quantum theory von bohr niels (39 Ergebnisse)

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Originalbroschur. 24cm. Zustand: Wie neu. 118 pages. In EXCELLENT shape. Sprache: Englisch Gewicht in Gramm: 300.

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Taschenbuch. Zustand: Neu. Neuware - This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.

hardcover. Zustand: Sehr gut. Gebraucht - Sehr gut Sg - leichte Beschädigungen oder Verschmutzungen, ungelesenes Mängelexemplar, gestempelt - Quantum Theory contains the seminal works of quantum theory from the early years of the 20th Century, representing breakthroughs in science that radically altered the landscape of modern knowledge: Quantum Theory of Line-Spectra by Niels Bohr and The Origin and Development of the Quantum Theory by Max Planck.

Buch. Zustand: Neu. Neuware - This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.

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(22 x 14,5 cm). VIII, 824 S. Mit Abbildungen und 18 teils gefalteten Tafeln. Halbleinwandband der Zeit. Erste Ausgabe. - Bohr beschreibt hier die Kathodenstrahlexperimente von Franck und Hertz mit Hilfe seiner Theorie, besonders den Übergang vom Normalzustand des Atoms in einen anderen stationären Zustand. "Die berühmten Stoßexperimente von Franck und Hertz wurden von Bohr sofort als Bestätigung der Existenz diskreter Energieniveaus aufgefaßt" (Röseberg, Bohr). - Stempel auf Titel. Einband gering berieben, sonst sauber und gut erhalten. - DSB 2, 239; Röseberg, Bohr Nr. 16 und 17. - Der Band enthält weiter Arbeiten von J. J. Thomson, Rayleigh, Bragg, Rutherford, Soddy etc.

Braunschweig und Berlin, Vieweg & Sohn, Julius Springer, 1921. 8vo. Bound in contemporary half cloth. Crossed out stamp on title-page. In "Zeitschrift für Physik. Hrasg. von Karl Scheel", vol. 6. Entire volume offered. [Bohr's paper:] pp. 1-9. [Entire volume: IV, 416 pp]. First edition of this seminal contribution to the correspondence principle. ".in the hands of Bohr and his school the correspondence principle was like "a magic wand that allowed the results of the classical wave theory to be of use for the quantum theory.but a costly price had to be paid. For taking resort to classical physics in order to establish quantum-theoretic predictions, or in other words, constructing a theory whose corroboration depends on premises which conflict with the substance of the theory, is of course a serious inconsistency from the logical point of view. Being fully aware of this difficulty, Bohr attempted repeatedly to show "the correspondence principle must be regarded purely as a law of quantum theory, which can in no way diminish the contrast between the postulates and electrodynamic theory." The earliest allusion to such a conception may perhaps be found as early as 1921 in a paper (the paper offered) in which Bohr briefly discussed the function of the principle."(Jammer).The volume contains paper by famous phycisists such as E. Brody, H. Pauli, M. Born, W. Pauli Jr. and many others.

Braunschweig und Berlin, Vieweg & Sohn, Julius Springer, 1921. 8vo. Bound in Contemporary half cloth. Stamp on title-page. In "Zeitschrift für Physik. Hrasg. von Karl Scheel", vol. 6. [Bohr's paper:] pp. 1-9. [Entire volume: IV, 416 pp]. First edition of this seminal contribution to the correspondence principle. ".in the hands of Bohr and his school the correspondence principle was like "a magic wand that allowed the results of the classical wave theory to be of use for the quantum theory.but a costly price had to be paid. For taking resort to classical physics in order to establish quantum-theoretic predictions, or in other words, constructing a theory whose corroboration depends on premises which conflict with the substance of the theory, is of course a serious inconsistency from the logical point of view. Being fully aware of this difficulty, Bohr attempted repeatedly to show "the correspondence principle must be regarded purely as a law of quantum theory, which can in no way diminish the contrast between the postulates and electrodynamic theory." The earliest allusion to such a conception may perhaps be found as early as 1921 in a paper (the paper offered) in which Bohr briefly discussed the function of the principle."(Max Jammer).The volume contains paper by famous phycisists such as E. Brody, H. Pauli, M. Born, W. Pauli Jr. and many others.

