It is generally believed that the uncertainty relation Δq Δp≥1/2ħ, where Δq and Δp are standard deviations, is the precise mathematical expression of the uncertainty principle for position and momentum in quantum mechanics. We show that actually it is not possible to derive from this relation two central claims of the uncertainty principle, namely, the impossibility of an arbitrarily sharp specification of both position and momentum (as in the single-slit diffraction experiment), and the impossibility of (...) the determination of the path of a particle in an interference experiment (such as the double-slit experiment).The failure of the uncertainty relation to produce these results is not a question of the interpretation of the formalism; it is a mathematical fact which follows from general considerations about the widths of wave functions.To express the uncertainty principle, one must distinguish two aspects of the spread of a wave function: its extent and its fine structure. We define the overall widthW Ψ and the mean peak width wψ of a general wave function ψ and show that the productW Ψ w φ is bounded from below if φ is the Fourier transform of ψ. It is shown that this relation expresses the uncertainty principle as it is used in the single- and double-slit experiments. (shrink)

Quantum mechanics is generally regarded as the physical theory that is our best candidate for a fundamental and universal description of the physical world. The conceptual framework employed by this theory differs drastically from that of classical physics. Indeed, the transition from classical to quantum physics marks a genuine revolution in our understanding of the physical world.

We consider the Heisenberg uncertainty principle of position and momentum in 3-dimensional spaces of constant curvature K. The uncertainty of position is defined coordinate independent by the geodesic radius of spherical domains in which the particle is localized after a von Neumann–Lüders projection. By applying mathematical standard results from spectral analysis on manifolds, we obtain the largest lower bound of the momentum deviation in terms of the geodesic radius and K. For hyperbolic spaces, we also obtain a (...) global lower bound \, which is non-zero and independent of the uncertainty in position. Finally, the lower bound for the Schwarzschild radius of a static black hole is derived and given by \, where \ is the Planck length. (shrink)

This paper considers the relationship between quantum uncertainty and the problem of God. Among the issues considered are the existence and essence ofGod, divine action, human freedom, and personal identity. In recent discussions concerning the relative merits of science and religion, thinkers like Ian Barbourand John Haught have suggested several such credible, albeit tentative, connections between the two on the basis of the epistemological limit imposed upon human knowledge by the Heisenberg Uncertainty Principle.

Responds to comments by G. Kempen (see record 1996-00289-001) regarding L. Frazier's (see record 1995-31821-001) comments regarding G. Kempen's (see record 1995-31826-001) comments on Frazier et al's (see record 1994-32229-001) article on processing discontinuous words. There are serious problems with Kempen's account of the data of Frazier et al. These problems involve the principle of uncertainty invoked by Kempen. It is unclear that all control items in the original Frazier et al study were open to a complex verb (...) analysis. Kempen's alternative account of the results is not only incomplete, but it is inconsistent with the English data and with half of the Dutch data, in addition to relying on a principle of parsing that is otherwise unmotivated. (PsycINFO Database Record (c) 2000 APA, all rights reserved) (unassigned). (shrink)

