That for an ideal gas it has to be the case that there's no volume dependence of the energy.

我们可以直接推导这个结果,即证明对理想气体，内能和气体体积无关。

麻省理工公开课 - 热力学与动力学课程节选

And again there, too, you saw an experimental result you were presented with that says, well at least to the extent that it could be measured, it was obviously getting very small.

再一次，你看到了一个,你经知道的实结果，至少在实验测量的范围内，对理想气体条件下的气体这一项很小。

麻省理工公开课 - 热力学与动力学课程节选

And that's because this is different from what it is in the ideal gas case.

因为这一项,和理想气体中的对应结果不同。

麻省理工公开课 - 热力学与动力学课程节选