5,665 research outputs found
Using simple elastic bands to explain quantum mechanics: a conceptual review of two of Aert's machine-models
From the beginning of his research, the Belgian physicist Diederik Aerts has
shown great creativity in inventing a number of concrete machine-models that
have played an important role in the development of general mathematical and
conceptual formalisms for the description of the physical reality. These models
can also be used to demystify much of the strangeness in the behavior of
quantum entities, by allowing to have a peek at what's going on - in structural
terms - behind the "quantum scenes," during a measurement. In this author's
view, the importance of these machine-models, and of the approaches they have
originated, have been so far seriously underappreciated by the physics
community, despite their success in clarifying many challenges of quantum
physics. To fill this gap, and encourage a greater number of researchers to
take cognizance of the important work of so-called Geneva-Brussels school, we
describe and analyze in this paper two of Aerts' historical machine-models,
whose operations are based on simple breakable elastic bands. The first one,
called the spin quantum-machine, is able to replicate the quantum probabilities
associated with the spin measurement of a spin-1/2 entity. The second one,
called the \emph{connected vessels of water model} (of which we shall present
here an alternative version based on elastics) is able to violate Bell's
inequality, as coincidence measurements on entangled states can do.Comment: 15 pages, 5 figure
Ephemeral properties and the illusion of microscopic particles
Founding our analysis on the Geneva-Brussels approach to quantum mechanics,
we use conventional macroscopic objects as guiding examples to clarify the
content of two important results of the beginning of twentieth century:
Einstein-Podolsky-Rosen's reality criterion and Heisenberg's uncertainty
principle. We then use them in combination to show that our widespread belief
in the existence of microscopic particles is only the result of a cognitive
illusion, as microscopic particles are not particles, but are instead the
ephemeral spatial and local manifestations of non-spatial and non-local
entities
Modeling Concept Combinations in a Quantum-theoretic Framework
We present modeling for conceptual combinations which uses the mathematical
formalism of quantum theory. Our model faithfully describes a large amount of
experimental data collected by different scholars on concept conjunctions and
disjunctions. Furthermore, our approach sheds a new light on long standing
drawbacks connected with vagueness, or fuzziness, of concepts, and puts forward
a completely novel possible solution to the 'combination problem' in concept
theory. Additionally, we introduce an explanation for the occurrence of quantum
structures in the mechanisms and dynamics of concepts and, more generally, in
cognitive and decision processes, according to which human thought is a well
structured superposition of a 'logical thought' and a 'conceptual thought', and
the latter usually prevails over the former, at variance with some widespread
beliefsComment: 5 pages. arXiv admin note: substantial text overlap with
arXiv:1311.605
Interpreting Quantum Particles as Conceptual Entities
We elaborate an interpretation of quantum physics founded on the hypothesis
that quantum particles are conceptual entities playing the role of
communication vehicles between material entities composed of ordinary matter
which function as memory structures for these quantum particles. We show in
which way this new interpretation gives rise to a natural explanation for the
quantum effects of interference and entanglement by analyzing how interference
and entanglement emerge for the case of human concepts. We put forward a scheme
to derive a metric based on similarity as a predecessor for the structure of
'space, time, momentum, energy' and 'quantum particles interacting with
ordinary matter' underlying standard quantum physics, within the new
interpretation, and making use of aspects of traditional quantum axiomatics.
More specifically, we analyze how the effect of non-locality arises as a
consequence of the confrontation of such an emerging metric type of structure
and the remaining presence of the basic conceptual structure on the fundamental
level, with the potential of being revealed in specific situations.Comment: 19 pages, 1 figur
What is Quantum? Unifying Its Micro-Physical and Structural Appearance
We can recognize two modes in which 'quantum appears' in macro domains: (i) a
'micro-physical appearance', where quantum laws are assumed to be universal and
they are transferred from the micro to the macro level if suitable 'quantum
coherence' conditions (e.g., very low temperatures) are realized, (ii) a
'structural appearance', where no hypothesis is made on the validity of quantum
laws at a micro level, while genuine quantum aspects are detected at a
structural-modeling level. In this paper, we inquire into the connections
between the two appearances. We put forward the explanatory hypothesis that,
'the appearance of quantum in both cases' is due to 'the existence of a
specific form of organisation, which has the capacity to cope with random
perturbations that would destroy this organisation when not coped with'. We
analyse how 'organisation of matter', 'organisation of life', and 'organisation
of culture', play this role each in their specific domain of application, point
out the importance of evolution in this respect, and put forward how our
analysis sheds new light on 'what quantum is'.Comment: 10 page
The Guppy Effect as Interference
People use conjunctions and disjunctions of concepts in ways that violate the
rules of classical logic, such as the law of compositionality. Specifically,
they overextend conjunctions of concepts, a phenomenon referred to as the Guppy
Effect. We build on previous efforts to develop a quantum model that explains
the Guppy Effect in terms of interference. Using a well-studied data set with
16 exemplars that exhibit the Guppy Effect, we developed a 17-dimensional
complex Hilbert space H that models the data and demonstrates the relationship
between overextension and interference. We view the interference effect as, not
a logical fallacy on the conjunction, but a signal that out of the two
constituent concepts, a new concept has emerged.Comment: 10 page
Quantum Experimental Data in Psychology and Economics
We prove a theorem which shows that a collection of experimental data of
probabilistic weights related to decisions with respect to situations and their
