What is Temperature?
 temperature describes how much more disordered a system becomes when a given amount of energy is added to it
high temperature: adding energy opens up few additional microstates
low temperature: adding energy opens up many additional microstates
Thermal equilibrium
 entropy is maximized for an isolated system at equilibrium
 total entropy of two subsystems is sum of entropy of each:
 consider transfer of energy from one subsystem to another
if entropy of one system goes up more than entropy of other system goes down, total entropy increases with energy transfer
equilibrium established when both rates of change are equal (T1=T2)
 (temperature is guaranteed to increase as energy is added)

Number of microstates having given E