Relative State Research Articles

Energy dependence of the pp → (pp) S-waveπ0 total cross section

The total cross section of the reaction pp→pp π 0 with the final nucleons in a relative S-state is calculated including, in addition to the direct production, also pion rescatterings in the πN s-wave and in the p-wave through the Δ (1232) isobar. The inclusion of rescatterings roughly doubles the cross section, but the results still underestimate by a factor of 3–4 a recent measurement near threshold. The calculated energy dependence is in agreement with the data. As the energy is increased, the cross section turns down due to a destructive interference between s-wave rescattering and the direct term, until the Δ contribution takes over and the cross section starts to rise again. The cross section calculated above 400 MeV is much larger than previous calculations indicate. At these energies d-wave pion production becomes comparable with s-wave, but accounts for only about 1% of the total experimental cross section. None of these mechanisms is thus able to account for the discrepancy between experiment and theory in pp→pp π 0 near threshold.

Quantum mechanics near closed timelike lines.

The methods of the quantum theory of computation are used to analyze the physics of closed timelike lines. This is dominated, even at the macroscopic level, by quantum mechanics. In classical physics the existence of such lines in a spacetime imposes paradoxical constraints on the state of matter in their past and also provides means for knowledge to be created in ways that conflict with the principles of the philosophy of science. In quantum mechanics the first of these pathologies does not occur. The second is mitigated, and may be avoidable without such spacetimes being ruled out. Several novel and distinctive (but nonparadoxical) quantum-mechanical effects occur on and near closed timelike lines, including violations of the correspondence principle and of unitarity. It becomes possible to clone quantum systems and to measure the state of a quantum system. A new experimental test of the Everett interpretation against all others becomes possible. Consideration of these and other effects sheds light on the nature of quantum mechanics.

One mind or many ? A note on the everett interpretation of quantum theory

The Everett interpretation of quantum theory requires either the existence of an infinite number of conscious minds associated with each brain or the existence of one universal consciousness. Reasons are given, and the two ideas are compared.

Conscious mind in the physical world

Part 1 Physics and conscious mind: physics as the theory of everything physics and the violation of experience physics and reductionism from physics to conscious mind. Part 2 Consciousness: what is consciousness? what is conscious? can a machine be conscious? what does consciousness do? the uniqueness of conscious mind the unconscious mind states of consciousness. Part 3 From classicla physics to the standard model: the classical era interference the quantum revolution the standard model the standard model of cosmology unanswered questions. Part 4 Philosophical background: words, wrds, mere words idealism realism materialism the mind-brain identity hypothesis dualism psychoneural pairs panpsychism process philosophy. Part 5 Experiments relevant to conscious mind: science needs experiments consciousness in animals blindsight the brain split brain experiments the effects on the brain of mental events the effects of consciousness on the external world. Part 6 Free will: a property of conscious mind freedom as the possibility of alternative action free-will as an illusion free-will and determinism the origin of free-will purpose and design summary of our conclusions about free-will. Part 7 Time: time and the laws of physics the experience of time time asymmetry and thermodynamics memory movement through time time and space. Part 8 Truth: facts and tautologies paradoxes axiometric systems Goedel's theorem does a machine tell the truth? Part 9 Quantum theory: particle-wave duality the wavefuction of quantum theory the probability interpretation of the wavefunction quantum theory and determinism quantum theory and external reality quantum theory and locality time and quantum mechanics. Part 10 What does quantum theory mean?: the interpretation problem the orthodox interpretation what can make a quantum theory measurment? consciousness and wavefunction reduction hidden-variable models the many-worlds interpretation of quantum theory knowledge and quantum theory. Part 11 Conscious mind and quantum physics: why does consciousness enter physics? the unique world of conscious mind free-will and quantum physics psychokinesis and quantum physics universal consciousness and clairvoyance are brain events microscopic. Part 12 Conclusions: is there an external world? is there anything else? why does it seem to matter so much? are we responsible ofr our actions? what is conscious mind?.

Self-generating Universe and many worlds

A novel, compact conceptual framework for the origin of the Universe is proposed, whereby the Universe is identified with a baby universe born ofitself. This picture indicates an intimate meshing of gravitation, space-time, and the quantum and offers a framework for the many-worlds interpretation of quantum theory.