Berlin, Springer, 1923. 8vo. In contemporary half cloth with gilt lettering. In "Zeitschrift für Physik" Bd. 13 & 14, 1923. Entire volumes offered, bound in one. Stamp to front free end paper, otherwise a fine and clean copy. Pp. 237-255. [Entire volume: V, (1) 426 pp.]. First edition. As Bohr in his 1918 paper (The quantum theory of line spectra) had discussed the expectation that there was a necessary connection between the classical and the future theory in the limit of large quantum numbers, and in a later paper (1920) named it "Korrespondenzprincip" (Principle of Correspondance), Bohr now in the paper offered discussed again the fundamental principles of Quantum Theory in connection with the Principle of Correspondence.Rosenfeld No 29.Also in the volume is Born & Heisenberg's paper, "Über Phasenbeziehungen bei den Bohrschen Modellen von Atomen und Molekeln", on Bohr's atomic model, being a part of Heisenberg's Habilitation, which he completed under Born in 1924 in Göttingen.Cassidy 1923a.

Braunschweig, Berlin, Vieweg & Sohn u. Julius Springer, 1924. 8vo. Bound in contemporary halfcloth. In "Zeitschrift für Physik", Bd. 24. (Entire volume offered). A stamp on titlepage otherwise fine and clean. Pp.69-87. [Entire volume: IV,412 pp]. First apperance (simultaneously printed in Philosophical Magazine) of a fundamental paper in the development of the Quantum Theory, as it here was set forth three fundamental ideas: 1. Slater's idea of 'a Virtual radiation field', 2. statistical conservation of energy and momentum, and 3. statistical independence of the processes of emission and absorption in distant atoms. (See Van der Waerden "Sources of Quantum Mechanics" No. 5)."In an effort to reconcile the particulate and wavelike properties of radiation, Bohr, Kramers, and Slater in 1924 formulated a new quantum theory of radiation. According to their hypothesis, momentum and energy-are conserved only statistically in interactions between radiation and matter." (DSB).The present paper became a great influence to Bothe and his Compton collisions and the Coincidence method which eventually resulted in him being awarded the Nobel Prize in Physics.

Braunschweig, Berlin, Vieweg & Sohn u. Julius Springer, 1924. 8vo. Contemp. hcloth. In: Zeitschrift für Physik", Bd. 24. IV,412 pp. (Entire volume offered). The paper: pp. 69-87. A stamp on titlepage. Clean and fine. First apperance (simultaneously printed in Philosophical Magazine) of a fundamental paper in the development of the Quantum Theory, as it here was set forth three fundamental ideas: 1. Slater's idea of 'a Virtual radiation field', 2. statistical conservation of energy and momentum, and 3. statistical independence of the processes of emission and absorption in distant atoms. (See Van der Waerden "Sources of Quantum Mechanics" No. 5).

Braunschweig, Berlin, Vieweg & Sohn u. Julius Springer, 1924. 8vo. Bound in contemporary halfcloth. In "Zeitschrift für Physik", Bd. 23 & 24. (Entire volume offered). No stamps, not an ex library copy. Fine and clean. Pp.69-87. [Entire volume: IV,412 pp]. First apperance (simultaneously printed in Philosophical Magazine) of a fundamental paper in the development of the Quantum Theory. Three fundamental ideas were set forth here: 1. Slater's idea of 'a Virtual radiation field', 2. statistical conservation of energy and momentum, and 3. statistical independence of the processes of emission and absorption in distant atoms. (See Van der Waerden "Sources of Quantum Mechanics" No. 5)."In an effort to reconcile the particulate and wavelike properties of radiation, Bohr, Kramers, and Slater in 1924 formulated a new quantum theory of radiation. According to their hypothesis, momentum and energy-are conserved only statistically in interactions between radiation and matter.".The present paper became a great influence to Bothe and his Compton collisions and the Coincidence method which eventually resulted in him being awarded the Nobel Prize in Physics.