The research has three objectives: 1) to study the concept of Heisenberg’s uncertainty principle, 2) to study the concept of reality and knowledge in Buddhist philosophy, and 3) to analyze the concept of Heisenberg’s uncertainty principle in Buddhist philosophical perspective. This is documentary research. In this research, it was found that Heisenberg's uncertainty principle refers to the experiment of thought while studying physical reality on smaller particles than atoms where at the present no theory (...) of Physics can clearly explain such properties. In this respect, the mentioned principle is utilized to predict the pairs of a certain attribute of physics, position, and momentum, for instance. The accuracy of position, however, cannot be precisely yielded in advance by such a principle. In other words, it is impossible to measure the position and momentum of a quantum particle at the same time. In the study of the ultimate reality on the matter in the Buddhist philosophy, it showed that corporeality in nature is conditioned by cause and effect and thereby falling under the three common characteristics: 1) impermanence, 2) state of suffering, and 3) state of non-substantiality. In the study of Heisenberg’s uncertainty principle in the Buddhist philosophical perspective, this research was found that the processes in acquiring certain knowledge of Heisenberg and Buddhist philosophy are by one another in the sense that such knowledge is methodologically acquired through experience, rationality, and intuition because both see the Reality in the same manners, that is, the physical reality is viewed by Heisenberg as the thing that goes under changing state of wave-particle all the times, and the matter is seen by Buddhist philosophy as the impermanence and change depending upon its factors involved and thereby is not-self. However, in the different aspect, on the one hand, Buddhist philosophy utilizes the knowledge on the matter to develop the morality and ethics by which the cessation of suffering could be respectively made, but on the other hand, Heisenberg somehow applies the certain knowledge on physical objects into quantum technology to accommodate the physical comfortability in living life. Suggestions in the application of knowledge gained from this research into benefit were that while Buddhist philosophy can make use of Heisenberg’s uncertainty principle to provide certain help at the time of explanation of three common characteristics being done through the scientific method, science also can utilize knowledge gained from Buddhist philosophy to expand the framework of scientific knowledge which is aimed at studying only the physical objects to be able to study the mental objects through the integration of three epistemological methods as well. (shrink)

We argue about quantum entanglement and the uncertainty principle through the tomographic approach. In the end of paper, we infer some epistemological implications.

This paper considers the relationship between quantum uncertainty and the problem of God. Among the issues considered are the existence and essence ofGod, divine action, human freedom, and personal identity. In recent discussions concerning the relative merits of science and religion, thinkers like Ian Barbourand John Haught have suggested several such credible, albeit tentative, connections between the two on the basis of the epistemological limit imposed upon human knowledge by the Heisenberg Uncertainty Principle.

Heisenberg's uncertainty principle is usually taken to express a limitation of operational possibilities imposed by quantum mechanics. Here we demonstrate that the full content of this principle also includes its positive role as a condition ensuring that mutually exclusive experimental options can be reconciled if an appropriate trade-off is accepted. The uncertainty principle is shown to appear in three manifestations, in the form of uncertainty relations: for the widths of the position and momentum distributions (...) in any quantum state; for the inaccuracies of any joint measurement of these quantities; and for the inaccuracy of a measurement of one of the quantities and the ensuing disturbance in the distribution of the other quantity. Whilst conceptually distinct, these three kinds of uncertainty relations are shown to be closely related formally. Finally, we survey models and experimental implementations of joint measurements of position and momentum and comment briefly on the status of experimental tests of the uncertainty principle. (shrink)

Stem cells are defined as having capacities for both self-renewal and differentiation. Many different entities satisfy this working definition. I show that this general stem cell concept is relative to a cell lineage, temporal duration, and characters of interest. Experiments specify values for these variables. So claims about stem cells must be understood in terms of experimental methods used to identify them. Furthermore, the stem cell concept imposes evidential constraints on interpretation of experimental results. From these constraints, it follows that (...) claims about stem cell capacities are inherently uncertain. This result has important implications for stem cell research. (shrink)

In this paper we critically analyse W. Heisenberg’s arguments against the ontology of point particles following trajectories in quantum theory, presented in his famous 1927 paper and in his Chicago lectures (1929). Along the way, we will clarify the meaning of Heisenberg’s uncertainty relation and help resolve some confusions related to it.

The term action of consciousness is used to refer to an influence, such as psychokinesis or free will, that produces an effect on matter that is correlated to mental intention, but not completely determined by physical conditions. Such an action could not conserve energy. But in that case, one wonders why, when highly accurate measurements are done, occasions of non-conserved energy (generated perhaps by unconscious PK) are not detected. A possible explanation is that actions of consciousness take place within the (...) limits of the uncertainty principle. Two models are reviewed that, using the latter assumption, propose that consciousness can originate an action potential in the brain. One (that of Eccles) uses the latter assumption only, and the other (that of Burns) additionally assumes that consciousness acts, within those limits, by ordering quantum fluctuations. (shrink)

