Linguistic copenhagen interpretation of quantum mechanics. Niels bohr, who articulated the copenhagen interpretation of quantum mechanics and mentored a generation of quantum physicists. By exploring two observationally equivalent yet conceptually incompatible views of quantum mechanics, james t. The copenhagen view of understanding the physical world stresses the importance of basing theory on what can be observed and measured experimentally. The matrix mechanics was an algebraic approach employing the technique of manipulating matrices.
Selfinterference embodies the essence of the particlewave formulation of quantum mechanics qm. The copenhagen interpretation was the first general attempt to. Niels bohrs copenhagen interpretation of quantum physics is perhaps the most comforting theory put forth. Perhaps it would be better to say everettian quantum mechanics. Part a looks with the various interpretations of quantum mechanics. Copenhagen interpretation of quantum theory and the. This information content remains constant at all times and is permutated oneto. The copenhagen and bohmian interpretations are rival theories, with the bohmian interpretation being more. He knew that a new mechanics was called for, and he was the one to name it, in 1924, even before its discovery. Abstract in the information interpretation of quantum mechanics, information is the most fundamental, basic entity. The current view is that entanglement is simply coherence, and measurement is decoherence. The copenhagen version of quantum mechanics is formulated in a vague prosaic way, inconsistencies and. In bohrs words, the wave and particle pictures, or the visual and causal representations, are complementary to each other.
Borns third confrontation with the limitations of the old quantum theory occurred another 5 years later, in 1923. Early on, these accounts had been perceived to be substantially different in terms of the mathematical techniques they employed. Why does one theory succeed while another, possibly clearer interpretation, fails. Copenhagen interpretation of quantum mechanics is incorrect. These graphics are meant to capture the essence of each interpretation. Quantum mechanics doesnt allow any truly supernatural phenomena to occur. The copenhagen interpretation of quantum mechanics a nd the question of causality a philosopher once said it is necessary for the very existence of science that the same co nditions always produce. Jan 28, 2020 the copenhagen interpretation considers two realms. The nature of einsteins objections to the copenhagen interpretation of quantum mechanics michel paty summary.
This information content remains constant at all times and is permutated onetoone throughout the system evolution. Although successful applications of quantum mechanics and explanation of quantum phenomena do not necessarily rely on the copenhagen interpretation, the question asked by einstein 70 years ago, i. The copenhagen interpretation considers two realms. Emerson bertrand russell said in 1930 that the desire to foist order upon chaos was born of fear. Quantum mechanics answers the call for an account of the bizarre results of this experiment. It is a project of the spring 2001 offering of oberlin colleges physics 412, applied quantum mechanics. The physical interpretation of the wavefunction arises because we declare that.
Pdf the copenhagen interpretation of quantum mechanics. Interpretations of quantum mechanics philsciarchive. Any experiment in physics, whether it refers to the phenomena of daily life or to atomic. The copenhagen interpretation is an expression of the meaning of quantum mechanics that was largely devised from 1925 to 1927 by niels bohr and werner heisenberg. Part c presents the london ticker tape interpretation of quantum mechanics it is the result of the authors investigation in part a and part b.
Heisenberg said later that it was the peculiar spirit of gottingen, borns faith that nothing short of a new selfconsist. Together with bohr, heisenberg forged what is commonly known as the copenhagen interpretation. The copenhagen interpretation was first posed by physicist. In what follows, i examine three main points which may help us to understand the. This would seem to be an example of the wave function collapse. The interpretation of quantum mechanics has been controversial since the introduction of quantum theory in the 1920s. Hidden variables present articleis known as the copenhagen interpretation because its main protagonist, niels bohr, worked in that city.
Is the copenhagen interpretation still the standard. Why were two theories matrix mechanics and wave mechanics. The founding father was mainly the danish physicist niels bohr, but also werner heisenberg, max born and other physicists made important contributions to the overall understanding of the atomic world that is. The two major interpretations of quantum mechanics are called the copenhagen and many worlds interpretations. Quantum mechanics quantum mechanics the interpretation of quantum mechanics. It is one of the oldest of numerous proposed interpretations of quantum mechanics, and remains one of the most commonly taught according to the copenhagen interpretation, physical systems generally do not have definite. However, it is possible to give an overview of the more popular interpretations while also grouping them into categories of like ch. Part b deals with the measurement process, which turns out to be a surprisingly rich topic. And it is a term that singles out a class of conceptually similar interpretations, which includes proposals that are not generally referred to as modal ones. What are current interpretations of quantum mechanics, and. Indeed, much of the secon dary literature tended to dismiss him as a positivist, or portray him in his later. The copenhagen interpretation of quantum theory the copenhagen interpretation of quantum theory starts from a paradox. Copenhagen interpretation of quantum mechanics stanford.
