Doug Coleman ACF Abstract FY11

"Mechanical Foundations of Irreversibility in Nonequilibrium Statistical Mechanics"

Butler University Undergraduate Research Conference

Doug Coleman

Coffee creamer is readily seen to diffuse into coffee, but once mixed, is
never observed to separate back.  The second law of thermodynamics describes
this nonreversible event by stating that a closed system not in equilibrium
will evolve until it approaches its maximum value of entropy—in which case
the system has reached equilibrium—and its macrostate will not change.  Because
it is known that coffee, creamer, and all other matter is composed of
elementary particles whose interactions have been shown (in part) to be
calculable (at least within a statistical framework), the question can be
posed whether the second law of thermodynamics is a fundamental physical
law, or if it can be derived from first principles of mechanics, or perhaps
with something else such as statistics.  Specifically interesting is that
the microscopic dynamical equations thought to govern all macroscopic
system’s constituents are time symmetric, implying that the reversed time
evolution of any process should also be physically possible.  This
presentation will analyze the works of Boltzmann, Gibbs, and others who have
sought to derive or qualify the second law of thermodynamics in terms of the
underlying time reversible microscopic dynamics.  A personally developed
numerical simulation will be exhibited to illustrate the foundations and
paradoxes of Boltzmann’s ‘H-theorem’, and the presentation will attempt to
distill the literature regarding the pursuits of nonequilibrium statistical
mechanics to describe entropy increase of irreversible macroscopic

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