Bohr n iels (13 risultati)

(22,5 x 14,5 cm). SS. (449)-664. Mit Abbildungen und 7 teils gefalteten Tafeln. Moderner Pappband im Stil der Zeit mit beigebundenem Original-Umschlag. Erste Ausgabe. - Sehr sauber und gut erhalten. - DSB 2, 239; Röseberg, Bohr Nr. 17.

(26,5 x 19 cm). LXII, 1044 S. Mit zahlreichen Abbildungen. Halbleinwandband der Zeit. Erste Ausgabe von Bohrs Grundsatzartikel zum Komplementaritärprinzip. - "Bohrs Komplementaritätsauffassung läuft darauf hinaus, die logische Widerspruchsfreiheit der physikalischen Theorie durch Abwägen der Beobachtungs- und Definitionsmöglichkeiten für entsprechende Größenpaare herzustellen. Was komplementäre Eigenschaften sind, folgt in der Quantenmechanik aus der Theorie selbst. Sie werden durch die Heisenbergschen Unbestimmtheitsrelationen angegeben, die ihrerseits eine Folge der Nichtvertauschbarkeit der entsprechenden quantenmechanischen Symbole darstellen. Das Bohrsche Komplementaritätsargument besagt schließlich, daß die Beobachtungsbedingungen für eine Größe in Übereinstimmung mit der Heisenbergschen Unbestimmtheitsrelation die Definitionsmöglichkeit für die komplementäre Größe einschränken" (Röseberg, Niels Bohr). - Stempel auf Titel. Einband etwas berieben und bestoßen, sonst sauber und gut erhalten. - DSB 2, 239; Röseberg 66.…

(22 x 14 cm). VII, 848 S. Mit 12 teils doppelblattgroßen bzw. gefalteten Tafeln und einigen Textabbildungen. Moderner Halbleinwandband im Stil der Zeit. Erste Ausgabe dieser frühen und bedeutenden Arbeit, in der Bohr die Formel zur Berechnung des Wasserstoffspektrums korrigiert und in die neue Formel die relativistische Betrachung des Elektrons mit einfließen läßt. - Gut erhalten. - DSB 2, 239; Röseberg 14.…

(22 x 14 cm). VIII, 876 S. Mit Abbildungen und 10 teils gefalteten Tafeln. Halbleinwandband der Zeit. Erste Ausgabe dieser Vorarbeit zu seiner berühmten Veröffentlichung "On the Constitution of Atoms and Molecules". Bohr analysiert hier die Wechselwirkung zwischen alpha-Teilchen und Elektronen und verbessert die von C. G. Darwin aufgestellte Bremstheorie der alpha-Teilchen, die nun ausgezeichnet mit den empirischen Daten übereinstimmt. Der daraus ableitbare Zusammenhang zwischen optischen Größen, Bindungskräften und Anzahl der Elektronen ist dabei von besonderer Bedeutung. "In this paper the theory of the decrease of velocity of moving electrified particles in passing through matter is given in a form, such that the rate of the decrease in the velocity depends on the frequency of vibration of the electrons in the atoms of the absorbing material. Adopting Prof. Rutherford's theory of the constitution of atoms, it seems that it can be concluded with great certainty, from the absorption of alpha-rays, that a hydrogen atom contains only 1 electron outside the positively charged nucleus, and that a helium atom only contains 2 electrons outside the nucleus" (Conclusions). - Stempel auf Vorsatz. Rücken mit entferntem Label, sonst gut erhalten. - DSB 2, 239; Röseberg, Bohr Nr. 6. - Der Band enthält weiter Arbeiten von Rayleigh, Chadwick, Rutherford, Geiger, Bragg, Lodge etc.…

