Now my guess is that only a fraction of you are really doing that.

我猜你们只有一小部分人,会真正这么做

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

You cannot tell the mass, because what you are doing now is appealing to the notion of mass as something that's related to the pull of the Earth on the object.

你无法测出质量,因为你现在所做的是把质量,用地球对物体的引力给替代了

耶鲁公开课 - 基础物理课程节选