6,762 Matching Results

Search Results

Advanced search parameters have been applied.

Dealing with quantum weirdness: Holism and related issues

Description: Various issues are discussed in interpretation of quantum mechanics. All these explorations point toward the same conclusion, that some systems are holistically connected, i.e., some composite systems have properties that cannot, even in principle, be reduced to the properties of its subsystems. This is argued to be the central metaphysical lesson of quantum theory; this will remain pertinent even if quantum mechanics gets replaced by a superior theory. Chap. 2 discusses nonlocality and rules out hidden-variable theories that approximately reproduce the perfect correlations of quantum mechanics, as well as theories that obey locality conditions weaker than those needed to derive Bell`s inequality. Chap. 3 shows that SQUID experiments can rule out non-invasive measurability if not macrorealism. Chap. 4 looks at interpretational issues surrounding decoherence, the dissipative interaction between a system and its environment. Decoherence klcan help ``modal`` interpretations pick out the desired ``preferred`` basis. Chap. 5 explores what varieties of causation can and cannot ``explain`` EPR correlations. Instead of relying on ``watered down`` causal explanations, we should instead develop new, holistic explanatory frameworks.
Date: December 1, 1995
Creator: Elby, A.R.
Partner: UNT Libraries Government Documents Department

Science of consciousness and the hard problem

Description: Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced {open_quotes}I{close_quotes} directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experimential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced {open_quotes}I{close_quotes} can direct human behaviour.
Date: May 22, 1996
Creator: Stapp, H.P.
Partner: UNT Libraries Government Documents Department

Measurement accuracy, bit-strings, Manthey`s quaternions, and RRQM

Description: The author continues the discussion started last year. By now three potentially divergent research programs have surfaced in ANPA: (1) the Bastin-Kilmister understanding of the combinatorial hierarchy (Clive`s {open_quotes}Menshevik{close_quotes} position); (2) the author`s bit-string {open_quotes}Theory of Everything{close_quotes} (which Clive has dubbed {open_quotes}Bolshevik{close_quotes}); (3) Manthey`s cycle hierarchy based on co-occurrence and mutual exclusion that Clive helped him map onto quaternions (as an yet unnamed heresy?). Unless a common objective can be found, these three points of view will continue to diverge. The authors suggests the reconstruction of relativistic quantum mechanism (RRQM) as a reasonable, and attainable, goal that might aid convergence rather than divergence.
Date: February 1, 1995
Creator: Noyes, H. P.
Partner: UNT Libraries Government Documents Department

Decoherence, determinism and chaos revisited

Description: We suggest that the derivation of the free space Maxwell Equations for classical electromagnetism, using a discrete ordered calculus developed by L.H. Kauffman and T. Etter, necessarily pushes the discussion of determinism in natural science down to the level of relativistic quantum mechanics and hence renders the mathematical phenomena studied in deterministic chaos research irrelevant to the question of whether the world investigated by physics is deterministic. We believe that this argument reinforces Suppes` contention that the issue of determinism versus indeterminism should be viewed as a Kantian antinomy incapable of investigation using currently available scientific tools.
Date: November 15, 1994
Creator: Noyes, H. P.
Partner: UNT Libraries Government Documents Department

On the computer simulation of the EPR-Bohm experiment

Description: We argue that supraluminal correlation without supraluminal signaling is a necessary consequence of any finite and discrete model for physics. Every day, the commercial and military practice of using encrypted communication based on correlated, pseudo-random signals illustrates this possibility. All that is needed are two levels of computational complexity which preclude using a smaller system to detect departures from ''randomness'' in the larger system. Hence the experimental realizations of the EPR-Bohm experiment leave open the question of whether the world of experience is ''random'' or pseudo-random. The latter possibility could be demonstrated experimentally if a complexity parameter related to the arm length and switching time in an Aspect-type realization of the EPR-Bohm experiment is sufficiently small compared to the number of reliable total counts which can be obtained in practice. 6 refs.
Date: December 1, 1988
Creator: McGoveran, D.O.; Noyes, H.P. & Manthey, M.J.
Partner: UNT Libraries Government Documents Department

