But in fact, if you just run your fingers again and again over this floppy disk you are disorienting those particles or knocking them off perhaps altogether, depending on the medium.

事实上，如果你把手指一次次的在磁盘上面滑动,这些粒子就会变的无极性,或者把它们整个搞坏，而这取决于媒介。

哈佛公开课 - 计算机科学课程节选

It might bend and bow, that is it's not the forces of nature like the movement of the river that's knocking the bridge down, but it's just the failure of these materials over time, that they don't last as long as they might.

这桥可能会折断,不一定是洪水这样的自然灾害,导致了桥梁的坍塌,可能只是因为建桥的材料老化,这种材料没有那么持久耐用

耶鲁公开课 - 生物医学工程探索课程节选