- #1
Aidyan
- 180
- 14
Is entropy a measure of "disorder"?
In textbooks I never saw a definition of entropy given in terms of a "measure of disorder", and am wondering where this idea comes from? Clausius defined it as an "equivalent measure of change", but I do not see the relation with a concept of "order" or "disorder" which, as far as I know, are only intuitive concepts, not defined in physics. In statistical mechanics Boltzmann and Gibbs told us that there could be an interpretation of entropy as the logarithm of the number of possible microstates, but again, this isn't for me a definition for disorder. In fact, we could equally immagine a completely disordered system at (almost) absolute zero temperature and zero entropy, and nevertheless with a completely amorphous (i.e. disordered) crystal structure.
And yet, lots of people, even renewed physicists, when they speak to the public, they continue to speak of entropy as a measure of disorder. I never could understand where this comes from? I understand that popularizing difficult concepts to an audience of non experts needs simplified analogies, but I think everyone could equally well have an intuitive idea of entropy as a "measure of change", or the "measure of all possible configurations". I simply perceive the identification of entropy with disorder simply as false and misleading. And what is surprising is that primarly professional physicists are responsible for this. Or... am I missing something?
In textbooks I never saw a definition of entropy given in terms of a "measure of disorder", and am wondering where this idea comes from? Clausius defined it as an "equivalent measure of change", but I do not see the relation with a concept of "order" or "disorder" which, as far as I know, are only intuitive concepts, not defined in physics. In statistical mechanics Boltzmann and Gibbs told us that there could be an interpretation of entropy as the logarithm of the number of possible microstates, but again, this isn't for me a definition for disorder. In fact, we could equally immagine a completely disordered system at (almost) absolute zero temperature and zero entropy, and nevertheless with a completely amorphous (i.e. disordered) crystal structure.
And yet, lots of people, even renewed physicists, when they speak to the public, they continue to speak of entropy as a measure of disorder. I never could understand where this comes from? I understand that popularizing difficult concepts to an audience of non experts needs simplified analogies, but I think everyone could equally well have an intuitive idea of entropy as a "measure of change", or the "measure of all possible configurations". I simply perceive the identification of entropy with disorder simply as false and misleading. And what is surprising is that primarly professional physicists are responsible for this. Or... am I missing something?