Organic farming is expected to contribute to conserving national biodiversity on farms, especially remnant, old, and undisturbed small biotopes, forests, and permanent grassland. This objective cannot rely on the legislation of organic farming solely, and to succeed, farmers need to understand the goals behind it. A set of indicators with the purpose of facilitating dialogues between expert and farmer on wildlife quality has been developed and tested on eight organic farms. “Weed cover in cereal fields,” was used as an indicator (...) of floral and faunal biodiversity in the cultivated land, and “uncultivated biotope area” on the farm was used as a general measure of wildlife habitats. Functional grouping of herbaceous plants (discriminating between “high conservation value” plant species and “competitive”/“ruderal” species) and low mobility butterflies were used as indicators of conservation value, especially focusing on the few sites left with considerable remnant conservation value. The dialog processes revealed that the organic farmers’ ideas and goals of conservation of wildlife quality were not necessarily the same as for biologists; the farmers expressed very different opinions on the biological rooted idea, that wildlife quality is related to the absence of agricultural impact. However, farmers also stated that the information given by the indicators and especially the dialogue with the biologist had influenced their perception and awareness of wildlife. We conclude that, combined with a dialogue process, using these indicators when mapping wildlife quality could be an important key component of a farm wildlife management advisory tool at farm level. (shrink)
Separate focus on crop fertilization or feeding practices inadequately describes nitrogen (N) loss from mixed dairy farms because of (1) interaction between animal and crop production and between the production system and the manager, and (2) uncertainties of herd N production and crop N utilization. Therefore a systems approach was used to study N turnover and N efficiency on 16 conventional and 14 organic private Danish farms with mixed animal (dairy) and crop production. There were significant differences in N surplus (...) at the farm level (242 kg. N/ha. vs. 124 kg. N/ha. on conventional and organic dairy farms respectively) with a correlation between stocking rate and N surplus. N efficiency was calculated as the output of N in animal products divided by the net N import in fodder, manure and fertilizer. N turnover in herd and individual crops calculated on selected farms showed differences in organic and conventional crop N utilization. This is explained via a discussion of the rationality behind the current way of planning the optimum fertilizer application in conventional agriculture. The concept of marginal N efficiency is insufficient for correcting problems of N loss from dairy farms. Substantial reductions in N loss from conventional mixed dairy farms is probably unlikely without lower production intensity. The concept of mean farm unit N efficiency might be a way to describe the relation between production and N loss to facilitate regulation. This concept is linked to differing goals of agricultural development—i.e. intensification and separation vs. extensification and integration. It is discussed how studies in private farms—using organic farms as selected critical cases—can demonstrate possibilities for balancing production and environmental concern. (shrink)
— Niels Bohr, 19231 “There must be quite definite and clear grounds, why you repeatedly declare that one must interpret observations classically, which lie absolute ly in thei r essenc e. . . . It must belong to your deepest conviction—and I cannot understand on what you base it.”.
I argue that instead of a rather narrow focus on N. Bohr's account of complementarity as a particular and perhaps obscure metaphysical or epistemological concept (or as being motivated by such a concept), we should consider it to result from pursuing a particular method of studying physical phenomena. More precisely, I identify a strong undercurrent of Baconian method of induction in Bohr's work that likely emerged during his experimental training and practice. When its development is analyzed in light of Baconian (...) induction, complementarity emerges as a levelheaded rather than a controversial account, carefully elicited from a comprehensive grasp of the available experimental basis, shunning hasty metaphysically motivated generalizations based on partial experimental evidence. In fact, Bohr's insistence on the “classical” nature of observations in experiments, as well as the counterintuitive synthesis of wave and particle concepts that have puzzled scholars, seem a natural outcome (an updated instance) of the inductive method. Such analysis clarifies the intricacies of early Schrödinger's critique of the account as well as Bohr's response, which have been misinterpreted in the literature. If adequate, the analysis may lend considerable support to the view that Bacon explicated the general terms of an experimentally minded strand of the scientific method, developed and refined by scientists in the following three centuries. (shrink)
Niels Bohr, founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. Honner focuses on Bohr's epistemological lesson, the conviction that all our description of nature is dependent (...) on the words we use and the ways we can unambiguously use them. (shrink)
The Copenhagen interpretation, which informs the textbook presentation of quantum mechanics, depends fundamentally on the notion of ontological wave-particle duality and a viewpoint called “complementarity.” In this paper, Bohr's own interpretation is traced in detail and is shown to be fundamentally different from and even opposed to the Copenhagen interpretation in virtually all its particulars. In particular, Bohr's interpretation avoids the ad hoc postulate of wave function ‘collapse' that is central to the Copenhagen interpretation. The strengths and weakness of both (...) interpretations are summarized. ‡I thank Edward Mackinnon, Henry Folse, and Greg Anderson for valuable comments on the penultimate draft. The final responsibility for the paper rests with the author. †To contact the author, please write to: Bhaktivedanta Institute, 2334 Stuart Street, Berkeley, CA; e-mail: firstname.lastname@example.org. I have been unable to achieve a sharp formulation of Bohr's principle of complementarity despite much effort I have expended on it. (Einstein 1949, 674) While imagining that I understand the position of Einstein, as regards the EPR correlations, I have very little understanding of his principal opponent, Bohr. (Bell 1987, 155) Niels Bohr brain-washed a generation of physicists into believing that the problem had been solved fifty years ago. (Gell-Mann 1979, 29) Every sentence I say must be understood not as an affirmation, but as a question. (Niels Bohr, quoted in Jammer 1966, 175) Bohr's interpretation has never been fully clarified. It needs an interpretation itself, and only that will be its defense. (Weizsäcker 1971, 25). (shrink)
Manfred Frank and Niels Weidtmann (Eds.): Husserl und die Philosophie des Geistes Content Type Journal Article Pages 1-4 DOI 10.1007/s10743-011-9101-2 Authors Dan Zahavi, Center for Subjectivity Research, Department of Media, Cognition and Communication, University of Copenhagen, Copenhagen, Denmark Journal Husserl Studies Online ISSN 1572-8501 Print ISSN 0167-9848.
