Abstract
When a body approaches equilibrium, energy tends to a minimum and entropy tends to a maximum. Often, or usually, the two tendencies favour different configurations of the body. Thus energy is deterministic in the sense that it favours fixed positions for the atoms, while entropy randomizes the positions. Both may exert considerable forces in the attempt to reach their objectives. Therefore they have to compromise; indeed, under most circumstances it is the available free energy which achieves a minimum. For low temperatures that free energy is energy itself, while for high temperatures it is determined by entropy. Several examples are provided for the roles of energy and entropy as competitors: – Planetary atmospheres; – osmosis; – phase transitions in gases and liquids and in shape memory alloys, and – chemical reactions, viz. the Haber Bosch synthesis of ammonia and photosynthesis. Some historical remarks are strewn through the text to make the reader appreciate the difficulties encountered by the pioneers in understanding the subtlety of the concept of entropy, and in convincing others of the validity and relevance of their arguments.
Highlights
When a body approaches equilibrium, energy tends to a minimum and entropy tends to a maximum
The mid-nineteenth century saw the discovery of the two laws of thermodynamics, virtually simultaneously
In that case U + Epot + K − T0 S can obviously only decrease so that it tends to a minimum as equilibrium is approached, a stationary state in which all change has come to an end
Summary
The mid-nineteenth century saw the discovery of the two laws of thermodynamics, virtually simultaneously. It states that the rate of change of the entropy of a body is larger than the heating divided by the homogeneous surface temperature T0 of the body. There was quite some interest in the circles of the natural philosophers at the time, but – after a century and a half – scientists take a relaxed view of the heat death. They do not know whether it will occur or not and – unlike 19th century physicists – modern physicists have become resigned to the concept of ignoramus, -- and perhaps even to the concept of ignorabimus
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