Economic forecasting is famously unreliable. While this problem has traditionally been blamed on theories such as the efficient market hypothesis or even the butterfly effect, an alternative explanation is the role of money – something which is typically downplayed or excluded altogether from economic models. Instead, models tend to treat the economy as a kind of barter system in which money's only role is as an inert medium of exchange. Prices are assumed to almost perfectly reflect the 'intrinsic value' of (...) an asset. This paper argues, however, that money is better seen as an inherently dualistic phenomenon, which merges precise number with the fuzzy concept of value. Prices are not the optimal result of a mechanical, Newtonian process, but are an emergent property of the money system. And just as quantum physics has its uncertainty principle, so the economy is an uncertain process which can only be approximated by mathematical models. Acknowledging the dynamic and paradoxical qualities of money changes our ontological framework for economic modelling, and for making decisions under uncertainty. Applications to areas of risk analysis, forecasting and modelling are discussed, and it is proposed that a greater appreciation of the fundamental causes of uncertainty will help to make the economy a less uncertain place. (shrink)

It is shown that the uncertainty principle has nothing directly to do with the non-localisability of position and momentum for an individual system on the quantum logical view. The product Δ x· Δ p for localisation of the ranges of position and momentum of an individual system→ ∞ , while the quantities Δ X and Δ P in the uncertainty principle $\Delta X\cdot \Delta P\geq \hslash /2$ , must be given a statistical interpretation on the quantum (...) logical view. (shrink)

Heisenberg’s uncertainty principle is a milestone of twentieth-century physics. We sketch the history that led to the formulation of the principle, and we recall the objections of Grete Hermann and Niels Bohr. Then we explain that there are in fact two uncertainty principles. One was published by Heisenberg in the Zeitschrift für Physik of March 1927 and subsequently targeted by Bohr and Hermann. The other one was introduced by Earle Kennard in the same journal a couple (...) of months later. While Kennard’s principle remains untarnished, the principle of Heisenberg has recently been criticized in a way that is very different from the objections by Bohr and Hermann: there are reasons to believe that Heisenberg’s formula is not valid. Experimental results seem to support this claim. -/- . (shrink)

We show that the strong form of Heisenberg’s inequalities due to Robertson and Schrödinger can be formally derived using only classical considerations. This is achieved using a statistical tool known as the “minimum volume ellipsoid” together with the notion of symplectic capacity, which we view as a topological measure of uncertainty invariant under Hamiltonian dynamics. This invariant provides a right measurement tool to define what “quantum scale” is. We take the opportunity to discuss the principle of the symplectic (...) camel, which is at the origin of the definition of symplectic capacities, and which provides an interesting link between classical and quantum physics. (shrink)

We consider a space with Generalized Uncertainty Principle which can be obtained in the frame of the deformed commutation relations. In the space with GUP we have found transformations relating coordinates and times of moving and rest frames of reference in the first order over the parameter of deformation. In the non-relativistic case we find the deformed Galilean transformation which is rotation in Euclidian space–time. This transformation is similar to the Lorentz one but written for Euclidean space–time where (...) the speed of light is replaced by some velocity related to the parameter of deformation. We show that for relativistic particle in the space with GUP the coordinates of the rest and moving frames of reference satisfy the Lorentz transformation with some effective speed of light. (shrink)

A practical experiment using coincidence techniques is suggested to test the validity of the following concepts:(1) wave packet reduction and(2) the measurement-uncertainty principle for position and momentum. The suggested experiment uses the time-of-flight method to determine an electron's momentum and a coincident photon, emitted from a system excited by the electron, to determine its initial position. It is shown that this method does constitute a simultaneous measurement of position and momentum for a single system. Also, it is pointed (...) out that the traditional statement of the measurementuncertainty principle must be slightly modified even within the Copenhagen interpretation of quantum mechanics. (shrink)

