The High Frontier, by Gerard K. O'Neill
Consider a large hollow cylinder in space, 5km in diameter rotating at a speed of 220(+/-) m/s to provide artificial gravity of sorts on the inside surface(think an O'Neil Cylinder). Would there be an area along the axis that would experience "0 Gs" or apparent weightlessness? If so, how large would the area be and what would happen when leaving it? accelerating quickly outward and "falling" to the edge?