What with Statistical mechanics? Averages, distributions, deviation estimates of microstates: specification of the complete set of positions and momenta at any given time ( points on the constant energy hypersurface for Hamiltonian dynamics Ensemble average ergodic hypothesis A=(numbe va(e)=iIF a(x(t))dt T time, will visit all possible microscopic states availableto ant of A system that is ergodic is one which, given an infinite amoWhat With Statistical Mechanics? Averages, distributions, deviation estimates… … of microstates: specification of the complete set of positions and momenta at any given time (points on the constant energy hypersurface for Hamiltonian dynamics) Ensemble average & ergodic hypothesis: A system that is ergodic is one which, given an infinite amount of time, will visit all possible microscopic states available to it