EVOLUTION AND HUMAN DESTINY 

 ENTROPY AND "eXTROPY" 



The concept of the probability of existence of any 

 particular system of organization of matter is to some 

 extent expressed by the term entropy as it is used in 

 thermodynamics and physics. Yet the ready use of the 

 concept of entropy, unless the manner in which it is 

 employed is clearly defined, can easily lead to confu- 

 sion, as the meaning of the term is not always the same. 

 It is used in current literature to express two concepts 

 which, although they are ultimately perhaps identical, 

 nevertheless have their separate utilities. 



In so-called classical thermodynamics entropy gen- 

 erally is a measure of the available energy of a given 

 system under defined conditions, either in respect to 

 its surroundings or in respect to itself. Here an equal- 

 ization of the arrangement of matter, or energy within 

 the system, generally referred to as degradation, is 

 termed an increase of entropy. It is the difference be- 

 tween the entropies of states that is of importance. 

 Knowledge of absolute entropy is not essential, and is 

 generally lacking. 



Degradation corresponds generally to an increase of 

 randomness of the system. The more random the sys- 

 tem, the greater the a priori probability of its existence 

 as compared to the existence of some less random sys- 

 tem. 



However the original concept of entropy as measur- 

 ing the degree of randomness has in some of its appli- 



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