Realization of vector fields for quantum groups as pseudodifferential operators on quantum spaces

Description: The vector fields of the quantum Lie algebra are described for the quantum groups GL{sub q}(n), SL{sub q}(N) and SO{sub q}(N) as pseudodifferential operators on the linear quantum spaces covariant under the corresponding quantum group. Their expressions are simple and compact. It is pointed out that these vector fields satisfy certain characteristic polynomial identities. The real forms SU{sub q}(N) and SO{sub q}(N,R) are discussed in detail.
Date: January 24, 1995
Creator: Chu, Chong-Sun & Zumino, B.
Partner: UNT Libraries Government Documents Department

Localizability and the planck mass

Description: The author combines the assumption of environmental decoherence, as the mechanism generating the classical (i.e. no quantum interferences) nature of spacetime, with the limit on its other classical feature, point-like continuity, namely Planck length. As a result, quantum extended objects with masses larger than Planck mass have to derive their quantum behavior from long-range correlations; objects with masses smaller than Planck mass cannot display classical behavior.
Date: June 1, 1993
Creator: Ne`eman, Y.
Partner: UNT Libraries Government Documents Department

Scattering theory for the quantum envelope of a classical system

Description: Classical dynamics, reformulated in terms of its quantum envelope is studied for the stationary states of the interacting system. The dynamical variable of ``elapsed time`` plays a crucial role in this study. It is shown that the perturbation series for the elapsed time can be summed in various simple cases even when standard perturbation series diverge. For the special class of systems where the interactions fall off sufficiently fast at infinity one could define ``in`` and ``out`` states; and consequently the wave matrices and scattering matrices. The scattering phase shifts bear a simple relation to the time delay in scattering.
Date: December 31, 1993
Creator: Sudarshan, E. C. G.
Partner: UNT Libraries Government Documents Department

Complex scattering dynamics and the quantum Hall effects

Description: We review both classical and quantum potential scattering in two dimensions in a magnetic field, with applications to the quantum Hall effect. Classical scattering is complex, due to the approach of scattering states to an infinite number of dynamically bound states. Quantum scattering follows the classical behavior rather closely, exhibiting sharp resonances in place of the classical bound states. Extended scatterers provide a quantitative explanation for the breakdown of the QHE at a comparatively small Hall voltage as seen by Kawaji et al., and possibly for noise effects.
Date: December 16, 1994
Creator: Trugman, S. A.
Partner: UNT Libraries Government Documents Department

PHOTOTHERMAL DEFLECTION SPECTROSCOPY AND DETECTION

Description: The theory for a sensitive spectroscopy based on the photothermal deflection of a laser beam is developed. We consider cw and pulsed cases of both transverse and collinear photothermal deflection spectroscopy for solids, liquids, gases, and thin films. The predictions of the theory are experimentally verified, its implications for imaging and microscopy are given, and the sources of noise are analyzed. The sensitivity and versatility of photothermal deflection spectroscopy are compared with thermal lensing and photoacoustic spectroscopy.
Date: September 1, 1980
Creator: Jackson, W.; Amer, Nabil M.; Boccara, A. C. & Fournier, D.
Partner: UNT Libraries Government Documents Department

THERMAL RADIATION OF SPHERICAL AND CYLINDRICAL SOOT PARTICLES

Description: The effect of soot shape on soot radiation from flame and smoke is considered in the present study. It is realized that soot particles generally conglomerate into different shapes. while the limiting bounds are being either spherical or long chains. By modellirig the long chains as infinite cylinders, it is shown that the radiation extinction characteristics of the spherical and cylindrical soot are distinctly different, with that of the spherical particles exhibiting a cut-off wavelength phenomenon. Emissivity from a cloud of cylindrical particles is always higher than that of the spheres due to their higher extinction coefficients. Moreover, the effect of soot shape onradiation is more pronounced at typical smoke temperatures (300°K) than at flame temperatures. A simple experimental method is also proposed for determining the amount of cylindrical and spherical particles in a cloud.
Date: October 1, 1980
Creator: Lee, S. C. & Tien, C. L.
Partner: UNT Libraries Government Documents Department