(22 x 14,5 cm). VII, 1168 S. Mit zahlreichen Abbildungen und Tafeln. Halbleinwandband der Zeit. Erste Ausgabe. - "The Bohr-Kramers-Slater (BKS) theory was perhaps the final attempt at understanding the interaction of matter and electromagnetic radiation on the basis of the so-called 'Old quantum theory', in which quantum phenomena are treated by imposing quantum restrictions on classically describable behaviour. It was advanced in 1924, and sticks to a classical wave description of the electromagnetic field. It was perhaps more a program than a full physical theory, the ideas that are developed not being worked out in a quantitative way. One aspect, the idea of modelling atomic behaviour under incident electromagnetic radiation using 'virtual oscillators' at the absorption and emission frequencies, rather than the (different) apparent frequencies of the Bohr orbits, significantly led Born, Heisenberg and Kramers to explore mathematics that strongly inspired the subsequent development of matrix mechanics, the first form of modern quantum mechanics. The provocativeness of the theory also generated great discussion and renewed attention to the difficulties in the foundations of the old quantum theory. However, physically the most provocative element of the theory, that momentum and energy would not necessarily be conserved in each interaction but only overall, statistically, was soon shown to be in conflict with experiment" (Wikipedia). - Stempel auf Titel. Eine Tafel im Falz glatt durchtrennt. Rücken mit kleinem Fleck. Oberes Kapital mit kleinem Einriss, sonst gut erhalten. - DSB 2, 239.…

First edition. Octavo. 70 pages. Wrappers. A lecture presented in the Fysisk Forening on October 18, 1921. Swedish text.Presentation copy from the author, inscribed by him on the title-page to Professor V. Carlheim-Gyllensköld (1859-1934), who was member of the Academy of Sciences' Nobel Committee for Physics and thus involved in the election of Niels Bohr as the 1922 Nobel Laureate in physics.Near fine.…

Gr.8°. OHeft. Etwas gebräunt. Auf dem Vorderdeckel mit handschriftlicher Widmung des Autors: "Hr Professer K. Prytz aerbodigst fra Forf". Vorliegende Arbeit ist eine Fortsetzung von Bohrs Untersuchungen über die Oberflächenspannung des Wasser, für die er 1906 die Goldmedaille der Königl. Dänischen Akademie errang, und kennzeichnet den Zeitpunkt von Bohrs Abschied von der experimentellen Physik. Er widmete sie hier seinem Lehrer Peter Kristian Prytz (1851-1929), der auch sein Gutachter war. Schon 1911 beschäftigte er sich in seiner Dissertation mit der Theorie der Metallelektronen und gelangte 1913 zu seinem epochalen Atommodell, für das er 1922 den Nobelpreis bekam. Zu Prytz vgl. Poggendorff IV, 2, S. 1198. EN.…

(London, Harrison & Sons, 1909). Large 4to. Original printed wrappers" wrappers loose and with lack of paper, mostly to back wrapper, which is quite chipped and nicked, with tears, and lacking a bigger part of the upper right corner. Front wrapper merely lacking a few smaller pieces at the top, not affecting the presentation inscription. Pp. 281-317. Extremely scarce first edition, off-print issue with presentation-inscription, of Bohr's first published paper, constituting his only ever work in experimental physics. "His first research project, a precision measurement of the surface tension of water by the observation of a regularly vibrating jet, was completed in 1906, when he was still a student, and it won him the gold medal from the Academy of Sciences. It is a mature piece of work, remarkable for the care and thoroughness with which both the experimental and theoretical parts of the problem were handled." (DSB).The work is inscribed to renowned Danish physicist and meteorologist Dan la Cour (1876-1942), son of the great Poul la Cour (1846-1908), who is considered the "Danish Edison". The inscription reads as thus: "Hr. Docent D. la Cour/ ærbødigst/ fra/ Forfatteren." [In Danish, i.e.: "Mr. Assistant Professor D. la Cour/ with great respect / from/ the author."].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. This Bohr's fist paper grew out of a work which Bohr did in 1906, and for which he won a gold medal from the Academy of Sciences. The subject was to experimentally investigate a method, proposed by Lord Rayleigh, for measuring the surface tension of water by the observation of a regularly vibrating jet. "Bohr [.] included in his work essential improvements on Rayleigh's theory by taking into account the influence of the liquid's viscosity and of the ambient air, and by extending the earlier theory from infinitesimal to arbitrary large vibration amplitudes. In order to execute his experiments he had first of all to cope with one complication. The university had no physics laboratory." (Pais, p. 101). Bohr thus constructed many of the instruments himself using his father's laboratory. "I did the experiments completely alone alone in the physiological laboratory. it was a great amount of work", which was technically demanding." (Pais, p. 102). In spite of being Bohr's only ever work in experimental physics, it documents his deep understanding of the methods of experimentalists."On 23 February 1907 the Academy notified him that he had won its gold medal. In 1908 he submitted a modified version to the Royal Society in London. It was his first and last paper on experiments he himself performed. His second publication was his last to deal with surface tension of liquids" it was purely theoretical. Both papers were favorably referred to in later literature.The manuscript of the prize essay, never published in its original form, is preserved in the Bohr Archives. It is handwritten, by Harald Bohr [i.e. his brother]." (Pais, p. 102), Rosenfeld, Bohr Bibliography No. 1. Rosenfeld, Dictionary of Scientific Biography II, pp. 239. Pais, Niels Bohr's Times, pp. 101-02.…

