Experimental Issues in Quantum–Mechanical Time Measurement

Aephraim M. Steinberg

R. Edward Nather

Rodolfo Gambini, Jorge A. Pullin

In quantum gravity there is no notion of absolute time. Like all other quantities in the theory, the notion of time has to be introduced "relationally", by studying the behavior of some physical quantities in terms of others chosen as a "clock". We have recently introduced a consistent way of defining time relationally in general relativity. When quantum mechanics is formulated in terms of this new notion of time the resolution of the measurement problem can be implemented via decoherence without the usual pitfalls. The resulting theory has the same experimental results of ordinary quantum mechanics, but every time an event is produced or a measurement happens two alternatives are possible: a) the state collapses; b) the system evolves without changing the state. One therefore has two possible behaviors of the quantum mechanical system and physical observations cannot decide between them, not just as a matter of experimental limitations but as an issue of principle. This first-ever example of fundamental undecidability in physics suggests that nature may behave sometimes as described by one alternative and sometimes as described by another. This in particular may give new vistas on the issue of free will.

A. V. Lankin, Genri E. Norman

Abstract An analytical review of publications on the quantum mechanics of living matter is presented. This topic has appeared only in recent years. At the same time, its analysis leads to a discussion of fundamental problems that arose with quantum mechanics a hundred years ago: the nature of ‘the process of measuring and the duality of the relationship between classical and quantum mechanics. In considering these issues, the ideas of von Neumann, formulated in 1932, are followed and significantly developed taking into account new physical concepts and experimental data. The work of our senses: vision, smell, etc., is compared to ‘the process of measuring. The possible role of quantum processes in the nervous system is pointed out, photosynthesis and magnetoreception are discussed, the idea of the wave function collapse as a specific quality of life is developed, and unresolved fundamental issues are highlighted.

P. M. Harrington, Andrew N. Jordan, Kater W. Murch

Lawrence S. Schulman

This book is an introduction to the arrow of time in thermodynamics and cosmology, and develops a new quantum measurement theory in which the foregoing concepts play an essential role. The first chapter is an overview and 'route map' and is followed by an exposition of irreversibility, the expansion of the Universe and other arrows of time. The author examines the thesis that the thermodynamic arrow follows the cosmological one, and in doing so extends traditional statistical mechanics. The second part of the book presents a new theory of quantum measurement and possible experimental tests. This theory incorporates the extended statistical mechanics in an essential way. The last chapter discusses open experimental and theoretical issues. Written in a lively and accessible style, the text is liberally sprinkled with exercises. Each chapter ends with a resources section that includes notes, further reading, and technical appendices.