København, Bianco Lunos Bogtrykkeri, 1918 - 1922. 4to. Uncut unopened in the original printed wrappers. In "D. Kgl. Danske Vidensk. Selsk. Skrifter, afd., 8, række IV, 1-3" / "Mémoires de l'Académie Royale des Sciences et des Lettres de Danemark". Wrapper with a few minor nicks and tears but otherwise a very fine and clean copy. 118 pp. Collected offprint-edition of Bohr's seminal work "On the Quantum Theory of the Line-Spectra", marking the beginning of the quantum revolution in physics, introduced the concept of quantized energy levels, provided an explanation for the observed line spectra, and served as a foundational model that inspired further developments in quantum mechanics. It is conseidered one of Bohr's most important papers and the basis for his Nobel Prize. These papers give the first clear formulation of his 'correspondence principle' establishing the limit agreement of quantum and classical physics. "By 1918 Bohr had visualized, at least in outline, the whole theory of atomic phenomena. . He of course realized that he was still very far from a logically consistent framework wide enough to incorporate both the quantum postulates and those aspects of classical mechanics and electrodynamics that seemed to retain some validity. Nevertheless, he at once started writing up a synthetic exposition of his arguments and of all the evidence upon which they could have any bearing" in testing how well he could summarize what was known, he found occasion to check the soundness of his ideas and to improve their formulation. In the present case, however, he could hardly keep pace with the growth of the subject the paper he had in mind at the beginning developed into a four-part treatise, 'On the Theory of Line Spectra', publication of which dragged over four years without being completed" the first three parts appeared between 1918 and 1922, and the fourth, unfortunately, was never published. Thus, the full impact of Bohr's view remained confined to the small but brilliant circle of his disciples, who indeed managed better than their master to make them more widely known by the prompter publication of their own results" (D.S.B. 2: 246-47).

Bohr, Niels (1885-1962); H. A. Kramers (1894-1954); and John C. Slater (1900-1976). The quantum theory of radiation. In The London, Edinburgh, and Dublin Philosophical Magazine, 6th series, 47 (1924): 785-802. Whole number. 785-1056pp. 2 plates. 223 x 146 mm. Original printed wrappers, spine a bit chipped. Very good. First Edition in English, journal issue of the famous Bohr-Kramers-Slater (BKS) paper, in which Bohr and his co-authors attempted to do away with Einstein's light quanta by proposing a new quantum theory of radiation. The existence of light quanta had been proved experimentally by Arthur H. Compton's discovery of the Compton effect, the change in wavelength of x-rays scattered from a target at various angles. "Compton recognized that the shift in the wavelength of x-rays, if scattered by atoms, could be derived only by assuming the existence of radiation in the form of light-quanta, which collide with the electrons in atoms in elementary processes" (Mehra & Rechenberg, The Historical Development of Quantum Theory, 1, p. 554). However, Bohr disputed Compton's interpretation, and in 1924 published his paper with Kramers and Slater arguing that Compton's observations could be explained by assuming that in interactions between atoms and radiation, energy is only statistically conserved. "The most striking feature of this remarkable paper . . . was the renunciation of the classical form of causality in favor of a purely statistical description. Even the distribution of energy and momentum between the radiation field and the 'virtual oscillators' constituting the atomic systems was assumed to be statistical, the conservation laws being fulfilled only on the average" (Dictionary of Scientific Biography). The Bohr-Kramers-Slater radiation theory was disproved shortly after its publication by the experiments of Bothe and Geiger and of Compton and Simon, which established that the principles of energy conservation and of causality held true even at the most elementary level. "Nevertheless, this short-lived attempt exerted a profound influence on the course of events; what remained after its failure was the conviction that the classical mode of description of the atomic processes had to be entirely relinquished" (Dictionary of Scientific Biography). The BKS paper was first published in German in the Zeitschrift für Physik 24 (1924). .

