As a state evolving through time moves from a low-entropy condition to a high-entropy condition, if we choose to forget everything other than the macrostate to which it belongs, we end up knowing less and less about which state we actually have in mind. In other words, if we are told that a system belongs to a certain macrostate, the probability that it is any particular microstate within that macrostate decreases as the entropy increases, just because there are more possible microstates it could be. Our information about the state—how accurately we have pinpointed which microstate it is—goes
...more
