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Slobodan Perovic

Bio: Slobodan Perovic is an academic researcher from University of Belgrade. The author has contributed to research in topics: Bohr model & Complementarity (physics). The author has an hindex of 7, co-authored 27 publications receiving 210 citations. Previous affiliations of Slobodan Perovic include Keele University & Carleton University.

Papers
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05 Oct 1998
Abstract: Determination of Refractive Index of Highly Concentrated Solutions of NaCl and Glycerin using Total Internal Reflection (TIR) (14 points) Please read the general instructions in the separate envelope before you start this experiment. Dependence of Refractive Index of a Solution on Concentration Introduction: Basic Principle: When a beam of light is incident on a surface, reflection and refraction take place. When the surface is uneven (rough), these phenomena result in scattering light in all directions. If the surface is that of a transparent medium, then most of the light is transmitted (refracted) and a small portion of it is reflected. If the surface is opaque and polished (like a metallic surface), all the light is reflected. In this experiment, the green laser light is shonenormally into thewater inside a container. The container used has vertical walls. The laser beam first meets the smooth top water surface then it gets scattered from the rough bottom surface of container while producing a bright green spot on the bottom surface. This scattered light travels back into the water in all directions. This light again meets the top smooth surface of water and undergoes reflection, refraction and another phenomenon called total internal reflection (see Figure 1). The scattered rays that reach the top surface of the water at an angle greater than the critical angle, get totally internally reflected which results in a bright ring enclosing a dark region.

91 citations

Journal ArticleDOI
TL;DR: Schrodinger's ideas on interpreting quantum mechanics have been recently re-examined by historians and revived by philosophers of quantum mechanics as discussed by the authors, pointing to very different reasons why Schrodinger gave up pursuing his interpretation for 7 years.
Abstract: E. Schrodinger's ideas on interpreting quantum mechanics have been recently re-examined by historians and revived by philosophers of quantum mechanics. Such recent re-evaluations have focused on Schrodinger's retention of space–time continuity and his relinquishment of the corpuscularian understanding of microphysical systems. Several of these historical re-examinations claim that Schrodinger refrained from pursuing his 1926 wave-mechanical interpretation of quantum mechanics under pressure from the Copenhagen and Gottingen physicists, who misinterpreted his ideas in their dogmatic pursuit of the complementarity doctrine and the principle of uncertainty. My analysis points to very different reasons for Schrodinger's decision and, accordingly, to a rather different understanding of the dialogue between Schrodinger and N. Bohr, who refuted Schrodinger's arguments. Bohr's critique of Schrodinger's arguments predominantly focused on the results of experiments on the scattering of electrons performed by Bothe and Geiger, and by Compton and Simon. Although he shared Schrodinger's rejection of full-blown classical entities, Bohr argued that these results demonstrated the corpuscular nature of atomic interactions. I argue that it was Schrodinger's agreement with Bohr's critique, not the dogmatic pressure, which led him to give up pursuing his interpretation for 7 yr. Bohr's critique reflected his deep understanding of Schrodinger's ideas and motivated, at least in part, his own pursuit of his complementarity principle. However, in 1935 Schrodinger revived and reformulated the wave-mechanical interpretation. The revival reflected N. F. Mott's novel wave-mechanical treatment of particle-like properties. R. Shankland's experiment, which demonstrated an apparent conflict with the results of Bothe–Geiger and Compton–Simon, may have been additional motivation for the revival. Subsequent measurements have proven the original experimental results accurate, and I argue that Schrodinger may have perceived even the reformulated wave-mechanical approach as too tenuous in light of Bohr's critique.

25 citations

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TL;DR: The results concur with the results of other studies across the sciences showing that smaller research teams are more productive, and with the conjecture on curvilinear dependence of team size and efficiency.
Abstract: We employ data envelopment analysis on a series of experiments performed in Fermilab, one of the major high-energy physics laboratories in the world, in order to test their efficiency (as measured by publication and citation rates) in terms of variations of team size, number of teams per experiment, and completion time. We present the results and analyze them, focusing in particular on inherent connections between quantitative team composition and diversity, and discuss them in relation to other factors contributing to scientific production in a wider sense. Our results concur with the results of other studies across the sciences showing that smaller research teams are more productive, and with the conjecture on curvilinear dependence of team size and efficiency.

