There is something that one might be able to hold on to: the knob of something, the little flame of something that ; The grain of sand. -The grain of sand; but there is really not a decent metaphor for it, I think.

一个你可以依靠的支点：,一个不同寻常的想法，一个思想的小火花,就像一粒沙中看世界，-一粒沙中看世界;,不过我认为任何比喻都不够贴切。

普林斯顿公开课 - 人性课程节选

Something I can measure and I can tabulate, and when I turn my dT knob here I know what's going to happen to the enthalpy.

----热容，我们可以用实验，测出热容并成表,当我知道这里的变量。

麻省理工公开课 - 热力学与动力学课程节选

And the experimenter is back there with the speed knob and at random intervals he just speeds up the tape of their heart and then slows it down.

实验者回到实验室，带着录音设备,随机地,他加速了心跳的录音,然后又慢下来。

耶鲁公开课 - 心理学导论课程节选