If you took a 15 inch artillery shell moving at the velocity it typically goes at, and take that amount of kinetic energy versus the resistive capacity of a sheet of tissue paper, that's the scale that we're looking at here.

如果你有1个15英寸的炮弹,按照经典的速度移动，会消耗大量的动能,抵抗来自于一张薄纸的阻力，这就是我们在这儿看到的尺度。

麻省理工公开课 - 固态化学导论课程节选

Alumina is really stable, which is why it takes so much energy to make aluminum.

矾土相当稳定，这就是为什么需要消耗大量的能量制备铝了。

麻省理工公开课 - 固态化学导论课程节选