In: The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. Series 6 Vol. 30 = July-December 1915, No. 177, pp. 394-415; No. 178, pp. 581-612. Bound in half leather with gilt-stamped title on spine. Edges rubbed and spine slightly torn. Library stamps from Wilhelm von Siemens on title page and endpaper. Edges, endpaper, title page and some plate margins are brown-spotted. Poggendorff V, 139. - The complete Volume includes 18 plates, VII, 824 pp.- In this Volume are also included the following First Editions of: THOMSON, J.J., Conduction of Electricity through Metals. No. 175, pp. 192-202. Poggendorff V, 1254; THOMSON, J.J., The Mobility of Negative Ions at Low Pressures. No. 177, pp. 321-328; THOMSON, J.J., A Method of Finding the Coefficients of Absorption of the Different Constituents of a Beam of Heterogeneous Röntgen Rays, or the Periods and Coefficients of Damping of a Vibrating Dynamical System. No. 180, pp. 780-783. RUTHERFORD, E., J. BARNES and H. RICHARDSON, Maximum Frequency of the X Rays from a Coolidge Tube for Different Voltages. No. 177, pp. 339-360; RUTHERFORRD, E. and J. BARNES, Efficiency of Production of X Rays from a Coolidge Tube. No. 177, pp. 361-367. Poggendorff V, 1083. RICHARDSON, O.W., Metallic Conduction. No. 176, pp. 295-299. Poggendorff V, 1046. Sprache: Englisch.

Zustand: Very Good. First Edition. First edition of Niels Bohr's paper, "The Quantum Postulate and Atomic Theory," as published in Nature, vol. 121, no. 3050, pp. 561-608, April 14, 1928, the entire issue offered here, with Bohr's paper on pp. 580-590. Some soiling to covers, light creasing, ink stamp on front cover, a very good copy. Pages 581-588 are loose from binding. Rare in the original wrappers.

London, Macmillan and Co., 1928. Royal8vo. In recent full blue cloth with gilt lettering to spine. Extracted from "Nature", January - June, 1928, Vol. 121. Entire April 14-issue offered. Fine and clean. [Bohr:] Pp. 580-90. [Entire issue:] Pp. 561-608. First edition of Bohr's exceedingly influential statement of his 'complementarity' principle, the basis of what became known as the 'Copenhagen interpretation' of quantum mechanics. In the paper he coined the term 'complementarity' and thereby created an entire new fundamental principle of quantum mechanics."Immediately after Heisenberg's work on uncertainty relations, Bohr presented his concept of complementarity at a conference a Lake Como in Italy. Bohr's lecture marked the first attempt to provide a genuine philosophical underpinning to the new advances in physics. The uncertainty relations had provided Bohr a concrete measure of the consequences of the wave-particle duality and thereby a physics-based justification for the ideas he was working on. Bohr had already embraced the wave-particle duality underlying quantum theory and he presented the concept of complementarity as the fundamental feature of a new conceptual framework broad enough to include it" (Paul McEvoy, Niels Bohr). "For Bohr, complementarity was an almost religious belief that the paradoxes of the quantum world must be accepted as fundamental, not to be 'solved' or trivialized by attempts to find out 'what's really going on down there.' Bohr used the word in an unusual way: the 'complementarity' of waves and particles, for example (or of position and momentum), meant that when one existed fully, its complement did not exist at all" (Louisa Gilder, The Age of Entanglement). "The lecture was published in Nature in 1928 in a revised form It sparked significant debate in the years that followed and solidified the boundaries between those who accepted Bohr's view of the consequences of quantum theory and those who were seeking a more 'realistic' microscopic theory or a more realistic interpretation of quantum theory itself" (McEvoy, P. 70).The paper was published almost simultaneously in English, Danish, English, French and German, the present English publication being the first.

