ENDOPHYSICS by Otto E. Rossler ($38.00, hardcover, World Scientific Pub Co; ISBN: 9810227523) Visionary science at its best both in technical invocations of current theories and in the sense of the grand vision that unites and simplifies the actions of many disparate phenomena. Rossler's work should stimulate and exasperate simultaneously but which ever, it suggests plenty of possibilities.

There are two ways to look at the world from within and from without. "Endophysics" means "physics from within." Being inside the world leads to limitations which go beyond those discovered in formal systems by Godel. The topic, nevertheless, has a long history going back to the pre-Socratic philosophers. Its reinventor in modern times is R.J. Boscovich. In 1755, he published two papers on the same subject (space and time), one  titled "On Space and Time" and the other "On Space and Time as They Are Recognized by Us." In the 20th century, the topic has been pursued by Bohr, von Neumann, Popper and most recently David Finkelstein (who coined the name "endophysics" in a letter to the author). There is a strong link with virtual reality on the one hand, and with artificial universes generated in the computer ("molecular dynamics simulations") on the other.

The basic idea is that the "interface" between an internal observer and the rest of his or her universe the effective forcing function represents the sole reality that  (with an equation for a brain in 1974) exists, for the observer is a dream: The idea is due to Niels Bohr of the early 20th century, and to Hugh Everett thirty years later: being part of a universe a "participatory observer" (John Wheeler) distorts the world. In the computer age, the same insight comes naturally: objective reality has to be replaced by the notion of "interface reality." A generalization of relativity is implicit in this way of thinking. The two major predicted features of the world on the interface are "observer privateness" and "invisible change." experiments designed to expose these features, if they exist in the real world, can be suggested. "Most" properties of quantum mechanics appear to fit snugly into the proposed frame. The prospect of manipulating the interface arises. A "whole world change" in the spirit of Gaiter's time travel can possibly be accomplished, not only by appropriate manipulation of the weakly nonlinear macro-interface as proposed by him, but also by twisting the much more nonlinear micro-interface should it exist.