And once again Friday is here, bringing with it the weekly column "A Taste of Physics" — issue No. 10.
This time: the Leidenfrost effect, the science behind it, and its applications in everyday life.
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The Leidenfrost effect was described in detail in 1756 by a German scientist of the same name.
The effect describes what happens when a liquid meets an extremely hot surface: a layer of vapor forms between them, preventing direct contact.
For example — a drop of water falls onto an extremely hot pan. The bottom of the drop instantly vaporizes, causing the droplet to levitate and skitter across the pan for several seconds.
In the video you can see the reverse application of this phenomenon. A metal ball is heated to a high temperature over a flame, and when it is submerged in a liquid, a bubble of vapor forms around it — preventing the surrounding liquid from touching it and boiling.
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Understanding this phenomenon matters in the real world.
Imagine trying to cool down a nuclear reactor running at extremely high temperatures, only to find that all the water you spray toward it never actually makes contact — blocked by an insulating vapor layer. The reactor would continue to overheat with no effective way to cool it down.
In such cases, a special mesh structure is used to suppress the formation of the effect.
In research and development, the effect is exploited to isolate liquids and protect them from environmental contamination, as well as to propel liquid droplets at high speed across surfaces due to the near-complete absence of friction.
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