Macroscopic quantum phenomena (MQP) occur in a number of different systems. The majority of MQP research is done with electromagnetic circuits. The occurrence of MQP in alternative systems, the effects of the environment on MQP, the implications of MQP for measurement theory and quantum mechanics are discussed. This proceedings should therefore provide a nice balance of up-to-date results of MQP research, along with discussion of its implications and possible applications.

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 carne 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 axe 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 equalinterest to the reader of the proceedings.

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.

Due to its extraordinary predictive power and the great generality of its mathematical structure, quantum theory is able, at least in principle, to describe all the microscopic and macroscopic properties of the physical world, from the subatomic to the cosmological level. Nevertheless, ever since the Copen hagen and Gottingen schools in 1927 gave it the definitive formu lation, now commonly known as the orthodox interpretation, the theory has suffered from very serious logical and epistemologi cal problems. These shortcomings were immediately pointed out by some of the principal founders themselves of quantum theory, to wit, Planck, Einstein, Ehrenfest, Schrodinger, and de Broglie, and by the philosopher Karl Popper, who assumed a position of radical criticism with regard to the standard formulation of the theory. The aim of the participants in the workshop on Open Questions in Quantum Physics, which was held in Bari (Italy), in the Department of Physics of the University, during May 1983 and whose Proceedings are collected in the present volume, accord ingly was to discuss the formal, the physical and the epistemo logical difficulties of quantum theory in the light of recent crucial developments and to propose some possible resolutions of three basic conceptual dilemmas, which are posed respectively ~: (a) the physical developments of the Einstein-Podolsky-Rosen argument and Bell's theorem, i. e.