London, Taylor & Francis, 1915. Contemp. hcalf. Spine gilt, title- and tomelabels with gilt lettering. Spine a bit rubbed, some cracking to hinges, but covers not detached. In: "The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science", Vol. XXX, Sixth Series. VIII,824 pp., textillustr. and 18 plates. (Entire volume offered). Bohr's papers: pp. 394-413 and pp. 581-612. A stamp to verso of titlepage. Internally clean and fine. First appearance of a landmark paper in which Bohr found experimental support for his energy equation for electron orbits and of stationary states in the work of Franck and Hertz from 1914. Furthermore, Franck and Hertz unwittingly provided an independent confirmation of the concept of stationary state. In 1914 they observed an energy threshold in the electron-stopping power of mercury vapor. This threshold, Bohr explained the following year, corresponded to a transition between the normal state and another (first excited) stationary state of the mercury atom (and not, as Franck and Hertz had originally thought, to the ionization of the atom). The supramechanical stability implied by the assumption of stationary states was now empirically proved to comprehend stability with regard to electron impacts."Bohr had to frequently revise and refine his atomic model in light of new discoveries. One significant paper "On the Quantum Theory of Radiation and the Structure of the Atom," (the paper offered) added more specific details about atomic states. For example Bohr had earlier made the argument that electrons could jump from one orbit to another as energy was emitted or absorbed. In this paper, he theorezed that an atom possesses stationary states in which energy was neither emitted nor absorbed. Any emission or absorption that did occur, such as might induce an electron ump, would correspond to the transition between two stationary states."(sparknotes.com).An: the second paper offered. When Bohr had finished his importent paper on the hydrogen atom "On the Theory of Decrease of Velocity of Moving Electrified Particles on passing through Matter" 1913, he completed another paper on that subject (the paper offered), which includes the influence of effects due to relativity and to straggling (that is, the fluctuations in energy and in range of individual particles).(Pais p. 128).Rosenfeld no 13 a. 14.The volume contains further importent papers by J.J. THOMSON, W.H. BRAGG, RUTHERFORD & BARNES, SODDY & HITCHINS etc.

Copenhagen, Bianco Lunos, 1918. 4to. Both parts uncut and in the original printed wrappers. Wrappers detached and with small nicks and tears to extremities. Internally fine and clean. Part I unopened. 36 pp. + pp. (37) - 100. First editions, author's off-prints (with "Separate Copy" printed to front wrappers), presentation-copies, of the first two parts of Bohr's seminal work "On the Quantum Theory of the Line-Spectra" (which appeared in three parts and which was never finished, the third part of which, published 4 years later, is almost never found in presentation-sets), in which Bohr gave his first clear presentation of his groundbreaking "correspondence principle": "Which would play a pivotal role in the later development of atomic theory and its transformation into quantum mechanics." (Kragh, Quantum Generations, p. 56). It eventually became a cornerstone in the quantum mechanics formulated by Heisenberg and Schrödinger. "There was rarely in the history of physics a comprehensive theory which owed so much to one principle as quantum mechanics owed to Bohr's correspondence principle" (Jammer 1966, p. 118). The evolution of quantum theory is divided into two distinct periods" from 1900 to 1925, usually referred to as the period with the old quantum theory still grounded in classical physics and the second period with quantum mechanics from 1925 onwards. The general rules of quantum mechanics are very successful in describing objects on an atomic level. But macroscopic systems are accurately described by classical theories like classical mechanics and classical electrodynamics. If quantum mechanics were to be applicable to macroscopic objects, there must be some limit in which quantum mechanics reduces to classical mechanics. Bohr's correspondence principle demands that classical physics and quantum physics give the same answer when the systems become large. "A major tool he developed for dealing with quantum problem, [.], was the correspondence principle, which establishes links between predictions of the classical theory and expectations for the quantum theory." (Pais, Niels Bohr's Times, p. 20.). In this sense, the correspondence principle is not only an exceedingly important methodological principle, it also represents the transition to quantum mechanics and modern physics in general and it became the cornerstone of Bohr's philosophical interpretation of quantum mechanics which later would be closely tied to his thesis of complementarity and to the Copenhagen interpretation. Another version of the correspondence principle lives on in philosophical literature where it has taken form as a more general concept representing a development of new scientific theories."By 1918 Bohr had visualized, at least in outline, the whole theory of atomic phenomena. . He of course realized that he was still very far from a logically consistent framework wide enough to incorporate both the quantum postulates and those aspects of classical mechanics and electrodynamics that seemed to retain some validity. Nevertheless, he at once started writing up a synthetic exposition of his arguments and of all the evidence upon which they could have any bearing" in testing how well he could summarize what was known, he found occasion to check the soundness of his ideas and to improve their formulation. In the present case, however, he could hardly keep pace with the growth of the subject the paper he had in mind at the beginning developed into a four-part treatise, 'On the Theory of Line Spectra', publication of which dragged over four years without being completed" the first three parts appeared between 1918 and 1922 [of which the two first from 1918 are offered here], and the fourth, unfortunately, was never published. Thus, the full impact of Bohr's view remained confined to the small but brilliant circle of his disciples, who indeed managed better than their master to make them more widely known by the prompter publication of their own results" (D.S.B. II: 246-47).Inscribed to "Hr. Docent D. la Cour/ Venskabeligst/ fra/ Forfatteren" on both front wrappers. The renowned Danish physicist and meteorologist Dan la Cour (1876-1942), was the son of the great Poul la Cour (1846-1908), who is considered the "Danish Edison". Dan la Cour was the assistant of Niels Bohr's father, Christian Bohr, and a well known scientist. From 1903, he was head of the department of the Meteorological Institute, and from 1923 leader thereof. From 1908 he was Associate Professor at the Polytechnic College. His original scientific works are highly respected, as are his original apparati for measuring earth magnetism which are considered highly valuable. "His original intelligence, which in many ways resemble that of his father, also bore fruit in his patenting of various inventions: the "Pyknoprobe", developed to quickly determine the different layers of the sea" a use of termite in quickly heating food and drinks out in the open under unfavourable weather conditions." (From the Danish Encyclopaedia - own translation). He wrote a number of important and esteemed works and was member of the Danish Scientific Academy as well as many prominent international scientific commissions of meteorology and geophysics (i.e. president of the International Geodetical and Geophysical Union). He was also honorary Doctor at the George Washington University. Rosenfeld, Bohr-Bibliography, 15.