An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics corresponds to reality. The interpretation was largely devised in the years 19251927 by niels bohr and werner heisenberg. Interpretations of quantum mechanics semantic scholar. Although quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments not one prediction from quantum mechanics is found to be contradicted by experiments, there exist a number of contending.
The interpretation of quantum mechanics roland omnes. The popular views are defended in hundreds or journal articles and published books. When its measured, it instantaneously collapses in a single state. Historically, heisenberg wanted to base quantum theory solely on ob servable quantities such as the intensity. It is based on an idea called borns law of the wave function by the nobel prize laureate max born. The copenhagen interpretation is an interpretation of quantum mechanics in physics. Lazarou university of athens, greece physics department nuclear and elementary particle physics section may 2009 abstract quantum mechanics, almost 80 years after its arrival, is a well established and experimentally not falsified theory. A natural psicollapse to reality is developed in an equation with terms. For the better part of the last century, the most accepted explanation for why the same quantum particle may behave in different ways was the copenhagen interpretation. If i got it right, its heavily relaying on the two following principles among others. The nowadays most widely accepted interpretation of quantum mechanics is that of the copenhagen school, the copenhagen interpretation ci.
Cushing shows how historical contingency can be crucial to determining a theorys construction and its position among competing views. The copenhagen interpretation is a looselyknit informal collection of axioms or doctrines that attempt to express in everyday language the mathematical formalism of quantum mechanics. There are so many interpretations of quantum mechanics that it is difficult to summarize all of them succinctly. This article surveys nine different formulations of quantum mechanics. Based mainly on bohrs concepts, the formulation assumes an independent and essential validity of classical. The information interpretation of quantum mechanics. Almost no one asks whether what is known as the copenhagen interpretation was, in fact, bohrs view. Friends of the copenhagen interpretation, fewer in number than critics, credit bohr with deep insight into the novel way in which the quantum theory approaches the description of nature. Heisenberg and the interpretation of quantum mechanics. The copenhagen view of understanding the physical world stresses the importance of basing theory on. Why is the copenhagen interpretation of quantum physics the. Copenhagen interpretation simple english wikipedia, the. Although the copenhagen interpretation is commonly accepted, its usual formulation suffers from some serious drawbacks. Manyworlds is a reformulation of quantum theory which treats the process of observation or measurement entirely within the wavemechanics of quantum theory, rather than an input as additional assumption, as in the copenhagen interpretation.
Max borns statistical interpretation of quantum mechanics a. Max borns statistical interpretation of quantum mechanics. On the copenhagen interpretation of quantum mechanics. By explaining that particles exist in all states at once in coherent superposition our understanding of the universe is put slightly askew, but still remains somewhat comprehensible. My aim here is to explain as clearly as i can why quantum mechanics needs interpreting at. Orthodoxies on the interpretation of quantum theory. Why should one care about different formulations of mechanics when, in the end, each provides identical predictions. It says that a quantum particle doesnt exist in one state or another, but in all of its possible states at once. It was developed by werner heisenberg, niels bohr, and albert einstein in copenhagen in 1927. Responsible for the selfinterference is the wave nature of matter that is at the basis of the particlewave description of quantum mechanics within the copenhagen interpretation. Although its getting a run for its money from the manyworlds interpretation lately, many quantum physicists still assume the copenhagen interpretation is correct. Parsimony, sometime referred to as simplicity, is an effective criterion of theory choice in the case of quantum mechanics. Here i use orthodox to mean unitary evolution of the wave function only. It is a proper name that refers to a number of particular interpretations of quantum mechanics.
