properties of spacetime, another problem with this form of space drive is the possibility of creating a singularity in the field gradient within the vehicle.

An illustration of the space-time distortions generated by a Bias Drive can be found at

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