[London, Taylor & Francis], 1913. 8vo. Original printed wrappers. Excellent, very fresh copy, with only a two small marginal tears to front wrapper, no loss. Spine and cords completely fresh and fully intact. Pp. (1) +506-525. Scarce first edition, off-print issue with presentation-inscription, of Bohr's first paper on the Stark-effect, being the seminal paper in which Bohr for the first time applies his theory to electric effect and expresses his widening interest in quantum theory. The work is inscribed to the famous Danish physicist "Hr. Mag. scient. A.W. Marke/ med venlig Hilsen/ fra Forfatteren" ("Mr. Master of Sciences A.W. Marke/ with kind regards/ from the author"). Axel Waldbuhm Marke (1883 - 1942) was professor of Physics in Copenhagen. His scientific works were originally centred around magnetic investigations, for which he was trained by P. Weiss in Zürich, in 1914. Due to WWI, he had to return, however, and during the difficult journey back, he lost all of his records. In 1916 he published an important work on the thermomagnetic qualities of water, and he has written a number of highly praised text books on physics, optics, meteorology, and climatology. He was renowned for his great skills in popularizing difficult scientific results and was famous for his lectures. The Stark-effect (the shifting and splitting of spectral lines of atoms and molecules due to presence of an external static electric field) is named after Johannes Stark, who discovered it in 1913. Although Stark shortly after having discovered it became and ally of Nazi Germany and rejected the developments of modern physics, his discovery became of the utmost importance to the development of quantum theory."Once again we must go back to November 1913. On the 20th of that month Stark announced to the Prussian Academy of Sciences an important new discovery: when atomic hydrogen is exposed to a static electric field its spectral lines split, the amount of splitting being proportional to the field strength. (the linear Stak effect). After Rutherford read this news in "Nature", he at once wrote Bohr: "I think it is rather up to you at the present to write something on. electric effects."We now encounter for the first time the widening interest in quantum theory [.] Even before Bohr sat down to work on the Stark effect, Warburg from Berlin published an article in which the Bohr theory is applied to this new phenomenon. Bohr's own paper [i.e. the present] on the subject appeared in March 1914. The next year he returned to the same topic." (Pais, Niels Bohr's Times, p. 182). Rosenfeld: No. 10.

