2006 Nerenberg Lecture:
Dr. R. Stephen Berry

Dr. Peter Brown in his laboratory

Nerenberg Speaker Explores the Astounding Concept of Energy

By Mitchell Zimmer

Dr. R. Stephen Berry of the University of Chicago began the ninth Nerenberg Lecture with a slide that asked an easy question, “What is Energy?” He then added “I’m not so sure it’s such an easy question.” Consider the disparate modes of heat, light, gravity and more that can all be placed within the one concept of energy that has enormous predictive power. The idea of energy is a concept “that should astound us” he said.

Dr. Berry asks the audience what energy isThese days we tend to think that the idea of energy is obvious, however the road to this concept was a very long one. Galileo and Bacon thought heat was motion and Rumford observed that mechanical work is converted into heat. Later the philosophical idea formed that heat was an imaginative fluid named “caloric,” even today we say that heat flows from one place to another. Another debate in the eighteenth century was the case of describing motion as a concept of mass multiplied by velocity (M x v) or mass multiplied by the velocity squared (M x v2), to the minds of the natural philosophers of the day motion could only be one of the other. Today we have accepted that both equations have their place, the first describes momentum and the second is the equation for kinetic energy. These modern concepts would have been unfathomable during the time of the debate.

Since the time of Galileo, over 200 years of controversy and debate about the nature of heat energy had continued until Sadi Carnot began looking into steam power and developed the elegant idea of the ideal heat engine. This work contained the seeds of the second law of thermodynamics. Then, J. R. von Mayer was among the first to describe the conservation of energy and how it encompassed everything from gravitational acceleration to the processes in living organisms. From that point on, great strides were made in the development of the study of thermodynamics. The equations may alter for describing the gravitational attraction between galaxies, or there may be difficulties in dealing with the nanoscale where two phases of matter may co-exist over a band of pressures and temperatures, but these tools still work.

Berry noted that as studies progress to look at real world problems, which are far from the equilibrium states, researchers find that they need many more variables to describe a system. He demonstrated this point by looking at the efficiency of the automobile. He mentioned that the methods required today to calculate a 15 per cent increase in the efficiency of the engine just didn’t exist thirty years ago. The same rigor could used to decrease the energy wasted by industrial distillation by incorporating a temperature profile along the length of the column.

Dr. Berry receives plaque from Dr. Ted Hewitt

The Nerenberg Lecture is named after the late Morton (Paddy) Nerenberg, a much-loved professor and researcher born on 17 March-- hence his nickname. He was a Professor at Western for more than a quarter century, and a founding member of the Department of Applied Mathematics there. Nerenberg was a successful researcher and accomplished teacher; he believed in the unity of knowledge, that scientific and mathematical ideas belong to everyone, and that they are of human importance. He regretted that they had become inaccessible to so many, and anticipated serious consequences from it. The series honors his appreciation for the democracy of ideas. He died in 1993 at the age of 57. He is survived by his children Albert, Ben, and Simone.