The path-integral approach to quantum theory of continuous measurements has been developed in preceding works of the author. According to this approach the measurement amplitude determining probabilities of different outputs of the measurement can be evaluated in the form of a restricted path integral (a path integral “in finite limits”). With the help of the measurement amplitude, maximum deviation of measurement outputs from the classical one can be easily determined. The aim of the present paper is to express this variance (...) in a simpler and transparent form of a specific uncertainty principle (called the action uncertainty principle, AUP). The most simple (but weak) form of AUP is δS≳ℏ, whereS is the action functional. It can be applied for simple derivation of the Bohr-Rosenfeld inequality for measurability of gravitational field. A stronger (and having wider application) form of AUP (for ideal measurements performed in the quantum regime) is |∫ ′ t″ (δS[q]/δq(t))Δq(t)dt|≃ℏ, where the paths [q] and [Δq] stand correspondingly for the measurement output and for the measurement error. It can also be presented in symbolic form as Δ(Equation) Δ(Path) ≃ ℏ. This means that deviation of the observed (measured) motion from that obeying the classical equation of motion is reciprocally proportional to the uncertainty in a path (the latter uncertainty resulting from the measurement error). The consequence of AUP is that improving the measurement precision beyond the threshold of the quantum regime leads to decreasing information resulting from the measurement. (shrink)

The arguments presented by Gibbins in his Note are based on a sharp distinction between the product Δx·Δp, which refers to the ranges of position and momentum of an individual system, and the uncertainty principle ΔX·ΔP ≥ ħ/2, which expresses a statistical relation for an ensemble of systems. A critical role in Gibbins’ reasoning is played by the theorem T which states that the restriction of the dynamical variable of position x of an individual system to a finite (...) range Δx excludes the possibility of restricting the canonically conjugate dynamical variable of momentum p to a finite range Δp. (shrink)

In The Structure of Science, Ernest Nagel finds fault with Werner Heisenberg’s explication of the uncertainty principle. Nagel’s complaint is that this principle does not follow from the impossibility of measuring with precision both the position and the momentum of a particle, as Heisenberg intimates, rather it is the other way around. Recent developments in theoretical physics have shown that Nagel’s argument is more substantial than he could have envisaged. In particular it has become clear that there (...) are in fact two uncertainty principles; as a result, there are four pairs of quantities to examine, whereas Heisenberg considers only one. These findings throw new light on Nagel’s criticism. They enable us to see that his intuition was surprisingly apposite, but also make clear where his argument misses the mark. (shrink)

It is well known that, in classical theory, Liouville's theorem shows that if an ensemble of systems is distributed over a small element of volume in phase space, the ensemble fills a region of equal volume at all later instants of time. In quantum mechanics, the uncertainty principle is associated with the products of the errors in conjugate coordinates and momenta, and such products can be interpreted in terms of volume elements in phase space. Comparison of these two (...) facts leads to the assertion in the interesting volume on “Statistical Mechanics” recently published by J. E. and M. G. Mayer that “The Liouville theorem is essential for the complete understanding of the uncertainty principle. (shrink)

Time-delayed coincidence Mössbauer experiments, in which the spread in energy may be either greater or less than the natural linewidth, are discussed. This discussion leads to the conclusion that in the uncertainty relation ΔE Δt ≥ $\begin{array}{*{20}c} / \\ h \\ \end{array} /2$ , Δt should be interpreted as the duration time of the measurement and not as the lifetime of the state. Further analysis shows that confinement of photons to the region of space between emitter and absorber should (...) cause a frequency spread much larger than actually observed. This leads to the conclusion that to think of photons as being created at one point in space, traveling with the velocity of light to another point, then being absorbed or destroyed, is incorrect. (shrink)

An entangled pair of photons (1 and 2) are emitted in opposite directions. A narrow slit is placed in the path of photon 1 to provide the precise knowledge of its position on the y-axis and this also determines the precise y-position of its twin, photon 2, due to quantum entanglement. Is photon 2 going to experience a greater uncertainty in momentum, that is, a greater Δpy because of the precise knowledge of its position y? The experimental data show (...) Δy Δ py < h for photon 2. Can this recent realization of the thought experiment of Karl Popper signal a violation of the uncertainty principle? (shrink)

We establish, for the quantum system made up of a single free particle, the formula ΔE Δt≳(v/c) ħ, where ΔE is the precision to whichE can be ascertained in time Δt. The measurement can be carried out with zero disturbance inE itself.

