How to make a stream of water zig-zag using sound waves

This may look like a magical trick , but YouTube userBrusspupis just using the scientific discipline of sound waves and tv camera framing rate to make this stream of water dance .

Brusspup ran a condom hose past a speaker system and played a 24hz tone though the speaker , vibrate the tube with a 24hz sin wave . He then filmed the stream of water supply pour out of the tube with a 24 frame - per - sec photographic camera , capturing these curves . When he changes the frequency of the shade to 23hz , the water seems to be be active backward to the camera ’s eye . When he changes it to 25hz , it come out to be moving forwards , but in slow motion . To the defenseless eye , it look like an ordinary stream of water .

If you do n’t have a 24fps television camera , you may still see the curving body of water flow , but you ’ll need a strobe light flashing at the correct frequence .