Motion Reproduction
*Frame rates of monitors far exceed what is needed for movement update
*NTSC video: 30 updates per second
*Movies: 24 updates per second
*Most web video 10 to 15 frames/sec
Video works by half  frames and movies flash each image 2 to 3 times to get rid of flicker.

Apparent motion is different from next topic which is flicker.  A much lower rate of update is necessary for apparent motion than flicker as will be seen.

Flicker is much more of the problem.