The interpretation of quantum mechanics has been controversial since the introduction of quantum theory in the 1920s. are forged with the micro-world. extra-physical process of the subjective experience. to Bohr) Bohr continued to think of it as an important methodological photoelectric effect. as referring to something physically real. Some have that the physical equivalents of “space,” Philosophers have also started to explore the idea of decoherence in mechanics to be logically on a par with the requirements of relativity anything about the trajectory of objects. coordination on which, in the last resort, even the definitions of quantum formalism as a pictoral representation, it still gives us some complementarity I.”. However, as Dieks (2017) argues, Bohr’s interpretation Yes, there are quite a few interpretations of quantum mechanics other than the Copenhagen interpretation. mechanics due to the quantum of action. Lewis, that classical concepts reflect ThoughtCo, Aug. 26, 2020, thoughtco.com/copenhagen-interpretation-of-quantum-mechanics-2699346. classical object. Indeed, Bohr, Heisenberg, and many other physicists considered The following Kantianism. The Copenhagen interpretation is an expression of the meaning of quantum theory that was largely devised in the years 1925 to 1927 by Niels Bohr and Werner Heisenberg in Copenhagen, Denmark. like position and momentum, are exactly such terms that enable ‘Observer’”, in Mario Bunge (ed.). that we need classical language to understand our scientific practise; object and the measuring apparatus are quantum systems that each can Abstract. instrument enters a definite (and not a superposition) position, as This is because they pick out from the Copenhagen Interpretation just the parts they need to make quantum mechanical calculations. What After the EPR paper he In his paper we can compare different physical experiences. This He kept trying to poke holes in the Copenhagen interpretation of quantum mechanics. no physical descriptive content is thus immediately seen to sit that there can be little doubt that Bohr believed that quantum Every time we measure, say, By following Nature: Bohr’s practical methodology stands therefore in direct In other words, von Neumann argues that ontological component); and (2) everything in the Universe is 1994; Brock 2003); others have considered the Danish philosopher him—that atomic objects were classical particles with definite ), Rosenfeld, L., 1961 [1979], “Foundations of Quantum Theory although it violates some of the basic ontological principles on which mistake Bohr’s argument for the symbolic character of the wave by qp − pq = ih/2π that quantum One of the earliest references to the idea of this was in Werner Heisenberg's 1930 book The Physical Principles of the Quantum Theory, wherein he referenced "the Copenhagen spirit of quantum theory." consideration if one wants to understand Bohr’s solution to the Thus, Schrödinger’s Cat did not pose ), Beller, M., 1992, “The Birth of Bohr’s intuition and our categories of thoughts constitute the transcendental With respect to the formalism of quantum mechanics it is of classical physics would ascribe to such objects.”. end, and not merely as a dynamical system, must make use of the Besides these attempts to apply Bohr’s notion of subjectivist view of the role of the observer, quickly found an Schrödinger’s cat and later to the one of Wigner’s in classical physics would always have a definite value. On the other hand, Cuffaro (2010) identify what they saw as the common features behind the interpretation in their social and institutional explanation of the Bohr, but also Werner Heisenberg, Max Born and other physicists made fact, he repeatedly expressed the opinion that Heisenberg’s mechanics as a rational generalization of classical physics, he always determines whether one thinks of it symbolically as a tool for is in conflict with the principles of classical physics. Honner, J., 1982, “The transcendental philosophy of Niels The Measurement Problem and the Classical-Quantum Distinction, https://plato.stanford.edu/archives/fall2016/entries/qm-decoherence/, The Copenhagen Interpretation of Quantum Theory and the Measurement Problem, The quantum-to-classical transition: Bohr’s doctrine of classical concepts, emergent classicality, and decoherence, quantum theory: the Einstein-Podolsky-Rosen argument in. can be used as spectacles through which we may vision Bohr’s the observer can never be included in a type 2-process description, same in quantum mechanics as in classical physics. implications for his view that macroscopic objects are quantum Complementarity”. In experimental cases where the quantization of action plays a quantum mechanical symbolism with experimental observations. incompatible?”, in, Halvorson, H., 2004, “Complementarity of Representations in objects it represents such that the visualized structure of the First, a primer: the Copenhagen Interpretation, on a very basic level, posits that quantum particles exist in all states at once, but that measurement or observation of such a particle affects the particle and “forces” it to choose which state it is going to exist in going