Figure 5.

Calculated trajectories of light particles (using the same parameters as in Figure 4) in a rotating disc, in chambers of varying width. (a) Chamber width w = 5 mm. The red line shows the trajectory of a particle moving in a disc rotating with a constant angular velocity ω = 800 rpm. A weak angular acceleration (see the legend) is sufficient to cause a backward motion. (b) The same angular acceleration (the blue line) appears to be insufficient for a backward motion in a narrower chamber, w = 2.5 mm. The effect is achieved for a stronger Euler force (the light blue line). (c) In a very narrow chamber, w = 1 mm, even in the presence of rather strong angular accelerations the particle drifts towards the center of rotation. To turn the motion back, a very strong Euler force is required (see the legend).