Centrifuge RPM
Centrifugal acceleration and RPM versus radius. Radius is to body midline for similar head-to-foot hydrostatic pressure compared to 9.8 m/s² gravity). This neglects subtle long-term Coriolis effects, besides the obvious and well-known vestibular effects of motion in a rotating acceleration field.
a = \omega^2 R ~ so ~ R = a (gees) / omega^2 = 9.8 / ( \pi RPM / 60 )^2 = 3575 / RPM^2 meters for one gee