21 citations

Journal ArticleDOI
TL;DR: In this article, the authors trace various nonconventional explanations for the origin of the cosmic microwave background and discuss their merit, while analyzing the dynamics of their rejection, as well as the relevant physical and methodological reasons for it.
Abstract: We historically trace various non-conventional explanations for the origin of the cosmic microwave background and discuss their merit, while analyzing the dynamics of their rejection, as well as the relevant physical and methodological reasons for it. It turns out that there have been many such unorthodox interpretations; not only those developed in the context of theories rejecting the relativistic (“Big Bang”) paradigm entirely (e.g., by Alfven, Hoyle and Narlikar) but also those coming from the camp of original thinkers firmly entrenched in the relativistic milieu (e.g., by Rees, Ellis, Rowan-Robinson, Layzer and Hively). In fact, the orthodox interpretation has only incrementally won out against the alternatives over the course of the three decades of its multi-stage development. While on the whole, none of the alternatives to the hot Big Bang scenario is persuasive today, we discuss the epistemic ramifications of establishing orthodoxy and eliminating alternatives in science, an issue recently discussed by philosophers and historians of science for other areas of physics. Finally, we single out some plausible and possibly fruitful ideas offered by the alternatives.

13 citations

Journal ArticleDOI
TL;DR: This work identifies and explains some common features of the emergence, propagation, and cascading of SB-induced layers across the biosphere that are predicated on the thermodynamic openness and intrinsic functional incompleteness of the systems at stake.
Abstract: Symmetry-based explanations using symmetry breaking (SB) as the key explanatory tool have complemented and replaced traditional causal explanations in various domains of physics. The process of spontaneous SB is now a mainstay of contemporary explanatory accounts of large chunks of condensed-matter physics, quantum field theory, nonlinear dynamics, cosmology, and other disciplines. A wide range of empirical research into various phenomena related to symmetries and SB across biological scales has accumulated as well. Led by these results, we identify and explain some common features of the emergence, propagation, and cascading of SB-induced layers across the biosphere. These features are predicated on the thermodynamic openness and intrinsic functional incompleteness of the systems at stake and have not been systematically analyzed from a general philosophical and methodological perspective. We also consider possible continuity of SB across the physical and biological world and discuss the connection between Darwinism and SB-based analysis of the biosphere and its history.

12 citations


Cited by
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Journal ArticleDOI
01 Jan 1986
TL;DR: The New York Review ofBooks as mentioned in this paper is now over twenty years old and it has attracted controversy since its inception, but it is the controversies that attract the interest of the reader and to which the history, especially an admittedly impressionistic survey, must give some attention.
Abstract: It comes as something ofa surprise to reflect that the New York Review ofBooks is now over twenty years old. Even people of my generation (that is, old enough to remember the revolutionary 196os but not young enough to have taken a very exciting part in them) think of the paper as eternally youthful. In fact, it has gone through years of relatively quiet life, yet, as always in a competitive journalistic market, it is the controversies that attract the interest of the reader and to which the history (especially an admittedly impressionistic survey that tries to include something of the intellectual context in which a journal has operated) must give some attention. Not all the attacks which the New York Review has attracted, both early in its career and more recently, are worth more than a brief summary. What do we now make, for example, of Richard Kostelanetz's forthright accusation that 'The New York Review was from its origins destined to publicize Random House's (and especially [Jason] Epstein's) books and writers'?1 Well, simply that, even if the statistics bear out the charge (and Kostelanetz provides some suggestive evidence to support it, at least with respect to some early issues), there is nothing surprising in a market economy about a publisher trying to push his books through the pages of a journal edited by his friends. True, the New York Review has not had room to review more than around fifteen books in each issue and there could be a bias in the selection of

