Regarding the "Wagon Wheel Effect" (temporal aliasing), there is another consideration that I rarely see mentioned.
When the wheel is rotating under a stroboscopic lighting condition (such as photographing at 24 fps), the mind assumes that it is watching the same individual spoke rotating backwards.
For example, let's assume we are watching spoke #1. If the fps matches the wheel rotation exactly, we will see spoke #1 appear to stand still. Of course, this applies to all the spokes, but we are only interested in spoke #1.
When we change either the rate of rotation of the wheel or the fps, we will see spoke #1 apparently start to rotate backward or forward. As a matter of fact, the brain is assuming that we are watching spoke #1, when in fact we are seeing other identical spokes each time a frame is shot. It looks like spoke #1 is slowly moving backward, but in actuality we may be seeing other spokes "masquerading" as spoke #1 just because they happen to be positioned in the right place when the next frame is taken.
I used to work on mail processing machines that moved envelopes around at extremely high rates of speed. It was very hard to diagnose certain problems because the high rate of speed made everything a blur.
One day I made a strobe light with a very wide variable flash speed and with this I was able to "freeze" the motion of gears, pulleys, and envelopes. I could make the gears seem to stand still, or rotate backwards or forwards. I could make it look like the envelopes were standing still inside the machine, because the strobe light would flash every time a new envelope was at point "X". In reality, I wasn't looking at the same envelope standing still, but rather, I was looking at a different envelope at point "X" which was taking the place of the one ahead of it.
Yours in ever-increasing confusion,
Nos