The belief that thermodynamic systems can be expressed using statistics. It is mostly used to more accurately express a system where there are many microstates involving microscopically observable quantities (e.g. kinetic energy of particle 1, 2, 3, ... , n-1, n or Potential energy of particle 1, 2, 3, ..., n-1, n as opposed to quantities like pressure or volume).
What the author of this article should be revising now, Statistical Mechanics (or stat mech as it's more conveniently known) can be described by many physics students as a "cluster-fuck of endless equations and probability distribution functions designed to intentionally screw up their
mind altogether".
It is widely known that stat mech is utterly incomprehensible until the actual exam
day, when all the nonsensical examples and equations (most notably finding the entropy of an elastic
band expressed as a function of the number of links in
said band, and the expression of
gas molecules as masses on springs) seem to
reach perfect clarity and they tend to walk out with at least a 2-1.
