Everybody knows it, everybody does it: If the soup is too hot, you just blow on it and it cooles down – albeit often slower than desired.
As it is in all aspects of life, I can truly recommend asking the simple and insight-bringing question: Why? – Why does the soup get cooler if I blow on it?
Certainly, whether you blow on it or not, the soup cools down either way, just because the heat slowly disperses into the environment. Why, however, does the soup’s heat go away faster when you drain your lungs over it? When not blowing, the soup is surrounded by air – as it is when you are actually blowing. (It’s just that the air is a little bit moving in that case.) Did the air gain some kind of special cooling skills by going through your lungs? (Don’t you think this would be a little bit strange since the air from your lungs is even slightly warmer than the surrounding air?)
So why is it that I can cool my soup by blowing on it?
The answer to this question can certainly turn out so long that every soup has got cold on its own in the meantime. That’s why I will try to keep my answer short and reasonable.
(Source: Aha! Jokes, http://www.AhaJokes.com/)
Before I start, let me briefly note what we actually mean when talking about temperature:
A measure of temperature is, to put it simply, the average speed of the particles in the soup (where I don’t mean the soup garnishes – which don’t really move, as long as they…
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