I'm having trouble understanding the relationship between a system's energy level and its stability (in a general sense).
My understanding is that chemical and physical systems experience a driving force that pushes them toward the lowest possible energy state (ignoring quasisteady states and those things). Biochemistry calls this the Gibbs energy of reaction when the systems are chemical. The driving force represents the amount of nonPV (or useful) work that might be done by the system in moving toward that lowest energy level, and thus the system does the max amount of nonPV work by moving from an arbitrary energy level to the Gibbs energy minimum, or the energy level characterized by
[tex]
\begin{equation*}
\frac{dG}{dt} = 0.
\end{equation*}
[/tex]
But I do not understand why the driving force exists (i.e. why it is favorable thermodynamically for a system to minimize its free energy). In other words, I cannot tell from the the laws of thermodynamics why natural systems tend toward lowest energy states.
And I also do not understand why a stable system corresponds to a lowenergy one. My engineering prof. calls the state of lowest energy the state of maximum stability. Stability is a term that is tossed around a lot it seems, but I don't really understand what it means.
P.S. If the best answer would be something along the lines of "take a proper thermodynamics course," that would be fine.
Thanks
