Table of contents

Several problems in the theory of van der Waals forces are reviewed: the interaction of atoms, molecules, and small particles of condensed matter at large distances; the van der Waals interaction of atoms with the surface of condensed matter; and the interaction between macroscopic condensed objects of various shapes. These questions have attracted considerable interest in the literature in recent years. Numerous results on these questions are given. All topics are discussed from a common standpoint to the extent possible, on the basis of the understanding of the fluctuational origin of van der Waals forces. Analysis of the physics content of the theoretical results on van der Waals forces is emphasized.

A review is given of practically all the theoretical and experimental results on ferroelectric liquid crystals based on chiral smectics with molecular tilt. The symmetry aspects of the problem are examined, and the fundamentals of the phenomenological theory are discussed. The microscopic approach to the description of the dipolar ordering in tilted smectics is set forth, and several molecular models are considered. The critical behavior of a liquid crystal at the second-order transition between the smectic A and smectic C phases is also discussed. Considerable space is devoted to considering the relationship between the actual structure of the molecules and the size of the spontaneous polarization and to discussing the behavior of ferroelectric liquid crystals in various external fields. Data are presented on the physical parameters of the known liquid-crystal ferroelectrics. The article concludes with a discussion of the possibilities for practical application of ferroelectric liquid crystals.

The current state of the theory of biological evolution is reviewed. Evolution is compared with the cosmological processes of structure formation. Both occur in dissipative systems and are governed by export of entropy. The objections to Darwin's theory are discussed and rejected. A sufficient material for evolution is indicated, as determined by the vast supply of variability of organisms. The reasons for this variability are described. The problems of speciation are discussed and its similarity to phase transitions is demonstrated. The phenomena of punctuated equilibrium and phyletic gradualism are described and examples of both are given. Special attention is paid to directional evolution. The views of L.S. Berg are examined in detail. Directionality is governed by natural selection, and also by the type of organism that has evolved and its possible variations. The link between individual and evolutionary development is studied. Wolpert's theory of positional information is presented and the concept of the model theory of morphogenesis is outlined. It is shown that a number of traits of organisms may have no adaptive value. The evolution of the visual organ is described. The molecular foundations of evolution and the neutralist theory, according to which the evolution of proteins and nucleic acids occurs to a considerable extent independently of natural selection, are studied in detail. Arguments in favor of this theory are presented and its physical meaning disclosed, which reduces to degeneracy in the correspondence between the primary structure of a protein and its biologic function. The results are presented of current studies that indicate the inconstancy of genomes, with various pathways of altering their structure and regulation. Various aspects of applications of information theory to problems of evolution are examined in detail. The evolutionary significance of the value of information, as defined as its nonredundancy, or irreplaceability, is stressed. The connection between the value of information and its complexity is studied. The value of information increases in the course of evolution. In conclusion, the sufficiency of material and time for evolution and the correctness of Darwin's theory are noted. Current problems of evolutionary theory are pointed out.