[youtube http://www.youtube.com/watch?v=uENITui5_jU&version=3&hl=en_US]
It may look like the water in the video above is ignoring gravity. In reality it's a clever trick that involves disturbing the water using a sound frequency that matches the frame rate of the camera (in this case, 24 Hz).
By tuning the sound up or down slightly, it's possible to create the illusion that the water is flowing up or down at an impossibly slow rate.
Tags: brusspup, illusion, optical illusion, physics, sound, video, water, waves