The Leidonfrost Effect is cool

Lava from volcano.

You can test the Leidonfrost Effect at home right now. Check out this video.

Ever dip your hands in molten lead? (Skip to around 4 min)

Ever dip your hands in liquid nitrogen?

The explanation

All three phenomena are a result of the Leidonfrost effect. The explanation is pretty simple. When you put a drop of water on a very very hot pan, the first layer of water instantly vaporizes. The vapour then forms a cushion under the droplet which shields it from the pan. Air is a much poorer heat conductor than water, so the droplet could last quite a while before it eventually vaporizes.

It’s the same thing for the molten lead. Notice how they dipped their hand in water before they put it in lead. This water instantly vaporizes when it touches the lead and forms a water vapour cushion. This cushion acts like a pretty effective oven glove.

And you can probably guess how it works for liquid nitrogen. The boiling point of nitrogen is around -200^{\circ} C so when liquid nitrogen touches air, it instantly vaporizes. This forms a cushion around the liquid nitrogen and prevents your hand from freezing right off your arm.

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