The 2nd International Congress for the Unity of Science was held in Copenhagen from the 21st June to the 26th June 1936. Among the Danish participants was Jørgen Jørgensen, professor of philosophy at the University of Copenhagen and the leading figure of logical positivism in Denmark, and Niels Bohr, the famous physicist, the father of the atomic theory, and the originator of the Copenhagen Interpretation of quantum mechanics. In fact, the event took place in Bohr’s honorary mansion at Carlsberg. (...) Jørgensen was the main organizer of the event in close collaboration with Otto Neurath. The latter had already been in Copenhagen twice, and the second time he had had a chance to meet and discuss with Bohr on epistemological issues. Again in 1936 he and Jørgensen had discussions with Bohr at a time which presented a very important period in Bohr’s thinking because the year before he had been confronted with the EPR-paradox. This final confrontation with Einstein gave Bohr a reason to change parts of his arguments. During this period of time Jørgensen seems to have supported Bohr’s Copenhagen Interpretation whole-heartedly. The purpose of the present talk is to present both Bohr’s and Jørgensen’s philosophy in an attempt of showing to what extent Bohr’s view, as it sometimes has been claimed, is an example of positivistic philosophy within physics. (shrink)
Niels Bohr began his career with an attempt to give a correct descriptive account of the motion of electrons. When forced to abandon this interpretation, he adopted, but soon rejected, a hypothetical-deductive account. In his development of an interpretation for the new quantum theory Bohr began to concentrate on the way language functions to make descriptions possible. His later work on this problem and on the role of concepts in the foundations of science led him to anticipate some (...) of the basic ideas developed in Wittgenstein's Investigations. Bohr eventually saw his own analysis of the conditions of the possibility of unambiguous communication as the basis for making explicit the unity implicit in science. (shrink)
v. 1. Atomic theory and the description of nature -- v. 2. Essays 1932-1957 on atomic physics and human knowledge -- v. 3. Essays 1958-1962 on atomic physics and human knowledge -- v. 4. Causality and complementarity.
In this paper, the main outlines of the discussions between Niels Bohr with Albert Einstein, Werner Heisenberg, and Erwin Schrödinger during 1920–1927 are treated. From the formulation of quantum mechanics in 1925–1926 and wave mechanics in 1926, there emerged Born's statistical interpretation of the wave function in summer 1926, and on the basis of the quantum mechanical transformation theory—formulated in fall 1926 by Dirac, London, and Jordan—Heisenberg formulated the uncertainty principle in early 1927. At the Volta Conference in Como (...) in September 1927 and at the fifth Solvay Conference in Brussels the following month, Bohr publicly enunciated his complementarity principle, which had been developing in his mind for several years. The Bohr-Einstein discussions about the consistency and completeness of qnautum mechanics and of physical theory as such—formally begun in October 1927 at the fifth Solvay Conference and carried on at the sixth Solvay Conference in October 1930—were continued during the next decades. All these aspects are briefly summarized. (shrink)
We clarify Bohr’s interpretation of quantum mechanics by demonstrating the central role played by his thesis that quantum theory is a rational generalization of classical mechanics. This thesis is essential for an adequate understanding of his insistence on the indispensability of classical concepts, his account of how the quantum formalism gets its meaning, and his belief that hidden variable interpretations are impossible.