[London, Taylor & Francis], 1913. 8vo. Original printed wrappers. The fragile wrappers are detached, but fully intact. Merely tiny parts of the thin backstrip lacking. Three small tears to front wrapper, no loss, as well as a couple of creses. Back wrapper with a slight bend to the corner and minor fading to extremities. Pp. (9)-31. Scarce first edition, off-print issue with presentation-inscription, of Bohr's seminal first work on nuclear physics, being the work that lays the foundation for his atomic theory (published before his "On the Constitution of Atoms and Molecules"), in which he is able to conclude "that a hydrogen atom contains only 1 electron outside the positively charged nucleus, and that a helium atom only contains 2 electrons outside the nucleus ." "Bohr's 1913 paper on alpha-particles [i.e. the present], which he had begun in Manchester, and which had led him to the question of atomic structure, marks the transition to his great work, also of 1913, on that same problem. While still in Manchester, he had already begun an early sketch of those entirely new ideas." (Pais, p. 128). The present work must be considered one of the most important to the birth of modern atomic theory.The work is inscribed to renowned Danish physicist and meteorologist Dan la Cour (1876-1942), son of the great Poul la Cour (1846-1908), who is considered the "Danish Edison". The inscription reads as thus: "Hr. Docent Afdelingschef D. la Cour/ med venlig Hilsen/ fra/ Forfatteren." [In Danish, i.e.: "Mr. Assistant Professor Head of Department D. la Cour/ with kind regards/ from/ the author."].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. After finishing his studies in Copenhagen, Bohr went to Cambridge in order to pursue his studies on electron theory under the guidance of J.J. Thompson. Thompson, who was beginning to lose interest in the subject by now, did, however, not recognize the genious of the young Bohr, and as soon as he could, Bohr went to Manchester, where Ernest Rutherford had established a laboratory. "There, from March to July 1912, working with utmost concentration, he [i.e. Bohr] laid the foundation for his greatest achievements in physics, the theory of the atomic constitution." (DSB). Bohr's survey of the implications of Rutherford's atomic model had led him to attack the much harder problem which lay at the core of it, namely determining the exact nature of the relation between the atomic number and the number of electrons in the atom. "Bohr obtained a much deeper insight into the problem by a brilliant piece of work, which he - working, as he said, "day and night" - completed with astonishing speed" (DSB), that paper being the present "On the Theory of the Decrease of Velocity of Moving electrified Particles on passing through Matter", which thus constitutes his very first publication on the subject, published immediately after this dense period of 1912, in the Philosophical Magazine of January 1913. "The problem was one of immediate interest for Rutherford's laboratory: in their passage through a material medium, alpha particles continually lose energy by ionizing the atoms they encounter, at a rate depending on their velocity. Their energy loss limits the depth to which the particles can penetrate into the medium, and the relation between this depth, or range, and the velocity offers a way of determining this velocity. What Bohr did was to analyze the ionizing process on the basis of the Rutherford model of the atom and thus express the rate of energy loss in terms of the velocity by a much more accurate formula than had so far been achieved-a formula, in fact, to which modern quantum mechanics adds only nonessential refinements" (DSB). In the present work, Bohr was thus able to conclude: "In this paper the theory of the decrease of velocity of moving electrified particles in passing through matter is given in a form, such that the rate of the decrease in the velocity depends on the frequency of vibration of the electrons in the atoms of the absorbing material." as well as the seminal words that have been formative for the birth of the modern atomic theory: "Adopting Prof. Rutherford's theory of the constitution of atoms, it seems that it can be concluded with great certainty, from the absorption of alpha-rays, that a hydrogen atom contains only 1 electron outside the positively charged nucleus, and that a helium atom only contains 2 electrons outside the nucleus ". Bohr continues: "These questions and some further information about the constitution of atoms which may be got from experiments on the absorption of alpha-rays, will be discussed in more detail in a later paper." (pp. 30-31 of the original paper) - the last sentence referring directly to his three part "On the Constitution of Atoms and Molecules", in which he went on to present his postulates of the orbital structure of the electrons and their quantized radiation. Ro.…