The coulomb force and five solid-state phases of metals

Abstract With only the two-body Coulomb repulsion taken into account, a theoretical phase diagram for any metal includes the following phases (at least): an ordinary paramagnetic Fermi liquid, itinerant ferromagnetism, a CDW phase and an antiferromagnetic phase (either of which can become an insulator), and — surprisingly — a superconducting phase. With specific reference to CuO2 -based solids, it will be shown that the screened Coulomb force in a layered metal is not necessarily inimical to superconductivity, and can even account for the new phenomenon of high Tc superconductivity. Under certain circumstances, the two particles in each Cooper pair are in a relative s-state, but on adjacent layers, and Tc can exceed 100K.

Preferred basis in the many-worlds interpretation of quantum mechanics and quantum cosmology

The authors revive an old proposal of Zeh (1986) for the preferred basis in the many-worlds interpretation of quantum mechanics. The algorithm for this basis reduces to the eigenvalue problems for density matrices of subsystems splitting the quantum system into the observer and the observable counterpart. A semiclassical calculational method for these eigenvalue problems is developed and the dynamical properties of the preferred basis are investigated. Applications of this proposal to quantum cosmology are discussed.

Everett’s theory and the ‘‘many-worlds’’ interpretation

A distinction is made between the ‘‘popular many-worlds interpretation’’ and Everett’s ‘‘relative state’’ formulation of quantum mechanics. This distinction is claimed to be relevant to arguments raised against both schemes.

AGAINST MANY-WORLDS INTERPRETATIONS

This is a critical review of the literature on many-worlds interpretations, MWI, with arguments drawn partly from earlier critiques by Bell and Stein. The essential postulates involved in various MWI are extracted, and their consistency with the evident physical world is examined. Arguments are presented against MWI proposed by Everett, Graham and DeWitt. The relevance of frequency operators to MWI is examined; it is argued that frequency operator theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves provide a probability interpretation for quantum mechanics, and thus neither support existing MWI nor would be useful in constructing new MWI. Comments are made on papers by Geroch and Deutsch that advocate MWI. It is concluded that no plausible set of axioms exists for an MWI that describes known physics.

Schema evolution and the relational algebra

In this paper we discuss extensions to the conventional relational algebra to support both aspects of transaction time, evolution of a database's contents and evolution of a database's schema. We define a relation's schema to be the relation's temporal signature, a function mapping the relation's attribute names onto their value domains and class, indicating the extent of support for time. We also introduce commands to change a relation, now defined as a triple consisting of a sequence of classes, a sequence of signatures, and a sequence of states. A semantic type of system is required to identify semantically incorrect expressions and to enforce consistency constraints among a relation's class, signature and state following update. We show that these extensions are applicable, without change, to historical algebras that support valid time, yielding an algebraic language for the query and update of temporal databases. The additions preserve the useful properties of the conventional algebra.

Quantum mechanics without the projection postulate and its realistic interpretation

It is widely held that quantum mechanics is the first scientific theory to present scientifically internal, fundamental difficulties for a realistic interpretation (in the philosophical sense). The standard (Copenhagen) interpretation of the quantum theory is often described as the inevitable instrumentalistic response. It is the purpose of the present article to argue that quantum theory doesnot present fundamental new problems to a realistic interpretation. The formalism of quantum theory has the same states—it will be argued—as the formalisms of older physical theories and is capable of the same kinds of philosophical interpretation. This result is reached via an analysis of what it means to give a realistic interpretation to a theory. The main point of difference between quantum mechanics and other theories—as far as the possibilities of interpretation are concerned—is the special treatment given tomeasurement by the “projection postulate.” But it is possible to do without this postulate. Moreover, rejection of the projection postulate does not, in spite of what is often maintained in the literature, automatically lead to the many-worlds interpretation of quantum mechanics. A realistic interpretation is possible in which only the reality ofone (our) world is recognized. It is argued that the Copenhagen interpretation as expounded by Bohr is not in conflict with the here proposed realistic interpretation of quantum theory.

Introducing Schrödinger’s cat in the laboratory

A laboratory session that is designed to introduce students to the conceptual foundations of quantum mechanics is described. In this laboratory session, several experiments are used in order to illustrate the important ideas of superposition, interference, and the ‘‘collapse’’ of the wavefunction. These experiments form the basis for a discussion of four of the most popular interpretations of quantum mechanics that have been proposed over the years: the instrumentalist interpretation, hidden variable theories, the objective view of the wavefunction, and the many-worlds interpretation. As a finale, students are introduced to the paradox that epitomizes the interpretational problems of quantum mechanics: the paradox of Schrödinger’s cat.

Proposed Photon Interference Experiment for Test of Quantum Measurement Theories

We propose a possible experimental test of quantum measurement theories by means of a photon interference experiment, focusing on distinction between the many-Hilbert-spaces theory and the environment-induced-superselection-rule theory or the many-worlds interpretation.

