Animation in a flash
Look at the models- each one looks just a little different from the last. If we turn the handle, the models all seem to blur into one; if we hold down the button as well, that blur turns to flashing and changing images.
Each of these flashes shows us a different model, meaning that as we increase the number of flashes, we show more models and make the difference between each flash a little less noticeable.
If we turn the handle fast enough the flashes make the models appear to move. This is a key part of animation and relies on persistence of movement, which simply means that our brain fills the gaps between the separate flashes (or frames) because we know how that movement would appear normally.
The fastest we can animate the models on this exhibit is 30 frames per second; this is plenty as the eye can only see an average of around 20 frames per second.