時差N小時:熱量動能(上)

　　At one time it was believed that heat was a liquid.Sure, that sounds kind of crazy, but if you think for asecond, you might see why. Suppose you have anobject that’s very hot — say a metal spoon that’sbeen sitting in hot coffee. Pick it up and you can feelthe heat spreading to your hand. The longer you holdon, the more heat seems to enter your hand. Ouch!Well, maybe heat is an invisible liquid that poursfrom the spoon into your hand. After all, that theoryfits all the evidence, doesn’t it? But there’s aproblem. Another simple experiment you can doshows heat can’t be a liquid.

　　曾有一段時間，有人認為熱量是液體。當然，這聽起來有點瘋狂，但如果你仔細想一想，您可能會明白其中的道理。假設你有一個很熱的物體——放在熱咖啡中的一個金屬勺。拿起勺子，你能剛到熱量蔓延到你的手，握的時間越長。傳到你手上的熱量越多。哎喲!好吧，也許熱是一種無形的液體，它從勺子中倒入你的手中。畢竟，這理論符合所有的證據，不是嗎?但是有一個問題。你可以做另外一個簡單的實驗，來證明熱熱量不是液體。