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)
This proceedings volume contains most of the invited talks presented at the colloquium. The main topics treated are the model theory of arithmetic and algebra, the semantics of natural languages, and applications of mathematical logic to complexity theory. The volume contains both surveys by acknowledged experts and original research papers presenting advances in these disciplines.
The rapid rise of international collaborative science has enabled access to genomic data. In this article, it is argued that to move beyond mapping genomic variation to understanding its role in complex disease aetiology and treatment will require extending data sharing for the purposes of clinical research translation and implementation.
The 1995 Encyclopedia of Bioethics is an almost complete reworking of the original 1978 edition, due to the expanding nature of the field. The following article focuses on how the second edition of the Encyclopedia deals with the topic of “clinical ethics” and three related topics: “nursing ethics”, “trust”, and “conflict of interest”. We assess their relevance to the current developments in these fields and the Encyclopedia's usefulness as a resource to ethics consultants, researchers and clinicians. We emphasize the heterogeneity (...) of clinical ethics as a still new and evolving field. (shrink)
Unrecognized presuppositions about patient appearance have become increasingly important in medicine, medical ethics and medical law. Symptoms of these historically conditioned assumptions include common ageism, aesthetic surgery, and litigation about ‘wrongful life’. These phenomena suggest a societal intolerance for what is considered an ‘abnormal’ appearance. Among others, eighteenth-century artists and anatomists helped to set these twentieth-century precedents, actually measuring deviations of external traits to analogous deformations of the soul, and drawing moral conclusions from physiognomic measurements. Other eighteenth-century artists countered with (...) pathognomy, recognizing that uneven physical features may indicate humanity, instead of character flaws. We suggest that there is an important and as yet unrecognized role played by visual and perceptual preferences in our judgments concerning normalcy and anomaly. We further suggest a shift away from our current fashion-magazine, youth-oriented aesthetic, and towards an aesthetic of imperfection. Physicians and medical students can be made aware of their historically conditioned reactions to ‘abnormal’ appearing patients by studying the understandings and methods with which artists have portrayed those who are considered deformed in appearance. (shrink)
Here we discuss the challenge posed by self-organization to the Darwinian conception of evolution. As we point out, natural selection can only be the major creative agency in evolution if all or most of the adaptive complexity manifest in living organisms is built up over many generations by the cumulative selection of naturally occurring small, random mutations or variants, i.e., additive, incremental steps over an extended period of time. Biological self-organization—witnessed classically in the folding of a protein, or in the (...) formation of the cell membrane—is a fundamentally different means of generating complexity. We agree that self-organizing systems may be fine-tuned by selection and that self-organization may be therefore considered a complementary mechanism to natural selection as a causal agency in the evolution of life. But we argue that if self-organization proves to be a common mechanism for the generation of adaptive order from the molecular to the organismic level, then this will greatly undermine the Darwinian claim that natural selection is the major creative agency in evolution. We also point out that although complex self-organizing systems are easy to create in the electronic realm of cellular automata, to date translating in silico simulations into real material structures that self-organize into complex forms from local interactions between their constituents has not proved easy. This suggests that self-organizing systems analogous to those utilized by biological systems are at least rare and may indeed represent, as pre-Darwinists believed, a unique ascending hierarchy of natural forms. Such a unique adaptive hierarchy would pose another major challenge to the current Darwinian view of evolution, as it would mean the basic forms of life are necessary features of the order of nature and that the major pathways of evolution are determined by physical law, or more specifically by the self-organizing properties of biomatter, rather than natural selection. (shrink)