STRONG COUPLING EXPANSIONS FOR NON-INTEGRABLE HAMILTONIAN SYSTEMS

Description: We present a method for studying nonintegrable Hamiltonian systems H(I,{theta})=H{sub 0}(I)+kH{sub 1}(I,{theta}) (I,{theta} are action-angle variables) in the reg1me of large k. Our central tool is the conditional probability P(I,{theta},t|I{sub 0},{theta}{sub 0},t{sub 0}) that the system is at I,{theta} at time t given that it resided at I{sub 0},{theta}{sub 0} at t{sub 0}. An integral representation is given for this conditional probability. By discretizing the Hamiltonian equations of motion in small time steps, {epsilon}, we arrive at a phase volume preserving mapping which replaces the actual flow. When the motion on the energy surface E=H(I,{theta}) is bounded we are able to evaluate physical quantities of interest for large k and fixed {epsilon}. We also discuss the representation of P(I,{theta},t|I{sub 0},{theta}{sub 0},t{sub 0}) when an external random forcing is added in order to smooth the singular functions associated with the deterministic flow. Explicit calculations of a "diffusion" coefficient are given for a non-integrable system with two degrees of freedom. The limit {epsilon}{approaches}0 , which returns us to the actual flow, is subtle and is discussed.
Date: December 1, 1980
Creator: Abarbanel, Henry D.I. & Crawford, John David
Partner: UNT Libraries Government Documents Department

DIFFUSION IN VERY CHAOTIC HAMILTONIAN SYSTEMS

Description: We study nonintegrable Hamiltonian dynamics: H(I,{theta}}) = H{sub 0}(I)+kH{sub 1}(I,{theta}) for large k; that is, far from integrability. An integral representation is given for the conditional probability P(I,{theta},t|I{sub 0},{theta}{sub 0},t{sub 0}) that the system is at I,{theta} at t, given it was at I{sub 0},{theta}{sub 0} at t{sub 0}. By discretizing time into steps of size {epsilon}, we show how to evatuate physical observables for large k, fixed {epsilon}. An explicit calculation of a diffusion coefficient in a two degree of freedom problem is reported. Passage to {epsilon} = 0, the original Hamiltonian flow, discussed.
Date: December 1, 1980
Creator: Abarbanel, Henry D.I. & Crawford, John David
Partner: UNT Libraries Government Documents Department

Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources

Description: A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of #24;~1275#14;{degrees} C. At higher extraction voltages, the source appears to become emission limited with J #21;{>=} 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, {<=}#20;0.25 mm thick, has a measured lifetime of ~#24;40 hours at ~#24;1275#14;{degrees} C, when pulsed at 0.05 Hz and with pulse length of #24;~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. The source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.
Date: March 5, 2012
Creator: Roy, Prabir K.; Greenway, Wayne G. & Kwan, Joe W
Partner: UNT Libraries Government Documents Department

Source fabrication and lifetime for Li{sup +} ion beams extracted from alumino-silicate sources

Description: A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of ∼1275{degrees}C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A source with an alumino-silicate coating 6.35 mm in diameter and ≤0.25 mm thick, has a lifetime of ∼40 hours at ∼1275{degrees}C, when pulsed at 0.05 Hz and with pulse length of ∼6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Furthermore, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be extended if the temperature is reduced between pulses.
Date: February 10, 2012
Creator: Greenway, W. G. & Kwan, J. W.
Partner: UNT Libraries Government Documents Department

A compact neutron generator using a field ionization source

Description: Field ionization as a means to create ions for compact and rugged neutron sources is pursued. Arrays of carbon nano-#12;bers promise the high #12;eld-enhancement factors required for efficient field ionization. We report on the fabrication of arrays of #12;field emitters with a density up to 10{sup 6} tips/cm{sup 2} and measure their performance characteristics using electron field emission. The critical issue of uniformity is discussed, as are efforts towards coating the nano-fibers to enhance their lifetime and surface properties.
Date: October 31, 2011
Creator: Persaud, Arun; Waldmann, Ole; Kapadia, Rehan; Takei, Kuniharu; Javey, Ali & Schenkel, Thomas
Partner: UNT Libraries Government Documents Department

