Invisibility cloak research focuses on how to make light waves pass through an object as though nothing is there. Now what if you took that same basic principle and applied it to other types of waves — like those of vibration?
Tibetan singing bowls have been used to produce beautiful and eery sounds. Now physicists are using them when they're full of water to create a reverse-rainstorm.
Here's what a vibrating cymbal looks like at 1000 frames per second. Even the unblinking eye can't catch all that metal wriggling around like a crêpe caught in a strong breeze.