scholarly journals Robert Rosen’s relationalist understanding of biological states and quantum mechanics

2018 ◽  
Vol 61 (3) ◽  
pp. 5-21
Author(s):  
Slobodan Perovic
Keyword(s):  
Quantum Mechanics ◽  
Biological Systems ◽  
Quantum States ◽  
Cognitive Sciences ◽  
Robert Rosen

Robert Rosen?s intriguing ideas of a formalized framework to understand biological systems have been discussed across the life and cognitive sciences. Yet his crude account of physical states, quantum states in particular, seems to be irreconcilable with his account of biological states, thus preventing a pursuit of his framework as a general ontological account. A more subtle understanding of quantum states, however, leaves room for a relationalist understanding of physical states in general agreement with Rosen?s framework of biological states.

Quantum Theory

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Uncertainty Principle ◽  
Quantum Spin ◽  
Quantum States ◽  
Wave Functions ◽  
Symbolic Representations ◽  
Quantum Numbers ◽  
The Subject ◽  
Heisenberg's Uncertainty Principle

The subject of Chapter 8 is the fundamental principles of quantum theory, the abstract extension of quantum mechanics. Two of the entities explored are kets and operators, with kets being representations of quantum states as well as a source of wave functions. The quantum box and quantum spin kets are specified, as are the quantum numbers that identify them. Operators are introduced and defined in part as the symbolic representations of observable quantities such as position, momentum and quantum spin. Eigenvalues and eigenkets are defined and discussed, with the former identified as the possible outcomes of a measurement. Bras, the counterpart to kets, are introduced as the means of forming probability amplitudes from kets. Products of operators are examined, as is their role underpinning Heisenberg’s Uncertainty Principle. A variety of symbol manipulations are presented. How measurements are believed to collapse linear superpositions to one term of the sum is explored.

The Engineer

Rebel Genius ◽  
2016 ◽  
Author(s):  
Tara H. Abraham
Keyword(s):  
Artificial Intelligence ◽  
Reticular Formation ◽  
Research Laboratory ◽  
Biological Systems ◽  
Theoretical Modelling ◽  
Research Culture ◽  
Cognitive Sciences ◽  
New Research ◽  
Scientific Identity ◽  
The Brain

This chapter examines the ways that McCulloch’s new research culture at MIT’s Research Laboratory of Electronics shaped the evolution of his scientific identity into that of an engineer. This was an open, fluid, multidisciplinary culture that allowed McCulloch to shift his focus more squarely onto understanding the brain from the perspective of theoretical modelling, and to promote the cybernetic vision to diverse audiences. McCulloch’s practices, performed with a new set of student-collaborators, involved modeling the neurophysiology of perception, understanding reliability in biological systems, and pursuing knowledge of the reticular formation of the brain. The chapter provides a nuanced account of the relations between McCulloch’s work and the emerging fields of artificial intelligence and the cognitive sciences. It also highlights McCulloch’s identities as sage-collaborator and polymath, two roles that in part were the result of his students’ observations and in part products of his own self-fashioning.

Quantum mechanics, interpretation of

2018 ◽  
Author(s):  
Allen Stairs
Keyword(s):  
Quantum Mechanics ◽  
Microscopic Level ◽  
Quantum States ◽  
Quantum Mechanical ◽  
Quantum Superposition ◽  
Ordinary Objects ◽  
Making Sense ◽  
Interpretations Of Quantum Mechanics ◽  
The World

Quantum mechanics developed in the early part of the twentieth century in response to the discovery that energy is quantized, that is, comes in discrete units. At the microscopic level this leads to odd phenomena: light displays particle-like characteristics and particles such as electrons produce wave-like interference patterns. At the level of ordinary objects such effects are usually not evident, but this generalization is subject to striking exceptions and puzzling ambiguities. The fundamental quantum mechanical puzzle is ’superposition of states’. Quantum states can be added together in a manner that recalls the superposition of waves, but the effects of quantum superposition show up only probabilistically in the statistics of many measurements. The details suggest that the world is indefinite in odd ways; for example, that things may not always have well-defined positions or momenta or energies. However, if we accept this conclusion, we have difficulty making sense of such straightforward facts as that measurements have definite results. Interpretations of quantum mechanics are, in one way or another, attempts to understand the superposition of quantum states. The range of interpretations stretches from the metaphysically daring to the seemingly innocuous. But, so far, no single interpretation has commanded anything like universal agreement.

scholarly journals The Strange (Hi)story of Particles and Waves

2016 ◽  
Vol 71 (3) ◽  
pp. 195-212
Author(s):  
H. Dieter Zeh
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Quantum Theory ◽  
Excited States ◽  
Configuration Space ◽  
Historical Context ◽  
Quantum States ◽  
Wave Functions ◽  
General Readership ◽  
Boson Fields

AbstractThis is an attempt of a non-technical but conceptually consistent presentation of quantum theory in a historical context. While the first part is written for a general readership, Section 5 may appear a bit provocative to some quantum physicists. I argue that the single-particle wave functions of quantum mechanics have to be correctly interpreted as field modes that are “occupied once” (i.e. first excited states of the corresponding quantum oscillators in the case of boson fields). Multiple excitations lead to apparent many-particle wave functions, while the quantum states proper are defined by wave function(al)s on the “configuration” space of fundamental fields, or on another, as yet elusive, fundamental local basis.

scholarly journals Superposition Principle and Born’s Rule in the Probability Representation of Quantum States