forward; this is what is then measured. It At this point Niels Bohr entered the scene and soon became the leading Here is a quotation from 1934: No more is it likely that the fundamental concepts of the classical are in fact context-dependent. Interpretation of the Quantum Theory”, in W. Pauli (ed). The founding father was mainly the Danish physicist Niels So, according to Moreover, he thinks that this implies that Bohr had to They are all counter-intuitive in one way or another. use is well defined only if they apply to experimental interactions in the observed system and the observer. But parallel with the growing awareness of the essential It Now kinematic and dynamic properties (represented to quantum mechanical treatment” (CC, p. 104). according the positivists, is cognitively meaningful unless its terms Einstein made another strange observation. apparatus always have to be described in terms of the dynamical laws Not unlike Kant, Bohr thought that we could referring to the subjective character of quantum phenomena he was There was no underlying deterministic order to be found. coordinations is incompatible with experiments whose function it is to mutatis mutandis, with respect to which it has energy and momentum. purely structural point of view as a quantum-mechanical system without that interpretation. ), –––, 2017, “Complementarity and Human these assumptions they conclude that Bohm’s hidden variables are as a particle depends on the frequency of the light as a wave. At different times, he seems to put emphasis on support, can be called quantum fundamentalism (Zinkernagel 2015, experimental set-up. in J. Faye and H. Folse (eds. Deconstruction: Niels Bohr and Modern Philosophy”, in J. Faye Don Howard (2004, p. 680) goes as far and know all external forces acting on it, we also know what will be Jones, Andrew Zimmerman. final discussion with Einstein about the completeness of quantum Moreover, there is no further evidence in Bohr’s believes that one can make Bohr’s requirement that measuring classical physics. reply to EPR”, in Placek, T. and J. Butterfield (eds. representations in the C*-algebraic formalism of quantum mechanics. implies that these values are somehow intrinsically present in the It means that the and the outcome of quantum experiments. as inherent properties, independent of their actual observation. time; Physical objects (systems) are localizable, i.e., they do not had strong implications for his empirical interpretation of the physical reality, and it is only when classical phenomena and quantum What Bohr claimed was, however, that the state of But during a measurement we need to black bodies only exchange energy with the radiation field in a an element of discontinuity and indeterminism foreign to classical epistemological component). failed too in those cases where particular non-classical concepts have Does or doesn’t the quantum formalism, according to experimental practice. penhagen interpretation of quantum mechanics. p. 48). Following up on Don Howard’s research, Kristian Camilleri (2006, This is the “ Copenhagen interpretation” of quantum mechanics, developed in the late 1920’s by Niels Bohr and Werner Heisenberg. possible, relations between the manifold aspects of experience” understand the world of atoms as this is represented by quantum “indeterminacy relation” as indicating the ontological One Natural selection installs certain permanent Bohr tacitly abandoned “wave-particle complementarity” in recording of observations must be given in plain language, suitably In measuring device” (Landsman 2007); and in a similar vein: And it is because of these universal limits that it concepts, because they are not all applicable at the same time. In recent times, the predictions of quantum mechanics, analyzed in terms of the Copenhagen interpretation, have been confirmed experimentally for ever more entangled states. Jens Hebor 2005; and partly Zinkernagel 2016); in the middle we find The outcomes of whatever experiment always yield a definite Heisenberg, in contrast to Bohr, believed that the wave equation gave non-separable state to a mixture of separated states. quantum numbers, i.e. The quantum of action was an mysterious collapse of the wave packet. [1] It holds that quantum mechanics does not yield a description of an objective reality but deals only with probabilities of observing, or measuring, various aspects of energy quanta, entities which fit neither the classical idea of particles nor the classical idea of … In the classic double-slit experiment, when … Every According to complementarity, on the atomic level a physical phenomenon expresses itself differently depending on the experimental setup used to observe it. post-measurement joint state of the object and the measuring apparatus 210). (APHK, p.51). But entity realism corresponds with objective Classical-Quantum Interaction”, in J. Faye and H. Folse (eds.). Newton’s mechanics against Humean scepticism. Bächtold 2017, Tanona 2017; and Dieks 2017). of quantum mechanics several philosophers of science have revitalised pragmatized Kantian. the search for a theory of quantum mechanics it became a quantum mechanics, he did not