Copenhagen, Bianco Lunos, 1918. 4to. Original printed wrappers. Lower right corner of front wrapper bent. Small closed tear to front wrapper. Spine strip renewed. Otherwise fine and clean throughtout. First printing of the second part of Bohr's seminal work "On the Quantum Theory of the Line-Spectra" (which appeared in three parts and which was never finished), author's off-print (with "Separate copy" printed on front wrapper), presentation-copy, inscribed by Bohr: "Hr. Professor K. Prytz / med venlig Hilsen / fra Forfatteren"."By 1918 Bohr had visualized, at least in outline, the whole theory of atomic phenomena. . He of course realized that he was still very far from a logically consistent framework wide enough to incorporate both the quantum postulates and those aspects of classical mechanics and electrodynamics that seemed to retain some validity. Nevertheless, he at once started writing up a synthetic exposition of his arguments and of all the evidence upon which they could have any bearing" in testing how well he could summarize what was known, he found occasion to check the soundness of his ideas and to improve their formulation. In the present case, however, he could hardly keep pace with the growth of the subject the paper he had in mind at the beginning developed into a four-part treatise, 'On the Theory of Line Spectra', publication of which dragged over four years without being completed" the first three parts appeared between 1918 and 1922 [of which the second from 1918 is offered here], and the fourth, unfortunately, was never published. Thus, the full impact of Bohr's view remained confined to the small but brilliant circle of his disciples, who indeed managed better than their master to make them more widely known by the prompter publication of their own results" (D.S.B. 2: 246-47).The present second part deals with the hydrogen spectrum, whereas the first part dealt with the general theory, and the third with the spectra of elements of higher atomic structure. Peter Kristian Prytz (1851-1929), to whom the work is inscribed, was an important physicist of the generation before Bohr. He did immense work to better the conditions of the teaching of physics at the Polytechnic Institute in Copenhagen, where Bohr studied for many years and where he later became a teacher. Prytz introduced the teaching of experimental physics here and fought for more space, more apparatus, more money for teaching assistance and more time for teaching. Thus, he played a great role in the physics-environment in Copenhagen both during Bohr's years as a student and as a teacher.Most importantly, it was Prytz who (in 1907) attracted the necessary money for the institute which enabled him to create the physical laboratory that constituted the foundation of Danish experimental physics, the field of which Bohr became professor in 1916 (till 1920 - the years during which he was working on the "On the Quantum Theory of the Line Spectra").Rosenfeld, Bohr-Bibliography, 15.

Copenhagen, Levin & Munksgaard, 1933. + Berlin, Springer 1931. + Lancaster, American Physical Society, 1950. First paper: Published as no. 8 of vol. 12 in 'Kgl. Dankse Vid. Selsk. Math.-Fys. Medd.'. 8vo. Original printed wrappers. With the ownership signature of Danish physicist Mogens Pihl (Prof. of physics at Copenhagen University 1957-77). 65,(1) pp. Second paper: Published in 'Zeitschrift für Physik', vol. 69, pp.56-69. The entire volume in contemporary half cloth offered here.Third paper: Published in 'The Physical Review', vol. 78, no. 6, pp.794-798. The entire issue in original printed wrappers offered here. With rubber stamp of Danish physicist Christian Møller (Author of "The Theory of Relativity, 1952"). First editions of these fundamental papers in the development of quantum field theory. The process of measuring electromagnetic fields involves the observation of charged test bodies in those fields. Therefore the theory of electrodynamics is an inseparable extension of mechanics. A quantum theory of fields thus inherits, in some form, the limitations of measurement which lie at the foundation of quantum mechanics. In 1931 Landau and Peierls published a critical analysis of the consequences of such limitations in a relativistic quantum theory of fields (second paper offered). Landau and Peierls came to the negative conclusion that in several cases, the concept of momentum was without physical meaning and quantities such as the strength of a field was un-measurable. In their famous paper from 1933 Bohr and Rosenfeld (first paper offered) carefully reviewed the arguments of Landau and Peierls and showed, through the use of particular measuring arrangements, that a consistent quantum theory of fields is possible without further limitations than the ones which secure the consistency of quantum mechanics. The BR-paper is often credited with having laid the foundation for quantum electrodynamics. Bohr continued his work in this field, and in 1937 he completed a manuscript entitled "Field and Charge Measurement in Quantum Theory", but this was never published. When, in the late 1940s the important work on QED by Tomonaga, Schwinger, Dyson, and Feynman appeared in The Physical Review, Bohr and Rosenfeld again joined and published the essentials of the 1937 manuscript in the same journal (third paper offered).See Abraham Pais: Bohr's Times, pp.358-364. Mehra & Rechenberg: The Historical Development of Quantum Theory, vol. 6, pp.697-703. Collected Works of Niels Bohr, vol. 7, pp.3-33.