and if you've never been, don't do this, it's largely because there are these very sensitive moving parts and there are relatively few moving parts left in today's computers.

如果你没做过，不要做这些事情，主要是因为电脑里面有一些很敏感,且高速运转的部件,以及相对不运转的部件。

哈佛公开课 - 计算机科学课程节选