An epistemological interpretation of quantum mechanics hinges on the claim that the distinctive features of quantum mechanics can be derived from some distinctive features of an observational basis. In the information interpretation of quantum mechanics, information is the most fundamental, basic entity. What the subjective nature of wave function means that wave function is really a gadget that collects all the information about the system that may be known to an observer. The standard orthodox interpretation of quantum mechanics includes a projection postulate. The problem about quantum mechanics does not lie on its effectivity, but on its interpretation. Pdf on jan 1, 2002, tarja kalliotamminen and others published the copenhagen interpretation of quantum mechanics and the question of causality find. Its only when we observe its state that a quantum particle is essentially forced to choose one probability, and thats the state that we observe. Werner heisenberg was a pivotal figure in the development of quantum mechanics in the 1920s, and also one of its most insightful interpreters. This turn from physics to language does not only realize the remarkable extension of quantum mechanics but also yield the linguistic turn of descarteskant epistemology. Copenhagen interpretation of quantum theory the information. The copenhagen interpretation was first posed by physicist niels bohr in 1920.
Heisenberg forged what is commonly known as the copenhagen interpretation. The best read on this ever is quantum computing since democritus. Interpretation of quantum theory an overview version 2. However, the same experiment can also be explained within the bohmian and the geometric formulations of quantum mechanics. Although quantum mechanics has been applied to problems in physics with great success, some of its ideas seem strange. According to the copenhagen interpretation of qm, selfinterference by a doubleslit requires a large transverse coherence of the incident wavepacket such that it covers the separation between the slits.
Youngs aforementioned experiment in which a parallel beam of monochromatic light is passed through a pair of narrow parallel slits figure 5a. Yet heisenbergs philosophical viewpoint did not remain fixed over time, and his interpretation of. That is, they are mutually exclusive, yet jointly essential for a complete description of. The copenhagen and many worlds interpretations of quantum. It is one of the first usable models of quantum mechanics. The copenhagen interpretation is an expression of the meaning of quantum mechanics that was largely devised from 1925 to 1927 by niels bohr and werner.
As with our analysis of positions on the free will problem, there are many interpretations, some very popular with many adherents, some with only a few supporters. Quantum physics ii, lecture notes 1 mit opencourseware. Pragmatism, bohr, and the copenhagen interpretation of. A physical system is described completely by a state function if. Copenhagen interpretation of quantum theory and the measurement problem martin kober. At the quantum mechanics workshop to which these proceedings are dedicated, held in august 1997 at umbc, the participants were polled as to their preferred interpretation of quantum mechanics. The measurement process plays a vital role in quantum mechanics, and in ci this requires an outside. This may be in direct conflict with usage where orthodox quantum mechanics means the copenhagen interpretation.
Every quantized system is associated with a definite discrete amount of information. Wikipedia has a most comprehensive page on the interpretations of quantum mechanics. The nature of einsteins objections to the copenhagen. Modal interpretation of quantum mechanics the term modal interpretation is ambiguous. The copenhagen interpretation and the fall of physics in the 20th century by miles mathis we come to our own, and make friends with matter, which the ambitious chatter of the schools would persuade us to despise. Any experiment in physics, whether it refers to the phenomena of daily life or to atomic events, is to be described in the terms of classical physics. The interpretation of quantum mechanics britannica. The aim of any metaphysical interpretation of quantum mechanics is to account for. On the interpretation of quantum theoryfrom copenhagen to the. It is one of the oldest of numerous proposed interpretations of quantum mechanics, and remains one of the most commonly taught. The copenhagen interpretation of quantum mechanics was originally devised by niels bohr and werner heisenberg.
By einsteins statistical interpretation of quantum mechanics, however, an electron has a discrete position and momentum at all times during its flight, such that the wave function and the airy disk is only meaningful as a statistical description of the behavior of a large number of particles not of an individual particle. The copenhagen interpretation of quantum theory starts from a paradox. Since the late 1920s, the theory formulated by niels bohr and. The copenhagen interpretation was the first general attempt to understand the world of atoms as this is represented by quantum mechanics. A general methodology and specific formalism are used to restrict the copenhagen interpretation of quantum mechanics.
864 500 55 152 646 1057 1059 942 246 482 857 623 486 941 122 741 1424 1256 432 1521 957 297 187 709 1401 299 1013 932 1364 507 1079 1383 553 564 1007 743 998 91 794