This is really cool. Scientists have found a way to make water boil without causing any bubbles. How? Drop some superheated, nanoparticle-coated steel into the water.
The phenomenon is based on something called the Leidenfrost effect. That's where water coming in contact with a super hot substance will form a layer of vapor between it and the surface. In this experiment, scientists took steel balls and coated them in nanoparticles that gave them a rough surface. They then heated the balls to 400 degrees Celsius and dropped them into some water. That's where the cool part happens.
Instead of creating a bunch of bubbles around the balls, the layer of vapor created around the steel caused the bubbles that formed to stretch themselves around the ball's rough surface. That meant that the surrounding water was mostly undisturbed. It stayed that way all the way until the balls dropped back under boiling point.