Astronauts who spend long periods in outer space could be adversely affected by weightlessness. One way to simulate gravity is to shape the spaceship like a cylindrical shell that rotates, with the astronauts walking on the inside surface (Fig.5-32). Explain how this simulates gravity. Consider
(a) How objects fall,
(b) The force we feel on our feet, and
(c) Any other aspects of gravity you can think of.