Sankar Palchoudhury 101/673/A, College Para, P.O. Kharia, Ward No. 21, Dist. Jalpaiguri, Pin Code -735101, West Bengal, India sankarpalchoudhury@gmail.com International Journal of Fundamental Physical Sciences (IJFPS) 7 2 23-24 June, 2017 2231-8186 https://doi.org/10.14331/ijfps.2017.330103 The Brownian motion, thermodynamics performance, and atmospheric phenomena on Earth and celestial bodies are explained by the effect of infrared (IR) wave force on the outer surface of tiny particles such as atoms and molecules. The paper asserts that IR waves exert pressure leading to Brownian motion and particle behavior, and establishes a gas equation PS = CnAT to explain thermal and mechanical interactions, including thermodynamic conversion via piston motion in heat engines. Brownian Motion, Wave force, Outer surface, Exert https://creativecommons.org/licenses/by/4.0/