(22,5 x 14,5 cm). XIX, 155 S. Leinwandband der Zeit. Erste deutsche Ausgabe von zehn kleineren Abhandlungen, die hier erstmals zusammengefasst, mit einem Geleitwort Bohrs, erscheinen. - Stempel auf Vorsatz und Titel. Papierbedingt leicht gebräunt. Rücken gering ausgebleicht, sonst gut erhalten.

(23 x 15,5 cm). IV, 416 S. Mit zahlreichen Abbildungen. Halbleinwandband der Zeit. Erste Ausgabe dieser wegweisenden Arbeit auf dem Weg zum Korrespondenzprinzip. - Einband leicht berieben, sonst gut erhalten. - Der Band enthält weiter Arbeiten von E. Brody, J. Franck, M. Born, W. Pauli etc.

(22,5 x 15,5 cm). IV, 412 S. Mit 118 Abbildungen. Halbleinwandband der Zeit. Erste Ausgabe der Bohr-Kramers-Slater-Theorie. - "After Kramers had succeeded in extending the scope of the correspondence argument to the theory of optical dispersion - thus rounding off a treatment of the interaction of atomic systems with radiation that accounted for all emission, absorption, and scattering processes - Bohr ventured to propose a systematic formulation of the whole theory, in which what he called the virtual character of the classical model was emphasized. In this he was aided by Kramers and a young American visitor, J. C. Slater, and the new theory was published in 1924 under the authorship of all three. The most striking feature of this remarkable paper, 'The Quantum Theory of Radiation,' 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. This was going too far: the paper was hardly in print before A. H. Compton and A. W. Simon had established by direct experiment the strict conservation of energy and momentum in an individual process of interaction between atom and radiation. 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" (DSB). - Titel gestempelt, sonst sauber und wohlerhalten. - DSB 2, 247; Röseberg 48.…

FIRST EDITION. In perfect condition. First edition, first printing, the rare author's offprint issue. This is the sequel to Bohr & Kalckar's earlier work "On the transmutation of atomic nuclei by impact of material particles" which had introduced the "liquid-drop model" of the nucleus, a description of atomic nuclei in which the nucleons (neutrons and protons) behave like the molecules in a drop of liquid. If given sufficient extra energy (as by the absorption of a neutron), the spherical nucleus may be distorted into a dumbbell shape and then split at the neck into two nearly equal fragments, releasing energy. Here the authors treat the "optical model" which describes the atomic nuclei as similar to cloudy crystal balls in that, when struck by a beam of particles, they partially absorb the beam, partially scatter it, and partially transmit it in a way analogous to the behavior of light. "Using the optical theorem and Bohr's liquid-drop model of the nucleus, Placzek (1905-1955), Bohr (1885-1962), and Peierls (1935-2003) offered a fundamental theory of neutron-induced nuclear reactions. These works proved essential to the subsequent development of nuclear theory and to development of nuclear reactor design" (DSB). Although a footnote which appears at the end of the articles stating that "the details of this and of the other arguments of this note will be published in the Proceedings of the Copenhagen Academy," no other version of this paper ever appeared. DSB, II, pp. 239-255 (Bohr); DSB, XVIII, pp. 714-715 (Placzek).…