now you have this object which is going to tell you whether other things are in thermal equilibrium now.

现在你有了一个可以告诉你,其他物体是否处于,热平衡的物体。

麻省理工公开课 - 热力学与动力学课程节选

So if I get rid of these arrows, there's no heat flowing because they're in thermal equilibrium, then I can't have an arrow here.

所以如果我擦去这些箭头，没有热流存在,因为它们处于热平衡，那么这里也不能存在一个箭头。

麻省理工公开课 - 热力学与动力学课程节选