How to Make Water Droplets "Levitate" on Water (Using Vibrations)
You can take some really awesome photos of water droplets if you've got a fast enough camera (and flash), but water drops aren't just spectacular as photographic subjects—you can also make them a part of the photographic process by using a water drop as a DIY projection microscope and even a macro lens for your iPhone.
But as useful as a water drop can be, it's still way cooler when they're in front of the camera (as the subject). Recently, researchers from the National Autonomous University of Mexico figured out how to make a water drop levitate on the surface of water, just by putting it on a loudspeaker, which is just as fun to watch as dancing water droplets in space.
Normally, a drop of water will bounce on the surface before coalescing with the rest of the water. It turns out that if you vibrate the surface of the water, you can make it keep bouncing, making the drop look like it's levitating. The scientists were able to make multiple drops balance on the surface by using nonlinear standing waves, discovered by none other than Michael Faraday himself.
You can read more about the science behind it here.