2019 ◽  
Vol 1 (2) ◽  
pp. 130-150 ◽  
Author(s):  
Igor Ya. Doskoch ◽  
Margarita A. Man’ko
Keyword(s):  
Quantum Mechanics ◽  
Probability Distribution ◽  
Particle System ◽  
Superposition Principle ◽  
Quantum States ◽  
Particle State ◽  
Probability Representation ◽  
Tomographic Probability ◽  
Born’S Rule ◽  
System States

The basic notion of physical system states is different in classical statistical mechanics and in quantum mechanics. In classical mechanics, the particle system state is determined by its position and momentum; in the case of fluctuations, due to the motion in environment, it is determined by the probability density in the particle phase space. In quantum mechanics, the particle state is determined either by the wave function (state vector in the Hilbert space) or by the density operator. Recently, the tomographic-probability representation of quantum states was proposed, where the quantum system states were identified with fair probability distributions (tomograms). In view of the probability-distribution formalism of quantum mechanics, we formulate the superposition principle of wave functions as interference of qubit states expressed in terms of the nonlinear addition rule for the probabilities identified with the states. Additionally, we formulate the probability given by Born’s rule in terms of symplectic tomographic probability distribution determining the photon states.

scholarly journals A CLASS OF QUANTUM STATES WITH CLASSICAL-LIKE EVOLUTION

1994 ◽  
Vol 08 (29) ◽  
pp. 1823-1831 ◽  
Author(s):  
SALVATORE DE MARTINO ◽  
SILVIO DE SIENA ◽  
FABRIZIO ILLUMINATI
Keyword(s):  
Quantum Mechanics ◽  
Harmonic Oscillator ◽  
Coherent States ◽  
Quantum States ◽  
Time Dependent ◽  
Stationary States ◽  
Oscillator Potential ◽  
Classical Motion ◽  
Stochastic Formulation ◽  
New States

In the framework of the stochastic formulation of quantum mechanics we derive non-stationary states for a class of time-dependent potentials. The wave packets follow a classical motion with constant dispersion. The new states define a possible extension of the harmonic oscillator coherent states. As an explicit application, we study a sestic oscillator potential.

MACROSCOPICITY AND CLASSICALITY OF QUANTUM FLUCTUATIONS IN DE SITTER SPACE

1988 ◽  
Vol 03 (10) ◽  
pp. 929-940 ◽  
Author(s):  
SUMIO WADA
Keyword(s):  
Quantum Mechanics ◽  
Quantum Fluctuations ◽  
Quantum States ◽  
Wave Functions ◽  
Interpretation Of Quantum Mechanics ◽  
De Sitter Spacetime ◽  
Probabilistic Interpretation ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Matter Fields

On the basis of the non-probabilistic interpretation of quantum mechanics, we define “macroscopicity” and “classicality” of quantum fluctuations as closely related but separate concepts. Then these properties are examined in quantum states (wave functions) of matter fields in de Sitter spacetime.

scholarly journals QUANTUM COSMIC CENSOR: GRAVITATION MAKES REALITY UNDECIDABLE

2008 ◽  
Vol 17 (13n14) ◽  
pp. 2535-2538 ◽  
Author(s):  
RODOLFO GAMBINI ◽  
JORGE PULLIN
Keyword(s):  
Quantum Mechanics ◽  
Measurement Problem ◽  
Quantum States ◽  
Point Of View ◽  
Space And Time ◽  
Empirical Point

When one takes into account gravitation, the measurement of space and time cannot be carried out with infinite accuracy. When quantum mechanics is reformulated taking into account this lack of accuracy, the resolution of the measurement problem can be performed via decoherence without the usual pitfalls. The resulting theory has the same physical predictions of quantum mechanics with a reduction postulate, but is radically different, with the quantum states evolving unitarily in terms of the underlying variables. Gravitation therefore makes this worrisome situation, potentially leading to two completely different views of reality, irrelevant from an empirical point of view. It may, however, be highly relevant from a philosophical point of view.

scholarly journals Can We Describe Biological Systems with Quantum Mechanics?

2016 ◽  
Vol 698 ◽  
pp. 012009
Author(s):  
C G Granados-Ramírez ◽  
C G Benítez-Cardoza ◽  
M D Carbajal-Tinoco
Keyword(s):  
Quantum Mechanics ◽  
Biological Systems

NONLOCAL MEASUREMENTS IN THE TIME-SYMMETRIC QUANTUM MECHANICS

2006 ◽  
Vol 20 (11n13) ◽  
pp. 1528-1535 ◽  
Author(s):  
LEV VAIDMAN ◽  
IZHAR NEVO
Keyword(s):  
Quantum Mechanics ◽  
Quantum Systems ◽  
Quantum Measurements ◽  
Quantum States ◽  
Standard Quantum ◽  
Time Direction ◽  
Quantum Formalism ◽  
Symmetric Quantum ◽  
Time Symmetric Quantum Mechanics

Although for some nonlocal variables the standard quantum measurements which are reliable, instantaneous, and nondemolition, are impossible, demolition reliable instantaneous measurements of all variables are possible. It is shown that this is correct also in the framework of the time-symmetric quantum formalism, i.e. nonlocal variables of composite quantum systems with quantum states evolving both forward and backward in time are measurable in a demolition way. The result follows from the possibility to reverse with certainty the time direction of backward evolving quantum states.

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