As the end of the nineteenth century neared, it was clear to many in the physics community that if only Newton's equations plus Maxwell's equations could be solved adequately, there would really be nothing very new in physics on a fundamental level. Then came relativity and quantum mechanics. As we now approach the end of the twentieth century, it is clear to many in the physics community that if one could adequately solve somebody's gauge field theory (or somebody else's string model), then nothing fundamentally new would ever again enter into physics. To others in the physics community, it is somewhat doubtful that our present physical understanding of the world, especially of quantum mechanics, has reached such a pinnacle.This conference was organized to discuss the present state of affairs in our knowledge, both experimental and theoretical, of the basic tenets of quantum mechanics. Many fields of physics in which quantum mechanics plays a central role were included: (i) atomic and molecular beams; (ii) photon beams; (iii) atomic interference in atom-surface physics and atom wire physics; (iv) Bose-condensed systems; (v) quantum '1/f' noise; (vi) quantum electrodynamics effects in water, colloidal systems and biological systems; (vii) quantum interference in neutrino physics; (viii) periodic-in-time driven quantum systems; (ix) superconducting quantum circuits; and (x) quantum computer circuit elements.The large variety of different topics, all of current importance, allowed for various viewpoints that are usually not present when conferences devoted to narrower topics are held. The cross-fertilization of ideas was greatly appreciated by the participants, and will be of equal interest to the reader of the proceedings.

The foundations of quantum mechanics has acquired tremendous importance in recent years for three reasons: First, a large number of experiments have tested concepts which previously were purely theoretical. Second, ideas from the foundations of quantum mechanics are being applied now to many fields such as condensed matter physics, quantum statistics, quantum cosmology and quantum gravity. Third, difficulties in constructing a quantum cosmology and theory of gravity have made many theorists examine the foundations of quantum theory to see if quantum mechanics itself needs to be modified. Very distinguished physicists from around the world gave talks on their recent research on a variety of theoretical and experimental aspects on these subjects at this conference.

The book of Erwin Schrödinger about life evokes a variety of basic questions concerning the understanding of life in terms of modern physics rather than biochemistry. Problems of organization and regulation of biological systems cannot be understood by revealing only the chemical processes of the living state. A group of reputable physicists — among them the followers of Heisenberg and Fröhlich — and biologists came to this same conclusion through several workshops on this topic. This book contains their contributions, written from different viewpoints of theoretical physics and modern biology. These articles are valuable not only for understanding life, but also for creating new and non-invasive diagnostic and therapeutic tools in medicine; they also contribute importantly to a deeper understanding of evolutionary processes, including the development of consciousness.

The topics discussed in the Tutzing conference are applications of path integrals in quantum chaos, quantum tunneling, Monte Carlo methods, polarons, solid state physics, physical chemistry, and others. The reports by experts in the fields are timely; the results reported are mostly new. This volume reveals how broad the range of path integral applications has become.

Atomic Physics 15 extends the series of books containing the invited papers presented at each International Conference on Atomic Physics (ICAP). The ICAP, held every two years, provides the atomic physics community with an opportunity to review problems of current interest and to consider future directions in the field. This fifteenth meeting also celebrated the centenary of the discovery of the Zeeman effect.