A cylindrical habitat in space was proposed by G. K. O'Neill in 1974. If the habitat was 8.3 km in diameter and 28 km length would be able to have land, lakes, and multiple cities on the inside surface and clouds along its center. They would all be held in place by the rotation of the cylinder about its long axis.

How fast would the cylinder have to rotate (linear speed at the surface) to imitate the Earth's gravitational field at the walls of the cylinder?

It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (for example, would the velocity of a neutral particle be selected by passage through this device? ) the explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. if the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. because the acc