A growing number of commentators have, in recent years, noted the important affinities in the views of Immanuel Kant and Niels Bohr. While these commentators are correct, the picture they present of the connections between Bohr and Kant is painted in broad strokes; it is open to the criticism that these affinities are merely superficial. In this essay, I provide a closer, structural, analysis of both Bohr's and Kant's views that makes these connections more explicit. In particular, I demonstrate (...) the similarities between Bohr's argument, on the one hand, that neither the wave nor the particle description of atomic phenomena pick out an object in the ordinary sense of the word, and Kant's requirement, on the other hand, that both ‘mathematical’ (having to do with magnitude) and ‘dynamical’ (having to do with an object's interaction with other objects) principles must be applicable to appearances in order for us to determine them as objects of experience. I argue that Bohr's ‘complementarity interpretation’ of quantum mechanics, which views atomic objects as idealizations, and which licenses the repeal of the principle of causality for the domain of atomic physics, is perfectly compatible with, and indeed follows naturally from a broadly Kantian epistemological framework. (shrink)
The Copenhagen interpretation, which informs the textbook presentation of quantum mechanics, depends fundamentally on the notion of ontological wave-particle duality and a viewpoint called “complementarity”. In this paper, Bohr’s own interpretation is traced in detail and is shown to be fundamentally different from and even opposed to the Copenhagen interpretation in virtually all its particulars. In particular, Bohr’s interpretation avoids the ad hoc postulate of wave function ‘collapse’ that is central to the Copenhagen interpretation. The strengths and weakness of both (...) interpretations are summarized. (shrink)
In this paper, I try to explain the philosophical problems that Niels Bohr felt had been exposed by the discovery of the "quantum of action," and by the emergence of the quantum theory that arose in large part as a result of his efforts. I won't have space to make the case adequately here, but my own view is that we have not yet fully digested the message brought to us by Bohr's "Copenhagen Interpretation" of Quantum Mechanics, and I (...) suspect that it will finally prove to be every bit as revolutionary as Bohr thought it was. (shrink)
Murdoch describes the historical background of the physics from which Bohr's ideas grew; he traces the origins of his idea of complementarity and discusses its meaning and significance. Special emphasis is placed on the contrasting views of Einstein, and the great debate between Bohr and Einstein is thoroughly examined. Bohr's philosophy is revealed as being much more subtle, and more interesting than is generally acknowledged.
Although it is, often considered a form of anti-realism, here it is argued that Bohr's complementarity viewpoint must accept entity realism based on its analysis of the causal interaction involved in observation. However, because Bohr accepts the quantum postulate he must reject the view that the goal of theory is to represent the independently existing object apart from observation. Thus he abandons the spectator account of knowledge and with it the correspondence theory of truth. In this respect his view is (...) parallel to the positions held by Hacking, Cartwright, and Ellis. (shrink)
Soviet attitude towards Bohr reflects changes in the ideological approach to science. During the last period before Stalin's death ?danov proclaimed the campaign against Western influence in Soviet philosophy and science. Nevertheless the physicist M. A. Markov tried to introduce complementarity as a materialistic interpretation of quantum?mechanics in 1948. He was officially condemned. This was followed by a period (1948?54) during which heavy attacks were made against the Copenhagen school. In 1958, after a personal exchange of thoughts with Bohr, academician (...) Fock declared complementarity and probability to be irreversible steps towards a new insight into physical reality, at the same time correcting some of Bohr's epistemological conceptions. (shrink)
The idiotypic network theory (INT) was conceived by the Danish immunologist Niels Kaj Jerne in 1973/1974. It proposes an overall view of the immune system as a network of lymphocytes and antibodies. The paper tries to offer a reconstruction of the genesis of the theory, now generally discarded and of mostly historical interest, first of all, by taking into account the context in which Jerne’s theoretical proposal was advanced. It is argued the theory challenged, in a sense, the supremacy (...) of the clonal selection theory (CST), this being regarded as the predominant paradigm in the immunological scenario. As CST found shortcomings in explaining certain phenomena, anomalies, one could view INT as a competing paradigm claiming to be able to make sense of such phenomena in its own conceptual framework. After a summary outline of the historical background and some relevant terminological elucidations, a narrative of the various phases of elaboration of the theory is proposed, up to its official public presentation. (shrink)
Peut-on faire du cerveau, cet « organe de l’âme », un objet scientifique et philosophique ? À l’heure où les certitudes ont peut-être remplacé les doutes et le questionnement sur la légitimité et les conditions rendant possible la poursuite d’un tel objectif, la lecture du Discours de Sténon sur l’anatomie du cerveau semble s’imposer. L’aveu d’ignorance de l’auteur qui ouvre le texte est à la fois déconcertant et extrêmement rassurant. Loin de promettre aux lecteurs d’être en mesure de « cont..