THE HOT CHOCOLATE EFFECT

Description: The "hot chocolate effect" was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the ten percent accuracy of the experiments.
Date: December 1, 1980
Creator: Crawford, Frank S.
Partner: UNT Libraries Government Documents Department

Retrocausal Effects as a Consequence of Quantum Mechanics Refined to Accommodate the Principle of Sufficient Reason

Description: The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at the pragmatic level, in cases where the reason behind nature's choice of response is unknown, but that the usual statistics can become biased in an empirically manifest way when the reason for the choice is empirically identifiable. It is shown here that if the statistical laws of quantum mechanics were to be biased in this way then the basically forward-in-time unfolding of empirical reality described by orthodox quantum mechanics would generate the appearances of backward-time-effects of the kind that have been reported in the scientific literature.
Date: May 10, 2011
Creator: Stapp, Henry P.
Partner: UNT Libraries Government Documents Department

LOCALITY AND REALITY

Description: Einstein's principle that no signal travels faster than suggests that observations in one spacetime region should not depend on whether or not a radioactive decay is detected in a spacelike separated region. This locality property is incompatible with the predictions of quantum theory, and this incompatibility holds independently of the questions of realism, objective reality, and hidden variables. It holds both in the pragmatic quantum theory of Bohr and in realistic frameworks. It is shown here to hold in a completed realistic quantum theory that reconciles Einstein's demand for a description of reality itself with Bohr's contention that quantum theory is complete. This completed realistic quantum theory has no hidden variables, and no objective reality in which observable attributes can become definite independently of observers. The, theory is described in some detail, with particular attention to those aspects related to the question of locality. This completed realistic quantum theory is in principle more comprehensive than Bohr.' s pragmatic quantum theory because it is not limited in principle by the requirement that the observed system be physically separated from the observing one. Applications are discussed.
Date: February 1, 1980
Creator: Stapp, Henry P.
Partner: UNT Libraries Government Documents Department

Equation of State of Classical Systems of Charged Particles

Description: Recent developments in the classical theory of fully ionized gases and strong electrolyte solutions are reviewed, and are used to discuss the equation of state at high temperature and low densities. The pressure is calculated using the ring-integral approximation, and quantitative estimates of higher correction terms are given. The effect of short-range repulsive forces is shown by comparing the results with two kinds of potential functions: hard spheres of diameter a, and "soft" spheres for which the short-range potential cancels the Coulomb potential at the origin, and decreases exponentially with distance. It is found that the use of either type of potential extends the range of validity of the ring integral approximation to considerably higher densities and lower temperatures. Since there is little difference in the results for the hard spheres and the soft spheres in this range, the latter is investigated more extensively since it is more easily handled by analytical methods. The expressions derived for the free energy of a system of charged particles can also be used in ionization equilibrium calculations, and the effect of electrostatic interactions on the equilibrium concentrations of various kinds of ions is indicated.
Date: April 26, 1962
Creator: Brush, S. G.; DeWitt, H. E. & Trulio, J. G.
Partner: UNT Libraries Government Documents Department

RECIPROCAL PASSIVE MODE-LOCKING OF A RHODAMINE 6G DYE LASER AND THE Ar+ PUMP LASER

Description: A rhodamine 6G dye laser, internally pumped within the extended cavity of an Ar{sup +} ion laser, is mode-locked when its cavity length is matched to half that of the pump laser: the 5145 {Angstrom} argon laser line is passively mode-locked by the combination of the saturable absorption and the lasing action of the dye which is in turn synchronously pumped and mode-locked. Tunable (5650 {Angstrom} to 5950 {Angstrom}) ~10 pSec pulses are generated, and the average output power is ~ 80 mW.
Date: October 1, 1980
Creator: Yasa, Zafer A. & Amer, Nabil M.
Partner: UNT Libraries Government Documents Department