Eq. 17 indicates that B's record is always opposite to A's exportation in contrast to Eq. 13 and Eq. 14. The symmetry of action and reaction is destroyed. However, A and B don't lie. A unique explanation is that A rotates around B, and B spins at the request of two forces. The mechanism will be addressed in the volumetric force. It should be pointed out that the premise is isothermal. The force of temperature difference is discussed in the above paragraph. In Eq. 3 and Eq. 4, 𝑙𝑛 is the most oversized item under the ordinary conditions , . Hence, the force of temperature difference is overwhelmingly more potent than the volumetric force.