2,430 citations

Book
01 Jan 1996
TL;DR: A review of the collected works of John Tate can be found in this paper, where the authors present two volumes of the Abel Prize for number theory, Parts I, II, edited by Barry Mazur and Jean-Pierre Serre.
Abstract: This is a review of Collected Works of John Tate. Parts I, II, edited by Barry Mazur and Jean-Pierre Serre. American Mathematical Society, Providence, Rhode Island, 2016. For several decades it has been clear to the friends and colleagues of John Tate that a “Collected Works” was merited. The award of the Abel Prize to Tate in 2010 added impetus, and finally, in Tate’s ninety-second year we have these two magnificent volumes, edited by Barry Mazur and Jean-Pierre Serre. Beyond Tate’s published articles, they include five unpublished articles and a selection of his letters, most accompanied by Tate’s comments, and a collection of photographs of Tate. For an overview of Tate’s work, the editors refer the reader to [4]. Before discussing the volumes, I describe some of Tate’s work. 1. Hecke L-series and Tate’s thesis Like many budding number theorists, Tate’s favorite theorem when young was Gauss’s law of quadratic reciprocity. When he arrived at Princeton as a graduate student in 1946, he was fortunate to find there the person, Emil Artin, who had discovered the most general reciprocity law, so solving Hilbert’s ninth problem. By 1920, the German school of algebraic number theorists (Hilbert, Weber, . . .) together with its brilliant student Takagi had succeeded in classifying the abelian extensions of a number field K: to each group I of ideal classes in K, there is attached an extension L of K (the class field of I); the group I determines the arithmetic of the extension L/K, and the Galois group of L/K is isomorphic to I. Artin’s contribution was to prove (in 1927) that there is a natural isomorphism from I to the Galois group of L/K. When the base field contains an appropriate root of 1, Artin’s isomorphism gives a reciprocity law, and all possible reciprocity laws arise this way. In the 1930s, Chevalley reworked abelian class field theory. In particular, he replaced “ideals” with his “idèles” which greatly clarified the relation between the local and global aspects of the theory. For his thesis, Artin suggested that Tate do the same for Hecke L-series. When Hecke proved that the abelian L-functions of number fields (generalizations of Dirichlet’s L-functions) have an analytic continuation throughout the plane with a functional equation of the expected type, he saw that his methods applied even to a new kind of L-function, now named after him. Once Tate had developed his harmonic analysis of local fields and of the idèle group, he was able prove analytic continuation and functional equations for all the relevant L-series without Hecke’s complicated theta-formulas. Received by the editors September 5, 2016. 2010 Mathematics Subject Classification. Primary 01A75, 11-06, 14-06. c ©2017 American Mathematical Society

2,014 citations

01 Jan 1995
TL;DR: In this paper, the authors propose a method to improve the quality of the data collected by the data collection system. But it is difficult to implement and time consuming and computationally expensive.
Abstract: 本文对国际科学计量学杂志《Scientometrics》1979-1991年的研究论文内容、栏目、作者及国别和编委及国别作了计量分析,揭示出科学计量学研究的重点、活动的中心及发展趋势,说明了学科带头人在发展科学计量学这门新兴学科中的作用。

1,636 citations

01 Jan 1980
TL;DR: The longwave part of the microwave background spectrum is quite well described by the Rayleigh-leans law as discussed by the authors, and in the shortwave part the intensity is observed to decrease in accordance with the blackbody spectrum.
Abstract: hypothesis. The longwave part of the microwave background spectrum is quite well described by the Rayleigh-leans law. In the shortwave part the intensity is observed to decrease in accordance with the blackb ody spectrum. The radiation is extremely isotropic on both large and small scales. There is no noticeable polarization. Interest has now shifted to departures of the spectrum from that of a blackbody. Also of great interest are measurements of angular anisotropy, small-scale angular fluctuations, and polarization. What is known already is that these distortions and deviations (both spectral and angular) are small. We believe the universe may never have been completely uniform. Even in the earliest stages there may have been small perturbations of matter and radiation densities, and ofthe velocit y field. The fireball h ypothesis requires such perturbations to account for the formation of galaxies and clusters of galaxies. Observations of the microwave background are a powerful method of investigating such pertu rbations. Even perturbations that are dissipated by viscosity, thermal conductivity, and nonlinear effects too early to influence the present structure of the universe could have dis torted

513 citations