Brownian motion is the random movement of particles in a gas or liquid caused by the unequal bombardment of other molecules in the medium. In 1827, Robert Brown first noticed that a pollen grain suspended in water was moving in a random pattern. Later in 1905, Albert Einstein derived a quantitative expression for Brownian motion using the kinetic theory of molecules. Brownian motion is that it’s all around us! The Brownian motion model applies to everyday life: it explains how molecules are transferred throughout a cell to the navigation of robots on random terrain to computing genetic drift in biology to the prediction of stock prices in finance. The movement of pollen grains on still water. Dispersal of pollutants in the air. It is amazing how physics and science have given humanity a way to deal with random situations. All thanks to the Brownian motion.

Julius Mayer was the first person to state the law of the conservation of energy, one of the most fundamental tenets of modern-day physics. The law of the conservation of energy states that the total mechanical energy of a system remains constant in an isolated system of objects that interact with each other only by way of conservative forces.

J = R/(Cp – Cv)

R is the ideal gas constant expressed in work units. Cp and Cv are the specific heats at constant pressure and constant volume. They are expressed in heat units. One problem with Mayer’s work was that he had an accurate value of R, but Cp and Cv data were flawed. Therefore, his value of J was far less accurate than Joule. We call the law of conservation of energy the First Law of Thermodynamics. It says energy is conserved over its many forms’ potential, kinetic, thermal, and so on. Energy can neither be created nor destroyed.