That limit will be some arrow we can call the velocity at the time and it will always be tangent to the curve.

那个极限也就是一个矢量,我们称之为瞬时速度,并且它总是和轨迹相切的

耶鲁公开课 - 基础物理课程节选

So I think it's pretty clear when Socrates starts talking about what's visible versus what's invisible, he doesn't limit himself to vision, he means to be talking about all of the 5 senses.

所以我认为很清楚的是，苏格拉底,在谈论何为有形,何为无形的时候，并没有局限在看这一种感官上,他要谈的是所有的五种感官。

耶鲁公开课 - 死亡课程节选

I'm going to call it r. It's going to be the gas constant, and now I have r times t is equal to the limit, p goes to zero of p r.

如果去掉p趋于0的条件,在有限压强下都,保持RT=pV的关系。

麻省理工公开课 - 热力学与动力学课程节选