This second book in the 'Middle Way Philosophy' series develops five general principles that are distinctive to the universal Middle Way as a practical response to absolutization. These begin with the consistent acknowledgement of human uncertainty (scepticism), and follow through with openness to alternative possibilities (provisionality), the importance of judging things as a matter of degree (incrementality), the clear rejection of polarised absolute claims (agnosticism) and the cultivation of cognitive and emotional states that will help us resolve conflict (integration).

A challenge faced by defenders of the precautionary principle is to clarify when the evidence that a harmful event might occur suffices to regard this prospect as a real possibility. Plausible versions of the principle must articulate some epistemic threshold, orde minimisrequirement, which specifies when precautionary measures are justified. Critics have argued that formulating such a threshold is problematic in the context of the precautionary principle. First, this is because the precautionary principle appears to be ambiguous (...) about the distinction between risk and uncertainty: should the principle merely be invoked when evidential probabilities are absent, or also when probabilities have low epistemic credentials? Secondly, defenders of the precautionary principle face an aggregation puzzle: in judging whether or not thede minimisrequirement has been met, how should first-order evidential probabilities and their second-order epistemic standing be aggregated? This article argues that the ambiguity can be resolved, and the epistemological puzzle can be solved. Focusing on decisions in the context of climate uncertainty, I advance a version of the precautionary principle that serves as a plausible decision rule, to be adopted in situations where its main alternative—cost–benefit analysis—does not deliver. (shrink)

Generalized anxiety disorder is among the world’s most prevalent psychiatric disorders and often manifests as persistent and difficult to control apprehension. Despite its prevalence, there is no integrative, formal model of how anxiety and anxiety disorders arise. Here, we offer a perspective derived from the free energy principle; one that shares similarities with established constructs such as learned helplessness. Our account is simple: anxiety can be formalized as learned uncertainty. A biological system, having had persistent uncertainty in (...) its past, will expect uncertainty in its future, irrespective of whether uncertainty truly persists. Despite our account’s intuitive simplicity—which can be illustrated with the mere flip of a coin—it is grounded within the free energy principle and hence situates the formation of anxiety within a broader explanatory framework of biological self-organization and self-evidencing. We conclude that, through conceptualizing anxiety within a framework of working generative models, our perspective might afford novel approaches in the clinical treatment of anxiety and its key symptoms. (shrink)

This essay examines the relationship between the precautionary principle and uncertainty factors used by toxicologists to estimate acceptable exposure levels for toxic chemicals from animal experiments. It shows that the adoption of uncertainty factors in the United States in the 1950s can be understood by reference to the precautionary principle, but not by cost-benefit analysis because of a lack of relevant quantitative data at that time. In addition, it argues that uncertainty factors continue to be (...) relevant to efforts to implement the precautionary principle and that the precautionary principle should not be restricted to cases involving unquantifiable hazards. (shrink)

A challenge faced by defenders of the precautionary principle is to clarify when the evidence that a harmful event might occur suffices to regard this prospect as a real possibility. Plausible versions of the principle must articulate some epistemic threshold, or de minimis requirement, which specifies when precautionary measures are justified. Critics have argued that formulating such a threshold is problematic in the context of the precautionary principle. First, this is because the precautionary principle appears to (...) be ambiguous about the distinction between risk and uncertainty: should the principle merely be invoked when evidential probabilities are absent, or also when probabilities have low epistemic credentials? Secondly, defenders of the precautionary principle face an aggregation puzzle: in judging whether or not the de minimis requirement has been met, how should first-order evidential probabilities and their second-order epistemic standing be aggregated? This article argues that the ambiguity can be resolved, and the epistemological puzzle can be solved. Focusing on decisions in the context of climate uncertainty, I advance a version of the precautionary principle that serves as a plausible decision rule, to be adopted in situations where its main alternative—cost–benefit analysis—does not deliver. (shrink)