disjunction cannot be modeled within a classical probabilistic weight structure
in case the experimental data contain the effect referred to as the
'disjunction effect' in psychology. We identify different experimental
situations in psychology, more specifically in concept theory and in decision
theory, and in economics (namely situations where Savage's Sure-Thing Principle
is violated) where the disjunction effect appears and we point out the common
nature of the effect. We analyze how our theorem constitutes a no-go theorem
for classical probabilistic weight structures for common experimental data when
the disjunction effect is affecting the values of these data. We put forward a
simple geometric criterion that reveals the non classicality of the considered
probabilistic weights and we illustrate our geometrical criterion by means of
experimentally measured membership weights of items with respect to pairs of
concepts and their disjunctions. The violation of the classical probabilistic
weight structure is very analogous to the violation of the well-known Bell
inequalities studied in quantum mechanics. The no-go theorem we prove in the
present article with respect to the collection of experimental data we consider
has a status analogous to the well known no-go theorems for hidden variable
theories in quantum mechanics with respect to experimental data obtained in
quantum laboratories. For this reason our analysis puts forward a strong
argument in favor of the validity of using a quantum formalism for modeling the
considered psychological experimental data as considered in this paper.Comment: 15 pages, 4 figure
Estimating stellar oscillation-related parameters and their uncertainties with the moment method
The moment method is a well known mode identification technique in
asteroseismology (where `mode' is to be understood in an astronomical rather
than in a statistical sense), which uses a time series of the first 3 moments
of a spectral line to estimate the discrete oscillation mode parameters l and
m. The method, contrary to many other mode identification techniques, also
provides estimates of other important continuous parameters such as the
inclination angle alpha, and the rotational velocity v_e. We developed a
statistical formalism for the moment method based on so-called generalized
estimating equations (GEE). This formalism allows the estimation of the
uncertainty of the continuous parameters taking into account that the different
moments of a line profile are correlated and that the uncertainty of the
observed moments also depends on the model parameters. Furthermore, we set up a
procedure to take into account the mode uncertainty, i.e., the fact that often
several modes (l,m) can adequately describe the data. We also introduce a new
lack of fit function which works at least as well as a previous discriminant
function, and which in addition allows us to identify the sign of the azimuthal
order m. We applied our method to the star HD181558, using several numerical
methods, from which we learned that numerically solving the estimating
equations is an intensive task. We report on the numerical results, from which
we gain insight in the statistical uncertainties of the physical parameters
involved in the moment method.Comment: The electronic online version from the publisher can be found at
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1467-9876.2005.00487.
Recent MOST space photometry
The Microvariability and Oscillations of STars (MOST) photometric satellite
has already undertaken more than 64 primary campaigns which include some
clusters and has obtained observations of >850 secondary stars of which ~180
are variable. More than half of the variables pulsate, with the majority being
of B-type. Since 2006 January, MOST has operated with only a single CCD for
both guiding and science. The resulting increase in read-out cadence has
improved precision for the brightest stars. The 2007 light curve for Procyon
confirms the lack of predicted p-modes with photometric amplitudes exceeding 8
ppm as we found in 2004 and 2005. p-modes have been detected in other
solar-type stars as well as pre-main sequence objects, roAp and delta Scuti
variables. g-modes have been detected in a range of slowly pulsating B stars,
Be stars and beta Cephei variables. Differential rotation has been defined for
several spotted solar-type stars and limits set to the albedo of certain
transiting planets and the presence of other perturbing planets. The mission is
expected to continue as long as the experiment operates.Comment: 9 pages, 7 figures, from HELAS-II meetin
The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings
CONTEXT. Gamma Doradus stars (hereafter gamma Dor stars) are known to exhibit
gravity- and/or gravito-intertial modes that probe the inner stellar region
near the convective core boundary. The non-equidistant spacing of the pulsation
periods is an observational signature of the stars' evolution and current
internal structure and is heavily influenced by rotation.
AIMS. We aim to constrain the near-core rotation rates for a sample of gamma
Dor stars, for which we have detected period spacing patterns.
METHODS. We combined the asymptotic period spacing with the traditional
approximation of stellar pulsation to fit the observed period spacing patterns
using chi-squared optimisation. The method was applied to the observed period
spacing patterns of a sample of stars and used for ensemble modelling.
RESULTS. For the majority of stars with an observed period spacing pattern we
successfully determined the rotation rates and the asymptotic period spacing
values, though the uncertainty margins on the latter were typically large. This
also resulted directly in the identification of the modes corresponding with
the detected pulsation frequencies, which for most stars were prograde dipole
gravity and gravito-inertial modes. The majority of the observed retrograde
modes were found to be Rossby modes. We further discuss the limitations of the
method due to the neglect of the centrifugal force and the incomplete treatment
of the Coriolis force.
CONCLUSION. Despite its current limitations, the proposed methodology was
successful to derive the rotation rates and to identify the modes from the
observed period spacing patterns. It forms the first step towards detailed
seismic modelling based on observed period spacing patterns of moderately to
rapidly rotating gamma Dor stars.Comment: 12 pages, 15 figures, 5 tables. Accepted for publication in Astronomy
& Astrophysic
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