Imagine a circular spaceship rotating in deep space. If Alice, rotating along with the ship, tosses a ball straight up in the air, she will see it follow a curved path. This plot shows the path of the ball across the ship, while Alice stays at the bottom. You can make the ship bigger or smaller, change how hard Alice throws the ball, or change the angular velocity of the ship.

This trajectory was calculated by analyzing the situation from an inertial reference frame: a nonrotating astronaut floating freely outside the ship. Once the solution was found in this frame, it was transformed back to the accelerated frame. Details on the calculation are available at http://www.scribd.com/doc/3880728/rotating-ship.