Water and Sound experiment

Excellent :cool:

Another one … clever shizzle

?

Not sure why the video disappeared but have just re-added it (I hope) using the same link :doze:

I think I understand why (even without Googling the answer - if you could even figure out what to Google) … but am probably wrong - perhaps one of our more learned members could clarify if they understand? I’ll PM Julian/Mr Jetstream :hehe:

I reckon it’s because as the speaker produces the soundwave - it interrupts the water in the tube … 24 times a second … (which is the same frame rate that TV/film/video is generally recorded) … So … each frame of the video captures each interrupted droplet of water in the same place each time …

At 23 hertz - there is a fraction more water getting through the tube per second without being interrupted … thus the water looks like it is flowing backwards … because each second the water is in a slightly different place when the film captures it.

This makes sense in my head … but my explanation might be poor … and is also a bit of a guess … so if I’m wrong - I look forward to being corrected :smiley:

I also assumed it was a feature of frame rate harmonisation/interference.