Abstract
The laws of classical mechanics are rebuilt in the frame of new thermodynamics. Heat is the sum of kinetic energy, system work, and system potential of gas, while force is the linear gradients of heat variation. Exporters and importers of force are evident in terms of exotherm and endotherm. Temperature and volume gradients create asymmetric forces driving rotation and spin (self-rotation). It verifies that force transfer doesn’t need a medium. As an outstanding achievement, a succinct and general equation is derived to predict the equilibrium distance of molecular interaction: L_e=∛((3π^(α-1) m_A g)/(4N_A RT)), without using any assumption, such as van der Waals force and dispersion force. In addition, the origins and attributes of repulsion and attraction are disclosed. Predicting results are applausive. For example, at 298 K, Le for N2, O2, and CH4 are 3.11, 3.11, and 3.68 Å, comparable to the data adopted in MD simulations of the literature. All these results indicate that the world is created by evaporation (sublimation) – condensation. It is believed that all objects, from tiny atoms to giant objects like planets, are thermal equilibrium systems. The new thermodynamics can describe them from the internal structure to the outer behaviors.