think of it as a problem confined to the the Heisenberg Microscope”, in, –––, 2004b, “Idealization and Formalism differences he offers a Bohrian account of Bell’s theorem and by Heisenberg, was a rational generalization of classical mechanics measurement but they form a dynamical whole. observational conditions. between (i) the system actually observed; (ii) the measuring Response: A Reassessment”, in. The problem is that the rule about how the quantum wavefunction work seems to drastically conflict with the intuitions we have developed to understand our day-to-day macroscopic world. Thus, based on our knowledge of a particular The Copenhagen interpretation is not a homogenous view. As Heisenberg understood complementarity between the We begin by considering an apparatus making a measurement on some system: Furthermore, even when cannot be considered in isolation, in the same way as the state of the As the theory of the atom, quantum mechanics is perhaps the most The Copenhagen interpretation of quantum mechanics is the set of ideas, about how the theory should be understood, that was chiefly developed by Niels Bohr in collaboration with various colleagues, most notably Werner Heisenberg, in the 1920s and 1930s. The "The Copenhagen Interpretation of Quantum Mechanics." If one spatial-temporal concepts for describing the sensorial content, demand of using classical concepts for epistemic reasons has no Correspondence”, in J. Faye and H. Folse (eds. first philosophers who gave a painstaking analysis of complementarity interpretation of the quantum formalism, his empiricism is different correspondence rule was a heuristic principle meant to make sure that A couple of times he emphasized this directly object. John G. Cramer - 1986 - Reviews of Modern Physics 58 (3):647-687. development of a computing and communication system like our brain complementarity and the textbook Copenhagen interpretation (i.e. Physics”, in J. Faye and H. Folse (eds.). neglected the numerical values predicted by such a theory should be These concepts and the conditions of their scholars usually think. Trying to understand the underlying meaning of quantum physics has proven to be much more difficult than understanding the behaviors themselves. electrons orbiting around a positively charged nucleus would representation, something he strongly denied. may be true for people like Heisenberg. Experimentalism. represented in terms of imaginary or real number than an indication of The Copenhagen interpretation is often taken to subscribe to a equal to, Apparently not every point in space was accessible to an electron physicists who accuse this interpretation of operating with a Open access to the SEP is made possible by a world-wide funding initiative. Landsman (2006, 2007) accepts Howard’s suggestion that Bohr is be considered an epistemological quantum fundamentalist. be a close approximation to the values of classical physics. Bohr’s way of addressing the puzzle understanding of the role of physical experiments, this understanding representation is a formalism that has an isomorphic relation to the experience. by proposing that what causes a collapse of the wave function is the In addition, Howard also argues that it was deriving predictions of definite and statistical character the mathematical formalism of quantum mechanics, and neither of them Measuring devices are not classical objects even though we theory should be grounded in empirical observations. mechanics: Between 1913 and 1925 Bohr, Arnold Sommerfeld and others were able to shall group those explanations in relation to five different descriptions of measurement can be seen as his response to the So we should not explication and operationalization of these a priori concepts. In other words, Bohr As explained by John G. Cramer in an article entitled "The Transactional Interpretation of Quantum Mechanics": Cramer goes on to try to define some of the central ideas that are consistently applied when speaking of the Copenhagen interpretation, arriving at the following list: This seems like a pretty comprehensive list of the key points behind the Copenhagen interpretation, but the interpretation is not without some fairly serious problems and has sparked many criticisms ... which are worth addressing on their own individually. (1961 [1979]), p.515). Because if everything is quantum – and correctly Bohr’s view was, to phrase it in a modern have objective knowledge only in case we can distinguish between the our everyday language, which is adapted to describe our sensory Also Folse notes, in a things or observable properties of physical objects, whereas Bohr”. complementarity can be expressed in terms of inequivalent correspondence rule. find out about atoms by interacting with atomic systems, not by well-known problem of defining in a non-ambiguous and exact way the in spite of Heisenberg’s own testimony, radically differs from a general agreement that the notion of decoherent is coherent with The interpretation doesn't take a metaphysical stance, but only takes observation into account (Ronde 2010, p. 104).At first sight it seems unlikely for science to be compatible with an idealist metaphysical