However, it is not ridiculous for a system. To some extent, imaginatively like a traffic accident on a highway, a wave of stopping cars forms soon after the kinetic energy of two cars vanishes. The energy loss of the highway system is much more significant than that of two cars. It indicates that the kinetic energy loss of some particles in a random system is just a triggering factor of an incident where every molecule spontaneously joins to carve up space as needed that the liquefied molecules left, thereby flying for an extra distance along a specific direction to do work. In this way, the system can release energy quickly to attain thermal equilibrium. It is not a paradox to the law of energy conversation but a different system choice. Therefore, classical mechanics suits an adiabat system but not an isolated one.