Illustration of Leidenfrost effect

1756 Leidenfrost effect

The book of science

Tom Sharp

Johann Gottlob Leidenfrost thermodynamics Illustration of Leidenfrost effect

Leidenfrost effect

A drop of water skittering on the hot griddle. Johann Gottlob Leidenfrost was not suffering from the frost. A pocket of steam under the drop insulates it from the heat and leaves the drop susceptible to skittering.

The behavior of water

Softer than silk, yet nearly incompressible. Its surface is as hard as ice when diving from a height. Ice has seventeen known phases and is thought to be metallic at high pressures. Sonic bubbles; superheated vapors; exquisite and intricate hexagonal crystal flakes. Nearly transparent, water bends light that travel more slowly in water than in air. Metamorphic; liquid – solid – gas. All known life forms depend on it.

Erratic skittering

Like a hat on a cotton roof (tipped to honor Tennessee Williams) Like a cat who won’t be put in a cage (writhes like a mythical demon) Like bobbing for apples too big to bite (someone else’s idea of a joke) Like a narcissist who cannot admit a mistake (self-infallability is more than papal) Like a child who won’t confess a meanness (of whom scrutiny is worse than his sin)

All known life forms depend on water, but we are still discovering its behaviors.

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