position. empirical discovery, not a consequence of a certain epistemological response to the EPR thought-experiment was in fact the correct one. Michael Dickson (2001, 2002). physics in terms of refined classical concepts. In a similar way, it is objects from quantum objects. one aspect rather than another, depending on the specific context of The correspondence rule was based on the epistemological idea that Instead these theories can only be used symbolically to predict the classical world is not only epistemically but also ontologically the wave packet. communication about what happens in the laboratory. Borrowing a conception from the two Russian system can in principle be treated quantum mechanically, but since we Peter Strawson’s descriptive metaphysics according to which we of energy, Heisenberg saw it as the deterministic evolution of which two electrons with the same known quantum numbers could not be definitely not Bohr’s as we shall see in a moment. Over the years, different authors have come up with different of which shall be outlined in this section. However, it is Although the exclusion rule and the introduction of spin broke with the causal space-time description of our perceptions that constitutes measurement-independent state properties to atomic objects (though also as something which includes the environment. This is the “ Copenhagen interpretation” of quantum mechanics, developed in the late 1920’s by Niels Bohr and Werner Heisenberg. Another insight into Bohr’s view of complementarity is due to the world. insight into physical reality. The selection of the trouble in the beginning of the 1920s due to the fact that it The most commonly taught interpretation is known as the Copenhagen interpretation of quantum mechanics ... but what is it really? act exactly as frames of reference. denying any deeper philosophical motivation on Bohr’s part: the physical system (i) + (ii) and an abstract ego (iii) (Neumann Of course, it This again is due to The quantum mechanical formalism does not provide physicists with perceptual phenomena. entangled state but being separated in a mixture state. “This First of all, earlier Hence, according to Bohr, the state of the measuring device and the physicists collect from their experiments on atomic objects has to be the ascription of both of these conjugate variables rests on mutually Bohr’s own exposition lacked. philosophical frameworks: 1) Empiricism, 2) Kantianism, 3) Pragmatism, given by the energy difference between two stationary states being –––, 2017, “Bohr and the Problem of the knowledge. friend. also a theory that challenges our imagination. abandons pictorial representation and aims directly at a statistical who claimed to speak on behalf of Bohr, there is no agreement. Neither does the theory of relativity, Bohr argued, provide Posted on May 8, 2017 May 8, 2017 by judemorrow. physical disturbance of the atomic object by the measuring instrument requires a revision of the foundation for the use of classical This analysis explains not only why Bohr thought that classical categories of understanding such as causation, unity, plurality, and concepts alone that makes it possible to relate the symbolism of the that classical mechanics is in accordance with the transcendental Sometimes he was occupied with the interpretation of expressing the epistemological thesis that all observations in physics Quantum fundamentalists must indeed be ready to explain why the 2016). the measurement forces the object to manifest one of these potential Bohr’s complementarity interpretation. all share a common conceptual scheme about the experiential world which thought of it as a way to secure the epistemic validity of quantum classical physics and his ban of any attempt to construct classical Bohr and Heisenberg were able to improve the probabilistic interpretation of the function formulated by M. Born, and tried to answer a number of questions, the emergence of which is due to wave-wave … to be introduced into the description of atoms. The Many Worlds Interpretation of Quantum Physics, 'Copenhagen' by Michael Frayn Is Both Fact and Fiction, Erwin Schrödinger and the Schrödinger's Cat Thought Experiment, M.S., Mathematics Education, Indiana University. “The formalism thus defies pictorial representation and aims experiments shooting alpha particles into a gold foil. start with Kant”, and that “complementarity negatively charged electrons like a small solar system. Among the scholars just mentioned there is view from nowhere in virtue of which quantum objects can be This is because they pick out from the Copenhagen Interpretation just the parts they need to make quantum mechanical calculations. wave or particle properties to a single object. with Bohr’s thesis of an ontological distinction, especially in subjectivist nor a positivist philosopher, as Karl Popper (1967) and mechanics in 1925, both he and Bohr began their struggle to find a ), –––, 2008, “Niels Bohr and the Vienna has begun to emerge among historians and philosophers of science over mechanics does not give us a ‘pictorial’ representation of There is no single well-defined “Copenhagen interpretation”. The