Dave Hax makes helpful videos that illustrate science experiments, such as how to get an egg inside a bottle, and essential interpersonal skills, such as how to steal pizza without getting caught.
For this trick, Hax shows how to burn a candle underwater. Yes, really! All you need is a bowl of water, a candle, and a lighter. When properly arranged, the candle wick will continue to burn even when it's below the level of the surface of the water.
-via Laughing Squid