The many-worlds and relative states interpretations of quantum mechanics, and the quantum Zeno paradox

The quantum Zeno paradox is examined within the many-worlds and relative states interpretations of quantum mechanics. In the many-worlds interpretation the effect is predicted to persist. The possibility of recombining worlds is not expected to be relevant. In the simplest form of relative states interpretation the effect may be avoided but this form of interpretation experiences difficulties in coping with conventional problems of quantum theory. The more complex version of the relative states interpretation, which takes account of the correlations of system with apparatus, predicts the occurrence of the paradox.

Many views of one world-an interpretation of quantum theory

An interpretation of quantum theory, based on the ideas of Everett (1957), but apparently different from that which is normally regarded as the many-worlds interpretation, is described.

Low energy pion absorption and the quasi-deuteron mechanism

We have re-examined the quasi-deuteron model for pion absorption in complex nuclei. A purely phenomenological parametrization of the π NN → NN absorption operator is constructed, based on a partial wave decomposition. For low energy pion absorption on NN pairs in relative s-states, six partial wave amplitudes enter. We apply our model to the absorption of stopped pions. Within a PWIA we first clarify which information is contained in the various ( π −, nn) coincident distributions. Realistic DWIA calculations have been performed for 12C and 16O and compared with both inclusive and exclusive data. It appears that most existing data can be understood independently from any detailed dynamical model for the elementary absorption process. An upper limit on absorption mechanisms other than quasi-deuteron absorption of 25% at threshold has been obtained.

Interpreting the wave function of the universe

The Many-Worlds Interpretation of quantum mechanics is used to determine the meaning of the universal wave function of quantum cosmology. More precisely, the Many-Worlds Interpretation is used to distinguish those quantities in quantum cosmology which are measurable, and hence physically meaningful, from those which are not. A number of rather surprising conclusions are drawn from the analysis. First, it is not possible to measure the expectation value of any universal operator and so such expectation values are physically meaningless. Second, it is physically (although not mathematically) meaningless to talk about eigenstates of the Universal Hamiltonian. Third, before a measurement of the radius of the Universe is made it makes no sense to say the Universe has a radius. Fourth, after the first two radius measurements are made, the Universe can be said to have all radii consistent with the support of the universal wave function and the wave function of the measuring apparatus; in effect, the Universe splits into an infinite number of branches, in each of which the time evolution is observed to be very close to the classical evolution. Fifth, any universal wave function which does not violate a Quantum Copernican Cosmological Principle will automatically solve the Flatness Problem without having to invoke inflation. In effect, quantum cosmology allows us to have “inflation without inflation”. All of these conclusions are illustrated with a closed Friedmann universe quantized in conformal time. My quantization procedure allows only one solution to Schrödinger's equation, and this solution solves the Flatness Problem. I show that the ADM quantization method plus the Hartle-Hawking initial foundary condition gives the same result.

The relative states and many-world interpretations of quantum mechanics and the EPR problem

The basic contributions to the concept of the many-worlds interpretation of quantum mechanics are analysed. It is found necessary to divide them into two classes corresponding to (a) the relative-states interpretation (RSI), which avoids problems of measurement, but is found generally unconvincing, and (b) the many-worlds interpretation (MWI), which is more comprehensible, but has all the problems of the von Neumann scheme. The EPR problem is tackled using each interpretation. The RSI finds no problem, while the MWI meets the same difficulties as conventional interpretations.

Quantum theory as a universal physical theory

The problem of setting up quantum theory as a universal physical theory is investigated. It is shown that the existing formalism, in either the conventional or the Everett interpretation, must be supplemented by an additional structure, the “interpretation basis.” This is a preferred ordered orthonormal basis in the space of states. Quantum measurement theory is developed as a tool for determining the interpretation basis. The augmented quantum theory is discussed.

Cosmology and the pilot wave interpretation of quantum mechanics

Bell has recently revived the pilot wave interpretation of de Broglie and Bohm as a possible scheme for interpreting wave functions in quantum cosmology. I argue that the pilot wave interpretation cannot be applied consistently to systems whose wave functions split into macroscopically distinguishable states. At some stage the pilot wave interpretation must either tacitly invoke wave function reduction in the same manner as the Copenhagen interpretation, or else abandon locality by requiring physical particles to move faster than light. Consequently, the many-worlds interpretation is the only known realist interpretation of the quantum mechanical formalism which can be extended to quantum cosmology.