In the cited section from his book The Nature of the Physical World Arthur Eddington gives shuffling a deck of cards as an example of entropy increase and states that the "order will never come back however long you shuffle" (he does later concede this is an extremely remote possibility). The reason for this is that the number of possible orderings of a card deck - or microstates in entropy terms - for a 52 card deck is factorial 52 - an astronomically large number. However for a 5 card deck the corresponding figure is factorial 5, or 120. A much less onerous number. We all probably remember instances of this kind of mild entropy reversal. |