I like science and the cool things you can do with it like chemical reactions and Tesla coils. This video belongs to that category, the cool science. It is an experiment that uses two regular things, water and sound. I bet you have both of them in your house and you can do this on your own. The experiment is very simple but very impressive. Based on the frequency of the woofer you see the water drops frozen or moving backwards into the tube. Stop reading and press play to watch the video.