时差N小时:空中楼阁 To Build Castles In The Air

　　Castles are usually enormous structures requiringstrong foundations and the use of heavyconstruction materials such as stone. If thefoundations are not strong enough, the castle couldcollapse. The idea of building a castle in the air-with no foundation at all-is, of course,ridiculous. That is why this idiom is used todescribe ideas that are not realistic, as if they aredreams or fantasies. So when someone describes aplan or course of action that we believe may beimpossible to achieve, we tell him, "You're buildingcastles in the air."

　　城堡通常是一个很大的建筑，需要有坚实的基础，还要用到大量石头之类的建筑材料。如果城堡的基础不够牢固，很可能会坍塌。建立在空中的城堡是没有基础的。因此，“在空中建城堡”当然是一个很荒谬的想法。因此，我们可以使用这个成语形容那些不太现实的想法——因为这种想法往往是梦想或幻想罢了。所以，当有人描述一个计划或行动时，我们觉得那是不可能实现的，就可以告诉他：“你的想法就如空中楼阁一样。”

　　A similar idiom is "building castles in the sand." We know that, on a beach, sand castles areinevitably and easily destroyed by the tide. They are not built to last a long time. So when wesay someone is "building castles in the sand," we mean they are creating something that won'tendure very long.

　　类似的一个成语是“在沙滩上建城堡。”我们知道，沙滩上的城堡不可避免地而且很容易被海浪摧毁，不可能持久。所以，我们说有人是“在沙滩上建城堡”，意思就是他们正在创造的东西持续不了多长时间。