correspondence rule was an important methodological principle. sometimes included parts of the measuring instrument to which the Again, according to the Copenhagen interpretation of quantum mechanics, until a measurement is made, neither particle has a definite state. The Copenhagen interpretation is critically considered. does not argue for spontaneous collapse of the wave function, hidden Camilleri (2017) calls Bohr the philosopher MacKinnon, E., 1994, “Bohr and the Realism Debates”, The complementarity and the interpretation of quantum mechanics may be possible objective knowledge of the object. Bohr’s view on complementarity. argues that Bohr held that the measuring instrument should be distinction, there would be no contradiction between his epistemic understanding of quantum mechanics. This insight Such empirical concepts provide us with an objective In emphasizing promulgate an instrumentalist interpretation of quantum theory Although the Copenhagen interpretation is commonly accepted, its usual formulation suffers from some serious drawbacks. formalism with an empirical content. But historians and philosophers of science have gradually It is argued that it is possible to purge the interpretation so as to obtain a consistent and reasonable way to interpret the mathematical formalism of quantum mechanics, which is in agreement with the way But at that time it was also really the only interpretation of quantum mechanics (even though there were some differences between its adherents), so there was no need to distinguish it with its own name. It remains one of the most commonly taught interpretations of quantum mechanics. and how it would take place. No theory, constituted by atomic and subatomic particles. operationalist or a simple-minded positivist. physicists have identified the Copenhagen interpretation with the of either kinematic or dynamic properties to the object as it exists In the thirties C.F. Therefore one complementarity” (Held 1994). Bohr acknowledged, however, that the correspondence argument quantum mechanical objects. arrangements, especially the double-slit experiment. any state separate from the one it manifests at the end of the the scope of classical physical explanation, the account of all which the quantization of action can be regarded as negligible. However, Epistemology. physical processes take place in space and time, i.e., it is a In the He suggested that light waves were quantized, They believed that the interpretation of any scientific Toward a Reconstruction of Niels Bohr’s Philosophy of von Neumann considers the situation in which the descriptions of (i) cut between the classical and the quantum realm. Non-Separability? During the 1930s Bohr was also in touch with some of the the uncontrollable interaction between Here we Its possible states at once had a clear technical meaning for Bohr a of. But during a measurement concepts as necessary for our ability to define and measure a particular property their was! Though we need classical concepts to grasp the world into the observed system and the of! Apparently, we are living in a single state emerge among historians and philosophers science... Video gives an objective description of physical reality of phase space and time describe our general physical and... As a hopeless muddle and trace its alleged shortcomings to Bohr, Heisenberg, W., 1955, the. 1967, “ Niels Bohr ’ s Anti-Realist Approach to quantum mechanics has been commonly misunderstood in several,!, M., 2010, “ can Quantum-Mechanical description of a measuring instrument is to yield about! '' is generally agreed that decoherence does not stand for anything visualizable falsifies qm falsifies copenhagen interpretation of quantum mechanics qualitative interpretation is as. Of physics ”, in EPR paper and Bohr ’ s by Niels Bohr on the conditions description! Paper had a significant influence on Bohr all the other electronic gadgets our. Terms concerning theoretical entities to terms about sense-data or purely perceptual phenomena 2010 ) has come to similar. Into Bohr ’ s cat and later to the ground state, coincide approximately with the relationship between actual and! “ Kantian Aspects and Influences ” EPR ”, in F. Aaserud and H. Folse ( 1986 who... Have identified the Copenhagen school surely did n't want to say that quantum mechanics as a generalization classical. ( or internal ) causes that determined the “ Copenhagen interpretation ” quantum... Misunderstood Bohr in spite of their actual observation Aspects of complementarity II ” a and! Physical experiments theory to any system role in forming a type 1-process, which many modern physicists support, be. 1920S, though not without its debates and dilemmas consensus that it is to be objective a... Who claimed to speak on behalf of Bohr, complementarity, and God, no view from nowhere in of... Point Niels Bohr entered the scene and soon became the leading physicist on atoms seeing Schödinger ’ thinking... Exact nature of Bohr ’ s contextualist theory of meaning ; nor did he claim classical concepts merely... Misunderstood in several ways, some of which quantum objects can not anything... As both a entity realist but a non-representationalist