Notice on some mistakes in the concept of Entropy in Jim Al-khalili book The World According to Physics-

No need here for introductions about the definition of entropy, the relationships it enters into, or the evaluation of the book, and I think that all this is easy to find for those who search for it in books and the internet, but the intention is to warn about a mistake made by this writer, which is a common mistake for others as well, which is to expand the concept of entropy and its relationships outside its specific field, which the concept is valid only within its limits. Entropy at its origin is a statistical concept related to systems consisting of minute parts that move in free random motion. The concept of entropy is based on the probability theory and comes to describe the overall results of the performance of such systems, and one of these results is that a system closed to itself always changes from order to chaos, it changes from agglomeration to dispersion, and from a state in which it is able to expend useful energy to a state in which it is incapable of useful work.. Etc. It is true that this concept can be generalized to many fields other than matter molecules if these fields have similar statistical systems. The incorrect thing is that these concepts and relations related to entropy cannot be applied to any phenomenon of gravity because the bodies that are attracted to each other by forces will not be free-moving and the s concepts and results that we have reached from the study of systems with free parts do not apply to them, therefore, the author's statement, for example, in p177 that that this difference is a fundamental difference is that by calculating the probabilities there is a very small probability that the gas will spontaneously compress inward without any external influence, only that it happens its randomly moving particles all moved towards one point, and this does not happen in gravity, there is no possibility that a rock will move up from the earth on its own ..