Physical significance of entropy or of the second law

by Joseph Frederic Klein

. PLANCK does not make the preceding statement, but gives instead a rigorous proof based on cyclical considerations.

SECTION B
GENERAL CONCLUSION AS TO ENTROPY CHANGES

Now that the existence and value of entropy have been established for every state of any body, we can proceed to draw general conclusions in much the same way as that followed with the ideal gases. The general result is:

"IT IS IN NO WAY POSSIBLE TO DIMINISH THE ENTROPY OF A SYSTEM OF BODIES WITHOUT HAVING CHANGES REMAIN IN OTHER BODIES."

If we admit to the system all the bodies participating in the process, this theorem becomes:

"Every physical and chemical process occurring in Nature takes place in such a way that there is an increase in the sum of the entropies of the bodies in any way participating in the process."

We will close with BOLTZMANN'S statement:

"The driving motive (or impelling cause) in all natural events is the difference between the existing entropy and its maximum value."