Last time we discussed the ideal early days of thermophysical properties. Specifically we looked into the progression of the ideal gas law by the natural philosophers and eventually physicists that culminated in the virial equation of state in 1905. After this, physicists generally took the research into the micro-scale and using statistical thermodynamics to show how quantum phenomena affect bulk properties. Over the years many intermolecular potential assumptions have been mapped to the virial equation to model bulk properties — hard-sphere potentials, soft-sphere potentials, squishy-sphere potentials, staticky-sphere potentials, non-spherical potentials, etc. Even going to direct solution of the Schrodinger wave equation to determine the … » More …

Flash back to the literal days of Sir Isaac Newton and horse drawn carriages. Natural Philosophy was the hobby of the wealthy elite. It is in these humble beginnings that we learn the story of thermodynamic properties and equations of state.

Robert Boyle (1627-1691) was one of the first “scientists”, actually at the time known as a natural chemist, to consider the behavior of gases while changing temperature and pressure. It’s widely considered that his laboratory assistant, Robert Hooke (from Hooke’s Law) built one of Boyle’s original apparatus on the assumption that air was a fluid of particles connected by small invisible springs. … » More …