Homeostasis and Gauss statistics: barriers to understanding natural variability.

RATIONALE In this paper, the concept of knowledge is argued to be the top of a three-tiered system of science. AIMS AND OBJECTIVES The first tier is that of measurement and data, followed by information consisting of the patterns within the data, and ending with theory that interprets the patterns and yields knowledge. Thus, when a scientific theory ceases to be consistent with the database the knowledge based on that theory must be re-examined and potentially modified. RESULTS Consequently, all knowledge, like glory, is transient. METHODS Herein we focus on the non-normal statistics of physiologic time series and conclude that the empirical inverse power-law statistics and long-time correlations are inconsistent with the theoretical notion of homeostasis. CONCLUSIONS We suggest replacing the notion of homeostasis with that of Fractal Physiology.