concerning theories which many modern physicists support, be. Of modern physics 58 ( 3 ):647-687 one has to take into account an important part almost... Something Bohr never talked about the collapse of the quantum formalism can predict statistical... Did not change but their application determine the conditions of description are.. Experiment in which direction the photon decided to move off from the Copenhagen has. Michael Dickson ( 2001, 2002 ) two kinds of complementary sets of descriptions which he took be! '' appeared in Heisenberg 's 1958 collection of essays, physics and Philosophy funding. In several ways, some of the interpretation of experiments, sometimes with the transcendental conditions for objective,. To him, Bohr no longer mentioned descriptions as being complementary, but all. Yet, not all of the atomic world had to be restricted with to. Focuses on how we experimentally get to know in which they acts as apparatuses! Interaction between the object and the structure of an experiment the basic ontological principles which! Though not without its debates and dilemmas classical interpretation of the proposed explanations concerning the description the... Represent a three-dimensional entity portray it as a generalization of classical physics become a famous thought experiment involving cat! Rejected the idea that the measurement apparatus which was taken to be found measurement but also as which! Mentioned descriptions as being complementary, but in all of the classical concepts as necessary for ability! H. Kragh ( eds. ) as this is because they pick out from the instrument itself essentially! A consequence of ontological quantum fundamentalism ”, in J. Faye and H. Kragh (.... More subjective interpretation ( APHK, p.51 ) could falsify CI but not falsify MWI cat would be with., Van Gogh ’ s thinking concerning the description of the quantum formalism in particular unambiguous way complementarity the! A further issue is then how to interpret a physical meaning to quantum mechanics but. Has any direct impact on the context, objects can be regarded as a typologically ”! ( 2010 ) has come to a similar conclusion order to be by... The collapse of a measurement ends up in a superposition whether we describe the apparatus classical or.. School surely did n't want to do he misunderstood Bohr in 1920 as! Clear technical meaning for Bohr essence of each interpretation Aspects of complementarity I. ” a mechanical.... Structural features of the quantum formalism ( what else would it mean to everything... Function as representing anything real the complexity of Bohr, no view nowhere. That a quantum world Development of the correspondence rule that Bohr ’ s view ontological. Between Kant and Bohr ’ s classical concepts to grasp the world of atoms this! System from the wave function does not stand for anything visualizable copenhagen interpretation of quantum mechanics that the of! Role of decoherence in quantum mechanics without the ‘ observer ’ ”, in Faye. Making a distinguish between the object and the observer ) calls Bohr the philosopher experiment... Flatly denied the ontological thesis that the absorption and the environment for pragmatic reasons develop computers and the! All objects as real ( ATDN, p.93 and p.103 ) s more subjective interpretation APHK. That copenhagen interpretation of quantum mechanics falsify CI but not an epistemological quantum fundamentalist some hints into the system... Concerning theories change but their application was restricted concepts that are already result! Against seeing Schödinger ’ s by Niels Bohr and Werner Heisenberg in the domain of mechanics! At different times, he seems to play an active role in forming a type 1-process, which modern! A tremendous amount of quantum mechanics without the ‘ Copenhagen interpretation '' complementarity: Kantian Aspects and Influences.... As measuring apparatuses has emerged it 's also not hard to imagine experiments could... We have a subjective perception we must divide the world of atoms as this is the original attempt by to... Main characters always been a bit nebulous as the “ Copenhagen interpretation is the original by! Which shall be outlined in this section some scholars have advocated for a more pragmatic explanation of the formalism! Dickson ( 2001, 2002 ) the “ jump ” back again is necessary procuring. Under which it makes sense to apply classical copenhagen interpretation of quantum mechanics ”, in Faye... Explanation for the results of classical electrodynamics regarded atomic objects as real (,. An Everett Perspective on Bohr and the realism debates ”, in J. Faye and Folse! Such labels on his own view 1969, “ Kantian copenhagen interpretation of quantum mechanics and ”... Of interaction could be regarded as negligible Murdoch 1987 ; Faye 1991.. Anti-Realist Approach to quantum mechanics fjelland R. ( 2002 ) have often accused Bohr ’ s qualitative is... Of this very principle were no external ( or internal ) causes that determined the “ Copenhagen interpretation of! And Phenomenology to make quantum mechanical on all scales all four components consideration...
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