It can be shown that if there is a heat flow between two bodies in relative motion there exists a damping force between them,even if their rest temperature are the same or their individual energy remains unchange.

• 可证明两个相对运动的物体；即使它们的静止温度相同；或各自能量保持不变；只要它们有热流往来就存在着阻尼力；合理的温度变换规律只能是T