Short Course

THE CONCEPT OF INFORMATION AND ITS ROLE IN PHYSICS AND BIOLOGY

Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires

30 September to 4 October, 2002

Juan G. Roederer

Geophysical Institute, University of Alaska-Fairbanks and The Abdus Salam International Centre for Theoretical Physics, Trieste

It seems silly to offer a course on information . Is it not that we live in the Information Age and that therefore, everybody is supposed to know what information is? Yet, strangely, during the last twenty years an increasing number of physicists, biologists, neuroscientists and philosophers have been engaged in a vigorous discussion a battle of minds at times about the very definition of information, its meaning and its relationship to entropy, complexity, life and the Cosmos itself. Certainly, since the times of von Neumann and Shannon, the classical theory of information, a fundamental ingredient of communications and computer technology, has had a tremendous success in laying down the basis for the quantitative understanding of transmission, storage and degradation of information amount and content. But it has not offered (nor ever intended to do so) a formal and objective definition of information per se, free of any connotation of human use.

At the present time, some questions under discussion are: Can the rigorous methods of physics describe that strange but well-recognized property of information, namely the fact that the mere form, shape or pattern of something not its field, energy or forces can lead to dramatic change in a system? Or is information irreducible to the laws of physics and chemistry? Are information and complexity related concepts? Does the Universe, in its evolution, constantly generate new information? Or are information and information-processing exclusive attributes of living systems, related to the very definition of life? If that were the case, what happens with the physical meanings of entropy in statistical mechanics or wave function in quantum mechanics? How many distinct classes of information and information processing do exist in the biological world? How does information appear in Darwinian evolution? Is information inextricably linked to purpose and intentionality? Does the human brain have unique properties or capabilities in terms of information processing? In what ways does information processing bring about human self-consciousness?

As soon as one begins digging for answers, one gains a new look at the very foundations of physics and biology. The purpose of this course is to present this multidisciplinary subject to interested graduate students and practitioners of physics, biology, neurosciences and philosophy. Specific topics will include the discussion of a formal definition of the concept of information, showing that it does not play any role in the physical inanimate world; a discussion of the ways in which we, nevertheless, do use information in physics; an analysis of the types of information in biology; and an examination of what is known about information-processing in the brain. Much of this subject is still highly controversial, and will necessarily require the adoption of personal points of view. Our basic premise will be: We human beings need the concept of information to describe and understand the Universe, but the Universe does not need it to function except when life forms are involved .

This short course, to be given in Spanish, will consist of five sessions of 90 minutes each, divided into 45 minutes of formal lecture and 45 minutes of discussion. All the preliminary information will be posted on the web page: http://www.gi.alaska.edu/~jgr/.

The background paper is On the Concept of Information and its Role in Nature , available in pdf format for downloading at this web site. A version without figures is also available here. Other relevant papers and literature references, as well as information on the location and times of the lectures, will be posted during the coming weeks.