Entropy and Information Theory: Uses and Misuses



Prof. Arieh Ben-Naim | Department of Physical Chemistry,The Hebrew University of Jerusalem, Israel | November 4, 2022 – 14h00 | FEUP Sala B022


In this talk, I will discuss some of the most common misuses, and misapplications of the concept of entropy and the Second Law of Thermodynamics. This talk is basically a brief summary of my book on: “Entropy, the Greatest Blunder in the History of Science”.

In the first part of my talk, I will present three different but equivalent definitions of entropy, then a few formulations of the Second Law. I will also discuss briefly the “Shannon measure of information” (SMI) in Information Theory, which is sometimes referred to as “Entropy.”

Following these definitions, I will discuss the framework of applicability of the concepts of Entropy, SMI, and the Second Law.
In the second part, I will show that the thermodynamic entropy, of any system, is timeless, and then examine the question of whether either living systems or the entire universe fall within the framework of applicability of the concepts of SMI and of Entropy. I will conclude that much of the confusion that exists in both thermodynamics and in Information Theory is due to people’s ignorance about the framework of applicability of these concepts.

Arieh Ben-Naim is a professor of physical chemistry who retired in 2003 from the Hebrew University of Jerusalem. He has made major contributions over 40 years to the theory of the structure of water, aqueous solutions and hydrophobic-hydrophilic interactions. He is mainly concerned with theoretical and experimental aspects of the general theory of liquids and solutions. In recent years, he has advocated the use of information theory to better understand and advance statistical mechanics and thermodynamics.


[Host: Joaquim L Faria, Associate Laboratory, LSRE-LCM]