Okay, look at this:
This is a remake of an experiment by Brusspup that shows what happens when a stream of water is run past a 24hz sine wave: the hose vibrates and the water appears to do a zig-zag pattern that you can’t see with the naked eye but can be captured, as here, with video recorded at 24fps. (A strobe light would also do the trick) Changing the frequency to 23hz makes the water look like it’s going backwards; at 25hz, it goes forward but slowed down. At the YouTube page, you’ll find instructions on recreating this for yourself.
The original:
is this fake?
You could use a strobe-light do see it with the naked eye, as suggested.
Or just blink 23 times per second. Whatever is easiest for you.
That’s pretty fun. I just wish it worked with the eye (in person) instead of being a camera trick.