ABSTRACT
Continuing our appeal to phenomenological derivations, we come to an experimental technique that is very simple to use and has a clean calculus derivation. Despite the simplicity of the measurement of viscosity, it is very useful in several areas of chemistry (polymers), aerodynamics (airplane wing design), hydrodynamics (boat hull design), pharmaceutical delivery (oral delivery in syrups), biophysics (blood flow), and material science (polymers). We are mainly motivated by a need to support the revolutionary Boltzmann’s kinetic molecular theory of gases (KMTG; in Chapter 3) with some experimental method. The Boltzmann KMTG can be treated in a cyclical set of selffulfilling equations (perhaps because it is true!), but a skeptic would require some sort of measurement, mainly because it assumes the existence of very small atoms=molecules never seen individually. Even today there are only a few ‘‘pictures’’ of fat Au atoms on surfaces and x-ray diffraction structures of molecules in crystals. The preponderance of evidence for the size and structure of molecules is firm but indirect. Here, we want to discuss Poiseuille’s (Pwaz-e-ay’s) law of viscosity for laminar flow [1,2] because it offers several useful applications, but primarily it will be a way to verify Boltzmann’s KMTG.
