If I open a new deck of cards the sequence is known. If I shuffle them, the sequence is unknown. If I then memorize the sequence, it is again known. State 1: New deck State 2: Shuffled deck State 3: Shuffled deck after I have memorized the sequence State 4: Re-shuffled deck I have computed the entropy difference of the deck sequence between state 1 and state 2. Many of us will have done the same as an introductory exercise in the second law of thermodynamics. If I skip step 3 then it seems to me I must say that state 2 has equivalent entropy to state 4, but if I don't skip step 3 then it seems that delta entropy (1->2) must equal the delta entropy (2->4). Entropy really is a thermodynamic property - it is not just a mind game. Is there any way to conceptually relate the entropy of the sequence of a deck of cards to the entropy in a container of gas so they both have the same 'amount' of physical significance? One seems to be a state of mind and the other seems to be a thermodynamic property, but both share a common mathematical model.