• Theodore Hall

This paper examines artificial gravity from the point of view of a person living and moving within a rotating habitat. First, it reviews the literature on comfort conditions for rotation. Next, it analyzes the relative motion of free-falling objects and the apparent slopes of surfaces to reveal the geometry of the effective gravitational field, its variation from Earth-normal gravity, and its variation within the supposed comfort zone for rotation. Finally, it examines the role of gravity in perception psychology and architectural design theory to explore the implications of artificial gravity for habitat design. An architectural grammar comprising wall, floor, and ceiling elements in particular orientations with respect to gravity is common sense. Nevertheless, its application to artificial gravity may be inadequate. Due to Coriolis accelerations and cross-coupled rotations, not only the up-down (radial) but also the east-west (tangential) directions emerge as gravitationally distinct. Inasmuch as architecture is powerless to mask these distinctions, it would do well to help the inhabitants adapt to them. It may do this by providing visual or other cues to assist orientation, as well as by arranging activities to minimize off-axis motion.